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Sample records for flow cerebral metabolic

  1. Hypothermia reduces cerebral metabolic rate and cerebral blood flow in newborn pigs

    International Nuclear Information System (INIS)

    Busija, D.W.; Leffler, C.W.

    1987-01-01

    The authors examined effects of hypothermia on cerebral metabolic rate and cerebral blood flow in anesthetized, newborn pigs (1-4 days old). Cerebral blood flow (CBF) was determined with 15-μm radioactive microspheres. Regional CBF ranged from 44 to 66 ml·min -1 ·100 g -1 , and cerebral metabolic rate was 1.94 ± 0.23 ml O 2 ·100 g -1 ·min -1 during normothermia (39 degree C). Reduction of rectal temperature to 34-35 degree C decreased CBF and cerebral metabolic rate 40-50%. In another group of piglets, they examined responsiveness of the cerebral circulation to arterial hypercapnia during hypothermia. Although absolute values for normocapnic and hypercapnic CBF were reduced by hypothermia and absolute values for normocapnic and hypercapnic cerebrovascular resistance were increased, the percentage changes from control in these variables during hypercapnia were similar during normothermia and hypothermia. In another group of animals that were maintained normothermic and exposed to two episodes of hypercapnia, there was no attenuation of cerebrovascular dilation during the second episode. They conclude that hypothermia reduces CBF secondarily to a decrease in cerebral metabolic rate and that percent dilator responsiveness to arterial hypercapnia is unaltered when body temperature is reduced

  2. Cerebral blood flow and metabolism during isoflurane-induced hypotension in patients subjected to surgery for cerebral aneurysms

    DEFF Research Database (Denmark)

    Madsen, J B; Cold, G E; Hansen, E S

    1987-01-01

    Cerebral blood flow and cerebral metabolic rate for oxygen were measured during isoflurane-induced hypotension in 10 patients subjected to craniotomy for clipping of a cerebral aneurysm. Flow and metabolism were measured 5-13 days after the subarachnoid haemorrhage by a modification of the classi......Cerebral blood flow and cerebral metabolic rate for oxygen were measured during isoflurane-induced hypotension in 10 patients subjected to craniotomy for clipping of a cerebral aneurysm. Flow and metabolism were measured 5-13 days after the subarachnoid haemorrhage by a modification......). Controlled hypotension to an average MAP of 50-55 mm Hg was induced by increasing the dose of isoflurane, and maintained at an inspired concentration of 2.2 +/- 0.2%. This resulted in a significant decrease in CMRO2 (to 1.73 +/- 0.16 ml/100 g min-1), while CBF was unchanged. After the clipping...

  3. Cerebral blood flow and metabolism during exercise: implications for fatigue

    DEFF Research Database (Denmark)

    Seifert, T.; Lieshout, J.J. van; Secher, Niels

    2008-01-01

    During exercise: the Kety-Schmidt-determined cerebral blood flow (CBF) does not change because the jugular vein is collapsed in the upright position. In contrast, when CBF is evaluated by (133)Xe clearance, by flow in the internal carotid artery, or by flow velocity in basal cerebral arteries......, a approximately 25% increase is detected with a parallel increase in metabolism. During activation, an increase in cerebral O(2) supply is required because there is no capillary recruitment within the brain and increased metabolism becomes dependent on an enhanced gradient for oxygen diffusion. During maximal...... whole body exercise, however, cerebral oxygenation decreases because of eventual arterial desaturation and marked hyperventilation-related hypocapnia of consequence for CBF. Reduced cerebral oxygenation affects recruitment of motor units, and supplemental O(2) enhances cerebral oxygenation and work...

  4. Unchanged cerebral blood flow and oxidative metabolism after acclimatization to high altitude

    DEFF Research Database (Denmark)

    Møller, Kirsten; Paulson, Olaf B; Hornbein, Thomas F.

    2002-01-01

    The authors investigated the effect of acclimatization to high altitude on cerebral blood flow and oxidative metabolism at rest and during exercise. Nine healthy, native sea-level residents were studied 3 weeks after arrival at Chacaltaya, Bolivia (5,260 m) and after reacclimatization to sea level....... At high altitude at rest, arterial carbon dioxide tension, oxygen saturation, and oxygen tension were significantly reduced, and arterial oxygen content was increased because of an increase in hemoglobin concentration. Global cerebral blood flow was similar in the four conditions. Cerebral oxygen delivery...... and cerebral metabolic rates of oxygen and glucose also remained unchanged, whereas cerebral metabolic rates of lactate increased slightly but nonsignificantly at high altitude during exercise compared with high altitude at rest. Reaction time was unchanged. The data indicate that cerebral blood flow...

  5. Cerebrospinal fluid ionic regulation, cerebral blood flow, and glucose use during chronic metabolic alkalosis

    International Nuclear Information System (INIS)

    Schroeck, H.K.; Kuschinsky, W.

    1989-01-01

    Chronic metabolic alkalosis was induced in rats by combining a low K+ diet with a 0.2 M NaHCO3 solution as drinking fluid for either 15 or 27 days. Local cerebral blood flow and local cerebral glucose utilization were measured in 31 different structures of the brain in conscious animals by means of the iodo-[14C]antipyrine and 2-[14C]deoxy-D-glucose method. The treatment induced moderate [15 days, base excess (BE) 16 mM] to severe (27 days, BE 25 mM) hypochloremic metabolic alkalosis and K+ depletion. During moderate metabolic alkalosis no change in cerebral glucose utilization and blood flow was detectable in most brain structures when compared with controls. Cerebrospinal fluid (CSF) K+ and H+ concentrations were significantly decreased. During severe hypochloremic alkalosis, cerebral blood flow was decreased by 19% and cerebral glucose utilization by 24% when compared with the control values. The decrease in cerebral blood flow during severe metabolic alkalosis is attributed mainly to the decreased cerebral metabolism and to a lesser extent to a further decrease of the CSF H+ concentration. CSF K+ concentration was not further decreased. The results show an unaltered cerebral blood flow and glucose utilization together with a decrease in CSF H+ and K+ concentrations at moderate metabolic alkalosis and a decrease in cerebral blood flow and glucose utilization together with a further decreased CSF H+ concentration at severe metabolic alkalosis

  6. Cerebral blood flow and metabolism during exercise: implications for fatigue.

    Science.gov (United States)

    Secher, Neils H; Seifert, Thomas; Van Lieshout, Johannes J

    2008-01-01

    During exercise: the Kety-Schmidt-determined cerebral blood flow (CBF) does not change because the jugular vein is collapsed in the upright position. In contrast, when CBF is evaluated by (133)Xe clearance, by flow in the internal carotid artery, or by flow velocity in basal cerebral arteries, a approximately 25% increase is detected with a parallel increase in metabolism. During activation, an increase in cerebral O(2) supply is required because there is no capillary recruitment within the brain and increased metabolism becomes dependent on an enhanced gradient for oxygen diffusion. During maximal whole body exercise, however, cerebral oxygenation decreases because of eventual arterial desaturation and marked hyperventilation-related hypocapnia of consequence for CBF. Reduced cerebral oxygenation affects recruitment of motor units, and supplemental O(2) enhances cerebral oxygenation and work capacity without effects on muscle oxygenation. Also, the work of breathing and the increasing temperature of the brain during exercise are of importance for the development of so-called central fatigue. During prolonged exercise, the perceived exertion is related to accumulation of ammonia in the brain, and data support the theory that glycogen depletion in astrocytes limits the ability of the brain to accelerate its metabolism during activation. The release of interleukin-6 from the brain when exercise is prolonged may represent a signaling pathway in matching the metabolic response of the brain. Preliminary data suggest a coupling between the circulatory and metabolic perturbations in the brain during strenuous exercise and the ability of the brain to access slow-twitch muscle fiber populations.

  7. Cerebral blood flow, oxygen and glucose metabolism with PET in progressive supranuclear palsy

    International Nuclear Information System (INIS)

    Otsuka, Makoto; Ichiya, Yuici; Kuwabara, Yasuo

    1989-01-01

    Cerebral blood flow, cerebral oxygen metabolic rate and cerebral glucose metabolic rate were measured with positron emission tomography (PET) in four patients with progressive supranuclear palsy (PSP). Decreased blood flow and hypometabolism of oxygen and glucose were found in both subcortical and cortical regions, particularly in the striatum including the head of the caudate nucleus and the frontal cortex. The coupling between blood flow and metabolism was preserved even in the regions which showed decreased blood flow and hypometabolism. These findings indicated the hypofunction, as revealed by decreased blood flow and hypometablolism on PET, both in the striatum and the frontal cortex, and which may underlie the pathophysiological mechanism of motor and mental disturbance in PSP. (author)

  8. The Coupling of Cerebral Metabolic Rate of Glucose and Cerebral Blood Flow In Vivo

    DEFF Research Database (Denmark)

    Hasselbalch, Steen; Paulson, Olaf Bjarne

    2012-01-01

    The energy supplied to the brain by metabolic substrate is largely utilized for maintaining synaptic transmission. In this regulation cerebral blood flow and glucose consumption is tightly coupled as well in the resting condition as during activation. Quantification of cerebral blood flow...... not used for aerobic metabolism. Although some of the excess glucose uptake can be explained by lactate production, this phenomenon can still not account for the excess glucose uptake. Thus, more complex metabolic patterns in the brain might be reflected in the excess glucose uptake during activation......, and especially temporal relationships must be taken into account. What triggers the flow increase during functional brain activation is not entirely elucidated. The demand for excess glucose uptake may be important and a possible oxygen deficit in tissue distant from the capillaries is probably of minor...

  9. Low cerebral blood flow after cardiac arrest is not associated with anaerobic cerebral metabolism

    NARCIS (Netherlands)

    Hoedemaekers, C.W.E.; Ainslie, Philip N.; Hinssen, S.; Aries, M.J.; Bisschops, Laurens L.; Hofmeijer, Jeannette; van der Hoeven, J.G.

    2017-01-01

    Aim of the study Estimation of cerebral anaerobic metabolism in survivors and non-survivors after cardiac arrest. Methods We performed an observational study in twenty comatose patients after cardiac arrest and 19 healthy control subjects. We measured mean flow velocity in the middle cerebral artery

  10. Cerebral blood flow and oxygen metabolism after subarachnoid hemorrhage

    International Nuclear Information System (INIS)

    Ito, Hidemichi; Sakurai, Takashi; Hayashi, Tatsuo; Hashimoto, Takuo

    2004-01-01

    The mechanism of reduction of cerebral circulation in the early phase of aneurysmal subarachnoid hemorrhage (SAH) has not yet been clarified. Previous studies have variously indicated that cerebral blood flow (CBF) reduction may be due to cerebral vasospasm, an elevation in intracranial pressure (ICP), constriction of intraparenchymal arterioles, or metabolic reduction. The aim of this study is to investigate the relationship between cerebral circulation and oxygen metabolism. In 36 patients with aneurysmal SAH, the values of mean cerebral blood flow (mCBF), cerebral metabolic rate of oxygen (GMRO 2 ) and oxygen extraction fraction (OEF) were measured by using single photon emission computed tomography (SPECT) with arterial blood drawing and oxygen saturation of internal jugular bulb blood (SjO 2 ) in the acute stage (1-3 days after onset) and the spasm stage (7-10 days after onset). The patients in our study were selected by using the following criteria: no history of cerebrovascular or cardiopulmonary diseases; under the age of 70; the ruptured aneurysm was treated by clipping or coil embolization within 72 hours after onset; no symptoms of cerebral vasospasm; no signs of cerebral ischemic change on CT scans. These patients were divided into 2 groups according to the World Federation of Neurological Surgeons (WFNS) grading classification; the mild group (Grades I and II) consisted of 27 cases and the severe group (Grade IV) consisted of 9 cases. We studied differences in mCBF CMRO 2 , and OEF between the mild group and severe group. In the mild group, mCBF, CMRO 2 , and OEF were significantly higher than in the severe group during both the acute and the spasm stage. Also mCBF showed a direct correlation with CMRO 2 . All the patients were kept under the following conditions: the bed was positioned so that the upper body was raised at an angle at 30 deg; blood pressure was maintained at 130-150 mmHg and PaCO 2 of arterial blood was maintained at 35-40 mmHg; ICP

  11. Cerebral blood flow and oxygen metabolism in patients with Parkinson's disease

    International Nuclear Information System (INIS)

    Kitamura, Shin; Ujike, Takashi; Kuroki, Soemu; Sakamoto, Shizuki; Soeda, Toshiyuki; Terashi, Akiro; Iio, Masaaki.

    1988-01-01

    The purpose of this study was to determine functional changes in the cerebral cortex and basal ganglia in Parkinson's disease (PD). Cerebral blood flow (CBF), oxygen extraction fraction (OEF), and cerebral metabolic rate of oxygen (CMRO 2 ) were determined using 0-15 positron emission tomography in 10 PD patients and five age-matched healthy volunteers. There was a tendency among PD patients towards a decreased CBF and CMRO 2 in the cerebral cortex and basal ganglia. These values were significantly lower in the frontal cortex in the PD group than the control group. There was no difference in OEF between the groups. A more decreased cerebral oxygen metabolism was observed in patients staged as severer on the scale of Hoehn and Yahr. There was no correlation between cerebral oxygen metabolism and tremor, rigidity, or bradykinesis. A decreased cerebral oxygen metabolism was associated with mental disorders, such as depression, hallucination, and dementia. These results may provide an important clue for the understanding of mesocortical dopaminergic pathway and the relationship between PD and dementia. (N.K.)

  12. Cerebral blood flow and oxygen metabolism in patients with Parkinson's disease

    Energy Technology Data Exchange (ETDEWEB)

    Kitamura, Shin; Ujike, Takashi; Kuroki, Soemu; Sakamoto, Shizuki; Soeda, Toshiyuki; Terashi, Akiro; Iio, Masaaki

    1988-10-01

    The purpose of this study was to determine functional changes in the cerebral cortex and basal ganglia in Parkinson's disease (PD). Cerebral blood flow (CBF), oxygen extraction fraction (OEF), and cerebral metabolic rate of oxygen (CMRO/sub 2/) were determined using 0-15 positron emission tomography in 10 PD patients and five age-matched healthy volunteers. There was a tendency among PD patients towards a decreased CBF and CMRO/sub 2/ in the cerebral cortex and basal ganglia. These values were significantly lower in the frontal cortex in the PD group than the control group. There was no difference in OEF between the groups. A more decreased cerebral oxygen metabolism was observed in patients staged as severer on the scale of Hoehn and Yahr. There was no correlation between cerebral oxygen metabolism and tremor, rigidity, or bradykinesis. A decreased cerebral oxygen metabolism was associated with mental disorders, such as depression, hallucination, and dementia. These results may provide an important clue for the understanding of mesocortical dopaminergic pathway and the relationship between PD and dementia. (N.K.).

  13. Cerebral blood flow and metabolic abnormalities in Alzheimer's disease

    International Nuclear Information System (INIS)

    Matsuda, Hiroshi

    2001-01-01

    In this review I summarize observations of PET and SPECT studies about cerebral blood flow and metabolic abnormalities in Alzheimer's disease (AD). In very early AD flow or metabolism reduces first in the posterior cingulate gyrus and precuneus. This reduction may arise from functional deafferentation caused by primary neural degeneration in the remote area of the entorhinal cortex that is the first to be pathologically affected in AD. Then medial temporal structures and parietotemporal association cortex show flow or metabolic reduction as disease processes. The reason why flow or metabolism in medial temporal structures shows delay in starting to reduce in spite of the earliest pathological affection remains to be elucidated. It is likely that anterior cingulate gyrus is functionally involved, since attention is the first non-memory domain to be affected, before deficits in language and visuospatial functions. However few reports have described involvement in the anterior cingulate gyrus. Relationship between cerebral blood flow or metabolism and apolipoprotein E (APOE) genotype has been investigated. Especially, the APOEε4 allele has been reported to increase risk and to lower onset age as a function of the inherited dose of the ε4 allele. Reduction of flow or metabolism in the posterior cingulate gyrus and precuneus has been reported even in presymptomatic nondemented subjects who were cognitively normal and had at least a single ε4 allele. On the contrary the relation of ε4 allele to the progression rate of AD has been controversial from neuroimaging approaches. PET and SPECT imaging has become to be quite useful for assessing therapeutical effects of newly introduced treatment for AD. Recent investigations observed significant regional flow increase after donepezil hydrochloride treatment. Most of these observations have been made by applying computer assisted analysis of three-dimensional stereotactic surface projection or statistical parametric mapping

  14. Sympathetic influence on cerebral blood flow and metabolism during exercise in humans

    DEFF Research Database (Denmark)

    Seifert, Thomas; Secher, Niels H

    2011-01-01

    This review focuses on the possibility that autonomic activity influences cerebral blood flow (CBF) and metabolism during exercise in humans. Apart from cerebral autoregulation, the arterial carbon dioxide tension, and neuronal activation, it may be that the autonomic nervous system influences CBF...... perfusion and reduces the near-infrared determined cerebral oxygenation at rest, but not during exercise associated with an increased cerebral metabolic rate for oxygen (CMRO(2)), suggesting competition between CMRO(2) and sympathetic control of CBF. CMRO(2) does not change during even intense handgrip...

  15. Cerebral oxygen metabolism and cerebral blood flow in man during light sleep (stage 2)

    DEFF Research Database (Denmark)

    Madsen, P L; Schmidt, J F; Holm, S

    1991-01-01

    We measured cerebral blood flow (CBF) and cerebral metabolic rate of oxygen (CMRO2) during light sleep (stage 2) in 8 young healthy volunteers using the Kety-Schmidt technique with 133Xe as the inert gas. Measurements were performed during wakefulness and light sleep as verified by standard...... polysomnography. Unlike our previous study in man showing a highly significant 25% decrease in CMRO2 during deep sleep (stage 3-4) we found a modest but statistically significant decrease of 5% in CMRO2 during stage 2 sleep. Deep and light sleep are both characterized by an almost complete lack of mental activity....... They differ in respect of arousal threshold as a stronger stimulus is required to awaken a subject from deep sleep as compared to light sleep. Our results suggest that during non-rapid eye movement sleep cerebral metabolism and thereby cerebral synaptic activity is correlated to cerebral readiness rather than...

  16. Local cerebral blood flow and glucose metabolism during seizure in spontaneously epileptic El mice

    International Nuclear Information System (INIS)

    Hosokawa, Chisa; Ochi, Hironobu; Yamagami, Sakae; Kawabe, Joji; Kobashi, Toshiko; Okamura, Terue; Yamada, Ryusaku

    1995-01-01

    Local cerebral blood flow and glucose metabolism were examined in spontaneously epileptic El mice using autoradiography with 125 I-IMP and 14 C-DG in the interictal phase and during seizure. El (+) mice that developed generalized tonic-clonic convulsions and El (-) mice that received no stimulation and had no history of epileptic seizures were examined. The seizure non-susceptible, maternal strain ddY mice were used as control. Uptake ratios for IMP and DG in mouse brain were calculated using the autoradiographic density. In the interictal phase, the pattern of local cerebral blood flow of El (+) mice was similar to that of ddY and El (-) mice, and glucose metabolism in the hippocampus was higher in El (+) mice than in El (-) and ddY mice, but flow and metabolism were nearly matched. During seizure, no significant changed blood flow and increased glucose metabolism in the hippocampus, the epileptic focus, and no markedly changed blood flow and depressed glucose metabolism in other brain regions were observed and considered to be flow-metabolism uncoupling. These observations have never been reported in clinical or experimental studies of epilepsy. Seizures did not cause large regional differences in cerebral blood flow. Therefore, only glucose metabolism is useful for detection of the focus of secondary generalized seizures in El mice, and appeared possibly to be related to the pathophysiology of secondary generalized epilepsy in El mice. (author)

  17. Cerebral blood flow and metabolism during sleep

    DEFF Research Database (Denmark)

    Madsen, Peter Lund; Vorstrup, S

    1991-01-01

    A review of the current literature regarding sleep-induced changes in cerebral blood flow (CBF) and cerebral metabolic rate (CMR) is presented. Early investigations have led to the notion that dreamless sleep was characterized by global values of CBF and CMR practically at the level of wakefulness......, while rapid eye movement (REM) sleep (dream sleep) was a state characterized by a dramatically increased level of CBF and possibly also of CMR. However, recent investigations firmly contradict this notion. Investigations on CBF and CMR performed during non-REM sleep, taking the effect of different...... current state identify the physiological processes involved in sleep or the physiological role of sleep....

  18. Sympathetic influence on cerebral blood flow and metabolism during exercise in humans

    DEFF Research Database (Denmark)

    Seifert, Thomas; Secher, Niels H

    2011-01-01

    This review focuses on the possibility that autonomic activity influences cerebral blood flow (CBF) and metabolism during exercise in humans. Apart from cerebral autoregulation, the arterial carbon dioxide tension, and neuronal activation, it may be that the autonomic nervous system influences CBF...... perfusion and reduces the near-infrared determined cerebral oxygenation at rest, but not during exercise associated with an increased cerebral metabolic rate for oxygen (CMRO(2)), suggesting competition between CMRO(2) and sympathetic control of CBF. CMRO(2) does not change during even intense handgrip......-oxidative carbohydrate uptake during exercise. Adrenaline appears to accelerate cerebral glycolysis through a beta2-adrenergic receptor mechanism since noradrenaline is without such an effect. In addition, the exercise-induced cerebral non-oxidative carbohydrate uptake is blocked by combined beta 1/2-adrenergic blockade...

  19. Cerebral blood flow and oxygen metabolism in the Rett syndrome

    International Nuclear Information System (INIS)

    Yoshikawa, Hideto; Fueki, Noboru; Suzuki, Hisaharu; Sakuragawa, Norio; Iio, Masaaki

    1992-01-01

    Positron emission tomography (PET) was performed on six patients with the Rett syndrome and the results were compared with the concurrent clinical status of the patients. The cerebral metabolic rate of oxygen (CMRO 2 ) was low in five patients, and oxygen extraction fraction (OEF) was low in four patients; both had a tendency to decline with advancing age. Although the cause is unknown, it is suggested that impaired oxidative metabolism exists in the Rett syndrome. An analysis of the distribution among brain regions showed that the ratios of values for the frontal cortex to those for the temporal cortex for both the cerebral blood flow (CBF) and CMRO 2 were lower than those for the controls, which may indicate the loss of of hyperfrontality in the Rett syndrome. Distribution of brain metabolism may be immature in the Rett syndrome. (author)

  20. Cerebral blood flow response to functional activation

    DEFF Research Database (Denmark)

    Paulson, Olaf B; Hasselbalch, Steen G; Rostrup, Egill

    2010-01-01

    Cerebral blood flow (CBF) and cerebral metabolic rate are normally coupled, that is an increase in metabolic demand will lead to an increase in flow. However, during functional activation, CBF and glucose metabolism remain coupled as they increase in proportion, whereas oxygen metabolism only inc...... the cerebral tissue's increased demand for glucose supply during neural activation with recent evidence supporting a key function for astrocytes in rCBF regulation....

  1. Global cerebral blood flow and metabolism during acute hyperketonemia in the awake and anesthetized rat

    DEFF Research Database (Denmark)

    Linde, Rasmus; Hasselbalch, Steen G.; Topp, Simon

    2006-01-01

    and cerebral metabolism could not be explained by alterations in blood pH or arterial CO2 tension. By measuring cerebral intracellular pH by 31P nuclear magnetic resonance spectroscopy, it could further be concluded that the brain pH was unchanged during acute hyperketonemia. These observations indicate......In the human setting, it has been shown that acute increase in the concentration of ketone bodies by infusion of beta-hydroxybutyrate increased the cerebral blood flow (CBF) without affecting the overall cerebral metabolic activity. The mechanism by which this effect of ketone bodies was mediated...... that the mechanism responsible for the increase in CBF is rather a direct effect on the cerebral endothelium than via some metabolic interactions...

  2. Effects of hyperthermia on cerebral blood flow and metabolism during prolonged exercise in humans

    DEFF Research Database (Denmark)

    Nybo, Lars; Møller, Kirsten; Volianitis, Stefanos

    2002-01-01

    The development of hyperthermia during prolonged exercise in humans is associated with various changes in the brain, but it is not known whether the cerebral metabolism or the global cerebral blood flow (gCBF) is affected. Eight endurance-trained subjects completed two exercise bouts on a cycle...... ergometer. The gCBF and cerebral metabolic rates of oxygen, glucose, and lactate were determined with the Kety-Schmidt technique after 15 min of exercise when core temperature was similar across trials, and at the end of exercise, either when subjects remained normothermic (core temperature = 37.9 degrees C...... with control at the end of exercise (43 +/- 4 vs. 51 +/- 4 ml. 100 g(-1). min(-1); P glucose, and the cerebral metabolic rate was therefore higher at the end...

  3. Cerebral blood flow and metabolic abnormalities in Alzheimer's disease

    Energy Technology Data Exchange (ETDEWEB)

    Matsuda, Hiroshi [National Center of Neurology and Psychiatry, Kodaira, Tokyo (Japan). National Center Hospital for Mental, Nervous, and Muscular Disorders

    2001-04-01

    In this review I summarize observations of PET and SPECT studies about cerebral blood flow and metabolic abnormalities in Alzheimer's disease (AD). In very early AD flow or metabolism reduces first in the posterior cingulate gyrus and precuneus. This reduction may arise from functional deafferentation caused by primary neural degeneration in the remote area of the entorhinal cortex that is the first to be pathologically affected in AD. Then medial temporal structures and parietotemporal association cortex show flow or metabolic reduction as disease processes. The reason why flow or metabolism in medial temporal structures shows delay in starting to reduce in spite of the earliest pathological affection remains to be elucidated. It is likely that anterior cingulate gyrus is functionally involved, since attention is the first non-memory domain to be affected, before deficits in language and visuospatial functions. However few reports have described involvement in the anterior cingulate gyrus. Relationship between cerebral blood flow or metabolism and apolipoprotein E (APOE) genotype has been investigated. Especially, the APOE{epsilon}4 allele has been reported to increase risk and to lower onset age as a function of the inherited dose of the {epsilon}4 allele. Reduction of flow or metabolism in the posterior cingulate gyrus and precuneus has been reported even in presymptomatic nondemented subjects who were cognitively normal and had at least a single {epsilon}4 allele. On the contrary the relation of {epsilon}4 allele to the progression rate of AD has been controversial from neuroimaging approaches. PET and SPECT imaging has become to be quite useful for assessing therapeutical effects of newly introduced treatment for AD. Recent investigations observed significant regional flow increase after donepezil hydrochloride treatment. Most of these observations have been made by applying computer assisted analysis of three-dimensional stereotactic surface projection

  4. Frontiers in optical imaging of cerebral blood flow and metabolism.

    Science.gov (United States)

    Devor, Anna; Sakadžić, Sava; Srinivasan, Vivek J; Yaseen, Mohammad A; Nizar, Krystal; Saisan, Payam A; Tian, Peifang; Dale, Anders M; Vinogradov, Sergei A; Franceschini, Maria Angela; Boas, David A

    2012-07-01

    In vivo optical imaging of cerebral blood flow (CBF) and metabolism did not exist 50 years ago. While point optical fluorescence and absorption measurements of cellular metabolism and hemoglobin concentrations had already been introduced by then, point blood flow measurements appeared only 40 years ago. The advent of digital cameras has significantly advanced two-dimensional optical imaging of neuronal, metabolic, vascular, and hemodynamic signals. More recently, advanced laser sources have enabled a variety of novel three-dimensional high-spatial-resolution imaging approaches. Combined, as we discuss here, these methods are permitting a multifaceted investigation of the local regulation of CBF and metabolism with unprecedented spatial and temporal resolution. Through multimodal combination of these optical techniques with genetic methods of encoding optical reporter and actuator proteins, the future is bright for solving the mysteries of neurometabolic and neurovascular coupling and translating them to clinical utility.

  5. Focal physiological uncoupling of cerebral blood flow and oxidative metabolism during somatosensory stimulation in human subjects

    International Nuclear Information System (INIS)

    Fox, P.T.; Raichle, M.E.

    1986-01-01

    Coupling between cerebral blood flow (CBF) and cerebral metabolic rate of oxygen (CMRO 2 ) was studied using multiple sequential administrations of 15 O-labeled radiotracers and positron emission tomography. In the resting state an excellent correlation between CBF and CMRO 2 was found when paired measurements of CBF and CMRO 2 from multiple (30-48) brain regions were tested in each of 33 normal subjects. Regional uncoupling of CBF and CMRO 2 was found, however, during neuronal activation induced by somatosensory stimulation. Stimulus-induced focal augmentation of cerebral blood flow (29% mean) far exceeded the concomitant local increase in tissue metabolic rate (mean, 5%), when resting-state and stimulated-state measurements were obtained in each of 9 subjects. Stimulus duration had no significant effect on response magnitude or on the degree of CBF-CMRO 2 uncoupling observed. Dynamic, physiological regulation of CBF by a mechanism (neuronal or biochemical) dependent on neuronal firing per se, but independent of the cerebral metabolic rate of oxygen, is hypothesized

  6. Cerebral autoregulation and flow/metabolism coupling during cardiopulmonary bypass: the influence of PaCO2

    International Nuclear Information System (INIS)

    Murkin, J.M.; Farrar, J.K.; Tweed, W.A.; McKenzie, F.N.; Guiraudon, G.

    1987-01-01

    Measurement of 133 Xe clearance and effluent cerebral venous blood sampling were used in 38 patients to determine the effects of cardiopulmonary bypass, and of maintaining temperature corrected or noncorrected PaCO 2 at 40 mm Hg on regulation of cerebral blood flow (CBF) and flow/metabolism coupling. After induction of anesthesia with diazepam and fentanyl, mean CBF was 25 ml X 100 g-1 X min-1 and cerebral oxygen consumption, 1.67 ml X 100 g-1 X min-1. Cerebral oxygen consumption during nonpulsatile cardiopulmonary bypass at 26 degrees C was reduced to 0.42 ml X 100 g-1 X min-1 in both groups. CBF was reduced to 14-15 ml X 100 g-1 X min-1 in the non-temperature-corrected group (n = 21), was independent of cerebral perfusion pressure over the range of 20-100 mm Hg, but correlated with cerebral oxygen consumption. In the temperature-corrected group (n = 17), CBF varied from 22 to 32 ml X 100 g-1 X min-1, and flow/metabolism coupling was not maintained (i.e., CBF and cerebral oxygen consumption varied independently). However, variation in CBF correlated significantly with cerebral perfusion pressure over the pressure range of 15-95 mm Hg. This study demonstrates a profound reduction in cerebral oxygen consumption during hypothermic nonpulsatile cardiopulmonary bypass. When a non-temperature-corrected PaCO 2 of approximately 40 mm Hg was maintained, CBF was lower, and analysis of pooled data suggested that CBF regulation was better preserved, i.e., CBF was independent of pressure changes and dependent upon cerebral oxygen consumption

  7. Dynamic change in cerebral microcirculation and focal cerebral metabolism in experimental subarachnoid hemorrhage in rabbits.

    Science.gov (United States)

    Song, Jin-Ning; Chen, Hu; Zhang, Ming; Zhao, Yong-Lin; Ma, Xu-Dong

    2013-03-01

    Regional cerebral blood flow (rCBF) in the cerebral metabolism and energy metabolism measurements can be used to assess blood flow of brain cells and to detect cell activity. Changes of rCBF in the cerebral microcirculation and energy metabolism were determined in an experimental model of subarachnoid hemorrhage (SAH) model in 56 large-eared Japanese rabbits about 12 to 16-month old. Laser Doppler flowmetry was used to detect the blood supply to brain cells. Internal carotid artery and vein blood samples were used for duplicate blood gas analysis to assess the energy metabolism of brain cells. Cerebral blood flow (CBF) was detected by single photon emission computed tomography (SPECT) perfusion imaging using Tc-99m ethyl cysteinate dimer (Tc-99m ECD) as an imaging reagent. The percentage of injected dose per gram of brain tissue was calculated and analyzed. There were positive correlations between the percentage of radionuclide injected per gram of brain tissue and rCBF supply and cerebral metabolic rate for oxygen (P brain cells after SAH, and also found that deterioration of energy metabolism of brain cells played a significant role in the development of SAH. There are matched reductions in CBF and metabolism. Thus, SPECT imaging could be used as a noninvasive method to detect CBF.

  8. Cerebral autoregulation and flow/metabolism coupling during cardiopulmonary bypass: the influence of PaCO/sub 2/

    Energy Technology Data Exchange (ETDEWEB)

    Murkin, J.M.; Farrar, J.K.; Tweed, W.A.; McKenzie, F.N.; Guiraudon, G.

    1987-09-01

    Measurement of /sup 133/Xe clearance and effluent cerebral venous blood sampling were used in 38 patients to determine the effects of cardiopulmonary bypass, and of maintaining temperature corrected or noncorrected PaCO/sub 2/ at 40 mm Hg on regulation of cerebral blood flow (CBF) and flow/metabolism coupling. After induction of anesthesia with diazepam and fentanyl, mean CBF was 25 ml X 100 g-1 X min-1 and cerebral oxygen consumption, 1.67 ml X 100 g-1 X min-1. Cerebral oxygen consumption during nonpulsatile cardiopulmonary bypass at 26 degrees C was reduced to 0.42 ml X 100 g-1 X min-1 in both groups. CBF was reduced to 14-15 ml X 100 g-1 X min-1 in the non-temperature-corrected group (n = 21), was independent of cerebral perfusion pressure over the range of 20-100 mm Hg, but correlated with cerebral oxygen consumption. In the temperature-corrected group (n = 17), CBF varied from 22 to 32 ml X 100 g-1 X min-1, and flow/metabolism coupling was not maintained (i.e., CBF and cerebral oxygen consumption varied independently). However, variation in CBF correlated significantly with cerebral perfusion pressure over the pressure range of 15-95 mm Hg. This study demonstrates a profound reduction in cerebral oxygen consumption during hypothermic nonpulsatile cardiopulmonary bypass. When a non-temperature-corrected PaCO/sub 2/ of approximately 40 mm Hg was maintained, CBF was lower, and analysis of pooled data suggested that CBF regulation was better preserved, i.e., CBF was independent of pressure changes and dependent upon cerebral oxygen consumption.

  9. Cerebral circulation and metabolism with recovery of chronic poststroke aphasia

    International Nuclear Information System (INIS)

    Yamada, Tomoyuki; Kabasawa, Hidehiro; Matsubara, Michitaka; Hibino, Hiroaki; Kamimoto, Kaoru; Fukagawa, Kazutoshi

    2004-01-01

    The recruitment of cerebral circulation and oxygen metabolism in the particular brain areas responsible for poststroke aphasia are necessary for recovery. This study was undertaken to investigate changes in cerebral circulation and oxygen metabolism corresponding to improvement of aphasia. Twenty-nine right-handed chronic aphasic patients with left hemispheric stroke were studied. Aphasia was evaluated as the score of fluency, comprehension, repetition and naming by the Western Aphasia Battery (Japanese version). Concurrent with the evaluation of aphasia, positron emission tomography (PET) scans were performed. After several months of speech therapy, PET scans and evaluation of aphasia were reperformed. Both regional cerebral blood flow and the cerebral metabolic rate for oxygen significantly increased in the left upper superior and middle temporal gyri, and in the left upper inferior frontal gyrus in the fair recovery group for comprehension, repetition and naming. In the fair recovery group for fluency, the cerebral metabolic rate for oxygen significantly increased in the left upper superior and middle temporal gyri, but regional cerebral blood flow increased insignificantly in these areas. In the lower white matter of the right parietal lobe, both the regional cerebral blood flow and the cerebral metabolic rate for oxygen were significantly increased in the fair recovery group for all aphasic features. The recruitment of cerebral circulation and oxygen metabolism in the left temporo-parietal area, in the left inferior frontal area, and in the right deep parietal area are essentially responsible for the recovery of aphasia. (author)

  10. Cerebral blood flow and metabolism in patients with aphasia due to basal ganglionic lesion

    International Nuclear Information System (INIS)

    Kitamura, Shin; Kato, Toshiaki; Ujike, Takashi; Kuroki, Soemu; Terashi, Akiro

    1987-01-01

    Cerebral blood flow and metabolism in right handed eight patients with subcortical lesion and aphasia were measured to investigate the correlation between aphasia and functional changes in cerebral blood flow (CBF) and cerebral oxygen consumption (CMRO 2 ) in the cortex and the basal ganglionic region. All patients had no lesion in the cortex, but in the basal ganglionic region (putamen, caudate nucleus, internal capsule, and periventricular white matter) on CT images. Patients with bilateral lesion were excluded in this study. Six patients with cerebral infarction in the left basal ganglionic region and two patients with the left putammal hemorrhage were examined. Five patients had non fluent Broca's type speech, two patients had poor comprehension, fluent Wernicke-type speech and one patient was globally aphasic. CBF, CMRO 2 , and oxygen extraction fraction were measured by the positron emission tomography using 15 O 2 , C 15 O 2 inhalation technique. In addition to reduction of CBF and CMRO 2 in the basal ganglionic region, CBF and CMRO 2 decreased in the left frontal cortex especially posterior part in four patients with Broca's aphasia. In two patients with Wernicke type aphasia, CBF and CMRO 2 decreased in the basal ganglionic region and the left temporal cortex. In a globally aphasic patient, marked reduction of CBF and CMRO 2 was observed in the left frontal and temporal cortex, in addition to the basal ganglionic region. These results suggest that dysfunction of cortex as well as that of basal ganglionic region might be related to the occurence of aphasia. However, in one patient with Broca's ahasia, CBF and CMRO 2 were preserved in the cortex and metabolic reduction was observed in only basal ganglia. This case indicates the relation between basal ganglionic lesion and the occurrence of aphasia. These results suggest that measurements of cerebral blood flow and metabolism were necessary to study the responsible lesion for aphasia. (author)

  11. Cerebral O2 metabolism and cerebral blood flow in humans during deep and rapid-eye-movement sleep

    DEFF Research Database (Denmark)

    Madsen, P L; Schmidt, J F; Wildschiødtz, Gordon

    1991-01-01

    on examination of this question. We have now measured CBF and CMRO2 in young healthy volunteers using the Kety-Schmidt technique with 133Xe as the inert gas. Measurements were performed during wakefulness, deep sleep (stage 3/4), and rapid-eye-movement (REM) sleep as verified by standard polysomnography...... associated with light anesthesia. During REM sleep (dream sleep) CMRO2 was practically the same as in the awake state. Changes in CBF paralleled changes in CMRO2 during both deep and REM sleep.......It could be expected that the various stages of sleep were reflected in variation of the overall level of cerebral activity and thereby in the magnitude of cerebral metabolic rate of oxygen (CMRO2) and cerebral blood flow (CBF). The elusive nature of sleep imposes major methodological restrictions...

  12. Cerebral oxygen metabolism and cerebral blood flow in man during light sleep (stage 2)

    DEFF Research Database (Denmark)

    Madsen, P L; Schmidt, J F; Holm, S

    1991-01-01

    . They differ in respect of arousal threshold as a stronger stimulus is required to awaken a subject from deep sleep as compared to light sleep. Our results suggest that during non-rapid eye movement sleep cerebral metabolism and thereby cerebral synaptic activity is correlated to cerebral readiness rather than...

  13. Regional cerebral blood flow and oxygen metabolism in normal pressure hydrocephalus after subarachnoid hemorrhage

    Energy Technology Data Exchange (ETDEWEB)

    Ishikawa, Masatsune; Kikuchi, Haruhiko; Taki, Waro; Kobayashi, Akira; Nishizawa, Sadahiko; Yonekura, Yoshiharu; Konishi, Junji [Kyoto Univ. (Japan). Faculty of Medicine

    1989-05-01

    To clarify the pathophysiology of normal pressure hydrocephalus (NPH) after subarachnoid hemorrhage, the authors measured cerebral blood flow (CBF), cerebral oxygen metabolic rates (CMRO{sub 2}), the cerebral oxygen extraction fraction (OEF), and cerebral blood volume (CBV) in eight normal volunteers, six SAH patients with NPH, and seven patients without NPH by {sup 15}O-labeled gas and positron emission tomography (PET). In the NPH group, PET revealed a decrease in CBF in the lower regions of the cerebral cortex and a diffuse decrease in CMRO{sub 2}. The decrease in CBF in the lower frontal, temporal, and occipital cortices was significantly greater in the NPH than in the non-NPH group. Reduction of CMRO{sub 2} was also more extensive in the NPH group, and both CBF and CMRO{sub 2} were more markedly decreased in the lower frontal region. OEF was increased in all areas in both of the patient groups, but the increase was not significant in most areas. CBF, CMRO{sub 2} and OEF did not significantly differ between the non-NPH group and the normal volunteers. There was no significant difference in CBV among the three groups. These results indicate that NPH involves impairment of cerebral oxygen metabolism in the lower regions of the cerebral cortex, particularly in the lower frontal region. (author).

  14. Effect of anxiety on cortical cerebral blood flow and metabolism

    International Nuclear Information System (INIS)

    Gur, R.C.; Gur, R.E.; Resnick, S.M.; Skolnick, B.E.; Alavi, A.; Reivich, M.

    1987-01-01

    The relation between anxiety and cortical activity was compared in two samples of normal volunteers. One group was studied with the noninvasive xenon-133 inhalation technique for measuring cerebral blood flow (CBF) and the other with positron emission tomography (PET) using 18 Flurodeoxyglucose ( 18 FDG) for measuring cerebral metabolic rates (CMR) for glucose. The inhalation technique produced less anxiety than the PET procedure, and for low anxiety subjects, there was a linear increase in CBF with anxiety. For higher anxiety subjects, however, there was a linear decrease in CBF with increased anxiety. The PET group manifested a linear decrease in CMR with increased anxiety. The results indicate that anxiety can have systematic effects on cortical activity, and this should be taken into consideration when comparing data from different procedures. They also suggest a physiologic explanation of a fundamental behavioral law that stipulates a curvilinear, inverted-U relationship between anxiety and performance

  15. Sex differences of human cortical blood flow and energy metabolism

    DEFF Research Database (Denmark)

    Aanerud, Joel; Borghammer, Per; Rodell, Anders

    2017-01-01

    cerebral blood flow and cerebral metabolic rate of oxygen as functions of age in healthy volunteers of both sexes. Cerebral metabolic rate of oxygen did not change with age for either sex and there were no differences of mean values of cerebral metabolic rate of oxygen between men and women in cerebral...... cortex. Women had significant decreases of cerebral blood flow as function of age in frontal and parietal lobes. Young women had significantly higher cerebral blood flow than men in frontal and temporal lobes, but these differences had disappeared at age 65. The absent sex difference of cerebral energy...... turnover suggests that the known differences of synaptic density between the sexes are counteracted by opposite differences of individual synaptic activity....

  16. Value of cerebral blood flow rate and regional oxygen consumption studies in cerebral ischaemia

    Energy Technology Data Exchange (ETDEWEB)

    Clanet, M

    1987-06-18

    Studies of experimentally-induced ischaemia have shown that the intensity of neuronal suffering is related to the fall in perfusion rate. Below a certain level, called functional threshold, cerebral function is reversibly altered, whereas at a lower level (tissue necrosis threshold) the damage inflicted on neurons is irreversible. Between these two thresholds lies a ''penumbra zone''. This concept of thresholds must be mitigated by 2 parameters: duration of ischaemia and selective vulnerability of the various structures affected. Variations in blood flow rate only indirectly affect the state of tissues. Techniques developed from positron emission tomography make it possible to evaluate the metabolic activity of brain tissue in vivo: oxygen consumption (CMRO/sub 2/), oxygen extraction (EO/sub 2/) and glucose consumption (CMRG) which are thus correlated to cerebral blood flow and cerebral blood volume, sometimes also to tissue pH. Normal relations between blood flow rate and metabolism may be altered. Misery perfusion reflects a fall in cerebral blood flow with an increase in EO/sub 2/ and often a decrease in CMRO/sub 2/, whereas luxury perfusion reflects an increase in cerebral blood flow rate with reduction of CMRO/sub 2/, EO/sub 2/ and CMRG. The type of alteration encountered in human ischaemia varies according to the nature of the accident: studies of transient accidents emphasize the different haemodynamic aspects of occlusion of the wider arteries. The metabolic and haemodynamic profiles of established ischaemic accidents vary according to their type and to the time of the study, reflecting the complexity of the physiopathological mechanisms involved; they are frequently associated with metabolic repercussions at a distance from the ischaemic focus, which supports the concept of diaschisis.

  17. Value of cerebral blood flow rate and regional oxygen consumption studies in cerebral ischaemia

    International Nuclear Information System (INIS)

    Clanet, M.

    1987-01-01

    Studies of experimentally-induced ischaemia have shown that the intensity of neuronal suffering is related to the fall in perfusion rate. Below a certain level, called functional threshold, cerebral function is reversibly altered, whereas at a lower level (tissue necrosis threshold) the damage inflicted on neurons is irreversible. Between these two thresholds lies a ''penumbra zone''. This concept of thresholds must be mitigated by 2 parameters: duration of ischaemia and selective vulnerability of the various structures affected. Variations in blood flow rate only indirectly affect the state of tissues. Techniques developed from positron emission tomography make it possible to evaluate the metabolic activity of brain tissue in vivo: oxygen consumption (CMRO 2 ), oxygen extraction (EO 2 ) and glucose consumption (CMRG) which are thus correlated to cerebral blood flow and cerebral blood volume, sometimes also to tissue pH. Normal relations between blood flow rate and metabolism may be altered. Misery perfusion reflects a fall in cerebral blood flow with an increase in EO 2 and often a decrease in CMRO 2 , whereas luxury perfusion reflects an increase in cerebral blood flow rate with reduction of CMRO 2 , EO 2 and CMRG. The type of alteration encountered in human ischaemia varies according to the nature of the accident: studies of transient accidents emphasize the different haemodynamic aspects of occlusion of the wider arteries. The metabolic and haemodynamic profiles of established ischaemic accidents vary according to their type and to the time of the study, reflecting the complexity of the physiopathological mechanisms involved; they are frequently associated with metabolic repercussions at a distance from the ischaemic focus, which supports the concept of diaschisis [fr

  18. Cerebral blood flow and metabolism in multi-infarct dementia

    International Nuclear Information System (INIS)

    Ujike, Takashi; Terashi, Akiro; Soeda, Toshiyuki; Kitamura, Shin; Kato, Toshiaki; Iio, Masaaki.

    1985-01-01

    Cerebral blood flow and oxygen metabolism were studied in three aged normal volunteers and 10 patients with multi-infarct dementia (MID) by Positron Emission Tomography using O-15. The diagnosis of MID was done according to the Loeb's modified ischemic score and X-ray CT findings. The MID patients, whose X-ray CT showed localized low density areas in the subcortical white matter and basal ganglia and thalamus, were studied. No occulusion was observed at anterior cerebral artery and/or middle cerebral artery on cerebral angiography. All cases of MID were mild dementias. Regional CBF, rOEF and rCMRO 2 were measured by the steady state technique described by Terry Jones et al. The values of rCBF in MID patients were significantly low compared with those of aged normal subjects in frontal, temporal, occipital, parietal cortices and thalamus. The values of CMRO 2 in MID were significantly low in frontal, temporal, occipital cortices and thalamus compared with normal subjects'. The OEF was 0.46 in aged normal subjects, and 0.52 in MID patients. The MID patients in the early stage of dementia showed the increased oxygen extraction fraction, and this fact suggests that ischemia is a significant pathogenic mechanism in the production and progression of multi-infarct dementia. The decrease of CBF and CMRO 2 in MID compared from normal subjects' were most remarkable in frontal cortex. The impairment of mental functions in MID should be caused by the decreased neuronal activities in frontal association cortex. (author)

  19. Cerebral blood flow and metabolism during cardiopulmonary bypass with special reference to effects of hypotension induced by prostacyclin

    International Nuclear Information System (INIS)

    Feddersen, K.; Aren, C.; Nilsson, N.J.; Radegran, K.

    1986-01-01

    Cerebral blood flow and metabolism of oxygen, glucose, and lactate were studied in 43 patients undergoing aortocoronary bypass. Twenty-five patients received prostacyclin infusion, 50 ng per kilogram of body weight per minute, during cardiopulmonary bypass (CPB), and 18 patients served as a control group. Regional cerebral blood flow (CBF) was studied by intraarterially injected xenon 133 and a single scintillation detector. Oxygen tension, carbon dioxide tension, oxygen saturation, glucose, and lactate were measured in arterial and cerebral venous blood. Mean arterial blood pressure decreased during hypothermia and prostacyclin infusion to less than 30 mm Hg. The regional CBF was, on average, 22 (standard deviation [SD] 4) ml/100 gm/min before CPB. It increased in the control group during hypothermia to 34 (SD 12) ml/100 gm/min, but decreased in the prostacyclin group to 15 (SD 5) ml/100 gm/min. It increased during rewarming in the prostacyclin group. After CPB, regional CBF was about 40 ml/100 gm/min in both groups. The cerebral arteriovenous oxygen pressure difference decreased more in the control group than in the prostacyclin group during hypothermia. The cerebral metabolic rate of oxygen decreased in both groups from approximately 2 ml/100 gm/min to about 1 ml/100 gm/min during hypothermia, increased again during rewarming, and after CPB was at the levels measured before bypass in both groups. There was no difference between the groups in regard to glucose and lactate metabolism

  20. Dehydration accelerates reductions in cerebral blood flow during prolonged exercise in the heat without compromising brain metabolism

    DEFF Research Database (Denmark)

    Trangmar, Steven J; Chiesa, Scott T; Llodio, Iñaki

    2015-01-01

    Dehydration hastens the decline in cerebral blood flow (CBF) during incremental exercise, whereas the cerebral metabolic rate for O2 (CMRO2 ) is preserved. It remains unknown whether CMRO2 is also maintained during prolonged exercise in the heat and whether an eventual decline in CBF is coupled...... to fatigue. Two studies were undertaken. In study 1, 10 male cyclists cycled in the heat for ∼2 h with (control) and without fluid replacement (dehydration) while internal and external carotid artery blood flow and core and blood temperature were obtained. Arterial and internal jugular venous blood samples...... were assessed with dehydration to evaluate CMRO2 . In study 2, in 8 male subjects, middle cerebral artery blood velocity was measured during prolonged exercise to exhaustion in both dehydrated and euhydrated states. After a rise at the onset of exercise, internal carotid artery flow declined...

  1. Sex differences of human cortical blood flow and energy metabolism.

    Science.gov (United States)

    Aanerud, Joel; Borghammer, Per; Rodell, Anders; Jónsdottir, Kristjana Y; Gjedde, Albert

    2017-07-01

    Brain energy metabolism is held to reflect energy demanding processes in neuropil related to the density and activity of synapses. There is recent evidence that men have higher density of synapses in temporal cortex than women. One consequence of these differences would be different rates of cortical energy turnover and blood flow in men and women. To test the hypotheses that rates of oxygen consumption (CMRO 2 ) and cerebral blood flow are higher in men than in women in regions of cerebral cortex, and that the differences persist with aging, we used positron emission tomography to determine cerebral blood flow and cerebral metabolic rate of oxygen as functions of age in healthy volunteers of both sexes. Cerebral metabolic rate of oxygen did not change with age for either sex and there were no differences of mean values of cerebral metabolic rate of oxygen between men and women in cerebral cortex. Women had significant decreases of cerebral blood flow as function of age in frontal and parietal lobes. Young women had significantly higher cerebral blood flow than men in frontal and temporal lobes, but these differences had disappeared at age 65. The absent sex difference of cerebral energy turnover suggests that the known differences of synaptic density between the sexes are counteracted by opposite differences of individual synaptic activity.

  2. Effect of STA-proximal MCA bypass. Improvement of cerebral blood flow and metabolism and neuropsychological function

    Energy Technology Data Exchange (ETDEWEB)

    Ogawa, Akira; Funayama, Masayuki; Miura, Kazuyuki; Ogasawara, Kuniaki; Suzuki, Michiyasu; Kuroda, Kiyoshi; Sasaki, Toshiaki [Iwate Medical Univ., Morioka (Japan). School of Medicine

    1998-11-01

    We investigated cerebral blood flow (CBF) and metabolism in patients with hemodynamic ischemia by positron emission tomography (PET) and thermal diffusion flow meter. We also studied neuropsychological functions to evaluate the effects of surgical revascularization. Bypass surgery of the superficial temporal artery to the proximal middle cerebral artery was performed on 26 patients satisfying the following categories: stenosis or occlusive lesion in main cerebral arteries; no marked focus of infarction on CT or MRI. PET was performed before and 1 month after the operation, and CBF, the cerebral metabolic rate of oxygen (CMRO{sub 2}) and oxygen extraction fraction (OEF) were analyzed. Cerebrovascular reserve capacity (CVRC) was also calculated after acetazolamide challenge. CBF during the operation was continuously measured with a thermal diffusion flow meter. CO{sub 2} response of CBF was analyzed before and after anastomosis. Neuropsychological functions were evaluated by Hasegawa dementia scale revised (HDS-R), mini-mental state examination (MMSE) and Wechsler adult intelligence scale revised (WAIS-R). Before the operation, increase in OEF accorded with the decrease in CBF, and a significant relationship between both CBF and CVRC, and OEF and CVRC was found. A decrease in CVRC was noted prior to a decrease in CBF and elevation of OEF. CVRC caused by acetazolamide might reflect CO{sub 2} reactivity. Significant improvement of CBF and CVRC, and normalization of OEF were observed after the operation. Also, significant improvement of neuropsychological function was observed by HDS-R and WAIS-R. Disturbance in neuropsychological function might reflect elevation of OEF. (author)

  3. Effect of STA-proximal MCA bypass. Improvement of cerebral blood flow and metabolism and neuropsychological function

    International Nuclear Information System (INIS)

    Ogawa, Akira; Funayama, Masayuki; Miura, Kazuyuki; Ogasawara, Kuniaki; Suzuki, Michiyasu; Kuroda, Kiyoshi; Sasaki, Toshiaki

    1998-01-01

    We investigated cerebral blood flow (CBF) and metabolism in patients with hemodynamic ischemia by positron emission tomography (PET) and thermal diffusion flow meter. We also studied neuropsychological functions to evaluate the effects of surgical revascularization. Bypass surgery of the superficial temporal artery to the proximal middle cerebral artery was performed on 26 patients satisfying the following categories: stenosis or occlusive lesion in main cerebral arteries; no marked focus of infarction on CT or MRI. PET was performed before and 1 month after the operation, and CBF, the cerebral metabolic rate of oxygen (CMRO 2 ) and oxygen extraction fraction (OEF) were analyzed. Cerebrovascular reserve capacity (CVRC) was also calculated after acetazolamide challenge. CBF during the operation was continuously measured with a thermal diffusion flow meter. CO 2 response of CBF was analyzed before and after anastomosis. Neuropsychological functions were evaluated by Hasegawa dementia scale revised (HDS-R), mini-mental state examination (MMSE) and Wechsler adult intelligence scale revised (WAIS-R). Before the operation, increase in OEF accorded with the decrease in CBF, and a significant relationship between both CBF and CVRC, and OEF and CVRC was found. A decrease in CVRC was noted prior to a decrease in CBF and elevation of OEF. CVRC caused by acetazolamide might reflect CO 2 reactivity. Significant improvement of CBF and CVRC, and normalization of OEF were observed after the operation. Also, significant improvement of neuropsychological function was observed by HDS-R and WAIS-R. Disturbance in neuropsychological function might reflect elevation of OEF. (author)

  4. Acute effect of glucose on cerebral blood flow, blood oxygenation, and oxidative metabolism.

    Science.gov (United States)

    Xu, Feng; Liu, Peiying; Pascual, Juan M; Xiao, Guanghua; Huang, Hao; Lu, Hanzhang

    2015-02-01

    While it is known that specific nuclei of the brain, for example hypothalamus, contain glucose-sensing neurons thus their activity is affected by blood glucose level, the effect of glucose modulation on whole-brain metabolism is not completely understood. Several recent reports have elucidated the long-term impact of caloric restriction on the brain, showing that animals under caloric restriction had enhanced rate of tricarboxylic acid cycle (TCA) cycle flux accompanied by extended life span. However, acute effect of postprandial blood glucose increase has not been addressed in detail, partly due to a scarcity and complexity of measurement techniques. In this study, using a recently developed noninvasive MR technique, we measured dynamic changes in global cerebral metabolic rate of O2 (CMRO2 ) following a 50 g glucose ingestion (N = 10). A time dependent decrease in CMRO2 was observed, which was accompanied by a reduction in oxygen extraction fraction (OEF) with unaltered cerebral blood flow (CBF). At 40 min post-ingestion, the amount of CMRO2 reduction was 7.8 ± 1.6%. A control study without glucose ingestion was performed (N = 10), which revealed no changes in CMRO2 , CBF, or OEF, suggesting that the observations in the glucose study was not due to subject drowsiness or fatigue after staying inside the scanner. These findings suggest that ingestion of glucose may alter the rate of cerebral metabolism of oxygen in an acute setting. © 2014 Wiley Periodicals, Inc.

  5. Photoacoustic microscopy of cerebral hemodynamic and oxygen-metabolic responses to anesthetics

    Science.gov (United States)

    Cao, Rui; Li, Jun; Ning, Bo; Sun, Naidi; Wang, Tianxiong; Zuo, Zhiyi; Hu, Song

    2017-02-01

    General anesthetics are known to have profound effects on cerebral hemodynamics and neuronal activities. However, it remains a challenge to directly assess anesthetics-induced hemodynamic and oxygen-metabolic changes from the true baseline under wakefulness at the microscopic level, due to the lack of an enabling technology for high-resolution functional imaging of the awake mouse brain. To address this challenge, we have developed head-restrained photoacoustic microscopy (PAM), which enables simultaneous imaging of the cerebrovascular anatomy, total concentration and oxygen saturation of hemoglobin (CHb and sO2), and blood flow in awake mice. From these hemodynamic measurements, two important metabolic parameters, oxygen extraction fraction (OEF) and the cerebral metabolic rate of oxygen (CMRO2), can be derived. Side-by-side comparison of the mouse brain under wakefulness and anesthesia revealed multifaceted cerebral responses to isoflurane, a volatile anesthetic widely used in preclinical research and clinical practice. Key observations include elevated cerebral blood flow (CBF) and reduced oxygen extraction and metabolism.

  6. Time-dependent correlation of cerebral blood flow with oxygen metabolism in activated human visual cortex as measured by fMRI.

    Science.gov (United States)

    Lin, Ai-Ling; Fox, Peter T; Yang, Yihong; Lu, Hanzhang; Tan, Li-Hai; Gao, Jia-Hong

    2009-01-01

    The aim of this study was to investigate the relationship between relative cerebral blood flow (delta CBF) and relative cerebral metabolic rate of oxygen (delta CMRO(2)) during continuous visual stimulation (21 min at 8 Hz) with fMRI biophysical models by simultaneously measuring of BOLD, CBF and CBV fMRI signals. The delta CMRO(2) was determined by both a newly calibrated single-compartment model (SCM) and a multi-compartment model (MCM) and was in agreement between these two models (P>0.5). The duration-varying delta CBF and delta CMRO(2) showed a negative correlation with time (r=-0.97, PSCM, an incorrect and even an opposite appearance of the flow-metabolism relationship during prolonged visual stimulation (positively linear coupling) can result. The time-dependent negative correlation between flow and metabolism demonstrated in this fMRI study is consistent with a previous PET observation and further supports the view that the increase in CBF is driven by factors other than oxygen demand and the energy demands will eventually require increased aerobic metabolism as stimulation continues.

  7. Cerebral blood flow and metabolism in patients with aphasia due to basal ganglionic lesion

    Energy Technology Data Exchange (ETDEWEB)

    Kitamura, Shin; Kato, Toshiaki; Ujike, Takashi; Kuroki, Soemu; Terashi, Akiro

    1987-03-01

    Cerebral blood flow and metabolism in right handed eight patients with subcortical lesion and aphasia were measured to investigate the correlation between aphasia and functional changes in cerebral blood flow (CBF) and cerebral oxygen consumption (CMRO/sub 2/) in the cortex and the basal ganglionic region. All patients had no lesion in the cortex, but in the basal ganglionic region (putamen, caudate nucleus, internal capsule, and periventricular white matter) on CT images. Patients with bilateral lesion were excluded in this study. Six patients with cerebral infarction in the left basal ganglionic region and two patients with the left putammal hemorrhage were examined. Five patients had non fluent Broca's type speech, two patients had poor comprehension, fluent Wernicke-type speech and one patient was globally aphasic. CBF, CMRO/sub 2/, and oxygen extraction fraction were measured by the positron emission tomography using /sup 15/O/sub 2/, C/sup 15/O/sub 2/ inhalation technique. In addition to reduction of CBF and CMRO/sub 2/ in the basal ganglionic region, CBF and CMRO/sub 2/ decreased in the left frontal cortex especially posterior part in four patients with Broca's aphasia. In two patients with Wernicke type aphasia, CBF and CMRO/sub 2/ decreased in the basal ganglionic region and the left temporal cortex. In a globally aphasic patient, marked reduction of CBF and CMRO/sub 2/ was observed in the left frontal and temporal cortex, in addition to the basal ganglionic region. These results suggest that dysfunction of cortex as well as that of basal ganglionic region might be related to the occurence of aphasia. However, in one patient with Broca's ahasia, CBF and CMRO/sub 2/ were preserved in the cortex and metabolic reduction was observed in only basal ganglia. This case indicates the relation between basal ganglionic lesion and the occurrence of aphasia.

  8. Cerebral blood flow, oxidative metabolism and cerebrovascular carbon dioxide reactivity in patients with acute bacterial meningitis

    DEFF Research Database (Denmark)

    Møller, Kirsten; Strauss, Gitte Irene; Thomsen, Gerda

    2002-01-01

    BACKGROUND: The optimal arterial carbon dioxide tension (P(a)CO(2)) in patients with acute bacterial meningitis (ABM) is unknown and controversial. The objective of this study was to measure global cerebral blood flow (CBF), cerebrovascular CO(2) reactivity (CO(2)R), and cerebral metabolic rates...... and hyperventilation with single-photon emission computed tomography (SPECT) (14 patients) and/or the Kety-Schmidt technique (KS) (11 patients and all controls). In KS studies, CMR was measured by multiplying the arterial to jugular venous concentration difference (a-v D) by CBF. RESULTS: CBF did not differ...

  9. Cerebral blood flow and cerebral oxygen metabolism in thalamic hemorrhage

    International Nuclear Information System (INIS)

    Yasui, Nobuyuki; Asakura, Ken

    1987-01-01

    Cerebral blood flow (CBF), cerebral oxygen consumption (CMRO 2 ), oxygen extraction fraction (OEF) and cerebral blood volume (CBV) were studied in 20 cases of thalamic hemorrhage using positron CT and 15 O labeled gas steady-state inhalation method. CBF reduction was limited around the thalamus in the small sized hematoma. CBF were significantly diminished in the mean cortical, parietal, temporal, basal ganglia and thalamic area ipsilateral and cerebellar cortex contralateral to the medium sized hematoma. There was bilateral and diffuse CBF reduction in the large sized hematoma which was caused by increased intracranial pressure. CMRO 2 value were similary changed as CBF. OEF change showed within normal limit. Diffuse CBV reduction was observed in the large sized hematoma. This reduction was the result of decreased vascular bed caused by mass effect of the hematoma and hydrocephalus. Effect of surgical treatment such as ventricular drainage and hematoma evacuation were also discussed in correlation to CBF in some case using positron and single photon ECT. (author)

  10. Cerebral blood flow and metabolism of the patients with a carotid stenosis evaluated by SPECT and 1H-MRS

    International Nuclear Information System (INIS)

    Uno, Masaaki; Nishi, Kyouko; Shinno, Kiyohito; Nagahiro, Shinji; Ohtsuka, Hideki; Harada, Masafumi

    1998-01-01

    We examined cerebral blood flow (CBF) and metabolic states in patients with a severe carotid stenosis by SPECT and proton MRS ( 1 H-MRS). SPECT using 99m Tc-HMPAO and 1 H-MRS were performed in twenty five patients with over 70% carotid stenosis. Moreover, 10 patients were evaluated by these methods after carotid endarterectomy (CEA). N-acetyl-aspartate (NAA) on the ipsilateral side was reduced in 17 patients (Group A) while NAA of other 8 patients was not reduced (Group B). In Group A, although regional CBF was reduced in only 4 of 17 patients, 11 patients showed decline of cerebral vasoreactivity evaluated by acetazolamide injection. Concentration of NAA and regional CBF showed significant correlations. After CEA, ipsilateral NAA was increased significantly compared to preoperative NAA level. In 6 of 7 patients in Group A, cerebral vasoreactivity also improved postoperatively. These results indicated that ipsilatereal NAA metabolism and cerebral vasoreactivity can be improved after CEA. SPECT and 1 H-MRS were useful to evaluate CBF and metabolism in patients with carotid stenosis. (author)

  11. The effect of glycerol on regional cerebral blood flow, blood volume and oxygen metabolism

    International Nuclear Information System (INIS)

    Ishikawa, Masatsune; Kikuchi, Haruhiko; Nagata, Izumi; Yamagata, Sen; Taki, Waro; Kobayashi, Akira; Yonekura, Yoshiharu; Nishizawa, Sadahiko.

    1989-01-01

    Using positron emission tomography with 15 O-labelled CO 2 , O 2 and CO gases, the effects of glycerol on regional cerebral blood flow (CBF), blood volume (CBV) and oxygen metabolism (CMRO 2 ) were investigated in 6 patients with meningioma accompanying peritumoral brain edema. The same study was done in 5 normal volunteers. The changes of blood gases, hematocrit and hemoglobin were also examined. After a drip infusion of glycerol, the regional CBF increased not only in the peritumoral cortex and white matter but also in the intact cortex and white matter on the contralateral side. The increase of CBF was extensive and substantially there were no regional differences. In contrast, the changes of CMRO 2 were not significant. This was derived from the increase in oxygen extraction fraction throughout extensive areas including the peritumoral area. There were no changes in CBV. Hematocrit and hemoglobin decreased to a small degree. In the normal volunteers, the same findings were noted. Thus, glycerol increases the functional reserve for cerebral oxygen metabolism, not only in the peritumoral regions but also in the intact regions. The effects of glycerol on hemodynamics and metabolism were discussed with reference to some differences from mannitol. (author)

  12. Comparison of cerebral blood flow and metabolism to flumazenil binding potential in patients with hemodynamic ischemia

    International Nuclear Information System (INIS)

    Yukawa, Hirotsugu; Ogasawara, Kuniaki

    2003-01-01

    Because benzodiazepine receptors (BZR) are abundant in the cortex, an accumulation of 11 C-flumazenil which selectively bind to BZR may be useful as markers of neuron density. The aims of this study were to clarify the relationship between neuron density and cerebral oxygen metabolism and to investigate the usefulness of 11 C-flumazenil PET for detecting misery perfusion. The subjects were 16 patients with either internal carotid or middle cerebral arterial occlusive disease who underwent PET. Regional cerebral blood flow (CBF), regional cerebral oxygen extraction fraction (OEF), regional cerebral metabolic rate for oxygen (CMRO 2 ) and regional cerebrovascular reserve capacity (CVRC) to acetazolamide were calculated. After CBF study, flumazenil binding potential was measured using the [ 11 C] flumazenil bolus injection method. Forty-eight regions of interests (ROIs) were obtained in 16 patients. Flumazenil binding potential was correlated to CMRO 2 (r=0.337, p=0.0069), but in 7 of 48 ROIs, CMRO 2 decreased, whereas flumazenil binding potential did not change. Seventeen of 29 ROIs with decreased CVRC showed high OEF and the remaining 12 showed normal OEF. Flumazenil binding potential in ROIs with normal OEF was significantly lower than in those with high OEF (p=0.0003). This study demonstrated that 11 C-flumazenil PET is useful for detecting misery perfusion in patients with hemodynamic ischemia. (author)

  13. Neural Vascular Mechanism for the Cerebral Blood Flow Autoregulation after Hemorrhagic Stroke

    Directory of Open Access Journals (Sweden)

    Ming Xiao

    2017-01-01

    Full Text Available During the initial stages of hemorrhagic stroke, including intracerebral hemorrhage and subarachnoid hemorrhage, the reflex mechanisms are activated to protect cerebral perfusion, but secondary dysfunction of cerebral flow autoregulation will eventually reduce global cerebral blood flow and the delivery of metabolic substrates, leading to generalized cerebral ischemia, hypoxia, and ultimately, neuronal cell death. Cerebral blood flow is controlled by various regulatory mechanisms, including prevailing arterial pressure, intracranial pressure, arterial blood gases, neural activity, and metabolic demand. Evoked by the concept of vascular neural network, the unveiled neural vascular mechanism gains more and more attentions. Astrocyte, neuron, pericyte, endothelium, and so forth are formed as a communicate network to regulate with each other as well as the cerebral blood flow. However, the signaling molecules responsible for this communication between these new players and blood vessels are yet to be definitively confirmed. Recent evidence suggested the pivotal role of transcriptional mechanism, including but not limited to miRNA, lncRNA, exosome, and so forth, for the cerebral blood flow autoregulation. In the present review, we sought to summarize the hemodynamic changes and underline neural vascular mechanism for cerebral blood flow autoregulation in stroke-prone state and after hemorrhagic stroke and hopefully provide more systematic and innovative research interests for the pathophysiology and therapeutic strategies of hemorrhagic stroke.

  14. Positron emission tomography in cerebrovascular disease: The relationship between regional cerebral blood flow, blood volume and oxygen metabolism

    Energy Technology Data Exchange (ETDEWEB)

    Herold, S.

    1985-03-01

    Positron emission tomography in cerebrovascular disease has demonstrated the importance of the relationship between regional cerebral blood flow and the cerebral metabolic activity. In acute stroke it has been found that within the first hours after the onset of symptoms cerebral blood flow in the affected area is more depressed than cerebral oxygen utilisation. This relative preservation of oxygen utilisation results from an increase in the oxygen extraction ratio far above its normal value. However, the oxygen extraction fraction subsequently falls in the following days indicating the transition from a situation of possibly reversible ischaemia to irreversible infarction. In patients with carotid occlusive disease an increase in the oxygen extraction ratio has been observed only in very few cases. It has been shown, however, that at an earlier stage the relationship between CBF and CBV (as CBF/CBV-ratio) provides a sensitive measure of diminished perfusion pressure which could be helpful for the selection of patients for EC-IC bypass surgery. In patients with sickle cell anaemia it has been found that oxygen delivery to the brain is maintained by an increase in cerebral blood flow, whereas the oxygen extraction ratio is not increased despite the presence of a low oxygen affinity haemoglobin. Preliminary observations in classical migraine suggest an ischaemic situation during the attack.

  15. Sympathetic regulation of cerebral blood flow in humans : a review

    NARCIS (Netherlands)

    ter Laan, M.; van Dijk, J. M. C.; Elting, J. W. J.; Staal, M. J.; Absalom, A. R.

    Cerebral blood flow (CBF) is regulated by vasomotor, chemical, metabolic, and neurogenic mechanisms. Even though the innervation of cerebral arteries is quite extensively described and reviewed in the literature, its role in regulation of CBF in humans remains controversial. We believe that

  16. Dehydration accelerates reductions in cerebral blood flow during prolonged exercise in the heat without compromising brain metabolism.

    Science.gov (United States)

    Trangmar, Steven J; Chiesa, Scott T; Llodio, Iñaki; Garcia, Benjamin; Kalsi, Kameljit K; Secher, Niels H; González-Alonso, José

    2015-11-01

    Dehydration hastens the decline in cerebral blood flow (CBF) during incremental exercise, whereas the cerebral metabolic rate for O2 (CMRO2 ) is preserved. It remains unknown whether CMRO2 is also maintained during prolonged exercise in the heat and whether an eventual decline in CBF is coupled to fatigue. Two studies were undertaken. In study 1, 10 male cyclists cycled in the heat for ∼2 h with (control) and without fluid replacement (dehydration) while internal and external carotid artery blood flow and core and blood temperature were obtained. Arterial and internal jugular venous blood samples were assessed with dehydration to evaluate CMRO2 . In study 2, in 8 male subjects, middle cerebral artery blood velocity was measured during prolonged exercise to exhaustion in both dehydrated and euhydrated states. After a rise at the onset of exercise, internal carotid artery flow declined to baseline with progressive dehydration (P dehydration accelerates the decline in CBF without affecting CMRO2 and also restricts extracranial perfusion. Thus, fatigue is related to a reduction in CBF and extracranial perfusion rather than CMRO2 . Copyright © 2015 the American Physiological Society.

  17. Hepatic encephalopathy is associated with decreased cerebral oxygen metabolism and blood flow, not increased ammonia uptake

    DEFF Research Database (Denmark)

    Dam, Gitte; Keiding, Susanne; Munk, Ole Lajord

    2013-01-01

    Studies have shown decreased cerebral oxygen metabolism (CMRO(2)) and blood flow (CBF) in patients with cirrhosis with hepatic encephalopathy (HE). It remains unclear, however, whether these disturbances are associated with HE or with cirrhosis itself and how they may relate to arterial blood...... associated with HE rather than the liver disease as such. The changes in CMRO(2) and CBF could not be linked to blood ammonia concentration or CMRA....

  18. Relationship between relative cerebral blood flow, relative cerebral blood volume, and relative cerebral metabolic rate of oxygen in the preterm neonatal brain.

    Science.gov (United States)

    Nourhashemi, Mina; Kongolo, Guy; Mahmoudzadeh, Mahdi; Goudjil, Sabrina; Wallois, Fabrice

    2017-04-01

    The mechanisms responsible for coupling between relative cerebral blood flow (rCBF), relative cerebral blood volume (rCBV), and relative cerebral metabolic rate of oxygen ([Formula: see text]), an important function of the microcirculation in preterm infants, remain unclear. Identification of a causal relationship between rCBF-rCBV and [Formula: see text] in preterms may, therefore, help to elucidate the principles of cortical hemodynamics during development. We simultaneously recorded rCBF and rCBV and estimated [Formula: see text] by two independent acquisition systems: diffuse correlation spectroscopy and near-infrared spectroscopy, respectively, in 10 preterms aged between 28 and 35 weeks of gestational age. Transfer entropy was calculated in order to determine the directionality between rCBF-rCBV and [Formula: see text]. The surrogate method was applied to determine statistical significance. The results show that rCBV and [Formula: see text] have a predominant driving influence on rCBF at the resting state in the preterm neonatal brain. Statistical analysis robustly detected the correct directionality of rCBV on rCBF and [Formula: see text] on rCBF. This study helps to clarify the early organization of the rCBV-rCBF and [Formula: see text] inter-relationship in the immature cortex.

  19. Metabolic and circulatory evaluation of acute cerebral ischaemic accidents in man by positron emission tomography

    International Nuclear Information System (INIS)

    Depresseux, J.C.; Franck, G.; Van Cauwenberge, H.

    1987-01-01

    Positron emission tomography and oxygen-15 were used to evaluate the effects of an almitrine-raubasine combination on cerebral blood flow and oxydative metabolism in patients with acute cerebral ischaemia. In 5 patients, aged between 58 and 74 years, with cerebral ischaemic accident in the territory of the middle cerebral artery, blood flow rate, oxygen consumption and brain oxygen extraction were measured before and after a 90-min intravenous infusion of almitrine bismesilate 15 mg and raubasine 5 mg. Only one patient presented with initial relative luxury perfusion, the intensity of which was reduced by the combined treatment. The other 4 patients had focal reduction of cerebral blood flow and oxygen consumption prior to treatment. Satistical analysis conducted on three cerebral areas (epicentre of the lesion, anterior and posterior juxtalesional areas and homologous heterolateral areas) showed a significant 3.6% increase of oxygen consumption in the epicentre, both hemispheres included, and a significant increase of cerebral blood flow in all three areas (3% on the healthy side, 13% on the diseased side). No significant change in oxygen extraction was demonstrated. The authors conclude that acute almitrine-raubasine treatment has beneficial effects on the brain immediately after a cerebral vascular accident, reflecting respect of the circulation-metabolism couple [fr

  20. Metabolic and circulatory evaluation of acute cerebral ischaemic accidents in man by positron emission tomography

    Energy Technology Data Exchange (ETDEWEB)

    Depresseux, J C; Franck, G., Van Cauwenberge, H.

    1987-06-18

    Positron emission tomography and oxygen-15 were used to evaluate the effects of an almitrine-raubasine combination on cerebral blood flow and oxydative metabolism in patients with acute cerebral ischaemia. In 5 patients, aged between 58 and 74 years, with cerebral ischaemic accident in the territory of the middle cerebral artery, blood flow rate, oxygen consumption and brain oxygen extraction were measured before and after a 90-min intravenous infusion of almitrine bismesilate 15 mg and raubasine 5 mg. Only one patient presented with initial relative luxury perfusion, the intensity of which was reduced by the combined treatment. The other 4 patients had focal reduction of cerebral blood flow and oxygen consumption prior to treatment. Satistical analysis conducted on three cerebral areas (epicentre of the lesion, anterior and posterior juxtalesional areas and homologous heterolateral areas) showed a significant 3.6% increase of oxygen consumption in the epicentre, both hemispheres included, and a significant increase of cerebral blood flow in all three areas (3% on the healthy side, 13% on the diseased side). No significant change in oxygen extraction was demonstrated. The authors conclude that acute almitrine-raubasine treatment has beneficial effects on the brain immediately after a cerebral vascular accident, reflecting respect of the circulation-metabolism couple.

  1. Studies on so-called redistribution phenomenon of cerebral blood flow imaging

    International Nuclear Information System (INIS)

    Oba, Hiroshi

    1989-01-01

    To elucidate the relationship between so-called redistribution phenomenon and metabolism or viability of the brain tissue, a new quantitative triple-radionuclide autoradiography was developed, whereby making it possible to compare both late images and reditribution of IMP with cerebral metabolism in experimentally induced unilateral ischemic brain tissue of rats. Iodine-123 IMP and I-125 IMP were used as tracers for early and late imaging, and H-3 amino acid mixture or H-3 H-2 deoxyglucose as a tracer for protein synthesis or glucose metabolism imaging. There was no significant relationship between redistribution index and protein synthesis or glucose metabolism. Protein synthesis was remarkably decreased in the affected hemisphere regardless of redistribution index values. Although the redistribution indices showed a gentle peak at approximately 34 μ mol/100 g/ min of glucose metabolism, there was no obvious relationship between either late images or redistribution index images and glucose metabolism images. Redistribution indices showed a maximum value at approximately 40 to 50 ml/100 g/min of cerebral blood flow. Reverse redistribution was observed with 160 ml/100 g/min or more of flow. Thin layer chromatographic findings were similar in the affected and non-affected resions, suggesting redistribution of a lipophilic IMP metabolite of p-iodoamphetamine in the affected region. In vitro autoradiography revealed no significant reduction in binding ability of IMP to the affected ischemic cortex. In a computer simulation study for brain activity curve, brain activity at 150 min was found to be almost constant at more than 25 ml/100 g/min of flow. IMP redistribution was unlikely to reflect directly either brain metabolism or function, and both blood flow partition coefficient and blood flow values were independently responsible for cerebral kinetics of IMP. (N.K.)

  2. Cerebral blood flow in patients with dementia of Alzheimer's type

    DEFF Research Database (Denmark)

    Postiglione, A; Lassen, N A; Holman, B L

    1993-01-01

    In the normal brain as well as in Alzheimer's disease (AD), regional cerebral blood flow (CBF) is coupled to metabolic demand and, therefore, changes in CBF reflect variations in neuronal metabolism. The use of radionuclide techniques, such as positron emission tomography (PET) and single photon...

  3. Subcortical cerebral blood flow and metabolic changes elicited by cortical spreading depression in rat

    Energy Technology Data Exchange (ETDEWEB)

    Mraovitch, S.; Calando, Y.; Goadsby, P.J.; Seylaz, J. (Laboratoire de Recherches Cerebrovasculaire, Paris (France))

    1992-06-01

    Changes in cerebral cortical perfusion (CBF{sub LDF}), local cerebral blood flow (lCBF) and local cerebral glucose utilization (lCGU) elicited by unilateral cortical spreading depression (SD) were monitored and measured in separate groups of rats anesthetized with {alpha}-chloralose. CBF{sub LDF} was recorded with laser Doppler flowmetry, while lCBF and lCGU were measured by the quantitative autoradiographic ({sup 14}C)iodoantipyrine and ({sup 14}C)-2-deoxyglucose methods, respectively. SD elicited a wave of hyperemia after a latency of 2 to 3 min followed by an oligemic phase. Ninety minutes following the onset of SD cortical lCBF and lCGU were essentially the same as on the contralateral side and in sham-treated rats. However, alteration in the lCBF and lCGU in upper and lower brainstem persisted. The present results demonstrate that long-lasting cerebrovascular and metabolic alterations take place within the subcortical regions following SD. These regions provide an attractive site to integrate observations in man concerning spreading depression and the aura of migraine with the other features of the syndrome. 19 refs., 2 figs., 1 tab.

  4. Effect of cerebral blood flow on consciousness and outcome after head injury. Assessment by jugular bulb venous metabolism and IMP-SPECT

    Energy Technology Data Exchange (ETDEWEB)

    Imaizumi, Shigeki; Onuma, Takehide; Motohashi, Osamu; Kameyama, Motonobu; Ishii, Kiyoshi [Sendai City Hospital (Japan)

    2002-10-01

    This study was performed to elucidate the therapeutical value of arteriojugularvenous oxygen difference (AVDO{sub 2}) in the ultra-emergent period after head injury. Rational therapeutic strategy after severe head injury needs information concerning the dynamical change of cerebral blood flow (CBF) and metabolism. We monitored the cerebral venous metabolism within 6 hours after head injury until the day IMP-SPECT was performed. Whole brain cerebral blood flow detected by IMP-SPECT and AVDO{sub 2} at the same day was compared, which restored to the period within 6 hours after head injury. From this procedure, we could outline cerebral blood flow conditions by only AVDO{sub 2} without IMP-SPECT in the ultra-emergent period. Eighty-six patients with head injury who were carried to our emergency center in the period of recent 2 years aged ranging from 15 to 94 years were the subjects. They all performed jugular bulb cannulation within 6 hours after the accident (Martin's phase I: day 0) to know saturation of jugular vein (SjO{sub 2}), AVDO{sub 2} and AVL. They were monitored until the day IMP-SPECT was performed (Martin's phase II; day 1-3 or phase III; day 4-15). The correlation between CBF and AVDO{sub 2}. The effect of CBF and cerebral venous metabolism on consciousness and outcome was also analyzed. CBF and AVDO{sub 2} in phase II and III were reversely correlated (p<0.0001). Normal CBF corresponded with 5.0 vol% in AVDO{sub 2}. AVDO{sub 2} in all cases changed 6.2 vol% at phase I, 4.5 vol% at phase II and 5.1 vol% at phase III. Glasgow comascale (GCS) on admission under 8 (n=47) and over 9 (n=39) significantly differed in AVDO{sub 2} and CBF in the period of II and III. The patients with favorable consciousness showed low AVDO{sub 2} and hyperemia afterwards. Dead cases in phase I (n=19) showed high AVDO{sub 2} and low SjO{sub 2}. The patients with severe disability (SD) (n=13) showed high AVDO{sub 2} and low CBF and the patients with good recovery (GR

  5. Regional cerebral blood flow (rCBF) in psychiatry: Methodological issues

    International Nuclear Information System (INIS)

    Prohovnik, I.

    1984-01-01

    Traditionally, measurements of regional cerebral blood flow (rCBF) have been confined to neurology and nuclear medicine. Only one laboratory had concentrated on using this technique in psychiatric studies. Recently, however, rCBF has been increasingly used in psychiatry, and it seems appropriate at this time to examine the value and limitations of this method. The present article reviews selected methodological issues that may complicate the performance and interpretation of rCBF studies, with the aim of providing some means to evaluate published work and to plan further psychiatric research. In this paper, the term rCBF refers only to the two-dimensional, noninvasive methods that rely on inhalation or intravenous injection of xenon-133. The growing interest of rCBF to psychiatry stems mostly from the fact that this technique can indirectly map cerebral metabolism and, by interface, neural activity or information processing. Regional metabolism and blood flow are closely coupled to the human brain in the absence of gross pathology, and since psychiatric patients rarely present acute neurological abnormalities that might disrupt this coupling, one may infer regional metabolism from flow

  6. Cerebral blood flow measurement techniques in infants and children

    International Nuclear Information System (INIS)

    Kirsch, J.R.; Traystman, R.J.; Rogers, M.C.

    1985-01-01

    The tremendous growth of interest in neurologic intensive care and in the pathophysiology of the cerebral circulation in the past few years has resulted in increasing numbers of studies that document alterations in cerebral flow during the course of various diseases or as a response to treatment of them. Before pediatricians come to conclusions based on these studies, it is important to have an understanding of the techniques involved. The techniques are complex and difficult but are based on understandable principles. They also have limitations and are subject to misinterpretations. Pediatricians should become knowledgeable about some of these techniques and their limitations because it is likely that they will be applied with increasing frequency in the next several years. We are on the threshold of exciting discoveries in abnormalities of cerebral blood flow and cerebral metabolism not only in critically ill children but also in children with congenital and learning disorders

  7. Cerebral blood flow and metabolism during controlled hypotension with sodium-nitroprusside and general anaesthesia for total hip replacement a.m. Charnley

    International Nuclear Information System (INIS)

    Buenemann, L.; Jensen, K.; Thomsen, L.; Riisager, S.

    1987-01-01

    Cerebral blood flow (CBF) and cerebral metabolic rate of oxygen (CMRo 2 ) were studied during hypotension induced with sodium nitroprusside (SNP) in 10 patients undergoing total hip replacement a.m. Charnley. Cerebral blood flow was measured using an injection of xenon-133 into an arm vein. The decay curve was detected by five scintillation counters placed over each hemisphere and analysed with the Novo 10a cerebrograph. Blood samples were drawn from the radial artery and the jugular venous bulb to calculate the CMRo 2 . In the gropu as a whole, there were significant decreases in mean arterial pressure and in cerebrovascular resistance. There were no significant changes, in either CBF or CMRo 2 in the gropu as a whole, but there were substantial individual differences. In conclusion, the use of SNP-induced hypotension for extracranial surgery should be used only in patients monitored closely. (author)

  8. Differential effects of gaseous versus injectable anesthetics on changes in regional cerebral blood flow and metabolism induced by l-DOPA in a rat model of Parkinson's disease.

    Science.gov (United States)

    Bimpisidis, Zisis; Öberg, Carl M; Maslava, Natallia; Cenci, M Angela; Lundblad, Cornelia

    2017-06-01

    Preclinical imaging of brain activity requires the use of anesthesia. In this study, we have compared the effects of two widely used anesthetics, inhaled isoflurane and ketamine/xylazine cocktail, on cerebral blood flow and metabolism in a rat model of Parkinson's disease and l-DOPA-induced dyskinesia. Specific tracers were used to estimate regional cerebral blood flow (rCBF - [ 14 C]-iodoantipyrine) and regional cerebral metabolic rate (rCMR - [ 14 C]-2-deoxyglucose) with a highly sensitive autoradiographic method. The two types of anesthetics had quite distinct effects on l-DOPA-induced changes in rCBF and rCMR. Isoflurane did not affect either the absolute rCBF values or the increases in rCBF in the basal ganglia after l-DOPA administration. On the contrary, rats anesthetized with ketamine/xylazine showed lower absolute rCBF values, and the rCBF increases induced by l-DOPA were masked. We developed a novel improved model to calculate rCMR, and found lower metabolic activities in rats anesthetized with isoflurane compared to animals anesthetized with ketamine/xylazine. Both anesthetics prevented changes in rCMR upon l-DOPA administration. Pharmacological challenges in isoflurane-anesthetized rats indicated that drugs mimicking the actions of ketamine/xylazine on adrenergic or glutamate receptors reproduced distinct effects of the injectable anesthetics on rCBF and rCMR. Our results highlight the importance of anesthesia in studies of cerebral flow and metabolism, and provide novel insights into mechanisms mediating abnormal neurovascular responses to l-DOPA in Parkinson's disease. Copyright © 2017 Elsevier Inc. All rights reserved.

  9. Reduced cerebral blood flow and oxygen metabolism in extremely preterm neonates with low-grade germinal matrix- intraventricular hemorrhage

    Science.gov (United States)

    Lin, Pei-Yi; Hagan, Katherine; Fenoglio, Angela; Grant, P. Ellen; Franceschini, Maria Angela

    2016-05-01

    Low-grade germinal matrix-intraventricular hemorrhage (GM-IVH) is the most common complication in extremely premature neonates. The occurrence of GM-IVH is highly associated with hemodynamic instability in the premature brain, yet the long-term impact of low-grade GM-IVH on cerebral blood flow and neuronal health have not been fully investigated. We used an innovative combination of frequency-domain near infrared spectroscopy and diffuse correlation spectroscopy (FDNIRS-DCS) to measure cerebral oxygen saturation (SO2) and an index of cerebral blood flow (CBFi) at the infant’s bedside and compute an index of cerebral oxygen metabolism (CMRO2i). We enrolled twenty extremely low gestational age (ELGA) neonates (seven with low-grade GM-IVH) and monitored them weekly until they reached full-term equivalent age. During their hospital stay, we observed consistently lower CBFi and CMRO2i in ELGA neonates with low-grade GM-IVH compared to neonates without hemorrhages. Furthermore, lower CBFi and CMRO2i in the former group persists even after the resolution of the hemorrhage. In contrast, SO2 does not differ between groups. Thus, CBFi and CMRO2i may have better sensitivity than SO2 in detecting GM-IVH-related effects on infant brain development. FDNIRS-DCS methods may have clinical benefit for monitoring the evolution of GM-IVH, evaluating treatment response, and potentially predicting neurodevelopmental outcome.

  10. Cerebral blood flow and metabolism in a patient with motor aphasia by positron emission tomography using 15O2 and C15O2

    International Nuclear Information System (INIS)

    Kitamura, Shin; Terashi, Akiro; Kato, Toshiaki; Soeda, Toshiyuki; Iio, Masaaki.

    1986-01-01

    Cerebral blood flow and metabolism, in a patient with motor aphasia due to cerebral infarction of the left basal ganglionic region, were studied by positron emission tomography (PET) using 15 O 2 and C 15 O 2 . A 62-year-old woman, right handed, was admitted with a complaint of right hemiparesis. Motor aphasia developed on the following day of hospitalization. CT scan showed low density area in the left caduate nucleus, putamen, internal capsule, and centrum semiovale, but the cortex was intact on the images of CT scan. PET studies were performed 22 days and 92 days after onset of stroke. The first PET study revealed marked reduction of CBF (cerebral blood flow) in the left cortex and subcortex, but CMRO 2 (cerebral oxygen consumption) was relatively preserved and OEF (oxygen extraction fraction) increased. The second PET study showed recovery of CBF in the left cortex and increase of OEF vanished. CMRO 2 decreased in the left posterior frontal region and subcortex. Motor aphasia still continued at the time of the second PET study. Therefore, the left posterior frontal cortex lesion as well as the left subcortex lesion might be related to the occurrence of motor aphasia in this case. The thresholds of CBF and CMRO 2 for developing clinical symptoms are higher than those for developing low density on the images of CT scan. These results suggest the importance of the study of cerebral blood flow and metabolism in the study of the responsible lesion for aphasia. (author)

  11. Cerebral metabolism in experimental hydrocephalus: an in vivo 1H and 31P magnetic resonance spectroscopy study

    NARCIS (Netherlands)

    Braun, K. P.; van Eijsden, P.; Vandertop, W. P.; de Graaf, R. A.; Gooskens, R. H.; Tulleken, K. A.; Nicolay, K.

    1999-01-01

    Brain damage in patients with hydrocephalus is caused by mechanical forces and cerebral ischemia. The severity and localization of impaired cerebral blood flow and metabolism are still largely unknown. Magnetic resonance (MR) spectroscopy offers the opportunity to investigate cerebral energy

  12. Effects of CDP-choline on neurologic deficits and cerebral glucose metabolism in a rat model of cerebral ischemia

    Energy Technology Data Exchange (ETDEWEB)

    Kakihana, M.; Fukuda, N.; Suno, M.; Nagaoka, A.

    1988-02-01

    The effects of cytidine 5'-diphosphocholine (CDP-choline) on neurologic deficits and cerebral glucose metabolism were studied in a rat model of transient cerebral ischemia. Cerebral ischemia was induced by occluding both common carotid arteries for 20 or 30 minutes 24 hours after the vertebral arteries were permanently occluded by electrocautery. CDP-choline was administered intraperitoneally twice daily for 4 days after reestablishing carotid blood flow. CDP-choline at two dosages (50 and 250 mg/kg) shortened the time required for recovery of spontaneous motor activity in a dose-related manner; recovery time was measured early after reperfusion. Neurologic signs were observed for 10 days. High-dose CDP-choline improved neurologic signs in the rats within 20-30 minutes of ischemia. When cerebral glucose metabolism was assessed on Day 4, increases in the levels of glucose and pyruvate were accompanied by decreases in the synthesis of labeled acetylcholine from uniformly labeled (/sup 14/C)glucose measured in the cerebral cortex of rats with 30 minutes of ischemia. High-dose CDP-choline also attenuated changes in these variables. CDP-(1,2-/sup 14/C)choline injected intravenously 10 minutes after reperfusion was used for membrane lipid biosynthesis. These results indicate that CDP-choline has beneficial effects on brain dysfunction induced by cerebral ischemia, which may be due in part to the restorative effects of CDP-choline on disturbed cerebral glucose metabolism, probably by stimulating phospholipid biosynthesis.

  13. Effects of CDP-choline on neurologic deficits and cerebral glucose metabolism in a rat model of cerebral ischemia

    International Nuclear Information System (INIS)

    Kakihana, M.; Fukuda, N.; Suno, M.; Nagaoka, A.

    1988-01-01

    The effects of cytidine 5'-diphosphocholine (CDP-choline) on neurologic deficits and cerebral glucose metabolism were studied in a rat model of transient cerebral ischemia. Cerebral ischemia was induced by occluding both common carotid arteries for 20 or 30 minutes 24 hours after the vertebral arteries were permanently occluded by electrocautery. CDP-choline was administered intraperitoneally twice daily for 4 days after reestablishing carotid blood flow. CDP-choline at two dosages (50 and 250 mg/kg) shortened the time required for recovery of spontaneous motor activity in a dose-related manner; recovery time was measured early after reperfusion. Neurologic signs were observed for 10 days. High-dose CDP-choline improved neurologic signs in the rats within 20-30 minutes of ischemia. When cerebral glucose metabolism was assessed on Day 4, increases in the levels of glucose and pyruvate were accompanied by decreases in the synthesis of labeled acetylcholine from uniformly labeled [ 14 C]glucose measured in the cerebral cortex of rats with 30 minutes of ischemia. High-dose CDP-choline also attenuated changes in these variables. CDP-[1,2- 14 C]choline injected intravenously 10 minutes after reperfusion was used for membrane lipid biosynthesis. These results indicate that CDP-choline has beneficial effects on brain dysfunction induced by cerebral ischemia, which may be due in part to the restorative effects of CDP-choline on disturbed cerebral glucose metabolism, probably by stimulating phospholipid biosynthesis

  14. Positron emission tomography and cerebral metabolism

    International Nuclear Information System (INIS)

    Comar, D.; Maziere, M.; Zarifian, E.; Naquet, R.

    1979-01-01

    The association of new methods of labelling with short lived radioisotopes and of visualisation 'in vivo' of these labelled molecules by emission tomography, provide the possibility of studying brain metabolism at different levels. Two examples will illustrate the possibilities of this methodology. Cerebral metabolism of methionine- 11 C in phenylketonutic patients: The cerebral uptake of methionine was measured in 24 PKU children aged 1 to 40 months on a low protein diet. Ten of them were examined twice at intervals of several months. Stopping the diet for one week leads to an increase in blood phenylalanine and to a significant important decrease in brain uptake of labelled methionine. Futhermore, for children under treatment having a low phenylalanine blood concentration, brain uptake of methionine decreases with age between 1 and 40 months. These results suggest that the treatment of this disease should be started as soon as possible after birth. Cerebral metabolism of psychoactive drugs: The study of the brain distribution and kinetics of psychoactive drugs may help in understanding their mode of action. Chlorpromazine- 11 C was administered i.v. to schyzophrenic patients not previously treated with neuroleptics. In all patients the brain uptake of the drug was high and rapid, and was localized mainly in the grey matter, probably in proportion to the blood flow. Non-specific binding of this drug to brain proteins prevented visualization of specific binding to dopaminergic or αnor-adrenergic receptors. Specific receptor binding of benzodiazepines was however visualized in the brain of baboons after injection of 11 C-flunitrazepam (specific activity = 600 Ci/μmole) and subsequent displacement of this radioactive ligand by a pharmacological dose of Lorazepam

  15. Cerebral ketone body metabolism.

    Science.gov (United States)

    Morris, A A M

    2005-01-01

    Ketone bodies (KBs) are an important source of energy for the brain. During the neonatal period, they are also precursors for the synthesis of lipids (especially cholesterol) and amino acids. The rate of cerebral KB metabolism depends primarily on the concentration in blood; high concentrations occur during fasting and on a high-fat diet. Cerebral KB metabolism is also regulated by the permeability of the blood-brain barrier (BBB), which depends on the abundance of monocarboxylic acid transporters (MCT1). The BBB's permeability to KBs increases with fasting in humans. In rats, permeability increases during the suckling period, but human neonates have not been studied. Monocarboxylic acid transporters are also present in the plasma membranes of neurons and glia but their role in regulating KB metabolism is uncertain. Finally, the rate of cerebral KB metabolism depends on the activities of the relevant enzymes in brain. The activities vary with age in rats, but reliable results are not available for humans. Cerebral KB metabolism in humans differs from that in the rat in several respects. During fasting, for example, KBs supply more of the brain's energy in humans than in the rat. Conversely, KBs are probably used more extensively in the brain of suckling rats than in human neonates. These differences complicate the interpretation of rodent studies. Most patients with inborn errors of ketogenesis develop normally, suggesting that the only essential role for KBs is as an alternative fuel during illness or prolonged fasting. On the other hand, in HMG-CoA lyase deficiency, imaging generally shows asymptomatic white-matter abnormalities. The ability of KBs to act as an alternative fuel explains the effectiveness of the ketogenic diet in GLUT1 deficiency, but its effectiveness in epilepsy remains unexplained.

  16. Effects of forskolin on cerebral blood flow: implications for a role of adenylate cyclase

    International Nuclear Information System (INIS)

    Wysham, D.G.; Brotherton, A.F.; Heistad, D.D.

    1986-01-01

    We have studied cerebral vascular effects of forskolin, a drug which stimulates adenylate cyclase and potentiates dilator effects of adenosine in other vascular beds. Our goals were to determine whether forskolin is a cerebral vasodilator and whether it potentiates cerebral vasodilator responses to adenosine. We measured cerebral blood flow with microspheres in anesthetized rabbits. Forskolin (10 micrograms/kg per min) increased blood flow (ml/min per 100 gm) from 39 +/- 5 (mean +/- S.E.) to 56 +/- 9 (p less than 0.05) in cerebrum, and increased flow to myocardium and kidney despite a decrease in mean arterial pressure. Forskolin did not alter cerebral oxygen consumption, which indicates that the increase in cerebral blood flow is a direct vasodilator effect and is not secondary to increased metabolism. We also examined effects of forskolin on the response to infusion of adenosine. Cerebral blood flow was measured during infusion of 1-5 microM/min adenosine into one internal carotid artery, under control conditions and during infusion of forskolin at 3 micrograms/kg per min i.v. Adenosine alone increased ipsilateral cerebral blood flow from 32 +/- 3 to 45 +/- 5 (p less than 0.05). Responses to adenosine were not augmented during infusion of forskolin. We conclude that forskolin is a direct cerebral vasodilator and forskolin does not potentiate cerebral vasodilator responses to adenosine

  17. Determination of cerebral metabolic patterns in dementia using positron emission tomography

    International Nuclear Information System (INIS)

    Kuhl, D.E.

    1986-01-01

    With the introduction of the Kety-Schmidt method whole brain measurements of blood flow and metabolism were first applied to normal aged and demented patients. Chronically demented patients were consistently found to have marked reductions in cerebral blood flow, oxygen utilization, and glucose utilization when dementia was severe, and lesser reductions when it was mild. Others found that cerebral blood flow, oxygen utilization, and glucose utilization were decreased in parallel in late stages of Alzheimer's disease (AD) and multiple infarct dementia (MID). The intraarterial /sup 133/Xe method has been used to determine abnormalities in regional cerebral blood flow that correlate with cognitive deficits in patients with organic dementia, mostly Alzheimer's cases. Positron emission tomography (PET) and the /sup 18/F fluorodeoxyglycose (FDG) method have been applied to small numbers of demented patients with advanced AD. In general, decreases were found in global cerebral glucose utilization, but especially in temporal and parietal cortex. Others, using PET and the /sup 15/O/sub 2/ steady-state method, found a coupled decline in global cerebral blood flow and oxygen utilization that was correlated with increasing severity of dementia in both AD and MID, but there was no increase in oxygen extraction ratio, and therefore no evidence to support the existence of a chronic ischemic brain process. In this chapter, the author reviews some of the recent findings at UCLA using PET and the method in the study of normal aging and dementing disorders

  18. The cerebral blood flow and metabolism for Broca's aphasia using positron emission tomography

    International Nuclear Information System (INIS)

    Kato, Toshiaki

    1987-01-01

    A total of 11 patients with Broca's aphasia (BA) underwent positron emission tomography (PET) with the purpose of investigating the responsible region and the symptomatic flow and metabolism thresholds for BA. Computed tomography (CT) was concurrently performed. In the group of 3 patients undergoing PET with C-11 glucose, both PET and CT provided abnormal findings in the region that is thought to be responsible for BA (Broca's area), including the cortex and subcortex in the anterior region to Sylvian fissure. The Broca's area in the remaining one was shown as low C-11 accumulation area on PET and as isodensity on CT. The second group, consisting of 8 BA patients and 30 control patients without BA, underwent PET using O-15 steady method. PET showed reduction of regional cerebral blood flow (rCBF) and oxygen metabolic rate (rCMRO 2 ) in the Broca's area in all BA patients. Computed tomography showed abnormal low density in the Broca's area in 3 patients, and abnormal findings in the basal ganglionic region and subcortex without evidence for abnormal low density in the Broca's area in the other 5 patients. Comparison of rCBF and rCMRO 2 in BA patients with those in control patients may show the symptomatic thresholds to be 20 - 27 ml/100 g/min for rCBF and 2.0 ml/100 g/min for rCMRO 2 . (Namekawa, K.)

  19. Purine Metabolism in Acute Cerebral Ischemia

    Directory of Open Access Journals (Sweden)

    Ye. V. Oreshnikov

    2008-01-01

    Full Text Available Objective: to study the specific features of purine metabolism in clinically significant acute cerebral ischemia. Subjects and materials. Three hundred and fifty patients with the acutest cerebral ischemic stroke were examined. The parameters of gas and electrolyte composition, acid-base balance, the levels of malonic dialdehyde, adenine, guanine, hypox-anthine, xanthine, and uric acid, and the activity of xanthine oxidase were determined in arterial and venous bloods and spinal fluid. Results. In ischemic stroke, hyperuricemia reflects the severity of cerebral metabolic disturbances, hemodynamic instability, hypercoagulation susceptiility, and the extent of neurological deficit. In ischemic stroke, hyperuri-corachia is accompanied by the higher spinal fluid levels of adenine, guanine, hypoxanthine, and xanthine and it is an indirect indicator of respiratory disorders of central genesis, systemic acidosis, hypercoagulation susceptibility, free radical oxidation activation, the intensity of a stressor response to cerebral ischemia, cerebral metabolic disturbances, the depth of reduced consciousness, and the severity of neurological deficit. Conclusion. The high venous blood activity of xanthine oxidase in ischemic stroke is associated with the better neurological parameters in all follow-up periods, the better early functional outcome, and lower mortality rates. Key words: hyperuricemia, stroke, xanthine oxidase, uric acid, cerebral ischemia.

  20. Cerebral energy metabolism during induced mitochondrial dysfunction

    DEFF Research Database (Denmark)

    Nielsen, T H; Bindslev, TT; Pedersen, S M

    2013-01-01

    In patients with traumatic brain injury as well as stroke, impaired cerebral oxidative energy metabolism may be an important factor contributing to the ultimate degree of tissue damage. We hypothesize that mitochondrial dysfunction can be diagnosed bedside by comparing the simultaneous changes...... in brain tissue oxygen tension (PbtO(2)) and cerebral cytoplasmatic redox state. The study describes cerebral energy metabolism during mitochondrial dysfunction induced by sevoflurane in piglets....

  1. Marked reduction of cerebral oxygen metabolism in patients with advanced cirrhosis

    International Nuclear Information System (INIS)

    Kawatoko, Toshiharu; Murai, Koichiro; Ibayashi, Setsurou; Tsuji, Hiroshi; Nomiyama, Kensuke; Sadoshima, Seizo; Eujishima, Masatoshi; Kuwabara, Yasuo; Ichiya, Yuichi

    1992-01-01

    Regional cerebral blood flow (rCBF), cerebral metabolic rate of oxygen (rCMRO 2 ), and oxygen extraction fraction (rOEF) were measured using positron emission tomography (PET) in four patients with cirrhosis (two males and two females, aged 57 to 69 years) in comparison with those in five age matched controls with previous transient global amnesia. PET studies were carried out when the patients were fully alert and oriented after the episodes of encephalopathy. In the patients, rCBF tended to be lower, while rCMRO 2 was significantly lowered in almost all hemisphere cortices, more markedly in the frontal cortex. Our results suggest that the brain oxygen metabolism is diffusely impaired in patients with advanced cirrhosis, and the frontal cortex seems to be more susceptible to the systemic metabolic derangements induced by chronic liver disease. (author)

  2. Acute hypoxia increases the cerebral metabolic rate

    DEFF Research Database (Denmark)

    Vestergaard, Mark Bitsch; Lindberg, Ulrich; Aachmann-Andersen, Niels Jacob

    2016-01-01

    The aim of the present study was to examine changes in cerebral metabolism by magnetic resonance imaging of healthy subjects during inhalation of 10% O2 hypoxic air. Hypoxic exposure elevates cerebral perfusion, but its effect on energy metabolism has been less investigated. Magnetic resonance im...

  3. New insights into coupling and uncoupling of cerebral blood flow and metabolism in the brain.

    Science.gov (United States)

    Venkat, Poornima; Chopp, Michael; Chen, Jieli

    2016-06-30

    The brain has high metabolic and energy needs and requires continuous cerebral blood flow (CBF), which is facilitated by a tight coupling between neuronal activity, CBF, and metabolism. Upon neuronal activation, there is an increase in energy demand, which is then met by a hemodynamic response that increases CBF. Such regional CBF increase in response to neuronal activation is observed using neuroimaging techniques such as functional magnetic resonance imaging and positron emission tomography. The mechanisms and mediators (eg, nitric oxide, astrocytes, and ion channels) that regulate CBF-metabolism coupling have been extensively studied. The neurovascular unit is a conceptual model encompassing the anatomical and metabolic interactions between the neurons, vascular components, and glial cells in the brain. It is compromised under disease states such as stroke, diabetes, hypertension, dementias, and with aging, all of which trigger a cascade of inflammatory responses that exacerbate brain damage. Hence, tight regulation and maintenance of neurovascular coupling is central for brain homeostasis. This review article also discusses the waste clearance pathways in the brain such as the glymphatic system. The glymphatic system is a functional waste clearance pathway that removes metabolic wastes and neurotoxins from the brain along paravascular channels. Disruption of the glymphatic system burdens the brain with accumulating waste and has been reported in aging as well as several neurological diseases.

  4. Effect of graded hyperventilation on cerebral metabolism in a cisterna magna blood injection model of subarachnoid hemorrhage in rats

    DEFF Research Database (Denmark)

    Ma, Xiaodong; Bay-Hansen, Rikke; Hauerberg, John

    2006-01-01

    In subarachnoid hemorrhage (SAH) with cerebrovascular instability, hyperventilation may induce a risk of inducing or aggravating cerebral ischemia. We measured cerebral blood flow (CBF) and cerebral metabolic rates of oxygen (CMRO2), glucose (CMRglc), and lactate (CMRlac) at different PaCO2 level...

  5. Middle cerebral artery blood velocity and cerebral blood flow and O2 uptake during dynamic exercise

    DEFF Research Database (Denmark)

    Madsen, P L; Sperling, B K; Warming, T

    1993-01-01

    Results obtained by the 133Xe clearance method with external detectors and by transcranial Doppler sonography (TCD) suggest that dynamic exercise causes an increase of global average cerebral blood flow (CBF). These data are contradicted by earlier data obtained during less-well-defined conditions....... To investigate this controversy, we applied the Kety-Schmidt technique to measure the global average levels of CBF and cerebral metabolic rate of oxygen (CMRO2) during rest and dynamic exercise. Simultaneously with the determination of CBF and CMRO2, we used TCD to determine mean maximal flow velocity...... in the middle cerebral artery (MCA Vmean). For values of CBF and MCA Vmean a correction for an observed small drop in arterial PCO2 was carried out. Baseline values for global CBF and CMRO2 were 50.7 and 3.63 ml.100 g-1.min-1, respectively. The same values were found during dynamic exercise, whereas a 22% (P

  6. Regional effects of craniotomy on cerebral circulation and metabolism

    International Nuclear Information System (INIS)

    Abumiya, Takeo; Sayama, Ichiro; Asakura, Ken; Hadeishi, Hiromu; Mizuno, Makoto; Suzuki, Akifumi; Yasui, Nobuyuki; Shishido, Fumio; Uemura, Kazuo

    1990-01-01

    Regional effects of craniotomy on cerebral circulation and metabolism, such as regional cerebral blood flow (rCBF), regional cerebral oxygen consumption (rCMRO 2 ), regional oxygen extraction fraction (rOEF), and regional cerebral blood volume (rCBV) were examined by a PET (positron emission tomography) study concerning surgery that was performed on un-ruptured aneurysm patients. Eight patients with intracranial un-ruptured aneurysms were studied pre- and post-operatively by the 15 O labelled-gas steady-state method, using HEADTOME-III. All patients underwent aneurysmal surgery performed by the transsylvian approach. There was a significant increase in the mean OEF values taken from the whole-brains of 8 patients, but there was not a significant change in CBF, CMRO 2 or CBV. The increase in OEF was caused by decrease of O 2 content, which was caused by post-operative decrease in the Hb value. So, this OEF increase was not the direct effect of craniotomy. In 2 patients, the rCBF and rCMRO 2 , in the fronto-temporal region (where craniotomy was performed) increased post-operatively. This regional effect suggests transient reactive hyperemia following compressive ischemia during the operative procedure, and metabolic demands for recovery of brain function. In 2 other patients, who had relatively low rCBFs during the pre-operative study, rCBF and rCMRO 2 in the bi-frontal region had decreased more at the post-operative study. This change appears to have been caused by removal of cerebrospinal fluid and depression of the frontal lobe. From this study, it becomes evident that the regional effect of craniotomy on cerebral circulation and metabolism is not so great, when adequate microsurgical techniques are used. (author)

  7. A Bovine Hemoglobin-Based Oxygen Carrier as Pump Prime for Cardiopulmonary Bypass: Reduced Systemic Lactic Acidosis and Improved Cerebral Oxygen Metabolism During Low-flow in a Porcine Model

    Science.gov (United States)

    2010-11-10

    1 A bovine hemoglobin-based oxygen carrier as pump prime for cardiopulmonary bypass: reduced systemic lactic acidosis and improved cerebral...2010 2. REPORT TYPE Final Report 3. DATES COVERED (From - To) June 2007 - November 2010 4. TITLE AND SUBTITLE A bovine hemoglobin-based oxygen...carrier as pump prime for cardiopulmonary bypass: reduced systemic lactic acidosis and improved cerebral oxygen metabolism during low-flow in a

  8. Aerobic fitness is associated with greater hippocampal cerebral blood flow in children

    Directory of Open Access Journals (Sweden)

    Laura Chaddock-Heyman

    2016-08-01

    Full Text Available The present study is the first to investigate whether cerebral blood flow in the hippocampus relates to aerobic fitness in children. In particular, we used arterial spin labeling (ASL perfusion MRI to provide a quantitative measure of blood flow in the hippocampus in 73 7- to 9-year-old preadolescent children. Indeed, aerobic fitness was found to relate to greater perfusion in the hippocampus, independent of age, sex, and hippocampal volume. Such results suggest improved microcirculation and cerebral vasculature in preadolescent children with higher levels of aerobic fitness. Further, aerobic fitness may influence how the brain regulates its metabolic demands via blood flow in a region of the brain important for learning and memory. To add specificity to the relationship of fitness to the hippocampus, we demonstrate no significant association between aerobic fitness and cerebral blood flow in the brainstem. Our results reinforce the importance of aerobic fitness during a critical period of child development.

  9. Measurement of regional cerebral blood flow by positron emission tomography

    International Nuclear Information System (INIS)

    Herscovitch, P.; Powers, W.J.

    1987-01-01

    The principal advantage of positron emission tomography over other methods for measuring cerebral blood flow stems from the accurate, quantitative three-dimensional measurements of regional brain radioactivity that are possible with this technique. As a result, accurate quantitative measurements of regional cerebral blood flow can be obtained for both superficial and deep cerebral structures. The value of PET for investigating central nervous system physiology and pathology extends far beyond this, however. Through the use of different radiotracers and appropriate mathematical models, PET can be applied to the measurement of a wide variety of physiologic variables. Measurements of rCBF tell only part of the story. Experience with PET and with a variety of other techniques has taught us that rCBF is at times a poor indicator of the metabolic, functional, and biochemical status of cerebral tissue. It is only by understanding the interaction of all of these factors that our understanding of neurologic disease can advance. It is in the investigation of these complex relationships that the real value of PET resides

  10. The relationship between the cerebral blood flow, oxygen consumption and glucose metabolism in primary degenerative dementia

    Energy Technology Data Exchange (ETDEWEB)

    Kuwabara, Yasuo; Ichiya, Yuichi; Ichimiya, Atsushi; Sasaki, Masayuki; Akashi, Yuko; Yoshida, Tsuyoshi; Fukumura, Toshimitsu; Masada, Kouji [Kyushu Univ., Fukuoka (Japan). Faculty of Medicine

    1995-03-01

    The CBF, CMRO{sub 2} and CMRGlu were measured in patients with primary degenerative dementia including 5 patients with dementia of Alzheimer`s type and 4 patients with Pick`s disease, and then the correlation between the cerebral blood flow and energy metabolism was evaluated. The control subjects consisted of 5 age-matched normal volunteers. The CBF, CMRO{sub 2} and CMRGlu decreased in the bilateral frontal, temporal and parietal regions in the patients with Alzheimer`s dementia, while they decreased in the bilateral frontal and temporal regions in the patients with Pick`s disease. Both the CBF and CMRO{sub 2} were closely correlated with each other. However, the CMRGlu was more severely impaired than the CBF or CMRO{sub 2} in both pathological conditions. These results suggested that CMRGlu began to decrease before the reduction of the aerobic metabolism and thus measuring the CMRGlu is considered to be the most sensitive method for detecting abnormal regions in primary degenerative dementia. (author).

  11. The relationship between the cerebral blood flow, oxygen consumption and glucose metabolism in primary degenerative dementia

    International Nuclear Information System (INIS)

    Kuwabara, Yasuo; Ichiya, Yuichi; Ichimiya, Atsushi; Sasaki, Masayuki; Akashi, Yuko; Yoshida, Tsuyoshi; Fukumura, Toshimitsu; Masada, Kouji

    1995-01-01

    The CBF, CMRO 2 and CMRGlu were measured in patients with primary degenerative dementia including 5 patients with dementia of Alzheimer's type and 4 patients with Pick's disease, and then the correlation between the cerebral blood flow and energy metabolism was evaluated. The control subjects consisted of 5 age-matched normal volunteers. The CBF, CMRO 2 and CMRGlu decreased in the bilateral frontal, temporal and parietal regions in the patients with Alzheimer's dementia, while they decreased in the bilateral frontal and temporal regions in the patients with Pick's disease. Both the CBF and CMRO 2 were closely correlated with each other. However, the CMRGlu was more severely impaired than the CBF or CMRO 2 in both pathological conditions. These results suggested that CMRGlu began to decrease before the reduction of the aerobic metabolism and thus measuring the CMRGlu is considered to be the most sensitive method for detecting abnormal regions in primary degenerative dementia. (author)

  12. Non-invasive optical measurement of cerebral metabolism and hemodynamics in infants.

    Science.gov (United States)

    Lin, Pei-Yi; Roche-Labarbe, Nadege; Dehaes, Mathieu; Carp, Stefan; Fenoglio, Angela; Barbieri, Beniamino; Hagan, Katherine; Grant, P Ellen; Franceschini, Maria Angela

    2013-03-14

    Perinatal brain injury remains a significant cause of infant mortality and morbidity, but there is not yet an effective bedside tool that can accurately screen for brain injury, monitor injury evolution, or assess response to therapy. The energy used by neurons is derived largely from tissue oxidative metabolism, and neural hyperactivity and cell death are reflected by corresponding changes in cerebral oxygen metabolism (CMRO₂). Thus, measures of CMRO₂ are reflective of neuronal viability and provide critical diagnostic information, making CMRO₂ an ideal target for bedside measurement of brain health. Brain-imaging techniques such as positron emission tomography (PET) and single-photon emission computed tomography (SPECT) yield measures of cerebral glucose and oxygen metabolism, but these techniques require the administration of radionucleotides, so they are used in only the most acute cases. Continuous-wave near-infrared spectroscopy (CWNIRS) provides non-invasive and non-ionizing radiation measures of hemoglobin oxygen saturation (SO₂) as a surrogate for cerebral oxygen consumption. However, SO₂ is less than ideal as a surrogate for cerebral oxygen metabolism as it is influenced by both oxygen delivery and consumption. Furthermore, measurements of SO₂ are not sensitive enough to detect brain injury hours after the insult, because oxygen consumption and delivery reach equilibrium after acute transients. We investigated the possibility of using more sophisticated NIRS optical methods to quantify cerebral oxygen metabolism at the bedside in healthy and brain-injured newborns. More specifically, we combined the frequency-domain NIRS (FDNIRS) measure of SO2 with the diffuse correlation spectroscopy (DCS) measure of blood flow index (CBFi) to yield an index of CMRO₂ (CMRO₂i). With the combined FDNIRS/DCS system we are able to quantify cerebral metabolism and hemodynamics. This represents an improvement over CWNIRS for detecting brain health, brain

  13. Evaluation of cerebral blood flow, cerebral metabolism and cerebral function by magnetic resonance imaging

    International Nuclear Information System (INIS)

    Tanaka, Chuzo; Higuchi, Toshihiro; Umeda, Masahiro; Naruse, Shoji; Horikawa, Yoshiharu; Ueda, Satoshi; Furuya, Seiichi.

    1995-01-01

    The magnetic resonance (MR) method has the unique potentiality of detecting cerebral metabolites, cerebral blood flow and brain functions in a noninvasive fashion. We have developed several MR techniques to detect these cerebral parameters with the use of clinical MRI scanners. By modifying the MR spectroscopy (MRS) technique, both 31 P- and 1 H-MRS data can be obtained from multiple, localized regions (multi-voxel method) of the brain, and the distribution of each metabolite in the brain can be readily visualized by metabolite mapping. The use of diffusion weighted images (DWI) permits visualization of the anisotropy of water diffusion in white matter, and based on the difference of diffusion coefficiency, the differential diagnosis between epidermoid tumor and arachnoid cyst can be made. By employing dynamic-MRI (Dyn-MRI) with Gd-DTPA administration, it is possible to examine the difference in blood circulation between brain tumor tissue and normal tissue, as well as among different types of brain tumors. By using magnetization transfer contrast (MTC) imaging, it has become possible to detect brain tumors, and with a small dose of Gd-DTPA, to visualize the vascular system. Functional MRI (fMRI) visualizes the activated brain by using conventional gradient echo technique on conventional MRI scanners. This method has the unique characteristic of detecting a brain function with high spatial and temporal resolution by using the intrinsic substance. Moreover, the localization of motor and sensory areas was detected by noninvasive means within few minutes. The fMRI procedure will be used in the future to analyze the higher and complex brain functions. In conclusion, multi-modality MR is a powerful technique that is useful for investigating the pathogenesis of many diseases, and provides a noninvasive analytic modality for studying brain function. (author)

  14. Altered cerebral blood flow and glucose metabolism in patients with liver disease and minimal encephalopathy

    International Nuclear Information System (INIS)

    Lockwood, A.H.; Yap, E.W.; Rhoades, H.M.; Wong, W.H.

    1991-01-01

    We measured CBF and the CMRglc in normal controls and in patients with severe liver disease and evidence for minimal hepatic encephalopathy using positron emission tomography. Regions were defined in frontal, temporal, parietal, and visual cortex; the thalamus; the caudate; the cerebellum; and the white matter along with a whole-slice value obtained at the level of the thalamus. There was no difference in whole-slice CBF and CMRglc values. Individual regional values were normalized to the whole-slice value and subjected to a two-way repeated measures analysis of variance. When normalized CBF and CMRglc values for regions were compared between groups, significant differences were demonstrated (F = 5.650, p = 0.00014 and F = 4.58, p = 0.0073, respectively). These pattern differences were due to higher CBF and CMRglc in the cerebellum, thalamus, and caudate in patients and lower values in the cortex. Standardized coefficients extracted from a discriminant function analysis permitted correct group assignment for 95.5% of the CBF studies and for 92.9% of the CMRglc studies. The similarity of the altered pattern of cerebral metabolism and flow in our patients to that seen in rats subjected to portacaval shunts or ammonia infusions suggests that this toxin may alter flow and metabolism and that this, in turn, causes the clinical expression of encephalopathy

  15. Regional cerebral blood flow and metabolism in patients with transient global amnesia. A study using SPECT and 1H-MRS

    International Nuclear Information System (INIS)

    Ishihara, Tetsuya; Hirata, Koichi; Tatsumoto, Muneto; Yamazaki, Kaoru; Sato, Toshihiko.

    1997-01-01

    In 13 patients with transient global amnesia (TGA), we studied the clinical course and changes over time by means of imaging techniques such as SPECT. MRI, and proton MR spectroscopy ( 1 H-MRS). In the case of SPECT, a cerebral blood flow decrease at the time center of the temporal lobe persisted at least for more than one month. In many patients, no abnormal signs were found on MRI. Despite the presence of intracranial impairment of energy metabolism, no evidence of cerebral ischemia was obtained using 1 H-MRS at the acute and subacute stages. There were thus discrepancies between the symptoms and the findings of SPECT as well as the findings of 1 H-MRS. These data suggest that TGA may not necessarily be caused by cerebra1 ischemia. (author)

  16. Apparent brain temperature imaging with multi-voxel proton magnetic resonance spectroscopy compared with cerebral blood flow and metabolism imaging on positron emission tomography in patients with unilateral chronic major cerebral artery steno-occlusive disease

    Energy Technology Data Exchange (ETDEWEB)

    Nanba, Takamasa; Nishimoto, Hideaki; Murakami, Toshiyuki; Fujiwara, Shunrou; Ogasawara, Kuniaki [Iwate Medical University, Department of Neurosurgery, Iwate (Japan); Yoshioka, Yoshichika [Osaka University, Open and Transdisciplinary Research Initiatives, Osaka (Japan); Sasaki, Makoto; Uwano, Ikuko [Iwate Medical University, Institute for Biomedical Science, Iwate (Japan); Terasaki, Kazunori [Iwate Medical University, Cyclotron Research Center, Iwate (Japan)

    2017-09-15

    The purpose of the present study was to determine whether apparent brain temperature imaging using multi-voxel proton magnetic resonance (MR) spectroscopy correlates with cerebral blood flow (CBF) and metabolism imaging in the deep white matter of patients with unilateral chronic major cerebral artery steno-occlusive disease. Apparent brain temperature and CBF and metabolism imaging were measured using proton MR spectroscopy and {sup 15}O-positron emission tomography (PET), respectively, in 35 patients. A set of regions of interest (ROIs) of 5 x 5 voxels was placed on an MR image so that the voxel row at each edge was located in the deep white matter of the centrum semiovale in each cerebral hemisphere. PET images were co-registered with MR images with these ROIs and were re-sliced automatically using image analysis software. In 175 voxel pairs located in the deep white matter, the brain temperature difference (affected hemisphere - contralateral hemisphere: ΔBT) was correlated with cerebral blood volume (CBV) (r = 0.570) and oxygen extraction fraction (OEF) ratios (affected hemisphere/contralateral hemisphere) (r = 0.641). We excluded voxels that contained ischemic lesions or cerebrospinal fluid and calculated the mean values of voxel pairs in each patient. The mean ΔBT was correlated with the mean CBF (r = - 0.376), mean CBV (r = 0.702), and mean OEF ratio (r = 0.774). Apparent brain temperature imaging using multi-voxel proton MR spectroscopy was correlated with CBF and metabolism imaging in the deep white matter of patients with unilateral major cerebral artery steno-occlusive disease. (orig.)

  17. The responsible region and the symptomatic threshold of cerebral blood flow and oxygen metabolism for Broca's aphasia using positron emission tomography

    International Nuclear Information System (INIS)

    Kato, Toshiaki; Ujike, Takashi; Kitamura, Shin; Soeda, Toshiyuki; Terashi, Akiro

    1987-01-01

    This study was designed to investigate the responsible region and the symptomatic flow and metabolism threshold for Broca's aphasia. Regional cerebral blood flow (CBF) and oxygen metabolism (CMRO 2 ) were measured by positron emission tomography (PET) using 15 O steady state method in eight patients with Broca's aphasia due to cerebral infarction and thirty patients without aphasia. During scanning, patients closed their eyes and were kept free from any stimuration. X-CT scan revealed abnormal low density in Broca's area which includes cortex and subcortex in the anterior region to Sylvian fissure in three patients with aphasia. In the other five patients with aphasia X-CT scan showed no abnormal low density in Broca's area, showed it in basal ganglionic region and subcortex. PET study revealed reduction of CBF and CMRO 2 in Broca's area in all cases with Broca's aphasia. CBF and CMRO 2 of Broca's area of aphasic patients were compared to those of non aphasic patients to obtain the symptomatic threshold in CBF and CMRO 2 . The values of symptomatic threshold were 20 - 27 ml/100 g/min in CBF and 2.0 ml/100 g/min in CMRO 2 . The symptomatic threshold differed from the threshold for development of abnormal low density on X-CT, therefore the measurement of CBF and CMRO 2 were useful in studying the responsible region for aphasia. (author)

  18. Cerebral blood flow is reduced in patients with sepsis syndrome

    International Nuclear Information System (INIS)

    Bowton, D.L.; Bertels, N.H.; Prough, D.S.; Stump, D.A.

    1989-01-01

    The relationship between sepsis-induced CNS dysfunction and changes in brain blood flow remains unknown, and animal studies examining the influence of sepsis on cerebral blood flow (CBF) do not satisfactorily address that relationship. We measured CBF and cerebrovascular reactivity to CO 2 in nine patients with sepsis syndrome using the 133 Xe clearance technique. Mean CBF was 29.6 +/- 15.8 (SD) ml/100 g.min, significantly lower than the normal age-matched value in this laboratory of 44.9 +/- 6.2 ml/100 g.min (p less than .02). This depression did not correlate with changes in mean arterial pressure. Despite the reduction in CBF, the specific reactivity of the cerebral vasculature to changes in CO 2 was normal, 1.3 +/- 0.9 ml/100 g.min/mm Hg. Brain blood flow is reduced in septic humans; the contribution of this reduction to the metabolic and functional changes observed in sepsis requires further study

  19. Regional cerebral blood flow and metabolism in patients with transient global amnesia. A study using SPECT and {sup 1}H-MRS

    Energy Technology Data Exchange (ETDEWEB)

    Ishihara, Tetsuya; Hirata, Koichi; Tatsumoto, Muneto; Yamazaki, Kaoru [Dokkyo Univ., Tochigi (Japan). School of Medicine; Sato, Toshihiko

    1997-06-01

    In 13 patients with transient global amnesia (TGA), we studied the clinical course and changes over time by means of imaging techniques such as SPECT. MRI, and proton MR spectroscopy ({sup 1}H-MRS). In the case of SPECT, a cerebral blood flow decrease at the time center of the temporal lobe persisted at least for more than one month. In many patients, no abnormal signs were found on MRI. Despite the presence of intracranial impairment of energy metabolism, no evidence of cerebral ischemia was obtained using {sup 1}H-MRS at the acute and subacute stages. There were thus discrepancies between the symptoms and the findings of SPECT as well as the findings of {sup 1}H-MRS. These data suggest that TGA may not necessarily be caused by cerebra1 ischemia. (author)

  20. The study of 1H-MRS on monkey of resuscitation after cerebral selection ultra-profound hypothermic blood flow occlusion

    International Nuclear Information System (INIS)

    Pu Jun; Xu Wei; Fang Shaolong; Zhao Xinxiang; Feng Zhongtang; Jiang Jiyao

    2005-01-01

    Objective: To investigate the appearance and feature of 1 H/protion magnetic resonance spectroscopy ( 1 H-MRS) on resuscitation after cerebral selective ultra-profound hypothermic and blood flow occlusion. To study effects of cerebral biochemical metabolism after cerebral selective ultra-profound hypothermia and blood flow occlusion and to explore the validity and feasibility of it. Methods: Bilateral carotid arteries and jugular veins were clipped about 10 minutes before perfusion. Then selective cerebral circulation was established by perfusion of cooling lingers liquid through right internal carotid artery and flow out of left jugular vein with clip of other carotid arteries and jugular veins. Brain temperature reached (15.1 ± 0.9) degree C, while the body temperature maintained (32.50 ± 0.58) degree C. Cerebral blood recovered after 60 minutes of cerebral ischemia and monkey came back. The cerebral MAI and DWI as well as 1 H-MRS were examined 4, 24, 72 h, 21 days before and after cerebral selective ultro-profound hypothermia and blood flow occlusion. The peak of N-acetyl-aspartate (NAA), Choline (Cho), creatine and phosphocreatine (Cr, PCr) of VOL were compare with those of control group in different time. Results: MRI T 1 WI, MRI T 2 WI and DWI is normal in different time in different region; there was not a significant difference in the ratio of NAA/(Cr+PCr), Cho/(Cr+PCr) in ROI in different time in the different region in the light of statistical analysis (P>0.05). Conclusion: The light of cerebral biochemical metabolism, selective ultra-profound hypothermia is safety and may provide effective protective effects and safety during cerebral ischemia. (authors)

  1. The contribution of astrocytes to the regulation of cerebral blood flow

    Directory of Open Access Journals (Sweden)

    Clare eHowarth

    2014-05-01

    Full Text Available In order to maintain normal brain function, it is critical that cerebral blood flow (CBF is matched to neuronal metabolic needs. Accordingly, blood flow is increased to areas where neurons are more active (a response termed functional hyperemia. The tight relationships between neuronal activation, glial cell activity, cerebral energy metabolism and the cerebral vasculature, known as neurometabolic and neurovascular coupling, underpin functional MRI (fMRI signals but are incompletely understood. As functional imaging techniques, particularly BOLD fMRI, become more widely used, their utility hinges on our ability to accurately and reliably interpret the findings. A growing body of data demonstrates that astrocytes can serve as a ‘bridge’, relaying information on the level of neural activity to blood vessels in order to coordinate oxygen and glucose delivery with the energy demands of the tissue. It is widely assumed that calcium-dependent release of vasoactive substances by astrocytes results in arteriole dilation and the increased blood flow which accompanies neuronal activity. However, the signaling molecules responsible for this communication between astrocytes and blood vessels are yet to be definitively confirmed. Indeed, there is controversy over whether activity-induced changes in astrocyte calcium are widespread and fast enough to elicit such functional hyperemia responses. In this review, I will summarise the evidence which has convincingly demonstrated that astrocytes are able to modify the diameter of cerebral arterioles. I will discuss the prevalence, presence and timing of stimulus-induced astrocyte calcium transients and describe the evidence for and against the role of calcium-dependent formation and release of vasoactive substances by astrocytes. I will also review alternative mechanisms of astrocyte-evoked changes in arteriole diameter and consider the questions which remain to be answered in this exciting area of research.

  2. Influence of antihypertensive therapy on cerebral perfusion in patients with metabolic syndrome: relationship with cognitive function and 24-h arterial blood pressure monitoring.

    Science.gov (United States)

    Efimova, Nataliya Y; Chernov, Vladimir I; Efimova, Irina Y; Lishmanov, Yuri B

    2015-08-01

    To investigate the regional cerebral blood flow, cognitive function, and parameters of 24-h arterial blood pressure monitoring in patients with metabolic syndrome before and after combination antihypertensive therapy. The study involved 54 patients with metabolic syndrome (MetS) investigated by brain single-photon emission computed tomography, 24-h blood pressure monitoring (ABPM), and comprehensive neuropsychological testing before and after 24 weeks of combination antihypertensive therapy. Patients with metabolic syndrome had significantly poorer regional cerebral blood flow compared with control group: by 7% (P = 0.003) in right anterior parietal cortex, by 6% (P = 0.028) in left anterior parietal cortex, by 8% (P = 0.007) in right superior frontal lobe, and by 10% (P = 0.00002) and 7% (P = 0.006) in right and left temporal brain regions, correspondingly. The results of neuropsychological testing showed 11% decrease in mentation (P = 0.002), and 19% (P = 0.011) and 20% (P = 0.009) decrease in immediate verbal and visual memory in patients with MetS as compared with control group. Relationships between the indices of ABPM, cerebral perfusion, and cognitive function were found. Data showed an improvement of regional cerebral blood flow, ABPM parameters, and indicators of cognitive functions after 6 months of antihypertensive therapy in patients with MetS. The study showed the presence of diffuse disturbances in cerebral perfusion is associated with cognitive disorders in patients with metabolic syndrome. Combination antihypertensive treatment exerts beneficial effects on the 24-h blood pressure profile, increases cerebral blood flow, and improves cognitive function in patients with MetS. © 2015 John Wiley & Sons Ltd.

  3. Cigarette smoking impairs nitric oxide-mediated cerebral blood flow increase: Implications for Alzheimer's disease

    Directory of Open Access Journals (Sweden)

    Noboru Toda

    2016-08-01

    Full Text Available Cerebral blood flow is mainly regulated by nitrergic (parasympathetic, postganglionic nerves and nitric oxide (NO liberated from endothelial cells in response to shear stress and stretch of vasculature, whereas sympathetic vasoconstrictor control is quite weak. On the other hand, peripheral vascular resistance and blood flow are mainly controlled by adrenergic vasoconstrictor nerves; endothelium-derived NO and nitrergic nerves play some roles as vasodilator factors. Cigarette smoking impairs NO synthesis in cerebral vascular endothelial cells and nitrergic nerves leading to interference with cerebral blood flow and glucose metabolism in the brain. Smoking-induced cerebral hypoperfusion is induced by impairment of synthesis and actions of NO via endothelial nitric oxide synthase (eNOS/neuronal NOS (nNOS inhibition and by increased production of oxygen radicals, resulting in decreased actions of NO on vascular smooth muscle. Nicotine acutely and chronically impairs the action of endothelial NO and also inhibits nitrergic nerve function in chronic use. Impaired cerebral blood supply promotes the synthesis of amyloid β that accelerates blood flow decrease. This vicious cycle is thought to be one of the important factors involving in Alzheimer's disease (AD. Quitting smoking is undoubtedly one of the important ways to prevent and delay the genesis or slow the progress of impaired cognitive function and AD.

  4. Effects of nitrous oxide on cerebral haemodynamics and metabolism during isoflurane anaesthesia in man

    International Nuclear Information System (INIS)

    Algotsson, L.; Messeter, K.; Rosen, I.; Holmin. T.

    1992-01-01

    Seven normoventilated and five hyperventilated healthy adults undergoing cholecystectomy and anaesthetized with methohexitone, fentanyl and pancuronium were studied with measurement of cerebral blood flow (CBF), cereal metabolic rate of oxygen (CMRo 2 ), and quantified electroencephalography (EEG) under two sets of conditions: 1) 1.7% end-tidal concentration of isoflurane in air/oxygen: 2) 0.85% end-tidal concentration of isoflurane in nitrous oxide (N 2 O)/oxygen. The object was to study the effects of N 2 O during isoflurane anaesthesia on cerebral circulation, metabolism and neuroelectric activity. N 2 O in the anaesthetic gas mixture caused a 43% (P 2 was not significantly altered by N 2 O. EEG demonstrated an activated pattern with decreased low frequency activity and increased high frequency activity. The results confirm that N 2 O is a potent cerebral vasodilator in man, although the mechanisms underlying the effects on CBF are still unclear. (au)

  5. Cerebral Metabolic Changes Related to Oxidative Metabolism in a Model of Bacterial Meningitis Induced by Lipopolysaccharide

    DEFF Research Database (Denmark)

    Munk, Michael; Rom Poulsen, Frantz; Larsen, Lykke

    2018-01-01

    BACKGROUND: Cerebral mitochondrial dysfunction is prominent in the pathophysiology of severe bacterial meningitis. In the present study, we hypothesize that the metabolic changes seen after intracisternal lipopolysaccharide (LPS) injection in a piglet model of meningitis is compatible...... with mitochondrial dysfunction and resembles the metabolic patterns seen in patients with bacterial meningitis. METHODS: Eight pigs received LPS injection in cisterna magna, and four pigs received NaCl in cisterna magna as a control. Biochemical variables related to energy metabolism were monitored by intracerebral...... dysfunction with increasing cerebral LPR due to increased lactate and normal pyruvate, PbtO2, and ICP. The metabolic pattern resembles the one observed in patients with bacterial meningitis. Metabolic monitoring in these patients is feasible to monitor for cerebral metabolic derangements otherwise missed...

  6. Performance on Paced Auditory Serial Addition Test and cerebral blood flow in multiple sclerosis

    NARCIS (Netherlands)

    D'haeseleer, M.; Steen, C.; Hoogduin, J. M.; van Osch, M. J. P.; Fierens, Y.; Cambron, M.; Koch, M. W.; De Keyser, J.

    BackgroundTo assess the relationship between performance on the Paced Auditory Serial Addition Test (PASAT) and both cerebral blood flow (CBF) and axonal metabolic integrity in normal appearing white matter (NAWM) of the centrum semiovale in patients with multiple sclerosis (MS). MethodsNormal

  7. Cerebral blood flow in temporal lobe epilepsy: a partial volume correction study

    International Nuclear Information System (INIS)

    Giovacchini, Giampiero; Bonwetsch, Robert; Theodore, William H.; Herscovitch, Peter; Carson, Richard E.

    2007-01-01

    Previous studies in temporal lobe epilepsy (TLE) have shown that, owing to brain atrophy, positron emission tomography (PET) can overestimate deficits in measures of cerebral function such as glucose metabolism (CMR glu ) and neuroreceptor binding. The magnitude of this effect on cerebral blood flow (CBF) is unexplored. The aim of this study was to assess CBF deficits in TLE before and after magnetic resonance imaging-based partial volume correction (PVC). Absolute values of CBF for 21 TLE patients and nine controls were computed before and after PVC. In TLE patients, quantitative CMR glu measurements also were obtained. Before PVC, regional values of CBF were significantly (p glu in middle and inferior temporal cortex, fusiform gyrus and hippocampus both before and after PVC. A significant positive relationship between disease duration and AIs for CMR glu , but not CBF, was detected in hippocampus and amygdala, before but not after PVC. PVC should be used for PET CBF measurements in patients with TLE. Reduced blood flow, in contrast to glucose metabolism, is mainly due to structural changes. (orig.)

  8. Cerebral metabolism and vascular reactivity during breath-hold and hypoxic challenge in freedivers and healthy controls

    DEFF Research Database (Denmark)

    Vestergaard, Mark B.; Larsson, Henrik B.W.

    2017-01-01

    blood flow (CBF) and metabolic rate of oxygen (CMRO2), and magnetic resonance spectroscopy was used to measure the cerebral lactate, glutamate+glutamine, N-acetylaspartate and phosphocreatine+creatine concentrations in the occipital lobe. Fifteen freedivers and seventeen non-diver controls participated...

  9. Cerebral haemodynamic and metabolic changes in carotid artery occlusion: a PET study

    International Nuclear Information System (INIS)

    Samson, Y.; Loc'h, C.; Ottaviani, M.; Baron, J.C.; Bousser, M.

    1984-09-01

    Using the positron emission tomography, with the O 15 inhalation technique, the cerebral blood flow (CBF), the oxygen extraction fraction (OEF) and the cerebral metabolic rate of oxygen (CMRO 2 ) were studied in 37 patients with internal carotid artery (ICA) occlusion. In the territory of the occluded ICA, two pattern of focal anomaly have been observed: a CBF decrease with a ''compensatory'' OEF increase or a matched CBF and CMRO 2 decrease. On the other hand, as compared to age matched control values, CMRO 2 is significantly decreased in the territory of the occluded carotid only in patients with extensive neck vessels obstructive disease

  10. Cerebral hematocrit decreases with hemodynamic compromise in carotid artery occlusion: a PET study.

    Science.gov (United States)

    Yamauchi, H; Fukuyama, H; Nagahama, Y; Katsumi, Y; Okazawa, H

    1998-01-01

    This study investigated whether in patients with internal carotid artery occlusion the regional cerebral hematocrit correlates with cerebral hemodynamics or metabolic state and, if so, how the regional cerebral hematocrit changes in the hemodynamically compromised region. We used positron emission tomography to study seven patients with unilateral internal carotid artery occlusion and no cortical infarction in the chronic stage. The distributions of red blood cell and plasma volumes were assessed using oxygen-15-labeled carbon monoxide and copper-62-labeled human serum albumin-dithiosemicarbazone tracers, respectively. The calculated hematocrit value was compared with the hemodynamic and metabolic parameters measured with the oxygen-15 steady-state technique. In the cerebral cortex, the value of the cerebral hematocrit varied but was correlated with the hemodynamic and metabolic status. Stepwise regression analysis revealed that the large vessel hematocrit, the cerebral metabolic rate of oxygen, and the cerebral blood flow or the oxygen extraction fraction accounted for a significant proportion of variance of the cerebral hematocrit. The oxygen extraction fraction and the cerebral metabolic rate of oxygen negatively correlated with the cerebral hematocrit, whereas the cerebral blood flow correlated positively: patients with reduced blood supply relative to metabolic demand (decreased blood flow with increased oxygen extraction fraction) showed low hematocrit values. In carotid artery occlusion in the chronic stage, regional cerebral hematocrit may vary according to cerebral hemodynamics and metabolic status. Regional cerebral hematocrit may decrease with hemodynamic compromise unless oxygen metabolism concomitantly decreases.

  11. Discussion of the oxygen inhalation technique with O15 for the evaluation of cerebral metabolism/flow relationships in cerebro-vascular diseases

    International Nuclear Information System (INIS)

    Lenzi, G.L.; Jones, T.; Frackowiak, R.S.J.; Fieschi, C.

    1980-01-01

    The use of short lived radioisotopes, particularly 15 O, has opened up the possibility of studying both oxygen metabolism and blood flow in patients non-invasively. The results obtained with the oxygen inhalation technique (O.I.T.) and two dimensional imaging have been reported since 1976. Positron emission tomography represents an important technical advance on these initial studies. It permits the evaluation of regional CBF and cerebral metabolic rate of oxygen (CMRO 2 ) qualitatively and hopefully in the near future, in absolute quantitative terms using an essentially non-invasive technique. It will thus be possible to examine rCBF and rCMRO 2 across the spectrum of central nervous disorders systematically and longitudinally, though the necessity for having a cyclotron to produce the positron emitters will limit this to some extent. (Auth.)

  12. Plasma pH does not influence the cerebral metabolic ratio during maximal whole body exercise

    DEFF Research Database (Denmark)

    Volianitis, Stefanos; Rasmussen, Peter; Seifert, Thomas

    2011-01-01

    .05) following the Sal and Bicarb trials, respectively. Accordingly, the cerebral metabolic ratio decreased equally during the Sal and Bicarb trials: from 5.8 ± 0.6 at rest to 1.7 ± 0.1 and 1.8 ± 0.2, respectively. The enlarged blood-buffering capacity after infusion of Bicarb eliminated metabolic acidosis......Exercise lowers the cerebral metabolic ratio of O2 to carbohydrate (glucose + 1/2 lactate) and metabolic acidosis appears to promote cerebral lactate uptake. However, the influence of pH on cerebral lactate uptake and, in turn, on the cerebral metabolic ratio during exercise is not known. Sodium...... during maximal exercise but that did not affect the cerebral lactate uptake and, therefore, the decrease in the cerebral metabolic ratio....

  13. Cerebral venography and flow quantification with MR

    International Nuclear Information System (INIS)

    Mattle, H.; Elelman, R.R.; Reis, H.H.; O'Reilly, G.V.; Wentz, K.V.; O'Leary, D.H.; Finn, J.P.; Longmaid, H.E.

    1989-01-01

    The authors describe an approach for creating projection venograms of the head and quantifying flow in the cerebral veins and sinuses. A series of two- dimensional flow-compensated gradient-echo images were acquired. Signal from arteries was eliminated by application of a 5-cm-thick presaturation slab to the neck. The images were postprocessed with use of a maximum intensity projection algorithm to produce projection venograms. In addition, flow directionally, flow velocity, and, in the superior sagittal sinus (SSS), flow volume was assessed by means of a dynamic bolus tracking technique. Flow velocities in the SSS ranged from 20.1 to 45.5 cm/sec, and flow volumes from 269 to 612 mL/min. This technique was able to identify cerebral venous thrombosis and partial SSS obstruction, cerebral venous angiomas, and venous drainage of arteriovenous malformations and to demonstrate patency of the SSS with falx meningiomas

  14. Studies of cerebral atrophy and regional cerebral blood flow in patients with Parkinson's disease

    International Nuclear Information System (INIS)

    Kitamura, Shin

    1983-01-01

    Cerebral atrophy and regional cerebral blood flow (rCBF) of 25 patients with Parkinson's disease were studied. The rCBF was measured with the intra-arterial Xe-133 injection method. The results obtained were as follows: 1) Sixty four % of Parkinson's disease patients showed ventricular dilation, and 76% of Parkinson's disease patients showed cortical atrophy on the CT scan, but we had to allow for the effects of the natural aging process on these results. 2) No correlation was recognized either between cerebral atrophy and the severity of Parkinson's disease, or between cerebral atrophy and the duration of Parkinson's disease. 3) In Parkinson's disease patients, the mean rCBF was lower than that of normal control subjects. The difference was even more remarkable in older patients. Only 40% of Parkinson's disease patients showed hyperfrontal pattern. 4) There was no correlation either between the mean rCBF and the severity of Parkinson's disease, or between the mean rCBF and the duration of Parkinson's disease. There was no significant difference between the mean rCBF of Parkinson's disease patients receiving levodopa and that of untreated patients. 5) The mean rCBF decreased in patients with cerebral atrophy on the CT scan. 6) Parkinson's disease patients with intellectual impairment showed cerebral atrophy and a remarkable decrease of the mean rCBF. 7) The effect of aging on cerebral atrophy on the CT scan had to be allowed for, but judging from the decrease of the mean rCBF, the cerebral cortex is evidently involved in Parkinson's disease. 8) The rCBF decline in Parkinson's disease patients may be related with the diminished cortical metabolic rate due to a remote effect of striatal dysfunction and a disturbance of mesocortical dopaminergic pathways. (J.P.N.)

  15. Studies of cerebral atrophy and regional cerebral blood flow in patients with Parkinson's disease

    Energy Technology Data Exchange (ETDEWEB)

    Kitamura, Shin [Nippon Medical School, Tokyo

    1983-04-01

    Cerebral atrophy and regional cerebral blood flow (rCBF) of 25 patients with Parkinson's disease were studied. The rCBF was measured with the intra-arterial Xe-133 injection method. The results obtained were as follows: 1) Sixty four % of Parkinson's disease patients showed ventricular dilation, and 76% of Parkinson's disease patients showed cortical atrophy on the CT scan, but we had to allow for the effects of the natural aging process on these results. 2) No correlation was recognized either between cerebral atrophy and the severity of Parkinson's disease, or between cerebral atrophy and the duration of Parkinson's disease. 3) In Parkinson's disease patients, the mean rCBF was lower than that of normal control subjects. The difference was even more remarkable in older patients. Only 40% of Parkinson's disease patients showed hyperfrontal pattern. 4) There was no correlation either between the mean rCBF and the severity of Parkinson's disease, or between the mean rCBF and the duration of Parkinson's disease. There was no significant difference between the mean rCBF of Parkinson's disease patients receiving levodopa and that of untreated patients. 5) The mean rCBF decreased in patients with cerebral atrophy on the CT scan. 6) Parkinson's disease patients with intellectual impairment showed cerebral atrophy and a remarkable decrease of the mean rCBF. 7) The effect of aging on cerebral atrophy on the CT scan had to be allowed for, but judging from the decrease of the mean rCBF, the cerebral cortex is evidently involved in Parkinson's disease. 8) The rCBF decline in Parkinson's disease patients may be related with the diminished cortical metabolic rate due to a remote effect of striatal dysfunction and a disturbance of mesocortical dopaminergic pathways.

  16. Cerebral blood flow and oxygen metabolism in senile dementia of Alzheimer's type and vascular dementia with deep white matter changes

    International Nuclear Information System (INIS)

    Tohgi, H.; Yonezawa, H.; Takahashi, S.; Sato, N.; Kato, E.; Kudo, M.; Hatano, K.; Sasaki, T.

    1998-01-01

    Regional cerebral blood flow (rCBF), cerebral metabolic rate of oxygen (rCMRO 2 ), oxygen extraction fraction (rOEF), and cerebral blood volume (rCBV) were investigated using positron emission tomography (PET) in 16 patients with senile dementia of Alzheimer's type (SDAT), and compared with those of 6 nondemented and 3 demented patients with deep white matter high signal (DWMH) on T2-weighted MRI and 6 controls. rCBF, rCMRO 2 and rCBV were determined using C 15 O 2 , 15 O 2 and C 15 O, respectively. rCBF and CMRO 2 were significantly decreased in the frontal, parietal and temporal cortex (P 2 was significantly reduced in only the frontal and temporal cortex of demented patients (P < 0.05). rOEF was significantly increased in the parietal cortex of patients with SDAT and in the white matter of patients with SDAT or DWMH (P < 0.05), and the increase in the frontal white matter significantly paralleled the progression of dementia in patients with SDAT (P < 0.05). rCBV was significantly decreased in the parietal and temporal cortex of patients with SDAT (P < 0.05), but not in any areas of those with DWMH. (orig.)

  17. Brain energy metabolism and blood flow differences in healthy aging

    DEFF Research Database (Denmark)

    Aanerud, Joel; Borghammer, Per; Chakravarty, M Mallar

    2012-01-01

    Cerebral metabolic rate of oxygen consumption (CMRO(2)), cerebral blood flow (CBF), and oxygen extraction fraction (OEF) are important indices of healthy aging of the brain. Although a frequent topic of study, changes of CBF and CMRO(2) during normal aging are still controversial, as some authors......, and in the temporal cortex. Because of the inverse relation between OEF and capillary oxygen tension, increased OEF can compromise oxygen delivery to neurons, with possible perturbation of energy turnover. The results establish a possible mechanism of progression from healthy to unhealthy brain aging, as the regions...

  18. Cerebral intolerance during flow arrested carotid angioplasty.

    Science.gov (United States)

    St Louis, Myron; Park, Brian D; Dahn, Michael; Bozeman, Patricia

    2012-01-01

    The use of flow arrest as a means of providing cerebral protection during carotid angioplasty offers the advantages of improved efficiency of debris removal and the ability to provide protection under unfavorable (tortuous) anatomic circumstances. However, in contrast to the filtration methods of cerebral protection, this modality requires complete interruption of antegrade carotid artery flow during balloon angioplasty and stent deployment. We report our experience with 9 patients undergoing carotid angioplasty with the Mo.Ma device, which utilizes common and external carotid artery balloon occlusion during the angioplasty procedure. We assessed the clinical outcomes and intraprocedural hemodynamic data. The average duration of carotid occlusion was 8.3 minutes. Of the 9 patients, 2 patients (22%) experienced cerebral intolerance. No stroke occurred in this patient cohort. There appeared to be a poor relationship between procedure intolerance and the presence of significant contralateral stenosis or low carotid back pressure. Furthermore, the incidence of postangioplasty hypotension was not clearly related to cerebral intolerance. Carotid angioplasty with stenting can be safely conducted with flow arrest as an alternative to filter-type cerebral protection devices. However, because cerebral intolerance is not an infrequent occurrence with this approach, clinicians must be cognizant of management strategies for transient cerebral intolerance.

  19. Effects of intermittent theta burst stimulation on cerebral blood flow and cerebral vasomotor reactivity.

    Science.gov (United States)

    Pichiorri, Floriana; Vicenzini, Edoardo; Gilio, Francesca; Giacomelli, Elena; Frasca, Vittorio; Cambieri, Chiara; Ceccanti, Marco; Di Piero, Vittorio; Inghilleri, Maurizio

    2012-08-01

    To determine whether intermittent theta burst stimulation influences cerebral hemodynamics, we investigated changes induced by intermittent theta burst stimulation on the middle cerebral artery cerebral blood flow velocity and vasomotor reactivity to carbon dioxide (CO(2)) in healthy participants. The middle cerebral artery flow velocity and vasomotor reactivity were monitored by continuous transcranial Doppler sonography. Changes in cortical excitability were tested by transcranial magnetic stimulation. In 11 healthy participants, before and immediately after delivering intermittent theta burst stimulation, we tested cortical excitability measured by the resting motor threshold and motor evoked potential amplitude over the stimulated hemisphere and vasomotor reactivity to CO(2) bilaterally. The blood flow velocity was monitored in both middle cerebral arteries throughout the experimental session. In a separate session, we tested the effects of sham stimulation under the same experimental conditions. Whereas the resting motor threshold remained unchanged before and after stimulation, motor evoked potential amplitudes increased significantly (P = .04). During and after stimulation, middle cerebral artery blood flow velocities also remained bilaterally unchanged, whereas vasomotor reactivity to CO(2) increased bilaterally (P = .04). The sham stimulation left all variables unchanged. The expected intermittent theta burst stimulation-induced changes in cortical excitability were not accompanied by changes in cerebral blood flow velocities; however, the bilateral increased vasomotor reactivity suggests that intermittent theta burst stimulation influences the cerebral microcirculation, possibly involving subcortical structures. These findings provide useful information on hemodynamic phenomena accompanying intermittent theta burst stimulation, which should be considered in research aimed at developing this noninvasive, low-intensity stimulation technique for safe

  20. Marked reduction of cerebral oxygen metabolism in patients with advanced cirrhosis; A positron emission tomography study

    Energy Technology Data Exchange (ETDEWEB)

    Kawatoko, Toshiharu; Murai, Koichiro; Ibayashi, Setsurou; Tsuji, Hiroshi; Nomiyama, Kensuke; Sadoshima, Seizo; Eujishima, Masatoshi; Kuwabara, Yasuo; Ichiya, Yuichi (Kyushu Univ., Fukuoka (Japan). Faculty of Medicine)

    1992-01-01

    Regional cerebral blood flow (rCBF), cerebral metabolic rate of oxygen (rCMRO{sub 2}), and oxygen extraction fraction (rOEF) were measured using positron emission tomography (PET) in four patients with cirrhosis (two males and two females, aged 57 to 69 years) in comparison with those in five age matched controls with previous transient global amnesia. PET studies were carried out when the patients were fully alert and oriented after the episodes of encephalopathy. In the patients, rCBF tended to be lower, while rCMRO{sub 2} was significantly lowered in almost all hemisphere cortices, more markedly in the frontal cortex. Our results suggest that the brain oxygen metabolism is diffusely impaired in patients with advanced cirrhosis, and the frontal cortex seems to be more susceptible to the systemic metabolic derangements induced by chronic liver disease. (author).

  1. Effects of nitrous oxide on cerebral haemodynamics and metabolism during isoflurane anaesthesia in man

    Energy Technology Data Exchange (ETDEWEB)

    Algotsson, L.; Messeter, K. (Department of Anaesthesiology, University Hospital, Lund (Sweden)); Rosen, I. (Department of Clinical Neurophysiology, University Hospital, Lund (Sweden)); Holmin, T. (Department of Surgery, University Hospital, Lund (Sweden))

    1992-01-01

    Seven normoventilated and five hyperventilated healthy adults undergoing cholecystectomy and anaesthetized with methohexitone, fentanyl and pancuronium were studied with measurement of cerebral blood flow (CBF), cereal metabolic rate of oxygen (CMRo[sub 2]), and quantified electroencephalography (EEG) under two sets of conditions: (1) 1.7% end-tidal concentration of isoflurane in air/oxygen: (2) 0.85% end-tidal concentration of isoflurane in nitrous oxide (N[sub 2]O)/oxygen. The object was to study the effects of N[sub 2]O during isoflurane anaesthesia on cerebral circulation, metabolism and neuroelectric activity. N[sub 2]O in the anaesthetic gas mixture caused a 43% (P<0.05) increase in CBF during normocarbic conditions but no significant change during hypocapnia. CMRo[sub 2] was not significantly altered by N[sub 2]O. EEG demonstrated an activated pattern with decreased low frequency activity and increased high frequency activity. The results confirm that N[sub 2]O is a potent cerebral vasodilator in man, although the mechanisms underlying the effects on CBF are still unclear. (au).

  2. Low cerebral blood flow in hypotensive perinatal distress

    DEFF Research Database (Denmark)

    Lou, H C; Lassen, N A; Friis-Hansen, B

    1977-01-01

    was used for the cerebral blood flow measurements. The study confirmed that perinatal distress may be associated with low arterial blood pressure, and it was shown that cerebral blood flow is very low, 20 ml/100 g/min or less, in hypotensive perinatal distress. It is concluded that cerebral ischaemia plays...... a crucial role in the development of perinatal hypoxic brain injury....

  3. Cerebral glucose metabolic abnormality in patients with congenital scoliosis

    OpenAIRE

    Park, Weon Wook; Suh, Kuen Tak; Kim, Jeung Il; Ku, Ja Gyung; Lee, Hong Seok; Kim, Seong-Jang; Kim, In-Ju; Kim, Yong-Ki; Lee, Jung Sub

    2008-01-01

    A possible association between congenital scoliosis and low mental status has been recognized, but there are no reports describing the mental status or cerebral metabolism in patients with congenital scoliosis in detail. We investigated the mental status using a mini-mental status exam as well as the cerebral glucose metabolism using F-18 fluorodeoxyglucose brain positron emission tomography in 12 patients with congenital scoliosis and compared them with those of 14 age-matched patients with ...

  4. Bedside Evaluation of Cerebral Energy Metabolism in Severe Community-Acquired Bacterial Meningitis

    DEFF Research Database (Denmark)

    Rom Poulsen, Frantz; Schulz, Mette; Jacobsen, Anne

    2015-01-01

    BACKGROUND: Mortality and morbidity have remained high in bacterial meningitis. Impairment of cerebral energy metabolism probably contributes to unfavorable outcome. Intracerebral microdialysis is routinely used to monitor cerebral energy metabolism, and recent experimental studies indicate...... that this technique may separate ischemia and non-ischemic mitochondrial dysfunction. The present study is a retrospective interpretation of biochemical data obtained in a series of patients with severe community-acquired meningitis. METHODS: Cerebral energy metabolism was monitored in 15 patients with severe...... community-acquired meningitis utilizing intracerebral microdialysis and bedside biochemical analysis. According to previous studies, cerebral ischemia was defined as lactate/pyruvate (LP) ratio >30 with intracerebral pyruvate level

  5. Cerebral blood flow, glucose use, and CSF ionic regulation in potassium-depleted rats

    International Nuclear Information System (INIS)

    Schroek, H.; Kuschinsky, W.

    1988-01-01

    Rats were kept on a low-K + diet for 25 or 70 days. Local cerebral blood flow (LCBF) and local cerebral glucose utilization (LCGU) were measured in 31 different structures of the brain by means of the [ 14 C]iodoantipyrine and [ 14 C]2-deoxy-D-glucose method. After 25 and 70 days of K + depletion LCBF was decreased significantly in 27 and 30 structures, respectively, the average decrease being 19 and 25%. In contrast, average LCGU was not changed. Cisternal cerebrospinal fluid (CSF) K + concentration decreased significantly from 2.65 ± 0.02 mM in controls to 2.55 ± 0.02 mM and 2.47 ± 0.02 mM in the two treated groups. CSF [HCO 3 - ], pH, and Pco 2 were increased in K + -depleted animals. These data show that K + depletion induces an increase in CSF pH and a decrease in CSF K + concentration, both of which cause a reduction in cerebral blood flow. The increased CSF Pco 2 is secondary to the reduction of blood flow, since brain metabolism and arterial Pco 2 remained constant

  6. Evaluation of ocular acupuncture on cerebral infarction with cerebral blood flow perfusion imaging

    International Nuclear Information System (INIS)

    Li Yuge; Gao Qinyi; Wang Shuang; Zhao Yong

    2008-01-01

    To evaluate the immediate effect of ocular acupuncture on patients, an method of SPECT image of cerebral blood flow daily stress test was established. 10 patients diagnosed as cerebral infarction by CT or MRI were tested. They all received 99 Tc m -ECD SPECT imaging at twice before and after ocular acupuncture. By means of image subtraction technique and semi-quantitative method of regional interesting area, the change of regional cerebral blood flow was observed between the two images. Under restful state perfusion of cerebral blood flow in 18 foci was low at the frontal lobe, the cerebellum, the basal ganglia and temporal lobe. After ocular acupuncture, the perfusions were obviously increased in 16 foci among them and the reactivity of the frontal lobe and the cerebellum to ocular acupuncture was higher, the average improvement rate of which was 55.15% and 53.06% respectively, lower in the basal ganglia and temporal lobe, the average improvement rate was 31.79% and 36.67% respectively. 99 Tc m -ECD SPECT cerebral perfusion image has some significant clinic value for evaluating the effect of ocular acupuncture to treating cerebral infarction. (authors)

  7. Hemodynamic disturbances in cerebral ischemia; Correlation between positron emission tomographic and angiographic findings

    Energy Technology Data Exchange (ETDEWEB)

    Tenjin, Hiroshi; Ueda, Satoshi; Mizukawa, Norihiko; Imahori, Yoshio; Hino, Akihiko; Ohmori, Yoshio [Kyoto Prefectural Univ. of Medicine (Japan); Nakahashi, Hisamitsu

    1993-04-01

    Proper treatment of ischemic stroke requires better understanding of cerebral hemodynamic changes. The hemodynamic changes associated with ischemia were measured using positron emission tomography and related to angiographic findings in the subacute and chronic stages of 17 ischemia patients who showed symptoms of main trunk stenosis of the internal carotid artery system. The hemodynamic factors, cerebral blood flow, cerebral blood volume, cerebral metabolic rate for oxygen, oxygen extraction fraction, and flow/volume ratio, were measured in regions of interest determined from the angiographic stenosis (over 50%) and compared in each stage. The cerebral blood flow and flow/volume ratio in the territory downstream of the main trunk stenosis and cerebral metabolic rate for oxygen in the whole cortex were decreased in the subacute stage. In the chronic stage, cerebral blood flow and flow/volume ratio decreased mainly in borderzone areas. (author).

  8. Age differences in intercorrelations between regional cerebral metabolic rates for glucose

    International Nuclear Information System (INIS)

    Horwitz, B.; Duara, R.; Rapoport, S.I.

    1986-01-01

    Patterns of cerebral metabolic intercorrelations were compared in the resting state in 15 healthy young men (ages 20 to 32 years) and 15 healthy elderly men (ages 64 to 83 years). Controlling for whole-brain glucose metabolism, partial correlation coefficients were determined between pairs of regional cerebral metabolic rates for glucose determined by positron emission tomography using [18F]fluorodeoxyglucose and obtained in 59 brain regions. Compared with the young men, the elderly men had fewer statistically significant correlations, with the most notable reductions observed between the parietal lobe regions, and between the parietal and frontal lobe regions. These results suggest that cerebral functional interactions are reduced in healthy elderly men

  9. Fluorescence lifetime microscopy of NADH distinguishes alterations in cerebral metabolism in vivo.

    Science.gov (United States)

    Yaseen, Mohammad A; Sutin, Jason; Wu, Weicheng; Fu, Buyin; Uhlirova, Hana; Devor, Anna; Boas, David A; Sakadžić, Sava

    2017-05-01

    Evaluating cerebral energy metabolism at microscopic resolution is important for comprehensively understanding healthy brain function and its pathological alterations. Here, we resolve specific alterations in cerebral metabolism in vivo in Sprague Dawley rats utilizing minimally-invasive 2-photon fluorescence lifetime imaging (2P-FLIM) measurements of reduced nicotinamide adenine dinucleotide (NADH) fluorescence. Time-resolved fluorescence lifetime measurements enable distinction of different components contributing to NADH autofluorescence. Ostensibly, these components indicate different enzyme-bound formulations of NADH. We observed distinct variations in the relative proportions of these components before and after pharmacological-induced impairments to several reactions involved in glycolytic and oxidative metabolism. Classification models were developed with the experimental data and used to predict the metabolic impairments induced during separate experiments involving bicuculline-induced seizures. The models consistently predicted that prolonged focal seizure activity results in impaired activity in the electron transport chain, likely the consequence of inadequate oxygen supply. 2P-FLIM observations of cerebral NADH will help advance our understanding of cerebral energetics at a microscopic scale. Such knowledge will aid in our evaluation of healthy and diseased cerebral physiology and guide diagnostic and therapeutic strategies that target cerebral energetics.

  10. A novel Bayesian approach to accounting for uncertainty in fMRI-derived estimates of cerebral oxygen metabolism fluctuations.

    Science.gov (United States)

    Simon, Aaron B; Dubowitz, David J; Blockley, Nicholas P; Buxton, Richard B

    2016-04-01

    Calibrated blood oxygenation level dependent (BOLD) imaging is a multimodal functional MRI technique designed to estimate changes in cerebral oxygen metabolism from measured changes in cerebral blood flow and the BOLD signal. This technique addresses fundamental ambiguities associated with quantitative BOLD signal analysis; however, its dependence on biophysical modeling creates uncertainty in the resulting oxygen metabolism estimates. In this work, we developed a Bayesian approach to estimating the oxygen metabolism response to a neural stimulus and used it to examine the uncertainty that arises in calibrated BOLD estimation due to the presence of unmeasured model parameters. We applied our approach to estimate the CMRO2 response to a visual task using the traditional hypercapnia calibration experiment as well as to estimate the metabolic response to both a visual task and hypercapnia using the measurement of baseline apparent R2' as a calibration technique. Further, in order to examine the effects of cerebral spinal fluid (CSF) signal contamination on the measurement of apparent R2', we examined the effects of measuring this parameter with and without CSF-nulling. We found that the two calibration techniques provided consistent estimates of the metabolic response on average, with a median R2'-based estimate of the metabolic response to CO2 of 1.4%, and R2'- and hypercapnia-calibrated estimates of the visual response of 27% and 24%, respectively. However, these estimates were sensitive to different sources of estimation uncertainty. The R2'-calibrated estimate was highly sensitive to CSF contamination and to uncertainty in unmeasured model parameters describing flow-volume coupling, capillary bed characteristics, and the iso-susceptibility saturation of blood. The hypercapnia-calibrated estimate was relatively insensitive to these parameters but highly sensitive to the assumed metabolic response to CO2. Copyright © 2016 Elsevier Inc. All rights reserved.

  11. A novel Bayesian approach to accounting for uncertainty in fMRI-derived estimates of cerebral oxygen metabolism fluctuations

    Science.gov (United States)

    Simon, Aaron B.; Dubowitz, David J.; Blockley, Nicholas P.; Buxton, Richard B.

    2016-01-01

    Calibrated blood oxygenation level dependent (BOLD) imaging is a multimodal functional MRI technique designed to estimate changes in cerebral oxygen metabolism from measured changes in cerebral blood flow and the BOLD signal. This technique addresses fundamental ambiguities associated with quantitative BOLD signal analysis; however, its dependence on biophysical modeling creates uncertainty in the resulting oxygen metabolism estimates. In this work, we developed a Bayesian approach to estimating the oxygen metabolism response to a neural stimulus and used it to examine the uncertainty that arises in calibrated BOLD estimation due to the presence of unmeasured model parameters. We applied our approach to estimate the CMRO2 response to a visual task using the traditional hypercapnia calibration experiment as well as to estimate the metabolic response to both a visual task and hypercapnia using the measurement of baseline apparent R2′ as a calibration technique. Further, in order to examine the effects of cerebral spinal fluid (CSF) signal contamination on the measurement of apparent R2′, we examined the effects of measuring this parameter with and without CSF-nulling. We found that the two calibration techniques provided consistent estimates of the metabolic response on average, with a median R2′-based estimate of the metabolic response to CO2 of 1.4%, and R2′- and hypercapnia-calibrated estimates of the visual response of 27% and 24%, respectively. However, these estimates were sensitive to different sources of estimation uncertainty. The R2′-calibrated estimate was highly sensitive to CSF contamination and to uncertainty in unmeasured model parameters describing flow-volume coupling, capillary bed characteristics, and the iso-susceptibility saturation of blood. The hypercapnia-calibrated estimate was relatively insensitive to these parameters but highly sensitive to the assumed metabolic response to CO2. PMID:26790354

  12. Recovery of cerebral blood flow in unilateral chronic subdural hematoma. The correlation with cerebral re-expansion in elders

    International Nuclear Information System (INIS)

    Nemoto, Akio

    2003-01-01

    CT and SPECT were used to investigate the relationship between cerebral re-expansion and changes in cerebral blood flow underneath hematoma in elderly patients after surgery for chronic unilateral subdural hematoma. I studied 22 patients with mild hematoma, aged 43 to 82 years (mean 67 years). The patients were placed in either Group A (under 70 years) or Group B (70 years or over) to observe postoperative changes. CT and SPECT examinations were conducted before surgery and 1, 7 and 30 days after surgery, 4 times in total. Cerebral re-expansion was represented by the re-expansion rate (PER) comparing the pre- and postoperative thickness of the maximal hematoma in CT images. The rate of cerebral re-expansion was slowed in Group B (p<0.01). Cerebral re-expansion was characterized by biphasic, rapid or gradual re-expansion on postoperative day 1 with a significant difference between groups (p<0.01). Before surgery, cerebral blood flow on the affected side correlated with age (p<0.01), thougn blood flow was diminished in both groups. After surgery, cerebral blood flow on the affected side exceeded that on the unaffected side in Group A and transiently increased on postoperative day 1. Cerebral blood flow improved after surgery in both groups, with a significant difference in those changes over time (p<0.01). In both groups, cerebral re-expansion on postoperative days 7 and 30 correlated with cerebral blood flow on the affected side (p<0.05). The present results suggest that improvement in cerebral blood flow on the affected side is delayed in elderly patients, due to slower postoperative cerebral re-expansion. (author)

  13. Contribution of positron emission tomography to physiopathological study of cerebral ischemia in man

    Energy Technology Data Exchange (ETDEWEB)

    Baron, J C; Bousser, M G; Comar, D; Rougemont, D; Lebrun-Grandie, P [Commissariat a l' Energie Atomique, Centre Hospitalier Frederic Joliot, 91 - Orsay (France); Castaigne, P [Hopital de la Salpetriere, 75 - Paris (France)

    1983-12-29

    The development of positron emission tomography now allows the local study of cerebral blood flow, oxygen consumption and glucose utilization in ischemic stroke patients. In recent cerebral infarction, a disruption of the normal couple between flow and metabolism is almost constantly observed: in the first few days cerebral blood flow is either inadequate (persistant ischemia) or over-abundant (''luxury perfusion''), whereas a late ''luxury perfusion'' is almost constant within the necrotic area between the 10th and the 40th day. Threshold values for cerebral blood flow and oxygen consumption that are ultimately associated with necrosis or tissue integrity have been determined. A metabolic depression without C.T. Scan counterpart has been observed in various brain structures remote from the infarcted area per se. Lastly, the hemodynamic and metabolic effects of superficial-temporal-middle-cerebral-artery anastomosis have been studied.

  14. Low cerebral blood flow in hypotensive perinatal distress

    International Nuclear Information System (INIS)

    Lou, H.C.; Lassen, N.A.; Friis-Hansen, B.

    1977-01-01

    Hypoxic brain injury is the most important neurological problem in the neonatal period and accounts for more neurological deficits in children than any other lesion. The neurological deficits are notably mental retardation, epilepsy and cerebral palsy. The pathogenesis has hitherto been poorly understood. Arterial hypoxia has been taken as the obvious mechanism but this does not fully explain the patho-anatomical findings. In the present investigation we have examined the arterial blood pressure and the cerebral blood flow in eight infants a few hours after birth. The 133Xe clearance technique was used for the cerebral blood flow measurements. The study confirmed that perinatal distress may be associated with low arterial blood pressure, and it was shown that cerebral blood flow is very low, 20 ml/100 g/min or less, in hypotensive perinatal distress. It is concluded that cerebral ischaemia plays a crucial role in the development of perinatal hypoxic brain injury. (author)

  15. Database of normal human cerebral blood flow, cerebral blood volume, cerebral oxygen extraction fraction and cerebral metabolic rate of oxygen measured by positron emission tomography with {sup 15}O-labelled carbon dioxide or water, carbon monoxide and oxygen: a multicentre study in Japan

    Energy Technology Data Exchange (ETDEWEB)

    Ito, Hiroshi [Department of Radiology and Nuclear Medicine, Akita Research Institute of Brain and Blood Vessels, Akita (Japan); Department of Nuclear Medicine and Radiology, Division of Brain Sciences, Institute of Development, Aging and Cancer, Tohoku University, 4-1 Seiryo-Machi, 980-8575, Aoba-Ku, Sendai (Japan); Kanno, Iwao [Department of Radiology and Nuclear Medicine, Akita Research Institute of Brain and Blood Vessels, Akita (Japan); Kato, Chietsugu [Department of Nuclear Medicine, Hokkaido University School of Medicine, Sapporo (Japan); Sasaki, Toshiaki [Cyclotoron Research Center, Iwate Medical University, Morioka (Japan); Ishii, Kenji [Positron Medical Center, Tokyo Metropolitan Institute of Gerontology, Tokyo (Japan); Ouchi, Yasuomi [Positron Medical Center, Hamamatsu Medical Center, Hamakita (Japan); Iida, Akihiko [Nagoya City Rehabilitation Center, Nagoya (Japan); Okazawa, Hidehiko [PET Unit, Research Institute, Shiga Medical Center, Moriyama (Japan); Hayashida, Kohei [Department of Radiology, National Cardiovascular Center, Suita, Osaka (Japan); Tsuyuguchi, Naohiro [Department of Neurosurgery, Osaka City University Medical School, Osaka (Japan); Ishii, Kazunari [Division of Imaging Research, Hyogo Institute for Aging Brain and Cognitive Disorders, Himeji, Hyogo (Japan); Kuwabara, Yasuo [Department of Radiology, Faculty of Medicine, Kyushu University, Fukuoka (Japan); Senda, Michio [Department of Image-based Medicine, Institute of Biomedical Research and Innovation, Kobe (Japan)

    2004-05-01

    Measurement of cerebral blood flow (CBF), cerebral blood volume (CBV), cerebral oxygen extraction fraction (OEF) and cerebral metabolic rate of oxygen (CMRO{sub 2}) by positron emission tomography (PET) with oxygen-15 labelled carbon dioxide (C{sup 15}O{sub 2}) or {sup 15}O-labelled water (H{sub 2}{sup 15}O), {sup 15}O-labelled carbon monoxide (C{sup 15}O) and {sup 15}O-labelled oxygen ({sup 15}O{sub 2}) is useful for diagnosis and treatment planning in cases of cerebrovascular disease. The measured values theoretically depend on various factors, which may differ between PET centres. This study explored the applicability of a database of {sup 15}O-PET by examining between-centre and within-centre variation in values. Eleven PET centres participated in this multicentre study; seven used the steady-state inhalation method, one used build-up inhalation and three used bolus administration of C{sup 15}O{sub 2} (or H{sub 2}{sup 15}O) and {sup 15}O{sub 2}. All used C{sup 15}O for measurement of CBV. Subjects comprised 70 healthy volunteers (43 men and 27 women; mean age 51.8{+-}15.1 years). Overall mean{+-}SD values for cerebral cortical regions were: CBF=44.4{+-}6.5 ml 100 ml{sup -1} min{sup -1}; CBV=3.8{+-}0.7 ml 100 ml{sup -1}; OEF=0.44{+-}0.06; CMRO{sub 2}=3.3{+-}0.5 ml 100 ml{sup -1} min{sup -1}. Significant between-centre variation was observed in CBV, OEF and CMRO{sub 2} by one-way analysis of variance. However, the overall inter-individual variation in CBF, CBV, OEF and CMRO{sub 2} was acceptably small. Building a database of normal cerebral haemodynamics obtained by the{sup 15}O-PET methods may be practicable. (orig.)

  16. Effect of age on cerebral blood flow during hypothermic cardiopulmonary bypass

    International Nuclear Information System (INIS)

    Brusino, F.G.; Reves, J.G.; Smith, L.R.; Prough, D.S.; Stump, D.A.; McIntyre, R.W.

    1989-01-01

    Cerebral blood flow was measured in 20 patients by xenon 133 clearance methodology during nonpulsatile hypothermic cardiopulmonary bypass to determine the effect of age on regional cerebral blood flow during these conditions. Measurements of cerebral blood flow at varying perfusion pressures were made in patients arbitrarily divided into two age groups at nearly identical nasopharyngeal temperature, hematocrit value, and carbon dioxide tension and with equal cardiopulmonary bypass flows of 1.6 L/min/m2. The range of mean arterial pressure was 30 to 110 mm Hg for group I (less than or equal to 50 years of age) and 20 to 90 mm Hg for group II (greater than or equal to 65 years of age). There was no significant difference (p = 0.32) between the mean arterial pressure in group I (54 +/- 28 mm Hg) and that in group II (43 +/- 21 mm Hg). The range of cerebral blood flow was 14.8 to 29.2 ml/100 gm/min for group I and 13.8 to 37.5 ml/100 gm/min for group II. There was no significant difference (p = 0.37) between the mean cerebral blood flow in group I (21.5 +/- 4.6 ml/100 gm/min) and group II (24.3 +/- 8.1 ml/100 gm/min). There was a poor correlation between mean arterial pressure and cerebral blood flow in both groups: group I, r = 0.16 (p = 0.67); group II, r = 0.5 (p = 0.12). In 12 patients, a second cerebral blood flow measurements was taken to determine the effect of mean arterial pressure on cerebral blood flow in the individual patient. Changes in mean arterial pressure did not correlate with changes in cerebral blood flow (p less than 0.90). We conclude that age does not alter cerebral blood flow and that cerebral blood flow autoregulation is preserved in elderly patients during nonpulsatile hypothermic cardiopulmonary bypass

  17. Radiation-induced vasculopathy implicated by depressed blood flow and metabolism in a pineal glioma

    Energy Technology Data Exchange (ETDEWEB)

    Mineura, K; Sasajima, T; Kowada, M [Akita University Hospital (Japan). Neurosurgical Service; Saitoh, H [Oodate Municipal Hospital (Japan). Dept. of Neurosurgery; Shishido, F [Research Inst. of Brain and Blood Vessels, Akita (Japan)

    1993-08-01

    A case of radiation-induced vasculopathy of a pineal glioma was presented with haemodynamic and metabolic changes before and after radiotherapy. After radiation of 60 Gy with conventional fractionation (1.8-2.0 Gy daily, 5 days per week), regional blood flow, oxygen extraction fraction, metabolic rate of oxygen, kinetic metabolic rate of glucose and the rate constants (K2, K3) were markedly depressed (20% or greater) compared with the pre-irradiated study. 7 months after radiotherapy, the patient developed transient episodes of both right and left upper limb convulsion, terminating in generalized convulsion. When she developed status epilepticus, computed tomography showed extensive low density areas in the territory supplied by the right middle cerebral and the right posterior cerebral arteries. (author).

  18. Radiation-induced vasculopathy implicated by depressed blood flow and metabolism in a pineal glioma

    International Nuclear Information System (INIS)

    Mineura, K.; Sasajima, T.; Kowada, M.

    1993-01-01

    A case of radiation-induced vasculopathy of a pineal glioma was presented with haemodynamic and metabolic changes before and after radiotherapy. After radiation of 60 Gy with conventional fractionation (1.8-2.0 Gy daily, 5 days per week), regional blood flow, oxygen extraction fraction, metabolic rate of oxygen, kinetic metabolic rate of glucose and the rate constants (K2, K3) were markedly depressed (20% or greater) compared with the pre-irradiated study. 7 months after radiotherapy, the patient developed transient episodes of both right and left upper limb convulsion, terminating in generalized convulsion. When she developed status epilepticus, computed tomography showed extensive low density areas in the territory supplied by the right middle cerebral and the right posterior cerebral arteries. (author)

  19. Regional cerebral blood flow measurement in brain tumors

    International Nuclear Information System (INIS)

    Izunaga, Hiroshi; Hirota, Yoshihisa; Takahashi, Mutsumasa; Fuwa, Isao; Kodama, Takafumi; Matsukado, Yasuhiko

    1986-01-01

    The regional cerebral blood flow (CBF) was determined on seventeen patients with brain tumors. Ring type single photon emission CT (SPECT) was used following intravenous injection of 133 Xe. Case materials included eleven meningiomas and six malignant gliomas. Evaluation was performed with emphasis on the following points; 1. Correlation of the flow data within tumors to the angiographic tumor stains, 2. Influence of tumors on the cerebral blood flow of the normal brain tissue, 3. Correlation between degree of peripheral edema and the flow data of the affected hemispheres. There was significant correlation between flow data within tumors and angiographic tumor stains in meningiomas. Influence of tumors on cerebral blood flow of the normal tissue was greater in meningiomas than in gliomas. There was negative correlation between the degree of peripheral edema and the flow data of the affected hemisphere. It has been concluded that the measurement of CBF in brain tumors is a valuable method in evaluation of brain tumors. (author)

  20. Regional cerebral blood flow measurement in brain tumors

    Energy Technology Data Exchange (ETDEWEB)

    Izunaga, Hiroshi; Hirota, Yoshihisa; Takahashi, Mutsumasa; Fuwa, Isao; Kodama, Takafumi; Matsukado, Yasuhiko

    1986-10-01

    The regional cerebral blood flow (CBF) was determined on seventeen patients with brain tumors. Ring type single photon emission CT (SPECT) was used following intravenous injection of /sup 133/Xe. Case materials included eleven meningiomas and six malignant gliomas. Evaluation was performed with emphasis on the following points; 1. Correlation of the flow data within tumors to the angiographic tumor stains, 2. Influence of tumors on the cerebral blood flow of the normal brain tissue, 3. Correlation between degree of peripheral edema and the flow data of the affected hemispheres. There was significant correlation between flow data within tumors and angiographic tumor stains in meningiomas. Influence of tumors on cerebral blood flow of the normal tissue was greater in meningiomas than in gliomas. There was negative correlation between the degree of peripheral edema and the flow data of the affected hemisphere. It has been concluded that the measurement of CBF in brain tumors is a valuable method in evaluation of brain tumors.

  1. A reduced cerebral metabolic ratio in exercise reflects metabolism and not accumulation of lactate within the human brain

    DEFF Research Database (Denmark)

    Dalsgaard, Mads K; Quistorff, Bjørn; Danielsen, Else R

    2003-01-01

    During maximal exercise lactate taken up by the human brain contributes to reduce the cerebral metabolic ratio, O(2)/(glucose + 1/2 lactate), but it is not known whether the lactate is metabolized or if it accumulates in a distribution volume. In one experiment the cerebral arterio-venous differe......During maximal exercise lactate taken up by the human brain contributes to reduce the cerebral metabolic ratio, O(2)/(glucose + 1/2 lactate), but it is not known whether the lactate is metabolized or if it accumulates in a distribution volume. In one experiment the cerebral arterio......-venous differences (AV) for O(2), glucose (glc) and lactate (lac) were evaluated in nine healthy subjects at rest and during and after exercise to exhaustion. The cerebrospinal fluid (CSF) was drained through a lumbar puncture immediately after exercise, while control values were obtained from six other healthy.......0 to 0.9 +/- 0.1 mM (P ratio from 6.0 +/- 0.3 to 2.8 +/- 0.2 (P

  2. Postradiation regional cerebral blood flow in primates

    International Nuclear Information System (INIS)

    Cockerham, L.G.; Cerveny, T.J.; Hampton, J.D.

    1986-01-01

    Early transient incapacitation (ETI) is the complete cessation of performance during the first 30 min after radiation exposure and performance decrement (PD) is a reduction in performance at the same time. Supralethal doses of radiation have been shown to produce a marked decrease in regional cerebral blood flow in primates concurrent with hypotension and a dramatic release of mast cell histamine. In an attempt to elucidate mechanisms underlying the radiation-induced ETI/PD phenomenon and the postradiation decrease in cerebral blood flow, primates were exposed to 100 Gy (1 Gy = 100 rads), whole-body, gamma radiation. Pontine and cortical blood flows were measured by hydrogen clearance, before and after radiation exposure. Systemic blood pressures were determined simultaneously. Systemic arterial histamine levels were determined preradiation and postradiation. Data obtained indicated that radiated animals showed a decrease in blood flow of 63% in the motor cortex and 51% in the pons by 10 min postradiation. Regional cerebral blood flow of radiated animals showed a slight recovery 20 min postradiation, followed by a fall to the 10 min nadir by 60 min postradiation. Immediately, postradiation systemic blood pressure fell 67% and remained at that level for the remainder of the experiment. Histamine levels in the radiated animals increased a hundredfold 2 min postradiation. This study indicates that regional cerebral blood flow decreases postradiation with the development of hypotension and may be associated temporally with the postradiation release of histamine

  3. Cerebral Metabolism and the Role of Glucose Control in Acute Traumatic Brain Injury.

    Science.gov (United States)

    Buitrago Blanco, Manuel M; Prashant, Giyarpuram N; Vespa, Paul M

    2016-10-01

    This article reviews key concepts of cerebral glucose metabolism, neurologic outcomes in clinical trials, the biology of the neurovascular unit and its involvement in secondary brain injury after traumatic brain insults, and current scientific and clinical data that demonstrate a better understanding of the biology of metabolic dysfunction in the brain, a concept now known as cerebral metabolic energy crisis. The use of neuromonitoring techniques to better understand the pathophysiology of the metabolic crisis is reviewed and a model that summarizes the triphasic view of cerebral metabolic disturbance supported by existing scientific data is outlined. The evidence is summarized and a template for future research provided. Copyright © 2016 Elsevier Inc. All rights reserved.

  4. Hemodynamics in the cerebral cortex and basal ganglia

    International Nuclear Information System (INIS)

    Yamaguchi, Shinya; Fukuyama, Hidenao; Yamauchi, Hiroshi; Kimura, Jun

    1991-01-01

    We examined ten healthy volunteers using positron emission tomography (PET) in order to elucidate regional changes and correlations in the cerebral circulation and oxygen metabolism. We also studied eight lacunar stroke patients so as to disclose the influences of vascular risk factors and aging on the cerebral blood flow and metabolism. We can conclude from our result as follows: (1) Cerebral blood volume (CBV) was minimum in the basal ganglia and cerebral blood flow (CBF)/CBV ratio was higher than that of cerebral cortex in healthy volunteers; (2) CBF of gray matter in healthy volunteers correlated with CBV and cerebral metabolic rate of oxygen where oxygen extraction fraction inversely correlated with CBF, CBV, and CBF/CBV; and (3) the basal ganglia CBF/CBV ratio in lacunar stroke patients was lower than that of healthy volunteers. These findings suggested that the perfusion pressure in the basal ganglia was so high in the normal condition than the angionecrosis or occlusion in the perforating arteries would be induced, especially in the aged and hypertensive patients. (author)

  5. Modeling cerebral blood flow during posture change from sitting to standing

    DEFF Research Database (Denmark)

    Ottesen, Johnny T.; Olufsen, M.; Tran, H.T.

    2004-01-01

    extremities, the brain, and the heart. We use physiologically based control mechanisms to describe the regulation of cerebral blood flow velocity and arterial pressure in response to orthostatic hypotension resulting from postural change. To justify the fidelity of our mathematical model and control......Abstract Hypertension, decreased cerebral blood flow, and diminished cerebral blood flow velocity regulation, are among the first signs indicating the presence of cerebral vascular disease. In this paper, we will present a mathematical model that can predict blood flow and pressure during posture...

  6. Cerebral vascular control and metabolism in heat stress

    DEFF Research Database (Denmark)

    Bain, Anthony R; Nybo, Lars; Ainslie, Philip N

    2015-01-01

    implications and pathologies known to confound cerebral functioning during hyperthermia. A reduction in cerebral blood flow (CBF), derived primarily from a respiratory-induced alkalosis, underscores the cerebrovascular changes to hyperthermia. Arterial pressures may also become compromised because of reduced...

  7. Study of cerebral vascular diseases with radioisotopes in cerebral atherosclerotical subjects and/for subjects with sequelae of cerebral stroke, before and after use of the association piracetam-dihydroergotoxine

    International Nuclear Information System (INIS)

    Lara, P.F.; Ferreira, A.; Paulillo, L.F.; Cukierman, M.

    1985-01-01

    Twently subjects with cerebral sclerosis and/or sequelas of cerebral stroke were studied, before and after use of piracetam-dihydroergotoxine. We performed the complete hemispheric cerebral blood flow and cerebral scintigraphy, beyond clinical and neurological examination. Scintigraphies were unchanged. Cerebral circulation times, or both hemispheres, diminished. This occurred, probably, in relation with metabolic effects of both pharmaceutical drugs. The alpha sympatolytic and modulatory effects of dihydroergotoxine should be considered. (author) [pt

  8. Carbon balance studies of glucose metabolism in rat cerebral cortical synaptosomes

    Energy Technology Data Exchange (ETDEWEB)

    Bauer, U; Brand, K

    1982-07-01

    Synaptosomes were isolated from rat cerebral cortex and incubated with (U-/sup 14/C)-, (1-/sup 14/C)- or (6-/sup 14/C)glucose. Glucose utilization and the metabolic partitioning of glucose carbon in products were determined by isotopic methods. From the data obtained a carbon balance was constructed, showing lactate to be the main product of glucose metabolism, followed by CO/sup 2/, amino acids and pyruvate. Measuring the release of /sup 14/CO/sup 2/ from glucose labelled in three different positions allowed the construction of a flow diagram of glucose carbon atoms in synaptosomes, which provides information about the contribution of the various pathways of glucose metabolism. Some 2% of glucose utilized was calculated to be degraded via the pentose phosphate pathway. Addition of chlorpromazine, imipramine or haloperidol at concentrations of 10(-5) M reduced glucose utilisation by 30% without changing the distribution pattern of radioactivity in the various products.

  9. Dynamic exercise enhances regional cerebral artery mean flow velocity

    DEFF Research Database (Denmark)

    Linkis, P; Jørgensen, L G; Olesen, H L

    1995-01-01

    Dynamic exercise enhances regional cerebral artery mean flow velocity. J. Appl. Physiol. 78(1): 12-16, 1995.--Anterior (ACA) and middle (MCA) cerebral artery mean flow velocities (Vmean) and pulsatility indexes were determined using transcranial Doppler in 14 subjects during dynamic exercise afte...

  10. Cerebral metabolic abnormalities in congestive heart failure detected by proton magnetic resonance spectroscopy.

    Science.gov (United States)

    Lee, C W; Lee, J H; Kim, J J; Park, S W; Hong, M K; Kim, S T; Lim, T H; Park, S J

    1999-04-01

    Using proton magnetic resonance spectroscopy, we investigated cerebral metabolism and its determinants in congestive heart failure (CHF), and the effects of cardiac transplantation on these measurements. Few data are available about cerebral metabolism in CHF. Fifty patients with CHF (ejection fraction OGM) and parietal white matter (PWM). Absolute levels of the metabolites (N-acetylaspartate, creatine, choline, myo-inositol) were calculated. In PWM only creatine level was significantly lower in CHF than in control subjects, but in OGM all four metabolite levels were decreased in CHF. The creatine level was independently correlated with half-recovery time and duration of heart failure symptoms in PWM (r = -0.56, p OGM (r = 0.58, p < 0.05). Cerebral metabolic abnormalities were improved after successful cardiac transplantation. This study shows that cerebral metabolism is abnormally deranged in advanced CHF and it may serve as a potential marker of the disease severity.

  11. Asymmetry of cerebral glucose metabolism in very low-birth-weight infants without structural abnormalities.

    Directory of Open Access Journals (Sweden)

    Jae Hyun Park

    Full Text Available Thirty-six VLBW infants who underwent F-18 fluorodeoxyglucose (F-18 FDG brain PET and MRI were prospectively enrolled, while infants with evidence of parenchymal brain injury on MRI were excluded. The regional glucose metabolic ratio and asymmetry index were calculated. The asymmetry index more than 10% (right > left asymmetry or less than -10% (left > right asymmetry were defined as abnormal. Regional cerebral glucose metabolism were compared between right and left cerebral hemispheres, and between the following subgroups: multiple gestations, premature rupture of membrane, bronchopulmonary dysplasia, and low-grade intraventricular hemorrhage.In the individual analysis, 21 (58.3% of 36 VLBW infants exhibited asymmetric cerebral glucose metabolism. Fifteen infants (41.7% exhibited right > left asymmetry, while six (16.7% exhibited left > right asymmetry. In the regional analysis, right > left asymmetry was more extensive than left > right asymmetry. The metabolic ratio in the right frontal, temporal, and occipital cortices and right thalamus were significantly higher than those in the corresponding left regions. In the subgroup analyses, the cerebral glucose metabolism in infants with multiple gestations, premature rupture of membrane, bronchopulmonary dysplasia, or low-grade intraventricular hemorrhage were significantly lower than those in infants without these.VLBW infants without structural abnormalities have asymmetry of cerebral glucose metabolism. Decreased cerebral glucose metabolism are noted in infants with neurodevelopmental risk factors. F-18 FDG PET could show microstructural abnormalities not detected by MRI in VLBW infants.

  12. De-coupling of blood flow and metabolism in the rat brain induced by glutamate

    International Nuclear Information System (INIS)

    Hirose, Shinichiro; Momosaki, Sotaro; Sasaki, Kazunari; Hosoi, Rie; Abe, Kohji; Inoue, Osamu; Gee, A.

    2009-01-01

    Glutamate plays an essential role in neuronal cell death in many neurological disorders. In this study, we examined both glucose metabolism and cerebral blood flow in the same rat following infusion of glutamate or ibotenic acid using the dual-tracer technique. The effects of MK-801, an N-methyl-D-aspartate (NMDA) receptor antagonist, and 1,2,3,4-tetrahydro-6-nitro-2,3-dioxo-benzo[f]quinoxaline-7-sulfonamide (NBQX), an α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA)-kainate receptor antagonist, on the changes in the glucose metabolism and cerebral blood flow induced by glutamate were also examined. The rats were microinjected with glutamate (1 μmol/μl, 2 μl) or ibotenic acid (10 μg/μl, 1 μl) into the right striatum, and dual-tracer autoradiograms of [ 18 F]fluorodeoxyglucose (FDG) and [ 14 C]iofetamine (IMP) were obtained. MK-801 and NBQX were injected intravenously about 45 and 30 min, respectively, after the infusion of glutamate. De-coupling of blood flow and metabolism was noted in the glutamate-infused hemisphere (as assessed by no alteration of [ 18 F]FDG uptake and significant decrease of [ 14 C]IMP uptake). Pretreatments with MK-801, NBQX, or combined use of MK-801 and NBQX did not affect the de-coupling of the blood flow and metabolism induced by glutamate. A histochemical study revealed that about 20% neuronal cell death had occurred in the striatum at 105 min after the infusion of glutamate. In addition, a significant increase of the [ 18 F]FDG uptake and decrease of [ 14 C]IMP uptake were also seen in the rat brain infused with ibotenic acid. These results indicate that glutamate and ibotenic acid caused a significant de-coupling of blood flow and glucose metabolism in the intact rat brain during the early phase of neurodegeneration. It is necessary to evaluate the relation between metabotropic glutamate receptors and de-coupling of blood flow and metabolism. (author)

  13. Cerebral blood flow autoregulation is impaired in schizophrenia: A pilot study.

    Science.gov (United States)

    Ku, Hsiao-Lun; Wang, Jiunn-Kae; Lee, Hsin-Chien; Lane, Timothy Joseph; Liu, I-Chao; Chen, Yung-Chan; Lee, Yao-Tung; Lin, I-Cheng; Lin, Chia-Pei; Hu, Chaur-Jong; Chi, Nai-Fang

    2017-10-01

    Patients with schizophrenia have a higher risk of cardiovascular diseases and higher mortality from them than does the general population; however, the underlying mechanism remains unclear. Impaired cerebral autoregulation is associated with cerebrovascular diseases and their mortality. Increased or decreased cerebral blood flow in different brain regions has been reported in patients with schizophrenia, which implies impaired cerebral autoregulation. This study investigated the cerebral autoregulation in 21 patients with schizophrenia and 23 age- and sex-matched healthy controls. None of the participants had a history of cardiovascular diseases, hypertension, or diabetes. All participants underwent 10-min blood pressure and cerebral blood flow recording through finger plethysmography and Doppler ultrasonography, respectively. Cerebral autoregulation was assessed by analyzing two autoregulation indices: the mean blood pressure and cerebral blood flow correlation coefficient (Mx), and the phase shift between the waveforms of blood pressure and cerebral blood flow determined using transfer function analysis. Compared with the controls, the patients had a significantly higher Mx (0.257 vs. 0.399, p=0.036) and lower phase shift (44.3° vs. 38.7° in the 0.07-0.20Hz frequency band, p=0.019), which indicated impaired maintenance of constant cerebral blood flow and a delayed cerebrovascular autoregulatory response. Impaired cerebral autoregulation may be caused by schizophrenia and may not be an artifact of coexisting medical conditions. The mechanism underlying impaired cerebral autoregulation in schizophrenia and its probable role in the development of cerebrovascular diseases require further investigation. Copyright © 2017 Elsevier B.V. All rights reserved.

  14. Cerebral circulation, metabolism, and blood-brain barrier of rats in hypocapnic hypoxia

    International Nuclear Information System (INIS)

    Beck, T.; Krieglstein, J.

    1987-01-01

    The effects of hypoxic hypoxia on physiological variables, cerebral circulation, cerebral metabolism, and blood-brain barrier were investigated in conscious, spontaneously breathing rats by exposing them to an atmosphere containing 7% O 2 . Hypoxia affected a marked hypotension, hypocapnia and alkalosis. Cortical tissue high-energy phosphates and glucose content were not affected by hypoxia, glucose 6-phosphate lactate, and pyruvate levels were significantly increased. Blood-brain barrier permeability, regional brain glucose content and lumped constant were not changed by hypoxia. Local cerebral glucose utilization (LCGU) rose by 40-70% of control values in gray matter and by 80-90% in white matter. Under hypoxia, columns of increased and decreased LCGU and were detectable in cortical gray matter. Color-coded [ 14 C]2-deoxy-D-glucose autoradiograms of rat brain are shown. Local cerebral blood flow (LCBF) increased by 50-90% in gray matter and by up to 180% in white matter. Coupling between LCGU and LCBF in hypoxia remained unchanged. The data suggests a stimulation of glycolysis, increased glucose transport into the cell, and increased hexokinase activity. The physiological response of gray and white matter to hypoxia obviously differs. Uncoupling of the relation between LCGU and LCBF does not occur

  15. A Means for the Scintigraphic Imaging of Regional Brain Dynamics. Regional Cerebral Blood Flow and Regional Cerebral Blood Volume

    Energy Technology Data Exchange (ETDEWEB)

    Potchen, E. J.; Bentley, R.; Gerth, W.; Hill, R. L.; Davis, D. O. [Washington University School Of Medicine, St. Louis, MO (United States)

    1969-05-15

    The use of freely diffusable inert radioactive gas as a washout indicator to measure regional cerebral blood flow has become a standardized kinetic procedure in many laboratories. Recent investigations with this technique have led us to conclude that we can reliably distinguish regional flow with perfusion against regional flow without perfusion from the early portion of the curve. Based on a detailed study of the early curve kinetics in patients with and without cerebral vascular disease we have defined the sampling duration necessary for application of the Anger gamma camera imaging process to regional changes in cerebral radioactivity. Using a standard camera and a small computer, a procedure has been developed and based upon entire field to determine the time of maximum height followed by analysis of the data in a matrix. This will permit a contour plot presentation of calculated regional cerebral blood flow in millilitres per 100 grams perfused brain per minute. In addition, we propose to augment this data by the display of regional non-perfusion blood flow versus regional cerebral flow with perfusion. Preliminary investigation on sampling duration, and Compton scattering were prerequisite to clinical scintigraphy of regional cerebral blood flow. In addition, the method of interface for the conventional Anger gamma camera to digital computers used in this procedure are discussed. Applications to further assess regional cerebral dynamics by scintigraphy are presented. (author)

  16. Cerebral energy metabolism in streptozotocin-diabetic rats

    NARCIS (Netherlands)

    Biessels, G.J.; Braun, K.P.J.; Graaf, de R.A.; Eijsden, van P.; Gispen, W.H.; Nicolaij, K.

    2001-01-01

    Aims/hypothesis. It is increasingly evident that the brain is another site of diabetic end-organ damage. The pathogenesis has not been fully explained, but seems to involve an interplay between aberrant glucose metabolism and vascular changes. Vascular changes, such as deficits in cerebral blood

  17. Decreased cerebral glucose metabolism associated with mental deterioration in multi-infarct dementia

    International Nuclear Information System (INIS)

    Meguro, K.; Doi, C.; Yamaguchi, T.; Sasaki, H.; Matsui, H.; Yamada, K.; Kinomura, S.; Tohoku Univ.; Itoh, M.

    1991-01-01

    Cerebral glucose metabolism of 18 patients with multi-infarct dementia (MID) and 10 age-matched normal subjects were examined with positron emission tomography and the 18 -F-fluoro-deoxy-glucose technique. MID patients had significantly lower glucose metabolsim in all the grey matter regions measured and were also characterized by more individuality in metabolic pattern. MID patients were also evaluated as to intelligence quotient (IQ). A positive correlation between IQ as shown by the Tanaka-Binet test and glucose metabolism for the entire grey matter was found. The clinical applicability of this test for predicting cerebral metabolism is discussed. (orig.)

  18. Regional cerebral glucose metabolism in patients with Parkinson's disease with or without dementia

    Energy Technology Data Exchange (ETDEWEB)

    Sasaki, Masayuki; Ichiya, Yuichi; Hosokawa, Shinichi; Otsuka, Makoto; Kuwabara, Yasuo; Fukumura, Toshimitsu; Kato, Motohiro; Goto, Ikuo; Masuda, Kouji [Kyushu Univ., Fukuoka (Japan). Faculty of Medicine

    1992-11-01

    By means of positron emission tomography, the cerebral glucose metabolism in 5 patients with Parkinson's disease with dementia was compared with that in 9 patients without dementia, and that in 5 normal volunteers. The metabolic rates for glucose were measured by placing one hundred regions of interest. In the demented patients, cerebral glucose metabolism was diffusely decreased compared with that of the non-demented patients and the normal controls. The most significant decrease in glucose metabolism was observed in the angular gyrus (49.7% of the normal controls). The glucose metabolism in the cingulate, pre- and postcentral, occipital and subcortical regions was relatively spared (62.1 to 85.5% of the normal controls). In the patients without dementia, the glucose metabolism in each region was not significantly different from that in the normal controls. These results suggest that diffuse glucose hypometabolism in the cerebral cortex may correlate with that of patients with Parkinson's disease with dementia. (author).

  19. Cerebral glucose metabolism in Parkinson's disease

    Energy Technology Data Exchange (ETDEWEB)

    Martin, W R.W.; Beckman, J H; Calne, D B; Adam, M J; Harrop, R; Rogers, J G; Ruth, T J; Sayre, C I; Pate, B D [British Columbia Univ., Vancouver (Canada). TRIUMF Facility

    1984-02-01

    Local cerebral glucose utilization was measured in patients with predominantly unilateral Parkinson's disease using sup(18)F-2-fluoro-deoxyglucose and positron emission tomography. Preliminary results indicate the presence of asymmetric metabolic rates in the inferior basal ganglia. The structure comprising the largest portion of basal ganglia at this level is globus pallidus. These findings are consistent with metabolic studies on animals with unilateral nigrostriatal lesions in which pallidal hypermetabolism on the lesioned side has been demonstrated. Increased pallidal activity is likely secondary to a loss of inhibitory dopaminergic input to the striatum from substantia nigra.

  20. Cerebral glucose metabolism in Parkinson's disease

    International Nuclear Information System (INIS)

    Martin, W.R.W.; Beckman, J.H.; Calne, D.B.; Adam, M.J.; Harrop, R.; Rogers, J.G.; Ruth, T.J.; Sayre, C.I.; Pate, B.D.

    1984-01-01

    Local cerebral glucose utilization was measured in patients with predominantly unilateral Parkinson's disease using sup(18)F-2-fluoro-deoxyglucose and positron emission tomography. Preliminary results indicate the presence of asymmetric metabolic rates in the inferior basal ganglia. The structure comprising the largest portion of basal ganglia at this level is globus pallidus. These findings are consistent with metabolic studies on animals with unilateral nigrostriatal lesions in which pallidal hypermetabolism on the lesioned side has been demonstrated. Increased pallidal activity is likely secondary to a loss of inhibitory dopaminergic input to the striatum from substantia nigra

  1. Earley changes in cerebral blood flow following head exposure of rabbit at a mean absorbed dose of 1000 rads

    International Nuclear Information System (INIS)

    Dufour, Raymond.

    1978-10-01

    Observations were made on 5 animals after 12 head exposures. The local cerebral blood flow increased on the 1st hour and lasted during the following 15-20 h. Two particular responses were used to test cerebral vasotonicity: rate increases due to inhalation of CO 2 (5 p. cent CO 2 in air) and accompanying paradoxical sleep. Their decrease after irradiation was studied systematically by CO 2 tests whatever the rate level reached. These weaker increases were not the indication of an upper limit of the the rate, they also occurred when the rate fell back to its initial value. They appeared on the 2nd hour and lasted till the 48th hour. As a conclusion: head irradiation resulted in an early increase of cerebral blood flow lasting less than 24 h; the pattern of metabolic or myogenic regulation of intraparenchymatous vessels and neurogenic regulation of extraparenchymatous vessels would explain the observed phenomena better. The metabolic modifications of the irradiated tissue should result in vasodilation of intraparenchymatous vessels. The stimulating action of the neurovegetative centers would be shown by a decrease of the vessel responses to CO 2 at the level of the extraparenchymatous vessels [fr

  2. Measurement of cerebral blood flow by single photon emission tomography: principles and application to functional studies of the language areas

    International Nuclear Information System (INIS)

    Tran Dinh, Y.R.; Seylaz, J.

    1989-01-01

    Quantitative measurement of cerebral blood flow by single photon emission computerized tomography (SPECT) is a new technique which is particularly suitable for routine studies of cerebro-vascular diseases. SPECT can be used to examine the deep structures of the brain and cerebellum. The functional areas of the brain, which have hitherto been only accessible by clinical-anatomical methods, can be imaged by this technique, based on the correlation between cerebral blood flow and metabolism. The demonstration of preferential activation of temporal and frontal zones in the left hemisphere by active speech stimulation confirms the general principles of hemispheric lateralization of cerebral functions. In addition to this role in studying the physiology of normal subjects, the technique has practical pathological applications. Knowledge of hemispheric lateralization of spoken language should be a pre-operative test for cerebral lesion when there is a risk that surgical intervention may produce irreversible neuropsychological lesions [fr

  3. Caloric restriction increases ketone bodies metabolism and preserves blood flow in aging brain.

    Science.gov (United States)

    Lin, Ai-Ling; Zhang, Wei; Gao, Xiaoli; Watts, Lora

    2015-07-01

    Caloric restriction (CR) has been shown to increase the life span and health span of a broad range of species. However, CR effects on in vivo brain functions are far from explored. In this study, we used multimetric neuroimaging methods to characterize the CR-induced changes of brain metabolic and vascular functions in aging rats. We found that old rats (24 months of age) with CR diet had reduced glucose uptake and lactate concentration, but increased ketone bodies level, compared with the age-matched and young (5 months of age) controls. The shifted metabolism was associated with preserved vascular function: old CR rats also had maintained cerebral blood flow relative to the age-matched controls. When investigating the metabolites in mitochondrial tricarboxylic acid cycle, we found that citrate and α-ketoglutarate were preserved in the old CR rats. We suggest that CR is neuroprotective; ketone bodies, cerebral blood flow, and α-ketoglutarate may play important roles in preserving brain physiology in aging. Copyright © 2015 The Authors. Published by Elsevier Inc. All rights reserved.

  4. Regional cerebral blood flow in schizophrenics

    International Nuclear Information System (INIS)

    Uchino, Jun; Ohta, Yasuyuki; Nakane, Yoshibumi; Mori, Hiroyuki; Hirota, Noriyoshi; Yonekura, Masahiro.

    1987-01-01

    The present study on schizophrenics dealt with the relationship of regional cerebral blood flow (rCBF) to age, disease duration, and treatment length with chlorpromazine hydrochloride (CPZ). Regional cerebral blood flow in 28 cerebral regions of interest was measured by iv injection of X-133 in 54 schizophrenic patients and 39 healthy volunteers. Neither age nor dosage of CPZ significantly influenced rCBF. All patients, including 11 treated for a short period of time (6 months or less), were characterized by having a decreased rCBF over the whole cerebrum. Thirty-four patients treated for a long period of time (2 years or more) had a varied rCBF distribution in the left hemisphere, with the most predominant feature being the decrease in rCBF in the frontal lobe (i.e., ''hypofrontality''); however, there was no linear correlation between rCBF and disease duration. A decreased rCBE in the right occipital region was seen in patients with paranoid schizophrenia, suggesting that manifestations of symptoms may depend on disturbed regions. These results suggest that cerebral dysfunction in schizophrenic patients may not be restricted to the frontal lobe, but cover the whole cerebrum, and that nonuniform dysfunction in various regions of the cerebrum, including the frontal lobe, may be involved in manifestations of symptoms. (Namekawa, K.)

  5. Regional cerebral blood flow in schizophrenics

    Energy Technology Data Exchange (ETDEWEB)

    Uchino, J.; Ohta, Y.; Nakane, Y.; Mori, H.; Hirota, N.; Yonekura, M.

    1987-01-01

    The present study on schizophrenics dealt with the relationship of regional cerebral blood flow (rCBF) to age, disease duration, and treatment length with chlorpromazine hydrochloride (CPZ). Regional cerebral blood flow in 28 cerebral regions of interest was measured by iv injection of /sup 133/X in 54 schizophrenic patients and 39 healthy volunteers. Neither age nor dosage of CPZ significantly influenced rCBF. All patients, including 11 treated for a short period of time (6 months or less), were characterized by having a decreased rCBF over the whole cerebrum. Thirty-four patients treated for a long period of time (2 years or more) had a varied rCBF distribution in the left hemisphere, with the most predominant feature being the decrease in rCBF in the frontal lobe (i.e., hypofrontality); however, there was no linear correlation between rCBF and disease duration. A decreased rCBE in the right occipital region was seen in patients with paranoid schizophrenia, suggesting that manifestations of symptoms may depend on disturbed regions. These results suggest that cerebral dysfunction in schizophrenic patients may not be restricted to the frontal lobe, but cover the whole cerebrum, and that nonuniform dysfunction in various regions of the cerebrum, including the frontal lobe, may be involved in manifestations of symptoms.

  6. Regional cerebral glucose metabolism in systemic lupus erythematosus patients with major depressive disorder.

    Science.gov (United States)

    Saito, Tomoyuki; Tamura, Maasa; Chiba, Yuhei; Katsuse, Omi; Suda, Akira; Kamada, Ayuko; Ikura, Takahiro; Abe, Kie; Ogawa, Matsuyoshi; Minegishi, Kaoru; Yoshimi, Ryusuke; Kirino, Yohei; Ihata, Atsushi; Hirayasu, Yoshio

    2017-08-15

    Depression is frequently observed in patients with systemic lupus erythematosus (SLE). Neuropsychiatric SLE (NPSLE) patients often exhibit cerebral hypometabolism, but the association between cerebral metabolism and depression remains unclear. To elucidate the features of cerebral metabolism in SLE patients with depression, we performed brain 18F-fluoro-d-glucose positron emission tomography (FDG-PET) on SLE patients with and without major depressive disorder. We performed brain FDG-PET on 20 SLE subjects (5 male, 15 female). The subjects were divided into two groups: subjects with major depressive disorder (DSLE) and subjects without major depressive disorder (non-DSLE). Cerebral glucose metabolism was analyzed using the three-dimensional stereotactic surface projection (3D-SSP) program. Regional metabolism was evaluated by stereotactic extraction estimation (SEE), in which the whole brain was divided into segments. Every SLE subject exhibited cerebral hypometabolism, in contrast to the normal healthy subjects. Regional analysis revealed a significantly lower ER in the left medial frontal gyrus (p=0.0055) and the right medial frontal gyrus (p=0.0022) in the DSLE group than in the non-DSLE group. Hypometabolism in the medial frontal gyrus may be related to major depressive disorder in SLE. Larger studies are needed to clarify this relationship. Copyright © 2017 Elsevier B.V. All rights reserved.

  7. Regional cerebral metabolic correlates of WASO during NREM sleep in insomnia.

    Science.gov (United States)

    Nofzinger, Eric A; Nissen, Christoph; Germain, Anne; Moul, Douglas; Hall, Martica; Price, Julie C; Miewald, Jean M; Buysse, Daniel J

    2006-07-15

    To investigate the non-rapid eye movement (NREM) sleep-related regional cerebral metabolic correlates of wakefulness after sleep onset (WASO) in patients with primary insomnia. Fifteen patients who met DSM-IV criteria for primary insomnia completed 1-week sleep diary (subjective) and polysomnographic (objective) assessments of WASO and regional cerebral glucose metabolic assessments during NREM sleep using [18F] fluoro-2-deoxy-D-glucose positron emission tomography. Whole-brain voxel-by-voxel correlations, as well as region of interest analyses, were performed between subjective and objective WASO and relative regional cerebral metabolism using the statistical software SPM2. Subjective WASO was significantly greater than objective WASO, but the 2 measures were positively correlated. Objective WASO correlated positively with the percentage of stage 2 sleep and negatively with the percentage of stages 3 and 4 sleep. Both subjective and objective WASO positively correlated with NREM sleep-related cerebral glucose metabolism in the pontine tegmentum and in thalamocortical networks in a frontal, anterior temporal, and anterior cingulate distribution. Increased relative metabolism in these brain regions during NREM sleep in patients with insomnia is associated with increased WASO measured either subjectively or objectively. These effects are related to the lighter sleep stages of patients with more WASO and may result from increased activity in arousal systems during sleep and or to activity in higher-order cognitive processes related to goal-directed behavior, conflict monitoring, emotional awareness, anxiety, and fear. Such changes may decrease arousal thresholds and/or increase perceptions of wakefulness in insomnia.

  8. Dehydration affects cerebral blood flow but not its metabolic rate for oxygen during maximal exercise in trained humans

    DEFF Research Database (Denmark)

    Trangmar, Steven J; Chiesa, Scott T; Stock, Christopher G

    2014-01-01

    Intense exercise is associated with a reduction in cerebral blood flow (CBF), but regulation of CBF during strenuous exercise in the heat with dehydration is unclear. We assessed internal (ICA) and common carotid artery (CCA) haemodynamics (indicative of CBF and extra-cranial blood flow), middle...... cerebral artery velocity (MCA Vmean), arterial-venous differences and blood temperature in 10 trained males during incremental cycling to exhaustion in the heat (35°C) in control, dehydrated and rehydrated states. Dehydration reduced body mass (75.8 ± 3 vs. 78.2 ± 3 kg), increased internal temperature (38.......3 ± 0.1 vs. 36.8 ± 0.1°C), impaired exercise capacity (269 ± 11 vs. 336 ± 14 W), and lowered ICA and MCA Vmean by 12-23% without compromising CCA blood flow. During euhydrated incremental exercise on a separate day, however, exercise capacity and ICA, MCA Vmean and CCA dynamics were preserved. The fast...

  9. Modeling of Cerebral Oxygen Transport Based on In vivo Microscopic Imaging of Microvascular Network Structure, Blood Flow, and Oxygenation.

    Science.gov (United States)

    Gagnon, Louis; Smith, Amy F; Boas, David A; Devor, Anna; Secomb, Timothy W; Sakadžić, Sava

    2016-01-01

    Oxygen is delivered to brain tissue by a dense network of microvessels, which actively control cerebral blood flow (CBF) through vasodilation and contraction in response to changing levels of neural activity. Understanding these network-level processes is immediately relevant for (1) interpretation of functional Magnetic Resonance Imaging (fMRI) signals, and (2) investigation of neurological diseases in which a deterioration of neurovascular and neuro-metabolic physiology contributes to motor and cognitive decline. Experimental data on the structure, flow and oxygen levels of microvascular networks are needed, together with theoretical methods to integrate this information and predict physiologically relevant properties that are not directly measurable. Recent progress in optical imaging technologies for high-resolution in vivo measurement of the cerebral microvascular architecture, blood flow, and oxygenation enables construction of detailed computational models of cerebral hemodynamics and oxygen transport based on realistic three-dimensional microvascular networks. In this article, we review state-of-the-art optical microscopy technologies for quantitative in vivo imaging of cerebral microvascular structure, blood flow and oxygenation, and theoretical methods that utilize such data to generate spatially resolved models for blood flow and oxygen transport. These "bottom-up" models are essential for the understanding of the processes governing brain oxygenation in normal and disease states and for eventual translation of the lessons learned from animal studies to humans.

  10. Emesis, radiation exposure, and local cerebral blood flow in the ferret

    International Nuclear Information System (INIS)

    Tuor, U.I.; Kondysar, M.H.; Harding, R.K.

    1988-01-01

    We examined the sensitivity of the ferret to emetic stimuli and the effect of radiation exposure near the time of emesis on local cerebral blood flow. Ferrets vomited following the administration of either apomorphine (approx 45% of the ferrets tested) or peptide YY (approx 36% of those tested). Exposure to radiation was a very potent emetic stimulus, but vomiting could be prevented by restraint of the hindquarters of the ferret. Local cerebral blood flow was measured using a quantitative autoradiographic technique and with the exception of several regions in the telencephalon and cerebellum, local cerebral blood flow in the ferret was similar to that in the rat. In animals with whole-body exposure to moderate levels of radiation (4 Gy of 137 Cs), mean arterial blood pressure was similar to that in the control group. However, 15-25 min following irradiation there was a general reduction of local cerebral blood flow ranging from 7 to 33% of that in control animals. These cerebral blood flow changes likely correspond to a reduced activation of the central nervous system

  11. Quantification of cerebral blood flow via Duplex sonography

    International Nuclear Information System (INIS)

    Vogl, G.; Pohl, P.; Willeit, J.; Aichner, F.

    1987-01-01

    An attempt was made to measure quantitatively the total cerebral blood flow by means of Duplex sonography. In a group of healthy young subjects a median value for total cerebral blood flow was obtained amounting to 469 ml/min ± 30%, repeat measurements yielded a maximum deviation of ± 11%. In three patients the values obtained after severe apoplectic insult due to occlusion of the internal carotid artery were definitely below the value of the group of healthy subjects, whereas the value for the total blood flow was in the upper range of normal values in a patient with occlusion of the a. cerebri media. Comparative measurements of the regional cerebral blood flow with xenon 13 yielded in those patients with occlusion of the internal carotid artery a markedly reduced mean flow and in the patient with occlusion of the a. cerebri media a less markedly reduced mean flow. Regionally reduced perfusion was seen in all the four patients in the range of the clinically and computer tomographically well-known ischaemia zone. Thanks to the simplicity of this sonographic examination method it could be a useful decision parameter in determining the indication for a reconstruction of the carotid artery, especially in asymptotic patients. (orig.) [de

  12. Regional cerebral blood flow in schizophrenic patients

    International Nuclear Information System (INIS)

    Sagawa, Katsuo; Sibuya, Isoo; Oiji, Arata; Kawakatsu, Sinobu; Morinobu, Shigeru; Totsuka, Shiro; Kinoshita, Osami; Yazaki, Mitsuyasu.

    1990-01-01

    Seventy-six schizophrenic patients were examined by a Xe-133 inhalation method to determine regional cerebral blood flow. A decreased blood flow was observed in the frontal lobe, especially in the right inferior part. In a study on the relationship between disease subtypes and regional cerebral blood flow, negative symptoms were found more predominantly associated with dissolution type than delusion type. In the group of dissolution type, a decreased blood flow was observed in both the right inferior frontal lobe and the right upper hemisphere, in comparison to the group of delution type. Patients presenting with auditory hallucination had a significantly higher incidence of both negative and positive symptoms, as compared with those not presenting with it. In such patients, a significantly decreased blood flow was also seen in the left upper frontal lobe and the bilateral parietal lobe. Xe-133 inhalation method should assist in evaluating brain function in schizophrenic patients, thus leading to the likelihood of developing a new treatment modality. (N.K.)

  13. Analysis of cerebral blood flow and intracranial hypertension in critical patients with non-hepatic hyperammonemia.

    Science.gov (United States)

    Larangeira, Alexandre Sanches; Tanita, Marcos Toshiyuki; Dias, Marcos Antonio; Filho, Olavo Franco Ferreira; Delfino, Vinicius Daher Alvares; Cardoso, Lucienne Tibery Queiroz; Grion, Cintia Magalhães Carvalho

    2018-05-03

    Hyperammonemia in adults is generally associated with cerebral edema, decreased cerebral metabolism, and increased cerebral blood flow. The aim of this study was to evaluate the association between non-hepatic hyperammonemia and intracranial hypertension assessed by Doppler flowmetry and measurement of the optic nerve sheath. A prospective cohort study in critically ill patients hospitalized in intensive care units of a University Hospital between March 2015 and February 2016. Clinical data and severity scores were collected and the Glasgow coma scale was recorded. Serial serum ammonia dosages were performed in all study patients. Transcranial Doppler evaluation was carried out for the first 50 consecutive results of each stratum of ammonemia: normal (<35 μmol/L), mild hyperammonemia (≥35 μmol/L and < 50 μmol/L), moderate hyperammonemia (≥50 μmol/L and < 100 μmol/L), and severe hyperammonemia (≥100 μmol/L). The measurement of the optic nerve sheath was performed at the same time as the Doppler examination if the patient scored less than 8 on the Glasgow coma scale. There was no difference in flow velocity in the cerebral arteries between patients with and without hyperammonemia. Patients with hyperammonemia presented longer ICU stay. Optic nerve sheath thickness was higher in the group with severe hyperammonemia and this group presented an association with intracranial hypertension. Higher mortality was observed in the severe hyperammonemia group. There was an association between severe hyperammonemia and signs of intracranial hypertension. No correlation was found between ammonia levels and cerebral blood flow velocity through the Doppler examination.

  14. Cerebral oxygenation and energy metabolism in bacterial meningitis

    DEFF Research Database (Denmark)

    Larsen, Lykke

    Introduction: In a recent retrospective study of patients with severe bacterial meningitis we demonstrated that cerebral oxidative metabolism was affected in approximately 50% of the cases. An increase of lactate/pyruvate (LP) ratio above the upper normal limit, defined according to according...... bacterial meningitis; secondly to examine whether it is correct to separate the diagnosis of cerebral ischemia from mitochondrial dysfunction based exclusively on the biochemical pattern obtained during intracerebral microdialysis. Method: A prospective clinical study including patients with severe...... community acquired bacterial meningitis admitted to the Department of Infectious Diseases, Odense University Hospital, during the period January 2014 to June 2016. We relate data from measurements of brain tissue oxygen tension (PbtO2) to simultaneously recorded data reflecting cerebral cytoplasmic redox...

  15. The effects of anticholinergic drugs on regional cerebral blood flow, and oxygen metabolism in previously untreated patients with Parkinson's disease

    International Nuclear Information System (INIS)

    Obara, Satoko; Takahashi, Satoshi; Yonezawa, Hisashi; Sato, Yoshitomo

    1998-01-01

    Regional cerebral blood flow (rCBF) and oxygen metabolism (rCMRO 2 ) were measured using the steady-state 15 O technique and positron emission tomography (PET) in six previously untreated patients with Parkinson's disease before and after trihexyphenidyl (THP) treatment. The patients comprised of 4 men and 2 women with Hoehn-Yahr stage II-III. Their ages at the onset of the study ranged from 46 to 57 years (mean±SD, 51.8±3.7) and the duration of the illness ranged from 10 to 48 months (mean±SD, 28.8±15.5). The PET study, assessments of the disability and cognitive function were undergone twice. The first time assessments were done was when the patients were not receiving any drugs, and the second time was one to three months after administration of 6 mg THP. All patients showed clinical improvement after THP treatment. The mean disability score of Unified Parkinson's Disease Rating Scale decreased from 35.1 (SD±11.3) to 25.7 (SD±11.6). The cognitive function assessed by Hasegawa's dementia rating scale-revised, Mini-Mental State Examination, Wechsler Adult Intelligence Scale-Revised, and Wechsler Memory Scale-Revised, were not significantly different before and after the THP treatment. After the THP treatment, rCBF and rCMRO 2 decreased significantly in the striatum (about 15%) and all cerebral cortices (about 10%) on both sides contralateral and ipsilateral to the predominantly symptomatic limbs. We conclude that an anticholinergic THP decreases the rCBF and rCMRO 2 significantly in the cerebral cortices without cognitive impairment in early untreated patients with Parkinson's disease. (author)

  16. The evaluation of cerebral hemodynamics in patients with intracranial tumors by stable xenon CT; The effect of glycerol administration on regional cerebral blood flow

    Energy Technology Data Exchange (ETDEWEB)

    Shimoda, Masami; Kawamata, Fumio; Yamamoto, Masahiro; Ohsuga, Hitoshi; Hidaka, Mitsuru; Oda, Shinri; Shibuya, Naoki; Yamamoto, Isao; Sato, Osamu (Tokai Univ., Isehara, Kanagawa (Japan). School of Medicine)

    1989-04-01

    In evaluating cerebral regional blood flow (rCBF), stable xenon-enhanced tomography (XeCT) study associated with simultaneous blood sampling was applied in 15 cases of intracranial neoplasms. The effect of intravenous glycerol infusion on rCBF was also investigated. The results indicated that intratumoral rCBF values were not only variable and unrelated to their histological types and grades, but also were not correlated with the vascularity of the lesion as demonstrated by angiography. When a tumor mass was enhanced after the injection of iodinated contrast media, it proved to be useful in distinguishing tumor mass and its associated edema that the rCBF of the peritumoral edematous region was predominantly low (10{plus minus}5 ml/100 g/min). The regional cerebral blood flow in remote areas, both ipsilateral and contralateral to the lesion, was low in value, and there was no statistical significance between affected and sound sides. Following glycerol administration, rCBF was increased in the whole intracranial region, but not inside of the neoplasm, particularly when the intracranial pressure (ICP) was increased. It was assumed that the elevated rCBF after glycerol administration was due to the increase in the cerebral perfusion pressure resulting from the ICP reduction, the hemodilution effect, cerebral vessel dilatation after metabolic acidosis, and/or mechanically rectified microcirculation after edema reduction. (author).

  17. A study of cerebral circulation, metabolism and MRI findings in patients with chronic cerebral circulatory insufficiency

    International Nuclear Information System (INIS)

    Kondo, Susumu

    1995-01-01

    Chronic cerebral circulatory insufficiency (CCCI) is a recently proposed clinical entity characterized by symptoms such as dizziness, a feeling of heavy-headedness or vague numbness without any neurological signs or organic vascular lesions on CT. In order to elucidate its pathogenesis, ultrasonic quantitative blood flow measurement system, positron emission tomography (PET) and MRI were employed to study three groups of subjects: 60 subjects with CCCI (group A), 44 subjects with risk factors for cerebrovascular disease but without neurological abnormalities (group B), and 40 normal healthy volunteers (group C). The results are summarized as follows: Mean common carotid blood flow decreased with age in all groups. Common carotid blood flow was lowest in group A and second lowest in group B in every decade of patient age. PET study revealed that CBF and CMRO 2 in all regions examined were significantly lower in group A than in group C. The incidence of MR signal abnormalities in the white matter increased with age. Group A had the highest incidence, and group C had the lowest. Reduction in mean common carotid blood flow and cerebral blood flow was associated with increasing incidence and severity of MR signal abnormalities. These findings indicate that CCCI is a pathologic condition closely related to diffuse cerebral low perfusion resulting from cerebral arteriosclerosis. The symptoms seen in this condition, which are apt to be taken lightly, may warn of impending ischemic stroke. (author)

  18. Cerebral blood flow and metabolic patterns as predictors of response to bilateral anterior capsulotomy for obsessive-compulsive disorder: a retrospective study

    International Nuclear Information System (INIS)

    Borbely, K.; Babel, B.; Tron, L.; Nemeth, A.; Pataki, E.; Csigo, E.; Morocz, K.; Lukacs, E.

    2002-01-01

    Aims: Earlier Single Photon Emission Tomography (SPECT) and Positron Emission Tomography (PET) studies of patients with Obsessive-Compulsive Disorder (OCD) have demonstrated abnormal regional Cerebral Blood Flow (rCBF) and Cerebral Glucose Metabolic (rCGlM) pattern in the orbitofrontal-basal ganglia-thalamo-cortical circuits (OBgThC). OCD is characterized by intrusive, repetitive thoughts and/or behaviors that cause marked distress. In case of a severe, and medically and/or psycho therapeutically intractable disease surgical therapy remains the only possible solution. The purpose of this study was to evaluate rCBF and rCGlM patterns as potential predictors of treatment response to bilateral anterior capsulotomy. We performed rCBF SPECT and rCGlM PET studies in 5 patients with severe, intractable OCD before and after (3, 6 and 12 months) surgical therapy. Methods: The assessment included neurological, psychiatrical examination, CT, MRI, and neuropsychological evaluation. 99mTc-HMPAO-SPECT and 18F-FDG-PET studies were carried out with a standard technique for each patient. The data were analyzed visually and by a special region of interests (ROIs) program. The rCBF SPECT and glucose metabolic PET results were compared to clinical and neuropsychological findings. Results: The SPECT and PET measurements showed significant (p<0.05) rCBF and metabolic abnormalities in caudate nuclei, thalamus, singular and orbitofrontal cortex. There was a marked, but individually variable rCBF and rCGlM pattern before and after surgery. Additionally, the preoperative and postoperative rCBF and rCGlM data proved to be concordant with clinical and neuropsychological findings. Conclusion: Both SPECT and PET (before and after surgery) proved to be concordant with clinical and neuropsychological findings. However, rCGlM PET measurements had a higher sensitivity. Patients with higher preoperative rCBF and rCGlM rates of OBgThC circuits were associated with a better postoperative outcome. RCBF

  19. Glycopyrrolate abolishes the exercise-induced increase in cerebral perfusion in humans

    DEFF Research Database (Denmark)

    Seifert, Thomas; Fisher, James P; Young, Colin N

    2010-01-01

    Brain blood vessels contain muscarinic receptors that are important for cerebral blood flow (CBF) regulation, but whether a cholinergic receptor mechanism is involved in the exercise-induced increase in cerebral perfusion or affects cerebral metabolism remains unknown. We evaluated CBF and cerebral......(mean) during ergometer cycling (n = 8). Separate, randomized and counterbalanced trials were performed in control (no drug) conditions and following muscarinic cholinergic receptor blockade by glycopyrrolate. Glycopyrrolate increased resting heart rate from approximately 60 to approximately 110 beats min(-1...... abolished by glycopyrrolate (P important for the exercise-induced increase in cerebral perfusion without affecting the cerebral metabolic rate for oxygen....

  20. PET measurements of cerebral metabolism corrected for CSF contributions

    International Nuclear Information System (INIS)

    Chawluk, J.; Alavi, A.; Dann, R.; Kushner, M.J.; Hurtig, H.; Zimmerman, R.A.; Reivich, M.

    1984-01-01

    Thirty-three subjects have been studied with PET and anatomic imaging (proton-NMR and/or CT) in order to determine the effect of cerebral atrophy on calculations of metabolic rates. Subgroups of neurologic disease investigated include stroke, brain tumor, epilepsy, psychosis, and dementia. Anatomic images were digitized through a Vidicon camera and analyzed volumetrically. Relative areas for ventricles, sulci, and brain tissue were calculated. Preliminary analysis suggests that ventricular volumes as determined by NMR and CT are similar, while sulcal volumes are larger on NMR scans. Metabolic rates (18F-FDG) were calculated before and after correction for CSF spaces, with initial focus upon dementia and normal aging. Correction for atrophy led to a greater increase (%) in global metabolic rates in demented individuals (18.2 +- 5.3) compared to elderly controls (8.3 +- 3.0,p < .05). A trend towards significantly lower glucose metabolism in demented subjects before CSF correction was not seen following correction for atrophy. These data suggest that volumetric analysis of NMR images may more accurately reflect the degree of cerebral atrophy, since NMR does not suffer from beam hardening artifact due to bone-parenchyma juxtapositions. Furthermore, appropriate correction for CSF spaces should be employed if current resolution PET scanners are to accurately measure residual brain tissue metabolism in various pathological states

  1. Regional cerebral blood flow in schizophrenia

    International Nuclear Information System (INIS)

    Mathew, R.J.; Duncan, G.C.; Weinman, M.L.; Barr, D.L.

    1982-01-01

    Regional cerebral blood flow (rCBF) was measured via xenon133 inhalation technique in 23 patients with schizophrenia and 18 age- and sex-matched controls. The mean blood flow to both hemispheres was found to be lower for the patients. The patients and their controls did not differ on interhemispheric differences in blood flow. There were no differences in rCBF between medicated and unmedicated, subchronic and chronic, and paranoid and nonparanoid patients. Hallucinations were associated with reduced blood flow to several postcentral regions

  2. Regional cerebral blood flow in schizophrenia

    Energy Technology Data Exchange (ETDEWEB)

    Mathew, R.J.; Duncan, G.C.; Weinman, M.L.; Barr, D.L.

    1982-10-01

    Regional cerebral blood flow (rCBF) was measured via xenon133 inhalation technique in 23 patients with schizophrenia and 18 age- and sex-matched controls. The mean blood flow to both hemispheres was found to be lower for the patients. The patients and their controls did not differ on interhemispheric differences in blood flow. There were no differences in rCBF between medicated and unmedicated, subchronic and chronic, and paranoid and nonparanoid patients. Hallucinations were associated with reduced blood flow to several postcentral regions.

  3. The effects of incretin hormones on cerebral glucose metabolism in health and disease

    DEFF Research Database (Denmark)

    Nilsson, Malin; Gjedde, Albert; Brock, Birgitte

    2017-01-01

    Incretin hormones, notably glucagon-like peptide-1 (GLP-1), are gluco-regulatory hormones with pleiotropic effects also in the central nervous system. Apart from a local production of GLP-1, systemic administration of the hormone has been shown to influence a number of cerebral pathologies......, including neuroinflammation. Given the brains massive dependence on glucose as its major fuel, we here review the mechanistics of cerebral glucose transport and metabolism, focusing on the deleterious effects of both hypo- and hyperglycaemia. GLP-1, when administered as long-acting analogues...... or intravenously, appears to decrease transport of glucose in normoglycaemic conditions, without affecting the total cerebral glucose content. During hypoglycaemia this effect seems abated, whereas during hyperglycaemia GLP-1 regulates cerebral glucose metabolism towards stable levels resembling normoglycaemia...

  4. The clinical study of cerebral blood flow imaging in patients with early syphilis

    International Nuclear Information System (INIS)

    Liu Zengli; Shi Xin; Wu Jinchang; Tang Jun; Zhong Jijun

    2003-01-01

    Objective: To study the clinical value of cerebral blood flow imaging for evaluation of patients with early syphilis. Methods: Fifty-three patients with early syphilis underwent cerebral blood flow imaging using 99 Tc m -ethylenecysteinate dimer(ECD). Regional cerebral blood flow (rCBF) changes were analyzed. Results: The acquired images of 53 patients were graded as 5 types. The rCBF was significantly depressed in 48 of 53 patients mainly in the areas dominated by anterior cerebral artery and middle cerebral artery. Conclusion: Treponema pallidum (TP) could start invading central nervous system at the early stage of infection

  5. Cerebral blood flow in temporal lobe epilepsy: a partial volume correction study

    Energy Technology Data Exchange (ETDEWEB)

    Giovacchini, Giampiero [University Milano-Bicocca, Milan (Italy); Bonwetsch, Robert; Theodore, William H. [National Institute of Neurological Diseases and Strokes, Clinical Epilepsy Section, Bethesda, MD (United States); Herscovitch, Peter [National Institutes of Health, PET Department, Clinical Center, Bethesda, MD (United States); Carson, Richard E. [Yale PET Center, New Haven, CT (United States)

    2007-12-15

    Previous studies in temporal lobe epilepsy (TLE) have shown that, owing to brain atrophy, positron emission tomography (PET) can overestimate deficits in measures of cerebral function such as glucose metabolism (CMR{sub glu}) and neuroreceptor binding. The magnitude of this effect on cerebral blood flow (CBF) is unexplored. The aim of this study was to assess CBF deficits in TLE before and after magnetic resonance imaging-based partial volume correction (PVC). Absolute values of CBF for 21 TLE patients and nine controls were computed before and after PVC. In TLE patients, quantitative CMR{sub glu} measurements also were obtained. Before PVC, regional values of CBF were significantly (p<0.05) lower in TLE patients than in controls in all regions, except the fusiform gyrus contralateral to the epileptic focus. After PVC, statistical significance was maintained in only four regions: ipsilateral inferior temporal cortex, bilateral insula and contralateral amygdala. There was no significant difference between patients and controls in CBF asymmetry indices (AIs) in any region before or after PVC. In TLE patients, AIs for CBF were significantly smaller than for CMR{sub glu} in middle and inferior temporal cortex, fusiform gyrus and hippocampus both before and after PVC. A significant positive relationship between disease duration and AIs for CMR{sub glu}, but not CBF, was detected in hippocampus and amygdala, before but not after PVC. PVC should be used for PET CBF measurements in patients with TLE. Reduced blood flow, in contrast to glucose metabolism, is mainly due to structural changes. (orig.)

  6. Cerebral blood flow and cerebrovascular response to acetazolamide in patients with chronic alcoholism

    OpenAIRE

    Oishi, M; Mochizuki, Y; Takasu, T

    1997-01-01

    Cerebral blood flow and cerebrovascular response to acetazolamide were studied in 12 patients with chronic alcoholism and 12 age matched healthy controls. Blood flows in the cerebral cortex, thalamus, and putamen were significantly lower in the chronic alcoholic group than in the healthy control group. The increase in blood flow caused by acetazolamide did not show any significant difference between the two groups. These findings suggest that the decreased cerebral blood flow i...

  7. Effect of Body Temperature on the Radionuclide Evaluation of Cerebral Blood Flow

    International Nuclear Information System (INIS)

    Mustafa, S. . E- mail: seham@hsc.edu.kw; Elgazzar, A.H.; Gopinath, S.; Mathew, M.; Khalil, M.

    2006-01-01

    Changes in regional cerebral blood flow (rCBF) may reflect physiological correlates of the disease state. In neuro-imaging studies, some diseases have frequently been reported to be associated with reduced or increased rCBF. In a previous study we had shown evidence of heat induced vasoconstriction of the carotid artery, which is the main vessel supplying blood to the brain. This vasoconstriction may lead to a decrease in cerebral blood flow in hyperthermic patients. Most radionuclide studies used to assess cerebral blood flow are routinely performed without taking into consideration patients' body temperature. In this regard it may be noted that results of radionuclide cerebral perfusion studies may be affected by hyperthermia, which could lead to false positive studies or misinterpretation of results when they are performed on patients suffering from various cerebrovascular diseases. The objective of the present study was to investigate the importance of body temperature and its effect on the results of radionuclide cerebral perfusion studies. Cerebral blood flow was assessed using Tc-99m hexamethylpropyleneamineoxime (Tc-99m HMPAO) imaging. Baseline scintigraphic images of the brain were obtained in 10 rabbits using a gamma camera equipped with a low energy parallel hole and high resolution collimator interfaced with a computer. Repeat brain studies were performed on the same rabbits at 3 and 6 days after raising the body temperature by 2 deg. C and 4 deg. C respectively using the same imaging protocol. The counts per pixel were determined on control and hyperthermia images. The uptake of Tc-99m HMPAO in the brain was found to be significantly reduced following hyperthermia implying reduction in blood flow. This decrease in cerebral perfusion appears to be variable from region to region, being more in the cerebral hemispheres, frontal areas (olfactory lobes) than in the cerebellum. Based on the results, the authors conclude that a rise in body temperature might

  8. Regional cerebral blood flow measurement using a scintillation camera

    International Nuclear Information System (INIS)

    Heiss, W.D.

    1979-01-01

    A scintillation camera connected to auxillary equipment with off-line data processing or connected to an on-line dedicated computer system permits measurement of hemispheric and regional cerebral blood flow. Reliable flow values are obtained from regions limited in size by spatial resolution and the count rates achieved. Flow measurements obtained with the camera are able to resolve inhomogeneities of cerebral circulation in normal subjects. In a variety of clinical conditions, the localization, severity and extent of flow alterations are shown. Results of flow measurements in individual cases elucidate the pathogenesis of neurologic deficits, quantify the damage to the brain, indicate therapeutic measures of potential value and permit an estimation of the further clinical course. With restricted spatial resolution, flow measurements after intravenous 133 Xe injection are also feasible

  9. The effects of anticholinergic drugs on regional cerebral blood flow, and oxygen metabolism in previously untreated patients with Parkinson`s disease

    Energy Technology Data Exchange (ETDEWEB)

    Obara, Satoko; Takahashi, Satoshi; Yonezawa, Hisashi; Sato, Yoshitomo [Iwate Medical Univ., Morioka (Japan). School of Medicine

    1998-12-01

    Regional cerebral blood flow (rCBF) and oxygen metabolism (rCMRO{sub 2}) were measured using the steady-state {sup 15}O technique and positron emission tomography (PET) in six previously untreated patients with Parkinson`s disease before and after trihexyphenidyl (THP) treatment. The patients comprised of 4 men and 2 women with Hoehn-Yahr stage II-III. Their ages at the onset of the study ranged from 46 to 57 years (mean{+-}SD, 51.8{+-}3.7) and the duration of the illness ranged from 10 to 48 months (mean{+-}SD, 28.8{+-}15.5). The PET study, assessments of the disability and cognitive function were undergone twice. The first time assessments were done was when the patients were not receiving any drugs, and the second time was one to three months after administration of 6 mg THP. All patients showed clinical improvement after THP treatment. The mean disability score of Unified Parkinson`s Disease Rating Scale decreased from 35.1 (SD{+-}11.3) to 25.7 (SD{+-}11.6). The cognitive function assessed by Hasegawa`s dementia rating scale-revised, Mini-Mental State Examination, Wechsler Adult Intelligence Scale-Revised, and Wechsler Memory Scale-Revised, were not significantly different before and after the THP treatment. After the THP treatment, rCBF and rCMRO{sub 2} decreased significantly in the striatum (about 15%) and all cerebral cortices (about 10%) on both sides contralateral and ipsilateral to the predominantly symptomatic limbs. We conclude that an anticholinergic THP decreases the rCBF and rCMRO{sub 2} significantly in the cerebral cortices without cognitive impairment in early untreated patients with Parkinson`s disease. (author)

  10. Cerebral glucose metabolic abnormality in patients with congenital scoliosis

    International Nuclear Information System (INIS)

    Nam, H. Y.; Seo, G. T.; Lee, J. S.; Kim, S. C.; Kim, I. J.; Kim, Y. K.; Jeon, S. M.

    2007-01-01

    A possible association between congenital scoliosis and low mental status has been recognized, but there are no reports describing the mental status or cerebral metabolism in patients with congenital scoliosis in detail. We investigated the mental status using a mini-mental status exam as well as the cerebral glucose metabolism using F-18 fluorodeoxyglucose brain positron emission tomography in 12 patients with congenital scoliosis and compared them with those of 14 age-matched patients with adolescent idiopathic scoliosis. The mean mini-mental status exam score in the congenital scoliosis group was significantly lower than that in the adolescent idiopathic scoliosis group. Group analysis found that various brain areas of patients with congenital scoliosis showed glucose hypometabolisms in the left prefrontal cortex (Brodmann area 10), right orbitofrontal cortex (Brodmann area 11), left dorsolateral prefrontal cortex (Brodmann area 9), left anterior cingulate gyrus (Brodmann area 24) and pulvinar of the left thalamus. From this study, we could find the metabolic abnormalities of brain in patients with congenital scoliosis and suggest the possible role of voxel-based analysis of brain fluorodeoxyglucose positron emission tomography

  11. Cerebral glucose metabolic abnormality in patients with congenital scoliosis

    Energy Technology Data Exchange (ETDEWEB)

    Nam, H. Y.; Seo, G. T.; Lee, J. S.; Kim, S. C.; Kim, I. J.; Kim, Y. K.; Jeon, S. M. [Pusan National University Hospital, Pusan (Korea, Republic of)

    2007-07-01

    A possible association between congenital scoliosis and low mental status has been recognized, but there are no reports describing the mental status or cerebral metabolism in patients with congenital scoliosis in detail. We investigated the mental status using a mini-mental status exam as well as the cerebral glucose metabolism using F-18 fluorodeoxyglucose brain positron emission tomography in 12 patients with congenital scoliosis and compared them with those of 14 age-matched patients with adolescent idiopathic scoliosis. The mean mini-mental status exam score in the congenital scoliosis group was significantly lower than that in the adolescent idiopathic scoliosis group. Group analysis found that various brain areas of patients with congenital scoliosis showed glucose hypometabolisms in the left prefrontal cortex (Brodmann area 10), right orbitofrontal cortex (Brodmann area 11), left dorsolateral prefrontal cortex (Brodmann area 9), left anterior cingulate gyrus (Brodmann area 24) and pulvinar of the left thalamus. From this study, we could find the metabolic abnormalities of brain in patients with congenital scoliosis and suggest the possible role of voxel-based analysis of brain fluorodeoxyglucose positron emission tomography.

  12. Early Cerebral Hemodynamic, Metabolic, and Histological Changes in Hypoxic-Ischemic Fetal Lambs during Postnatal Life.

    Science.gov (United States)

    Rey-Santano, Carmen; Mielgo, Victoria E; Gastiasoro, Elena; Murgia, Xabier; Lafuente, Hector; Ruiz-Del-Yerro, Estibaliz; Valls-I-Soler, Adolf; Hilario, Enrique; Alvarez, Francisco J

    2011-01-01

    The hemodynamic, metabolic, and biochemical changes produced during the transition from fetal to neonatal life may be aggravated if an episode of asphyxia occurs during fetal life. The aim of the study was to examine regional cerebral blood flow (RCBF), histological changes, and cerebral brain metabolism in preterm lambs, and to analyze the role of oxidative stress in the first hours of postnatal life following severe fetal asphyxia. Eighteen chronically instrumented newborn lambs were randomly assigned to either a control group or the hypoxic-ischemic (HI) group, in which case fetal asphyxia was induced just before delivery. All the animals were maintained on intermittent positive pressure ventilation for 3 h after delivery. During the HI insult, the injured group developed acidosis, hypoxia, hypercapnia, lactic acidosis, and tachycardia (relative to the control group), without hypotension. The intermittent positive pressure ventilation transiently improved gas exchange and cardiovascular parameters. After HI injury and during ventilatory support, there continued to be an increased RCBF in inner regions among the HI group, but no significant differences were detected in cortical flow compared to the control group. Also, the magnitude of the increase in TUNEL positive cells (apoptosis) and antioxidant enzymes, and decrease of ATP reserves was significantly greater in the brain regions where the RCBF was not higher. In conclusion, our findings identify early metabolic, histological, and hemodynamic changes involved in brain damage in premature asphyxiated lambs. Such changes have been described in human neonates, so our model could be useful to test the safety and the effectiveness of different neuroprotective or ventilation strategies applied in the first hours after fetal HI injury.

  13. Early cerebral hemodynamic, metabolic and histological changes in hypoxic-ischemic fetal lambs during postnatal life

    Directory of Open Access Journals (Sweden)

    Carmen eRey-Santano

    2011-09-01

    Full Text Available The hemodynamic, metabolic and biochemical changes produce during transition from fetal to neonatal life could be aggravated if asphyctic event occur during fetal life. The aim of the study was to examine the regional cerebral blood flow (RCBF, histological changes, and cerebral brain metabolism in preterm lambs, and to analyze the role of oxidative stress for the first hours of postnatal life following severe fetal asphyxia. 18 chronically instrumented fetal lambs were assigned to: hypoxic-ischemic group, following fetal asphyxia animals were delivered and maintained on intermittent-positive-pressure-ventilation for 3 hours, and non-injured animals that were managed similarly to the previous group and used as control group. During hypoxic-ischemic insult, injured group developed acidosis, hypoxia, hypercapnia, latacidaemia and tachycardia in comparison to control group, without hypotension. Intermittent-positive-pressure-ventilation transiently improved gas exchange and cardiovascular parameters. After HI injury and during ventilation-support, the increased RCBF in inner zones was maintained for hypoxic-ischemic group, but cortical flow did not exhibit differences compared to the control group. Also, the increase of TUNEL positive cells (apoptosis and antioxidant enzymes, and decrease of ATP reserves was significantly higher in the brain regions where the RCBF were not increased.In conclusion, early metabolic, histological and hemodynamic changes involved in brain damage have been intensively investigated and reported in premature asphyctic lambs for the first 3 hours of postnatal life. Those changes have been described in human neonates, so our model could be useful to test the security and the effectiveness of different neuroprotective or ventilatory strategies when are applied in the first hours after fetal hypoxic-ischemic injury.

  14. In vivo imaging of cerebral energy metabolism with two-photon fluorescence lifetime microscopy of NADH.

    Science.gov (United States)

    Yaseen, Mohammad A; Sakadžić, Sava; Wu, Weicheng; Becker, Wolfgang; Kasischke, Karl A; Boas, David A

    2013-02-01

    Minimally invasive, specific measurement of cellular energy metabolism is crucial for understanding cerebral pathophysiology. Here, we present high-resolution, in vivo observations of autofluorescence lifetime as a biomarker of cerebral energy metabolism in exposed rat cortices. We describe a customized two-photon imaging system with time correlated single photon counting detection and specialized software for modeling multiple-component fits of fluorescence decay and monitoring their transient behaviors. In vivo cerebral NADH fluorescence suggests the presence of four distinct components, which respond differently to brief periods of anoxia and likely indicate different enzymatic formulations. Individual components show potential as indicators of specific molecular pathways involved in oxidative metabolism.

  15. Increased 20-HETE synthesis explains reduced cerebral blood flow but not impaired neurovascular coupling after cortical spreading depression in rat cerebral cortex

    DEFF Research Database (Denmark)

    Fordsmann, Jonas Christoffer; ko, Rebecca; Choi, Hyun B

    2013-01-01

    Cortical spreading depression (CSD) is associated with release of arachidonic acid (AA), impaired neurovascular coupling, and reduced cerebral blood flow (CBF), caused by cortical vasoconstriction. We tested the hypothesis that the released AA is metabolized by the cytochrome P450 enzyme to produce...... neurovascular coupling after CSD. These findings suggest that CSD-induced increments in 20-HETE cause the reduction in CBF after CSD, and that the attenuation of stimulation-induced CBF responses after CSD has a different mechanism. We suggest that blockade of 20-HETE synthesis may be clinically relevant...

  16. Single-photon emission tomography and cerebral blood flow

    International Nuclear Information System (INIS)

    Celsis, P.; Chan, M.; Marc-Vergnes, J.P.; Sveinsdottir, E.; Goldman, T.G.; Henriksen, L.; Paulson, O.B.; Stokely, E.M.; Lassen, N.A.

    1982-01-01

    This paper illustrates the capabilities of single-photon emission tomography in imaging local cerebral blood flows in man. The results purport the conclusion that a fairly good improvement has been achieved when compared to stationary detectors and that single-photon emission tomography is a well-suited tool for studying cerebral hemodynamics, especially within the framework of clinical studies [fr

  17. Decreased cerebral blood flow after administration of sodium bicarbonate in the distressed newborn infant

    DEFF Research Database (Denmark)

    Lou, H C; Lassen, N A; Fris-Hansen, B

    1978-01-01

    In the course of our studies on cerebral blood flow in newborn infants, we have observed a striking depressing effect of sodium bicarbonate infusion on cerebral blood flow which in some cases may severely aggravate cerebral ischemia. We measured cerebral blood flow before and after the treatment...... with 1 to 8 meqs of sodium bicarbonate in seven distressed newborn infants. The 133 Xe clearance technique was used. The results showed in six of the seven cases a decrease in cerebral blood flow, which in most cases was reduced to 14 to 22 ml/100 g/min, which is about half the value prior...... to the bicarbonate infusion. In one case an extreme reduction occurred: cerebral blood flow was reduced to 3 ml/100 g/min, well below the level compatible with tissue survival. The results are discussed with regard to the optimal treatment of the acidotic newborn....

  18. Effects of captopril on cerebral blood flow in normotensive and hypertensive rats

    International Nuclear Information System (INIS)

    Barry, D.I.; Paulson, O.B.; Jarden, J.O.; Juhler, M.; Graham, D.I.; Strandgaard, S.

    1984-01-01

    Cerebrovascular effects of the angiotensin converting enzyme inhibitor captopril were examined in normotensive and hypertensive rats. Cerebral blood flow was measured with the intracarotid 133 xenon injection method in halothane-anesthetized animals. The blood-brain barrier permeability of captopril (determined with an integral-uptake method) was negligible, the permeability-surface area product in most brain regions being 1 X 10(-5) cm3/g per second, that is, three to four times lower than that of sodium ion. When administered into the cerebral ventricles to bypass the blood-brain barrier, captopril had no effect on cerebral blood flow: furthermore, cerebral blood flow autoregulation (studied by raising and lowering blood pressure) was identical to that in controls. In contrast, when given intravenously, captopril had a marked effect on cerebral blood flow autoregulation--both the lower and upper limits of autoregulation being shifted to a lower pressure (by about 20 to 30 and 50 to 60 mm Hg, respectively), and the autoregulatory range was shortened by about 40 mm Hg. This effect may be ascribed to inhibition of converting enzyme in the cerebral blood vessels rather than within the brain

  19. [Assessment of maternal cerebral blood flow in patients with preeclampsia].

    Science.gov (United States)

    Mandić, Vesna; Miković, Zeljko; Dukić, Milan; Vasiljević, Mladenko; Filimonović, Dejan; Bogavac, Mirjana

    2005-01-01

    Systemic vasoconstriction in preeclamptic patients increases vascular resistance, and is manifested by increased arterial blood flow velocity. The aim of the study is to evaluate if there is a change of Doppler indices in maternal medial cerbral artery (MCA) in severe preeclampsia due to: 1) severity of clinical symptoms, 2) the begining of eclamptic attack and 3) the application of anticonvulsive therapy. A prospective clinical study included 92 pregnant women, gestational age 28-36 weeks. They were divided into three groups: normotensive (n=30), mild preeclampsia (n=33), and severe preeclampsia (n=29). We investigated maternal cerebral circulation by assessing the MCA. We registrated: pulsatility index (Pi), resistance index (Ri), systolic/diastolic ratio (S/D), and the maximum systolic, end diastolic and medium velocity. Patients with severe preeclampsia were divided into two subgroups. subgroup 1 included patients without symptoms of threatening eclampsia (n=18; 62.06%); while subgroup 2 included those with symptoms of preeclampsia (n=11; 37.94%). All patients with severe preeclampsia were treated with magnesium sulfate (MgSO4), and cerebral blood flow was measured before and after the treatment. Statistical analysis was done by oneway ANOVA, Student t-test and t-paired sample test. The difference was considered to be significant if ppreclampsia we found increased velocity values, Pi and Ri, especially in patients with signs of threatened eclampsia, suggesting that blood vessels changes are most prominent in severe preeclampsia. Cerebral blood flow meassurements can be used as a clinical test for the prediction of eclampsia. Magnesium-sulfate (MgSO4) has a signifficant role in prophylaxis and treatment of eclampsia, and, therefore, positive influence on reduction of cerebral ishemic lesions can be expected. We can conclude that changes of the cerebral blood flow can be evaluated by evaluating blood flow velocities in the medial cerebral artery. Velocities tend

  20. Aberrant Cerebral Blood Flow in Response to Hunger and Satiety in Women Remitted from Anorexia Nervosa

    OpenAIRE

    Christina E. Wierenga; Amanda Bischoff-Grethe; Grace Rasmusson; Ursula F. Bailer; Ursula F. Bailer; Laura A. Berner; Thomas T. Liu; Walter H. Kaye

    2017-01-01

    The etiology of pathological eating in anorexia nervosa (AN) remains poorly understood. Cerebral blood flow (CBF) is an indirect marker of neuronal function. In healthy adults, fasting increases CBF, reflecting increased delivery of oxygen and glucose to support brain metabolism. This study investigated whether women remitted from restricting-type AN (RAN) have altered CBF in response to hunger that may indicate homeostatic dysregulation contributing to their ability to restrict food. We comp...

  1. The effect of combined treatment with transcranial direct current stimulation on cerebral blood flow in patients with cerebral palsy

    Directory of Open Access Journals (Sweden)

    K. V. Yatsenko

    2017-02-01

    Full Text Available There is a close link between the activity of the brain and cerebral blood supply. Transcranial direct current stimulation (tDCS modulates the activity of the cerebral cortex and thus affects the cerebral blood flow. The aim of the study was to investigate the effect of combined treatment with tDCS on cerebral blood flow in patients with cerebral palsy (CP. Materials and Methods. 60 patients with various forms of cerebral palsy were examined and received the course of treatment. The comparison group was formed from 30 children who received the course of basic medical and rehabilitation procedures. The main group included 30 children who, in addition to the same therapy, received a course of tDCS. A transcranial Doppler ultrasound examination of head blood vessels was used for the study of cerebral hemodynamics in children with cerebral palsy before and after combined treatment with tDCS. Results. tDCS reduced asymmetry coefficient of blood flow velocity in the middle cerebral arteries (MCA by 12.3 %, whereas in the comparison group only by 2.5 %; in the anterior cerebral artery (ACA – 9.5 %, while in the comparison group – 0.8 %. tDCS significantly reduced the high mean blood flow velocity per cycle (MFV in the basilar artery (BA, MCA and ACA (21.7 %, 18.3 % and 7.8 %, respectively; in the comparison group no statistically significant positive dynamics was observed. tDCS significantly increased the low MVF in the BA, MCA and ACA (29.7 %, 21.2 % and 9.7 % respectively; a statistically significant increase of MVF by 9.9 % was only in the CMA in the comparison group of patients. Conclusions. Our data indicate that the use of tDCS in the combined treatment of CP patients improves cerebral hemodynamics in 87 % of patients, in contrast to 52 % in the comparison group. The addition of transcranial direct current stimulation method to the complex treatment of patients with cerebral palsy improves the effectiveness of treatment and may also

  2. Mechanisms of recovery from aphasia: evidence from serial xenon 133 cerebral blood flow studies

    International Nuclear Information System (INIS)

    Knopman, D.S.; Rubens, A.B.; Selnes, O.A.; Klassen, A.C.; Meyer, M.W.

    1984-01-01

    In 21 patients who suffered aphasia resulting from left hemisphere ischemic infarction, the xenon 133 inhalation cerebral blood flow technique was used to measure cerebral blood flow within 3 months and 5 to 12 months after stroke. In addition to baseline measurements, cerebral blood flow measurements were also carried out while the patients were performing purposeful listening. In patients with incomplete recovery of comprehension and left posterior temporal-inferior parietal lesions, greater cerebral blood flow occurred with listening in the right inferior frontal region in the late studies than in the early studies. In patients with nearly complete recovery of comprehension and without left posterior temporal-inferior parietal lesions, early listening studies showed diffuse right hemisphere increases in cerebral blood flow. Later listening studies in this latter patient group showed greater cerebral blood flow in the left posterior temporal-inferior parietal region. The study provides evidence for participation of the right hemisphere in language comprehension in recovering aphasics, and for later return of function in left hemisphere regions that may have been functionally impaired early during recovery

  3. Cerebral hemodynamic and metabolic changes in fulminant hepatic failure

    Directory of Open Access Journals (Sweden)

    Fernando Mendes Paschoal Junior

    Full Text Available ABSTRACT Intracranial hypertension and brain swelling are a major cause of morbidity and mortality of patients suffering from fulminant hepatic failure (FHF. The pathogenesis of these complications has been investigated in man, in experimental models and in isolated cell systems. Currently, the mechanism underlying cerebral edema and intracranial hypertension in the presence of FHF is multi-factorial in etiology and only partially understood. The aim of this paper is to review the pathophysiology of cerebral hemodynamic and metabolism changes in FHF in order to improve understanding of intracranial dynamics complication in FHF.

  4. Cerebral glucose metabolism in Wernicke's, Broca's, and conduction aphasia

    International Nuclear Information System (INIS)

    Metter, E.J.; Kempler, D.; Jackson, C.; Hanson, W.R.; Mazziotta, J.C.; Phelps, M.E.

    1989-01-01

    Cerebral glucose metabolism was evaluated in patients with either Wernicke's (N = 7), Broca's (N = 11), or conduction (N = 10) aphasia using 18 F-2-fluoro-2-deoxy-D-glucose with positron emission tomography. The three aphasic syndromes differed in the degree of left-to-right frontal metabolic asymmetry, with Broca's aphasia showing severe asymmetry and Wernicke's aphasia mild-to-moderate metabolic asymmetry, while patients with conduction aphasia were metabolically symmetric. On the other hand, the three syndromes showed the same degree of metabolic decline in the left temporal region. The parietal region appeared to separate conduction aphasia from both Broca's and Wernicke's aphasias. Common aphasic features in the three syndromes appear to be due to common changes in the temporal region, while unique features were associated with frontal and parietal metabolic differences

  5. Role of hypotension in decreasing cerebral blood flow in porcine endotoxemia

    International Nuclear Information System (INIS)

    Miller, C.F.; Breslow, M.J.; Shapiro, R.M.; Traystman, R.J.

    1987-01-01

    The role of reduced arterial blood pressure (MAP) in decreasing cerebral blood flow (CBF) during endotoxemia was studied in pentobarbital-anesthetized pigs. Microspheres were used to measure regional CBF changes during MAP manipulations in animals with and without endotoxin. Endotoxin decreased MAP to 50 mmHg and decreased blood flow to the cortex and cerebellum without affecting cerebral cortical oxygen consumption (CMRo 2 ). Elevating MAP from 50 to 70 mmHg during endotoxemia with norepinephrine did not change cortical blood flow or CMRo 2 but increased cerebellar blood flow. Brain stem blood flow was not affected by endotoxin or norepinephrine. When MAP was decreased to 50 mmHg by hemorrhage without endotoxin, no change in blood flow to cortex, cerebellum, or brain stem was observed from base-line levels. These results suggest that decreased MAP below a lower limit for cerebral autoregulation does not account for the decreased CBF observed after endotoxin

  6. Cerebral blood flow variations in CNS lupus

    International Nuclear Information System (INIS)

    Kushner, M.J.; Tobin, M.; Fazekas, F.; Chawluk, J.; Jamieson, D.; Freundlich, B.; Grenell, S.; Freemen, L.; Reivich, M.

    1990-01-01

    We studied the patterns of cerebral blood flow (CBF), over time, in patients with systemic lupus erythematosus and varying neurologic manifestations including headache, stroke, psychosis, and encephalopathy. For 20 paired xenon-133 CBF measurements, CBF was normal during CNS remissions, regardless of the symptoms. CBF was significantly depressed during CNS exacerbations. The magnitude of change in CBF varied with the neurologic syndrome. CBF was least affected in patients with nonspecific symptoms such as headache or malaise, whereas patients with encephalopathy or psychosis exhibited the greatest reductions in CBF. In 1 patient with affective psychosis, without clinical or CT evidence of cerebral ischemia, serial SPECT studies showed resolution of multifocal cerebral perfusion defects which paralleled clinical recovery

  7. Regional cerebral metabolic changes after acupuncture by FDG PET: Effects and methodology

    International Nuclear Information System (INIS)

    Guan, Y.H.; Zuo, C.T.; Zhao, J.; Lin, X.T.; Li, J.; Dong, J.C.

    2002-01-01

    Abstract Objectives: To observe the regional cerebral metabolism changes in cerebrovascular ischemic patients and normal volunteers while acupuncture by using FDG PET. To definite the locations of the influence of these acupoints on brain function in certain regions of the cerebrum, as well as to explore the laws of therapeutic effects of acupuncture on subjects and established the One-day method for brain FDG PET scan. Methods and Materials Using FDG PET, cerebral glucose metabolism and cerebral functional changes before and after electro-acupuncture treatment were investigated in 12 normal volunteers and 8 cerebrovascular ischemic patients. These subjects were treated with acupuncture in the following points: Hegu (LI4) and Quchi (LI11) of Hand Yang-Ming meridian, Zusanli (ST36) and Shangjuxu (ST37) of Foot Yang-Ming meridian and added Motor Area and Fengchi (B20). Limbs points were contralateral to the brain points. In the normal group, the side of the body treated by acupuncture was randomly selected and in the patients groups, the sides treated were on the side of paralysis. PET imaging was read by visual interpretation and calculated in multiple ROI semi-quantitative analysis method. Therefore, the image subject method was used to demonstrate the variety of glucose metabolism after acupuncture. Results One-day method was established in these studies. PET imaging was read by visual interpretation in blind method and calculated by semi-quantitative analysis. This results shows that cerebral glucose metabolism and cerebral functional activity of the normal is higher in the frontal lobe, temporal lobe, thalamus, Sensorimotor, Parietal bilaterally and cerebellum contralaterally. After acupuncture, the increase ratio of ipslateral glucose metabolism was between 23% and 38%; while the contralateral increase ratio between 22% and 40%. Above all, the variation in cerebral glucose metabolism was predominantly contralateral cerebral regions. The cerebrovascular ischemic

  8. Clinical research on quantitative imaging of cerebral blood flow using 123I-IMP

    International Nuclear Information System (INIS)

    Kinoshita, Hirofumi

    1987-01-01

    Cerebral blood flow measurement was performed using N-Isopropyl-p-( 123 I)-Iodoam-phetamine (IMP) and rotating gammacamera emission computed tomography (ECT), and a new quantitative profile curve was designed. There was a good correlation between the cerebral blood flow measured by intravenous Xe-133 method and that measured by IMP method in ten normal volunteers. IMP-ECT was performed in 40 patients with various cerebral diseases. The following results were obtained: 1. Minimum recognizable cerebral blood flow difference was 5 ml/100 g/min. 2. Quantitative redistribution was observed in approximately half of the cases which showed qualitative redistribution. 3. The incidence of crossed cerebellar diaschiasis was high among patients with significant cerebral disease (8 cases/10 cases). (author)

  9. Cerebral perfusion, oxygenation and metabolism during exercise in young and elderly individuals

    DEFF Research Database (Denmark)

    Fisher, James P; Hartwich, Doreen; Seifert, Thomas

    2013-01-01

    )), glucose and lactate across the brain. The molar ratio between the cerebral uptake of O(2) versus carbohydrate (O(2)-carbohydrate index; O(2) / [glucose + 0.5 lactate]; OCI), the cerebral metabolic rate of O(2) (CMRO(2)) and changes in mitochondrial O(2) tension (P(mito)O(2)) were calculated. W...

  10. Regional cerebral blood flow measurement with intravenous [15O]water bolus and [18F]fluoromethane inhalation

    International Nuclear Information System (INIS)

    Herholz, K.; Pietrzyk, U.; Wienhard, K.; Hebold, I.; Pawlik, G.; Wagner, R.; Holthoff, V.; Klinkhammer, P.; Heiss, W.D.

    1989-01-01

    In 20 patients with ischemic cerebrovascular disease, classic migraine, or angiomas, we compared paired dynamic positron emission tomographic measurements of regional cerebral blood flow using both [ 15 O]water and [ 18 F]fluoromethane as tracers. Cerebral blood flow was also determined according to the autoradiographic technique with a bolus injection of [ 15 O]water. There were reasonable overall correlations between dynamic [ 15 O]water and [ 18 F]fluoromethane values for cerebral blood flow (r = 0.82) and between dynamic and autoradiographic [ 15 O]water values for cerebral blood flow (r = 0.83). We found a close correspondence between abnormal pathologic findings and visually evaluated cerebral blood flow tomograms obtained with the two tracers. On average, dynamic [ 15 O]water cerebral blood flow was 6% lower than that measured with [ 18 F]fluoromethane. There also was a general trend toward a greater underestimation with [ 15 O]water in high-flow areas, particularly in hyperemic areas, probably due to incomplete first-pass extraction of [ 15 O]water. Underestimation was not detected in low-flow areas or in the cerebellum. Absolute cerebral blood flow values were less closely correlated between tracers and techniques than cerebral blood flow patterns. The variability of the relation between absolute flow values was probably caused by confounding effects of the variation in the circulatory delay time. The autoradiographic technique was most sensitive to this type error

  11. Regional cerebral blood flow characteristics of the Sturge-Weber syndrome

    International Nuclear Information System (INIS)

    Riela, A.R.; Stump, D.A.; Roach, E.S.; McLean, W.T. Jr.; Garcia, J.C.

    1985-01-01

    Four patients with the Sturge-Weber syndrome were studied using the non-invasive Xenon-133 inhalation technique. All four patients had decreased regional cerebral blood flow in the area of their lesion, and in two patients who were subsequently tested with 5% carbon dioxide inhalation, impaired vasomotor reactivity was documented. Diminished regional cerebral blood flow is consistent with previously described nuclide flow studies which demonstrated a delay in the initial perfusion blush in the region of the abnormal vasculature. The focal decrease in blood flow was greatest in the most severely affected patient, but was also prominent in the two younger patients, both of whom have excellent neurologic function. These studies suggest that localized decrease in blood flow and vasomotor dysfunction in Sturge-Weber syndrome can precede the occurrence of severe neurologic impairment and extensive cerebral atrophy and possibly be a major contributing factor in progressive dysfunction. A secondary observation was that the blood flow in the unaffected hemisphere was significantly greater in two children compared to the two adults and was similar to the age-related differences reported for normal children and adults

  12. Cerebral ammonia metabolism in hyperammonemic rats

    Energy Technology Data Exchange (ETDEWEB)

    Cooper, A J; Mora, S N; Cruz, N F; Gelbard, A S

    1985-06-01

    The short-term metabolic fate of blood-borne (/sup 13/N)ammonia was determined in the brains of chronically (8- or 14-week portacaval-shunted rats) or acutely (urease-treated) hyperammonemic rats. Using a freeze-blowing technique it was shown that the overwhelming route for metabolism of blood-borne (/sup 13/N)ammonia in normal, chronically hyperammonemic and acutely hyperammonemic rat brain was incorporation into glutamine (amide). However, the rate of turnover of (/sup 13/N)ammonia to L-(amide-/sup 13/N)glutamine was slower in the hyperammonemic rat brain than in the normal rat brain. The activities of several enzymes involved in cerebral ammonia and glutamate metabolism were also measured in the brains of 14-week portacaval-shunted rats. The rat brain appears to have little capacity to adapt to chronic hyperammonemia because there were no differences in activity compared with those of weight-matched controls for the following brain enzymes involved in glutamate/ammonia metabolism: glutamine synthetase, glutamate dehydrogenase, aspartate aminotransferase, glutamine transaminase, glutaminase, and glutamate decarboxylase. The present findings are discussed in the context of the known deleterious effects on the CNS of high ammonia levels in a variety of diseases.

  13. Energy metabolism of rat cerebral cortex, hypothalamus and hypophysis during ageing.

    Science.gov (United States)

    Villa, R F; Ferrari, F; Gorini, A

    2012-12-27

    Ageing is one of the main risk factors for brain disorders. According to the neuroendocrine theory, ageing modifies the sensitivity of hypothalamus-pituitary-adrenal axis to homoeostatic signals coming from the cerebral cortex. The relationships between the energy metabolism of these areas have not been considered yet, in particular with respect to ageing. For these reasons, this study was undertaken to systematically investigate in female Sprague-Dawley rats aged 4, 6, 12, 18, 24, 28 months and in 4-month-old male ones, the catalytic properties of energy-linked enzymes of the Krebs' cycle, electron transport chain, glutamate and related amino acids on different mitochondrial subpopulations, i.e. non-synaptic perikaryal and intra-synaptic (two types) mitochondria. The biochemical enzymatic pattern of these mitochondria shows different expression of the above-mentioned enzymatic activities in the investigated brain areas, including frontal cerebral cortex, hippocampus, striatum, hypothalamus and hypophysis. The study shows that: (i) the energy metabolism of the frontal cerebral cortex is poorly affected by physiological ageing; (ii) the biochemical machinery of non-synaptic perikaryal mitochondria is differently expressed in the considered brain areas; (iii) at 4-6 months, hypothalamus and hypophysis possess lower oxidative metabolism with respect to the frontal cerebral cortex while (iv), during ageing, the opposite situation occurs. We hypothesised that these metabolic modifications likely try to grant HPA functionality in response to the incoming external stress stimuli increased during ageing. It is particularly notable that age-related changes in brain bioenergetics and in mitochondrial functionality may be considered as remarkable factors during physiological ageing and should play important roles in predisposing the brain to physiopathological events, tightly related to molecular mechanisms evoked for pharmacological treatments. Copyright © 2012 IBRO

  14. Acute effects of thalamotomy and pallidotomy on regional cerebral metabolism, evaluated by PET

    NARCIS (Netherlands)

    Henselmans, JML; de Jong, BM; Pruim, J; Staal, MJ; Rutgers, AWF; Haaxma, R

    The subacute effect of thalamotomy and pallidotomy on regional cerebral metabolism was studied by means of Positron Emission Tomography (PET). In this way we aimed to identify the pattern of functional deafferentiation following a specific lesion in the basal ganglia. The cerebral distribution of

  15. Measurement of regional cerebral blood flow by intravenous administation of 133 xenon

    International Nuclear Information System (INIS)

    Ryding, E.

    1986-01-01

    Reviewing the background and the theory for rCFB measurements the following conditions are established for the use of flow measurement with 133-Xenon as a reliable indicator for indirect measurements of cerebral functional activity. 1. There is a strict coupling between rCBF and regional metabolism. This condition can only be considered to be fulfilled in the normal non-anoxic bran tissue. 2. There is a close correlation between the tissue and the venous concentration of 133-Xenin which can be reliably approximated by the blood-brain partition coefficient. This condition can be considered to be fullfilled in the normal flow range, but not in pathological conditions such as cerebrovascular occlusions. 3. Intercompartment diffusion of 133-Xenon has no significant effect upon the measurement of rCBF values. This condition appear to share its limitations for fulfilement with condition 2. 4. There is no significant contamination by the extracerebral flow components at IH or IV rCBF measurements. 5. There is a negligible 'look through' effect from surrounding areas to region with focal high or low blood flow. (U.W.)

  16. Persistence of cerebral metabolic abnormalities in chronic schizophrenia as determined by positron emission tomography

    International Nuclear Information System (INIS)

    Wolkin, A.; Jaeger, J.; Brodie, J.D.; Wolf, A.P.; Fowler, J.; Rotrosen, J.; Gomez-Mont, F.; Cancro, R.

    1985-01-01

    Local cerebral metabolic rates were determined by positron emission tomography and the deoxyglucose method in a group of 10 chronic schizophrenic subjects before and after somatic treatment and in eight normal subjects. Before treatment, schizophrenic subjects had markedly lower absolute metabolic activity than did normal controls in both frontal and temporal regions and a trend toward relative hyperactivity in the basal ganglia area. After treatment, their metabolic rates approached those seen in normal subjects in nearly all regions except frontal. Persistence of diminished frontal metabolism was manifested as significant relative hypofrontality. These findings suggest specific loci of aberrant cerebral functioning in chronic schizophrenia and the utility of positron emission tomography in characterizing these abnormalities

  17. Modeling Cerebral Blood Flow Control During Posture Change from Sitting to Standing

    DEFF Research Database (Denmark)

    Olufsen, Mette; Tran, Hien; Ottesen, Johnny T.

    2004-01-01

    , the heart, and venous valves. We use physiologically based control mechanisms to describe the regulation of cerebral blood velocity and arterial pressure in response to orthostatic hypotension resulting from postural change. Beyond active control mechanisms we also have to include certain passive non......Hypertension, decreased cerebral blood flow, and diminished cerebral blood flow regulation, are among the first signs indicating the presence of cerebral vascular disease. In this paper, we will present a mathematical model that can predict blood flow and pressure during posture change from sitting......-linearities in some of the compliance-pressure and resistance-pressure relationships. Futhermore, an acurate and physiologically based submodel, describing the dynamics of how gravity effects the blood distribution during suspine changes, is included. To justify the fidelity of our mathematical model and control...

  18. Relationship of 133Xe cerebral blood flow to middle cerebral arterial flow velocity in men at rest

    Science.gov (United States)

    Clark, J. M.; Skolnick, B. E.; Gelfand, R.; Farber, R. E.; Stierheim, M.; Stevens, W. C.; Beck, G. Jr; Lambertsen, C. J.

    1996-01-01

    Cerebral blood flow (CBF) was measured by 133Xe clearance simultaneously with the velocity of blood flow through the left middle cerebral artery (MCA) over a wide range of arterial PCO2 in eight normal men. Average arterial PCO2, which was varied by giving 4% and 6% CO2 in O2 and by controlled hyperventilation on O2, ranged from 25.3 to 49.9 mm Hg. Corresponding average values of global CBF15 were 27.2 and 65.0 ml 100 g min-1, respectively, whereas MCA blood-flow velocity ranged from 42.8 to 94.2 cm/s. The relationship of CBF to MCA blood-flow velocity over the imposed range of arterial PCO2 was described analytically by a parabola with the equation: CBF = 22.8 - 0.17 x velocity + 0.006 x velocity2 The observed data indicate that MCA blood-flow velocity is a useful index of CBF response to change in arterial PCO2 during O2 breathing at rest. With respect to baseline values measured while breathing 100% O2 spontaneously, percent changes in velocity were significantly smaller than corresponding percent changes in CBF at increased levels of arterial PCO2 and larger than CBF changes at the lower arterial PCO2. These observed relative changes are consistent with MCA vasodilation at the site of measurement during exposure to progressive hypercapnia and also during extreme hyperventilation hypocapnia.

  19. Regional cerebral glucose metabolism in patients with alcoholic Korsakoff's syndrome

    International Nuclear Information System (INIS)

    Kessler, R.M.; Parker, E.S.; Clark, C.M.; Martin, P.R.; George, D.T.; Weingartner, H.; Sokoloff, L.; Ebert, M.H.; Mishkin, M.

    1985-01-01

    Seven alcoholic male subjects diagnosed as having Korsakoff's syndrome and eight age-matched male normal volunteers were studied with /sup 18/F 2-fluoro-2-deoxy-D-glucose (2/sup 18/FDG). All subjects were examined at rest with eyes covered in a quiet, darkened room. Serial plasma samples were obtained following injection of 4 to 5 mCi of 2/sup 18/FDG. Tomographic slices spaced at 10mm axial increments were obtained (in-plane resolution = 1.75 cm, axial resolution = 1.78 cm). Four planes were selected from each subject, and a total of 46 regions of interest were sampled and glucose metabolic rates for each region calculated. The mean glucose metalbolic rate for the 46 regions in the Korsakoff subjects was significantly lower than that in the normal controls (5.17 +- .43 versus 6.6 +- 1.31). A Q-component analysis, which examined each subject's regional rates relative to his mean rate, revealed two distinct patterns in the Korsakoff group. Glucose metabolism was significantly reduced in 37 of the 46 regions sampled. Reduced cerebral glucose metabolism in a nondemented group of subjects has not previously been reported. The reduction in cortical metabolism may be the result of damage to sub-cortical projecting systems. The differing patterns of cerebral metabolism in Korsakoff's syndrome suggests subgroups with differing neuropathology. Regions implicated in memory function, medial temporal, thalamic and medial prefrontal were among the regions reduced in metabolism

  20. Upper limit of cerebral blood flow autoregulation in experimental renovascular hypertension in the baboon

    DEFF Research Database (Denmark)

    Strandgaard, S; Jones, J V; MacKenzie, E T

    1975-01-01

    The effect of arterial hypertension on cerebral blood flow was studied by the intracarotid 133Xe clearance method in baboons. The arterial blood pressure was raised in gradual steps with angiotensin. Baboons with renal hypertension of 8-12 weeks duration were studied along with normotensive baboons....... In initially normotensive baboons, cerebral blood flow remained constant until the mean arterial blood pressure had risen to the range of 140 to 154 mm Hg; thereafter cerebral blood flow increased with each rise in mean arterial blood pressure. In the chronically hypertensive baboons, cerebral blood flow...... remained constant until the mean arterial blood pressure had been elevated to the range of 155 to 169 mm Hg. Thus, in chronic hypertension it appears that there are adaptive changes in the cerebral circulation which may help to protect the brain from further increases in arterial blood pressure....

  1. Preliminary studies of regional cerebral blood flow changes in patients with leukoaraiosis

    International Nuclear Information System (INIS)

    Li Yaming; Ren Yan; He Qiu

    1997-01-01

    PURPOSE: To investigate changes of regional cerebral blood flow (rCBF) in leukoaraiosis (LA) lesion and cortical regions and analyse the relation between rCBF changes and dementia. METHODS: Regional cerebral blood flow perfusion imaging with SPECT was performed in 49 patients with subcortical multiple cerebral infarction, including 24 cases company LA [LA(+)], 25 cases not company LA[LA(-)] and 10 normal subjects. The relative analysis was made between rCBF changes and cognitive scores. RESULTS: Compared the LA(+) with control, the rCBFs in frontal, parietal, temporal cortexes and LA lesion significantly decreased (P<0.05). The rCBF of frontal, parietal cortexes and LA lesions was also significantly decreased (P<0.05) compared with LA(-) groups. The cognitive scores were significantly related with rCBF changes in frontal cortex and LA lesion (r = 0.765, P<0.01 and r = 0.439, P<0.05). CONCLUSION: In patients with subcortical multiple cerebral infarction company LA lesion, there were extensive ischemic hypoperfusion changes in the cortical regions and LA lesion, which may response to decreased cerebral function and had certain relationship with dementia. The examination with SPECT cerebral blood flow perfusion imaging had unique advantage and value

  2. Clinical significance of reduced cerebral metabolism in multiple sclerosis. A combined PET and MRI study

    International Nuclear Information System (INIS)

    Sun, Xiayan; Tanaka, Makoto; Kondo, Susumu; Okamoto, Koichi; Hirai, Shunsaku

    1998-01-01

    Magnetic resonance imaging (MRI) in patients with multiple sclerosis (MS) has provided major insights into the disease's natural history, and many studies have focussed on possible correlations between MRI findings and the clinical manifestations of MS. In contrast, there are few reports on possible relationships between functional imaging data and cognitive function. The present study assessed the relationship between clinical presentation and combined anatomical and functional imaging data in MS. Twenty patients with definite MS underwent MRI and positron emission tomography (PET) to evaluate cerebral blood flow (rCBF) and oxygen metabolism (rCMRO 2 ). The relationships between these neuroimaging findings and clinical data, including the Expanded Disability Status Scale (EDSS), Mini-mental status scale, Hasegawa Dementia Scale and relapse time, were evaluated with Spearman's rank correlation coefficients. A general reduction in rCBF and rCMRO 2 in the gray and white matter were found in the MS patients. EDSS was correlated with the number and size of the lesions on MRI and was negatively correlated with rCMRO 2 . A correlation between the decrease in rCMRO 2 and the level of cognitive impairment was also found. The severity of cerebral hypometabolism was also related to the number of relapses. Morphological and functional findings obtained by MRI and PET are closely related to the clinical status in MS. Our results suggest that measurement of cerebral metabolism in MS has the potential to be an objective marker for monitoring disease activity and to provide prognostic information. (author)

  3. Modulation of cerebral blood flow with transcutaneous electrical neurostimulation (TENS) in patients with cerebral vasospasm after subarachnoid hemorrhage

    NARCIS (Netherlands)

    ter Laan, Mark; van Dijk, J.M.C.; Stewart, Roy; Staal, Michiel J; Elting, Jan-Willem J.

    ObjectivesTranscutaneous electrical neurostimulation (TENS) and spinal cord stimulation have been shown to increase peripheral and cerebral blood flow. We postulate that certain pathological conditions attenuate cerebral autoregulation, which may result in a relative increase of the importance of

  4. Modulation of cerebral blood flow with transcutaneous electrical neurostimulation (TENS) in patients with cerebral vasospasm after subarachnoid hemorrhage

    NARCIS (Netherlands)

    Laan, M. ter; Dijk, J.M. van; Stewart, R.; Staal, M.J.; Elting, J.W.

    2014-01-01

    OBJECTIVES: Transcutaneous electrical neurostimulation (TENS) and spinal cord stimulation have been shown to increase peripheral and cerebral blood flow. We postulate that certain pathological conditions attenuate cerebral autoregulation, which may result in a relative increase of the importance of

  5. Cerebral autoregulation control of blood flow in the brain

    CERN Document Server

    Payne, Stephen

    2016-01-01

    This Brief provides a comprehensive introduction to the control of blood flow in the brain. Beginning with the basic physiology of autoregulation, the author goes on to discuss measurement techniques, mathematical models, methods of analysis, and relevant clinical conditions, all within this single volume. The author draws together this disparate field, and lays the groundwork for future research directions. The text gives an up-to-date review of the state of the art in cerebral autoregulation, which is particularly relevant as cerebral autoregulation moves from the laboratory to the bedside. Cerebral Autoregulation will be useful to researchers in the physical sciences such as mathematical biology, medical physics, and biomedical engineering whose work is concerned with the brain. Researchers in the medical sciences and clinicians dealing with the brain and blood flow, as well as industry professionals developing techniques such as ultrasound, MRI, and CT will also find this Brief of interest.

  6. Potentials of positron emission tomography for regional cerebral blood flow evaluation

    International Nuclear Information System (INIS)

    Depresseux, J.C.

    1982-01-01

    A general overview of the potentials of positron emission tomography and of positron-emitting radiopharmaceuticals for the evaluation of regional cerebral blood flow is proposed and discussed. Specific characteristics of this technique are described, with special stress on conceptual and methodological implications. Four different approaches to the problem of the determination of cerebral blood flow are distinguished: trapping equilibrium methods, steady state equilibrium methods, clearance methods and convoluted kinetic methods [fr

  7. Regional cerebral metabolic changes after acupuncture by FDG PET: effects and methodology

    International Nuclear Information System (INIS)

    Guan Yihui; Li Ji; Zuo Chuantao; Dong Jincheng; Zhao Jun; Lin Xiangtong

    2002-01-01

    In order to investigate the therapeutic mechanisms of acupuncture pints in cerebrovascular ischemic patients and normal volunteers, FDG PET was adopted. Changes in cerebral glucose metabolism and cerebral functional activity before and after electro-acupuncture treatment were studied in 12 normal volunteers and 11 cerebrovascular ischemic patients. The PET imaging was read by visual interpretation and calculated by semi-quantitative analysis. After acupuncture, cerebral glucose metabolism of the normal group is higher in the frontal lobe, temporal lobe, thalamus bilaterally and cerebellum contralaterally. The cerebrovascular ischemic patients had manifested greater response in their lesions than in their normal regions of the two tested groups, as well as than in their normal regions of the whole brain, after acupuncture treatment. The study shows that the regulatory effects of acupuncture on the central nervous system influence the brain at multiple-sections, multiple-directions and multiple-levels of brain function. It conforms to the holistic and bi-directions regulatory laws of acupuncture

  8. Studies of cerebral blood flow and metabolism in patients with senile dementia of the Alzheimer's type and diagnostic evaluation of the dementing illnesses by positron emission tomography

    International Nuclear Information System (INIS)

    Sakamoto, Shizuki

    1990-01-01

    This study was designed to determine cerebral dysfunction in senile dementia of the Alzheimer's type (SDAT). Regional cerebral blood flow (rCBF), oxygen extraction fraction and cerebral oxygen consumption (rCMRO 2 ) were studied in SDAT patients (n=16) and age-matched normal elderly people (n=5) by positron emission tomography (PET) using the O-15 labeled CO 2 and O 2 inhalation technique. The SDAT group had a significantly lower values in both rCBF and rCMRO 2 than the normal control. During the early stage of SDAT, rCMRO 2 was restricted to the temporal cortex; and it extended to the parietal and frontal cortices associated with a decreased rCBF as the disease progressed. Posterior temporal and posterior parietal association cortices were considered to be the most damageable part during the early stage. Bilateral differences in oxygen metabolism of the temporal and parietal cortices tended to be in accordance with clinical symptoms for disturbed speech and visuospatial function, suggesting the correlation between rCMRO 2 and rCBF in SDAT. Findings of PET in SDAT differed from those obtained in each patient with multi-infarct dementia or Pick disease, in that both rCBF and rCMRO 2 were inhomogeneously decreased over the whole cerebral cortex for multi-infarct dementia and in that homogeneously decreased rCBF and rCMRO 2 were restricted to the frontal and temporal cortices for Pick disease. PET may have a potential for differentiating various types of dementia. (N.K.)

  9. Improved cerebral energetics and ketone body metabolism in db/db mice

    DEFF Research Database (Denmark)

    Andersen, Jens V; Christensen, Sofie K; Nissen, Jakob D

    2017-01-01

    It is becoming evident that type 2 diabetes mellitus is affecting brain energy metabolism. The importance of alternative substrates for the brain in type 2 diabetes mellitus is poorly understood. The aim of this study was to investigate whether ketone bodies are relevant candidates to compensate...... metabolism in type 2 diabetes mellitus. The increased hippocampal ketone body utilization and improved mitochondrial function in db/db mice, may act as adaptive mechanisms in order to maintain cerebral energetics during hampered glucose metabolism....

  10. Cerebral oxygenation in the beach chair position for shoulder surgery in regional anesthesia: impact on cerebral blood flow and neurobehavioral outcome.

    Science.gov (United States)

    Aguirre, José A; Märzendorfer, Olivia; Brada, Muriel; Saporito, Andrea; Borgeat, Alain; Bühler, Philipp

    2016-12-01

    Beach chair position is considered a potential risk factor for central neurological events particularly if combined with low blood pressure. The aim of this study was to assess the impact of regional anesthesia on cerebral blood flow and neurobehavioral outcome. This is a prospective, assessor-blinded observational study evaluating patients in the beach chair position undergoing shoulder surgery under regional anesthesia. University hospital operating room. Forty patients with American Society of Anesthesiologists classes I-II physical status scheduled for elective shoulder surgery. Cerebral saturation and blood flow of the middle cerebral artery were measured prior to anesthesia and continued after beach chair positioning until discharge to the postanesthesia care unit. The anesthesiologist was blinded for these values. Controlled hypotension with systolic blood pressure≤100mm Hg was maintained during surgery. Neurobehavioral tests and values of regional cerebral saturation, bispectral index, the mean maximal blood flow of the middle cerebral artery, and invasive blood pressure were measured prior to regional anesthesia, and measurements were repeated after placement of the patient on the beach chair position and every 20 minutes thereafter until discharge to postanesthesia care unit. The neurobehavioral tests were repeated the day after surgery. The incidence of cerebral desaturation events was 5%. All patients had a significant blood pressure drop 5 minutes after beach chair positioning, measured at the heart as well as the acoustic meatus levels, when compared with baseline values (Psurgery (Pshoulder surgery had no major impact on cerebral blood flow and cerebral oxygenation. However, some impact on neurobehavioral outcome 24 hours after surgery was observed. Copyright © 2016 Elsevier Inc. All rights reserved.

  11. Measuring glucose cerebral metabolism in the healthy mouse using hyperpolarized C-13 magnetic resonance

    DEFF Research Database (Denmark)

    Mishkovsky, Mor; Anderson, Brian; Karlsson, Magnus

    2017-01-01

    The mammalian brain relies primarily on glucose as a fuel to meet its high metabolic demand. Among the various techniques used to study cerebral metabolism, C-13 magnetic resonance spectroscopy (MRS) allows following the fate of C-13-enriched substrates through metabolic pathways. We herein...... glucose is split into 3-carbon intermediates by aldolase. This unique method allows direct detection of glycolysis in vivo in the healthy brain in a noninvasive manner....... demonstrate that it is possible to measure cerebral glucose metabolism in vivo with sub-second time resolution using hyperpolarized C-13 MRS. In particular, the dynamic C-13-labeling of pyruvate and lactate formed from C-13-glucose was observed in real time. An ad-hoc synthesis to produce [2,3,4,6,6-H-2(5), 3...

  12. Cerebral blood flow response to changes in arterial carbon dioxide tension during hypothermic cardiopulmonary bypass in children

    International Nuclear Information System (INIS)

    Kern, F.H.; Ungerleider, R.M.; Quill, T.J.; Baldwin, B.; White, W.D.; Reves, J.G.; Greeley, W.J.

    1991-01-01

    We examined the relationship of changes in partial pressure of carbon dioxide on cerebral blood flow responsiveness in 20 pediatric patients undergoing hypothermic cardiopulmonary bypass. Cerebral blood flow was measured during steady-state hypothermic cardiopulmonary bypass with the use of xenon 133 clearance methodology at two different arterial carbon dioxide tensions. During these measurements there was no significant change in mean arterial pressure, nasopharyngeal temperature, pump flow rate, or hematocrit value. Cerebral blood flow was found to be significantly greater at higher arterial carbon dioxide tensions (p less than 0.01), so that for every millimeter of mercury rise in arterial carbon dioxide tension there was a 1.2 ml.100 gm-1.min-1 increase in cerebral blood flow. Two factors, deep hypothermia (18 degrees to 22 degrees C) and reduced age (less than 1 year), diminished the effect carbon dioxide had on cerebral blood flow responsiveness but did not eliminate it. We conclude that cerebral blood flow remains responsive to changes in arterial carbon dioxide tension during hypothermic cardiopulmonary bypass in infants and children; that is, increasing arterial carbon dioxide tension will independently increase cerebral blood flow

  13. The effect of ventricular assist devices on cerebral blood flow and blood pressure fractality

    International Nuclear Information System (INIS)

    Bellapart, Judith; Fraser, John F; Chan, Gregory S H; Tzeng, Yu-Chieh; Ainslie, Philip N; Dunster, Kimble R; Barnett, Adrian G; Boots, Rob

    2011-01-01

    Biological signals often exhibit self-similar or fractal scaling characteristics which may reflect intrinsic adaptability to their underlying physiological system. This study analysed fractal dynamics of cerebral blood flow in patients supported with ventricular assist devices (VAD) to ascertain if sustained modifications of blood pressure waveform affect cerebral blood flow fractality. Simultaneous recordings of arterial blood pressure and cerebral blood flow velocity using transcranial Doppler were obtained from five cardiogenic shock patients supported by VAD, five matched control patients and five healthy subjects. Computation of a fractal scaling exponent (α) at the low-frequency time scale by detrended fluctuation analysis showed that cerebral blood flow velocity exhibited 1/f fractal scaling in both patient groups (α = 0.95 ± 0.09 and 0.97 ± 0.12, respectively) as well as in the healthy subjects (α = 0.86 ± 0.07). In contrast, fluctuation in blood pressure was similar to non-fractal white noise in both patient groups (α = 0.53 ± 0.11 and 0.52 ± 0.09, respectively) but exhibited 1/f scaling in the healthy subjects (α = 0.87 ± 0.04, P < 0.05 compared with the patient groups). The preservation of fractality in cerebral blood flow of VAD patients suggests that normal cardiac pulsation and central perfusion pressure changes are not the integral sources of cerebral blood flow fractality and that intrinsic vascular properties such as cerebral autoregulation may be involved. However, there is a clear difference in the fractal scaling properties of arterial blood pressure between the cardiogenic shock patients and the healthy subjects

  14. Cerebral blood flow changes in cluster headache

    International Nuclear Information System (INIS)

    Norris, J.W.; Hachinski, V.C.; Cooper, P.W.

    1976-01-01

    Serial cerebral blood flod studies performed by the intra-carotid 133 Xenon method were fortuitously determined during the course of a cluster headache in a 32 year old man. The initial study was performed about 10 min after the headache began and showed values at the upper limit of normal. Twenty min after the headache started a second procedure showed that the autoregulatory response on hyperventilation was normal. Ergotamine tartrate was given intra-muscularly 23 min after the headache began and there was partial relief. A third cerebral blood flow estimation showed abnormally high values. The probable reasons for this are discussed. (author)

  15. Disparity in regional cerebral blood flow during electrically induced seizure

    DEFF Research Database (Denmark)

    Sestoft, D; Meden, P; Hemmingsen, R

    1993-01-01

    This is a presentation of 2 cases in which the intraictal regional cerebral blood flow distribution was measured with the 99mTc-HMPAO single photon emission computerized tomography technique during an electrically induced seizure. Although the seizure was verified as generalized on electroencepha......This is a presentation of 2 cases in which the intraictal regional cerebral blood flow distribution was measured with the 99mTc-HMPAO single photon emission computerized tomography technique during an electrically induced seizure. Although the seizure was verified as generalized...... electroencephalography-verified generalized seizures....

  16. EFFECT OF ACUPUNCTURE ON CEREBRAL IMAGES IN AUTISM CHILDREN

    Institute of Scientific and Technical Information of China (English)

    袁青; 马瑞玲; 张继武; 靳瑞

    2004-01-01

    Objective: To observe the effect of acupuncture on images in autism children. Methods: A total of 27 cases of autism children were subjected into this study. By using a SPECT, the cerebral images were collected before and after acupuncture treatment and analyzed according to the recommended methods in for assessing the state of blood flow, radioactivity quantity distribution and radioactivity count in bilateral hemispheres. "JIN's three-needling" was employed. The acupuncture treatment was given once every other day, with 4 months being a therapeutic course and an interval of one month between two courses. Results: After acupuncture treatment, of the 22 cases, 20 had remarkable improvement and 2 had improvement in cerebral blood flow, with the total effective rate of improving cerebral blood flow being 90.8%. Before the treatment there were significant differences between the left and right cerebrum (P0.05). After treatment, the radioactivity count in the whole brain decreased significantly in comparison with that of pretreatment (P<0.01). It indicates the improvement of cerebral blood flow and cellular metabolism after the treatment. Conclusion:Acupumcture con significantly improve cerebral blood flow in autism children.

  17. In-vivo measurements of regional acetylcholine esterase activity in degenerative dementia: comparison with blood flow and glucose metabolism.

    Science.gov (United States)

    Herholz, K; Bauer, B; Wienhard, K; Kracht, L; Mielke, R; Lenz, M O; Strotmann, T; Heiss, W D

    2000-01-01

    Memory and attention are cognitive functions that depend heavily on the cholinergic system. Local activity of acetylcholine esterase (AChE) is an indicator of its integrity. Using a recently developed tracer for positron emission tomography (PET), C-11-labeled N-methyl-4-piperidyl-acetate (C11-MP4A), we measured regional AChE activity in 4 non-demented subjects, 4 patients with dementia of Alzheimer type (DAT) and 1 patient with senile dementia of Lewy body type (SDLT), and compared the findings with measurements of blood flow (CBF) and glucose metabolism (CMRGlc). Initial tracer extraction was closely related to CBF. AChE activity was reduced significantly in all brain regions in demented subjects, whereas reduction of CMRGlc and CBF was more limited to temporo-parietal association areas. AChE activity in SDLT was in the lower range of values in DAT. Our results indicate that, compared to non-demented controls, there is a global reduction of cortical AChE activity in dementia. Dementia, cholinergic system, acetylcholine esterase, positron emission tomography, cerebral blood flow, cerebral glucose metabolism.

  18. Cerebral blood flow in patients with hypertensive intracerebral hemorrhage

    International Nuclear Information System (INIS)

    Sugiyama, Hirotaka

    1984-01-01

    Cerebral blood flow (CBF) is usually decreased in patients with hypertensive intracerebral hemorrhage. A total of 81 regional CBF measurements were performed using an Anger-type dynamic gamma camera with the Xe-133 intracarotid injection technique in 23 patients with thalamic hemorrhage, 18 with small putaminal hemorrhage, and 5 with large putaminal hemorrhage. The results were as follows: Bilateral CBF in thalamic hemorrhages was markedly reduced from 1 week to 2 or 3 weeks after onset; it then showed a tendency to increase from 4 weeks to 3 months. In putaminal hemorrhages, however, CBF in the affected hemisphere did not tend to increase despite increased CBF in the contralateral hemisphere. CBF of the affected hemisphere was plotted against the hematoma volume, and the biphasic curve showed an initial steep and subsequent gentle slope in both putaminal and thalamic hemorrhages. The degree of CBF reduction in the affected hemisphere was more evident in thalamic than in putaminal hemorrhages. However, the flow reduction in the contralateral hemisphere was more obvious in thalamic than in putaminal hemorrhages. Factors such as mean arterial blood pressure, partial pressure of arterial carbon dioxide, cerebrospinal fluid pressure, hematocrit and the degree of involvement of the internal capsule, as shown on CT scan were not directly related to CBF reduction. In conclusion, it is unlikely that the mass effect of the hematoma plays an important role in the discrepancy between CBF reduction in putaminal and thalamic hemorrhages. Rather, the discrepancy may result from the impairment of respective anatomical sites in the thalamic and putaminal regions. It is also suggested that ipsilateral as well as contralateral CBF reduction is probably caused by the decreased cortical metabolic demand. This may be based on the disruption of the transneural fiber pathways, which connect both the thalamus and putamen to the cerebral cortex. (author)

  19. Imaging cerebral 2-ketoisocaproate metabolism with hyperpolarized (13)C Magnetic Resonance Spectroscopic Imaging

    DEFF Research Database (Denmark)

    Butt, Sadia Asghar; Søgaard, Lise Vejby-Christensen; Magnusson, Peter O.

    2012-01-01

    The branched chain amino acid transaminase (BCAT) has an important role in nitrogen shuttling and glutamate metabolism in the brain. The purpose of this study was to describe the cerebral distribution and metabolism of hyperpolarized 2-keto[1-(13)C]isocaproate (KIC) in the normal rat using magnet...... & Metabolism advance online publication, 28 March 2012; doi:10.1038/jcbfm.2012.34....

  20. Dynamic emission tomography of regional cerebral blood flow

    International Nuclear Information System (INIS)

    Lassen, N.A.

    1984-01-01

    The author reviews three tomographic methods for measuring the regional cerebral blood flow: single photon transmission tomography; dual photon emission tomography; and single photon emission tomography. The latter technique is discussed in detail. (Auth.)

  1. Whole-brain blood flow and oxygen metabolism in the rat after halothane anesthesia

    Energy Technology Data Exchange (ETDEWEB)

    Gjedde, A; Hindfeldt, B [Cerebrovascular Research Center, Department of Neurology, The New York Hospital-Cornell Medical Center, New York, U.S.A.; Department of Neurology, University Hospital, Lund, Sweden)

    1975-01-01

    A recent modification of the Kety-Schmidt wash-out technique for /sup 133/xenon was used to measure whole-brain flow (CBF) and oxygen consumption (CMRsub(o2)) 1 to 4 hours after termination of halothane anesthesia in 15 Wistar rats. In this 3-hour experimental period, mean CBF and CMRsub(o2) were reduced to 29 and 43 percent of control values, respectively. CBF and CMRsub(o2) determined at the beginning and end of the experimental period were not significantly different from each other. Cerebral venous O/sub 2/ tension was significantly higher than in the control group, supporting recent suggestions of a primary, intrinsic effect of halothane on the homeostatic control of this variable. It is concluded that halothane is not useful for cerebral metabolic studies in the rat.

  2. Clinical implication and prognosis of normal baseline cerebral blood flow with impaired vascular reserve in patients with major cerebral artery occlusive disease

    International Nuclear Information System (INIS)

    Isozaki, Makoto; Arai, Yoshikazu; Kubota, Toshihiko; Kikuta, Ken-ichiro; Kudo, Takashi; Kiyono, Yasushi; Kobayashi, Masato; Okazawa, Hidehiko

    2010-01-01

    To investigate the prognosis of patients with cerebrovascular steno-occlusive disease who have preserved baseline cerebral blood flow (CBF) and reduced cerebral vasoreactivity (CVR), they were followed up after scans of positron emission tomography (PET). Fifty-seven patients with symptomatic unilateral major cerebral arterial occlusion or severe stenosis underwent O-15 gas and water PET scans to measure cerebral blood volume, metabolic rate of oxygen, oxygen extraction fraction (OEF), and CBF at the baseline and after acetazolamide administration. Thirty of them (mean age 60±10 years) had normal ipsilateral CBF, and were followed prospectively at least 30 months from the last ischemic event. They were medically treated for cerebral circulation and underlying diseases during follow-up periods. The primary endpoint was determined as stroke recurrence during the follow-up. Thirty patients were divided into two groups of reduced CVR (N=16, 63±8 years) and normal CVR (N=14, 56±10 years) on the basis of CVR values from healthy volunteers. None of them showed significant laterality in baseline CBF and OEF between the hemispheres although patients with reduced CVR showed a tendency of ipsilateral increases in OEF and CBV. Patients were followed up for 50.5±19.0 and 48.1±12.4 months in the reduced and normal CVR groups, respectively. Although one patient with reduced CVR died of heart disease, there was no incidence of ischemic events during follow-up periods for either group. In the present prospective study, patients with sufficient baseline CBF showed good prognosis and no difference in recurrent stroke risks even though they had poor CVR in the affected hemisphere, indicating that these patients can be treated by medication for cerebral circulation and baseline diseases if they have high risk factors for neurosurgical treatment. (author)

  3. Quantitative cerebral blood flow patterns with the short lived isotope 195m Au

    International Nuclear Information System (INIS)

    Lindner, P.; Nickel, O.

    1984-01-01

    A previously reported theory for quantitative cerebral blood flow measurements using intravenously injected nondiffusible radiotracers has been applied on patients after stroke and on volunteers undergoing a mental stimulation exercise. Quantitative measurements of cerebral blood flow patterns (in ml/min/100g) not only in p.a. but also in lateral views of the brain are possible by using of the short-lived (30 sec) isotope Au 195m. The energy spectrum of the eluate of the generator shows two strong photon peaks, one at 68 keV and a second at 262 keV. The 68 keV peak is suitable for perfusion studies in lateral views of the hemispheres, no 'look through' effect is seen. The 262 keV peak is good for studies in p.a. positions. The studies last less than 1 minute and can be repeated after 3 minutes. Parametric images for quantitative regional cerebral blood flow can be generated. The area of occluded vessels in the case of stroke can be made visible. Quantitative activation patterns of cerebral blood flow during mental stimulation can be generated. After optical stimulation a clear increase of blood flow was seen in the visual cortex. The results prove that not only with freely diffusible (like Xenon) but also with nondiffusible indicators like 195m Au it is possible to measure quantitatively cerebral blood flow patterns. Au 195m is very advantageous for quantitative clinical investigations of cerebrovascular disease. (Author)

  4. Depth discrimination in acousto-optic cerebral blood flow measurement simulation

    Science.gov (United States)

    Tsalach, A.; Schiffer, Z.; Ratner, E.; Breskin, I.; Zeitak, R.; Shechter, R.; Balberg, M.

    2016-03-01

    Monitoring cerebral blood flow (CBF) is crucial, as inadequate perfusion, even for relatively short periods of time, may lead to brain damage or even death. Thus, significant research efforts are directed at developing reliable monitoring tools that will enable continuous, bed side, simple and cost-effective monitoring of CBF. All existing non invasive bed side monitoring methods, which are mostly NIRS based, such as Laser Doppler or DCS, tend to underestimate CBF in adults, due to the indefinite effect of extra-cerebral tissues on the obtained signal. If those are to find place in day to day clinical practice, the contribution of extra-cerebral tissues must be eliminated and data from the depth (brain) should be extracted and discriminated. Recently, a novel technique, based on ultrasound modulation of light was developed for non-invasive, continuous CBF monitoring (termed ultrasound-tagged light (UTL or UT-NIRS)), and shown to correlate with readings of 133Xe SPECT and laser Doppler. We have assembled a comprehensive computerized simulation, modeling this acousto-optic technique in a highly scattering media. Using the combination of light and ultrasound, we show how depth information may be extracted, thus distinguishing between flow patterns taking place at different depths. Our algorithm, based on the analysis of light modulated by ultrasound, is presented and examined in a computerized simulation. Distinct depth discrimination ability is presented, suggesting that using such method one can effectively nullify the extra-cerebral tissues influence on the obtained signals, and specifically extract cerebral flow data.

  5. Cerebral blood flow measurement in cerebrovascular occlusive diseases

    International Nuclear Information System (INIS)

    Yanagihara, T.; Wahner, H.W.

    1984-01-01

    In order to evaluate cerebral blood flow (CBF) patterns among individual patients with increased statistical confidence, CBF measurements were carried out using the 133Xe-inhalation method and external head detectors. F1 values representing gray matter flow from 3 to 6 head detectors were averaged to form 16 different regions for each cerebral hemisphere. Normative values were obtained from 46 healthy volunteers, and data from individual regions were analyzed for absolute blood flow rates (ml/100g/min), for concordance between right and left hemispheres and as percent of mean hemispheric flow. CBF measurements were then carried out among 37 patients with cerebrovascular occlusive diseases, and results were compared with normative values. A high incidence of abnormal flows were detected among symptomatic patients with intracranial arterial stenosis or occlusion and those with extracranial internal carotid artery occlusion. By using the above method for data analysis, it was possible to delineate hypoperfused areas among these patients. Even though the 133Xe-inhalation method has inherent limitations, this is a practical and safe method for measurement of CBF which can provide reliable information useful for management of patients with cerebrovascular occlusive diseases, particularly when the results are presented with statistical confidence

  6. Cerebral glucose metabolism in childhood-onset obsessive-compulsive disorder

    International Nuclear Information System (INIS)

    Swedo, S.E.; Schapiro, M.B.; Grady, C.L.; Cheslow, D.L.; Leonard, H.L.; Kumar, A.; Friedland, R.; Rapoport, S.I.; Rapoport, J.L.

    1989-01-01

    The cerebral metabolic rate for glucose was studied in 18 adults with childhood-onset obsessive-compulsive disorder (OCD) and in age- and sex-matched controls using positron emission tomography and fludeoxyglucose F 18. Both groups were scanned during rest, with reduced auditory and visual stimulation. The group with OCD showed an increased glucose metabolism in the left orbital frontal, right sensorimotor, and bilateral prefrontal and anterior cingulate regions as compared with controls. Ratios of regional activity to mean cortical gray matter metabolism were increased for the right prefrontal and left anterior cingulate regions in the group with OCD as a whole. Correlations between glucose metabolism and clinical assessment measures showed a significant relationship between metabolic activity and both state and trait measurements of OCD and anxiety as well as the response to clomipramine hydrochloride therapy. These results are consistent with the suggestion that OCD may result from a functional disturbance in the frontal-limbic-basal ganglia system

  7. Phenobarbital and neonatal seizures affect cerebral oxygen metabolism: a near-infrared spectroscopy study.

    Science.gov (United States)

    Sokoloff, Max D; Plegue, Melissa A; Chervin, Ronald D; Barks, John D E; Shellhaas, Renée A

    2015-07-01

    Near-infrared spectroscopy (NIRS) measures oxygen metabolism and is increasingly used for monitoring critically ill neonates. The implications of NIRS-recorded data in this population are poorly understood. We evaluated NIRS monitoring for neonates with seizures. In neonates monitored with video-electroencephalography, NIRS-measured cerebral regional oxygen saturation (rSO2) and systemic O2 saturation were recorded every 5 s. Mean rSO2 was extracted for 1-h blocks before, during, and after phenobarbital doses. For each electrographic seizure, mean rSO2 was extracted for a period of three times the duration of the seizure before and after the ictal pattern, as well as during the seizure. Linear mixed models were developed to assess the impact of phenobarbital administration and of seizures on rSO2 and fractional tissue oxygen extraction. For 20 neonates (estimated gestational age: 39.6 ± 1.5 wk), 61 phenobarbital doses and 40 seizures were analyzed. Cerebral rSO2 rose (P = 0.005), and fractional tissue oxygen extraction declined (P = 0.018) with increasing phenobarbital doses. rSO2 declined during seizures, compared with baseline and postictal phases (baseline 81.2 vs. ictal 77.7 vs. postictal 79.4; P = 0.004). Fractional tissue oxygen extraction was highest during seizures (P = 0.002). Cerebral oxygen metabolism decreases after phenobarbital administration and increases during seizures. These small, but clear, changes in cerebral oxygen metabolism merit assessment for potential clinical impact.

  8. Effects of midazolam on cerebral blood flow in human volunteers

    International Nuclear Information System (INIS)

    Forster, A.; Juge, O.; Morel, D.

    1982-01-01

    The effects of intravenously administered midazolam on cerebral blood flow were evaluated in eight healthy volunteers using the 133 Xe inhalation technique. Six minutes after an intravenous dose of 0.15 mg/kg midazolam, the cerebral blood flow decreased significantly (P less than 0.001) from a value of 40.6 +/- 3.3 to a value of 27.0 +/- 5.0 ml . 100 g-1 . min-1. Cerebrovascular resistance (CVR) increased from 2.8 +/- 0.2 to 3.9 to 0.6 mmHg/(ml . 100 g-1 . min-1)(P less than 0.001). Mean arterial blood pressure decreased significantly (P less than 0.05) from 117 +/- 8 to 109 +/- 9 mmHg and arterial carbon dioxide tension increased from 33.9 +/- 2.3 to 38.6 +/- 3.2 mmHg (P less than 0.05). Arterial oxygen tension remained stable throughout the study, 484 +/- 95 mmHg before the administration of midazolam and 453 +/- 76 mmHg after. All the subjects slept after the injection of the drug and had anterograde amnesia of 24.5 +/- 5 min. The decrease in mean arterial blood pressure was probably not important since it remained in the physiologic range for cerebral blood flow autoregulation. The increase in arterial carbon dioxide tension observed after the midazolam injection may have partially counteracted the effect of this new benzodiazepine on cerebral blood flow. Our data suggest that midazolam might be a safe agent to use for the induction of anethesia in neurosurgical patients with intracranial hypertension

  9. Cerebral vasoreactivity to carbon dioxide during cardiopulmonary perfusion at normothermia and hypothermia

    International Nuclear Information System (INIS)

    Johnsson, P.; Messeter, K.; Ryding, E.; Kugelberg, J.; Stahl, E.

    1989-01-01

    With the pH-stat acid-base regulation strategy during hypothermic cardiopulmonary bypass (CPB), carbon dioxide (CO 2 ) is generally administered to maintain the partial pressure of arterial CO 2 at a higher level than with the alpha-stat method. With preserved CO 2 vasoreactivity during CPB, this induction of respiratory acidosis can lead to a much higher cerebral blood flow level than is motivated metabolically. To evaluate CO 2 vasoreactivity, cerebral blood flow was measured using a xenon 133 washout technique before, during, and after CPB at different CO 2 levels in patients who were undergoing coronary artery bypass grafting with perfusion at either hypothermia or normothermia. The overall CO 2 reactivity was 1.2 mL/100 g/min/mm Hg. There was no difference between the groups. The CO 2 reactivity was not affected by temperature or CPB. The induced hemodilution resulted in higher cerebral blood flow levels during CPB, although this was counteracted by the temperature-dependent decrease in the hypothermia group. After CPB, a transient increase in cerebral blood flow was noted in the hypothermia group, the reason for which remains unclear. The study shows that manipulation of the CO 2 level at different temperatures results in similar changes in cerebral blood flow irrespective of the estimated metabolic demand. This finding further elucidates the question of whether alpha-stat or pH-stat is the most physiological way to regulate the acid-base balance during hypothermic CPB

  10. Measurement of regional cerebral blood flow by xenon-enhanced computed tomography

    International Nuclear Information System (INIS)

    Nakagomi, Tadayoshi; Yoshimasu, Norio; Kim, Shi-in; Takano, Koichi; Segawa, Hiromu.

    1982-01-01

    Serial CT scanning was carried out during and after inhalation of 50% non-radioactive xenon in humans. Our results of this research was as follows; 1) In normal subjects, blood flow in gray matter was 82 +- 11 and that in white matter 24 +- 5 ml/100 gm/min. 2) The blood flow of the brain tumors was close to that of gray matter, whereas blood flow of edematous white matter surrounding the tumor was decreased. 3) The blood flow in cerebral infarctions was always decreased. Effect of STA-MCA bypass was also evaluated. 4) In cerebral arterio-venous malformations, the blood flow in the white matter surrounding nidus was not decreased. This method appeared to have several advantages over conventional isotope method and to provide useful clinical and research informations. (author)

  11. A simple technique to measure regional cerebral blood flow during intravascular ballon clamping

    International Nuclear Information System (INIS)

    Furuhata, Shigeru; Kubo, Atsushi; Kawase, Takeshi; Ibata, Yukio; Toya, Shigeo

    1988-01-01

    A case of giant internal carotid ophthalmic aneurysm was presented. In order to clarify whether the patient could tolerate carotid occlusion, a ballon clamping test was performed before surgery. The cerebral blood flow was measured using early imaging by single photon emission computed tomography (SPECT) with N-isopropyl-(iodine-123)-p-iodoamphetamine ( 123 I-IMP). When the ballon clamping test was performed the tracer was injected, and scanning was performed 35 minutes after removing the catheter. This tracer enabled a 'memory of blood flow' during temporary ischemia to determine the character of quick diffusion and slow wash out, that could not be performed by other methods of cerebral blood flow measurement. SPECT with 123 I-IMP can simplify the measurement of cerebral blood flow during the balloon clamping test. (author)

  12. Effects of head-up vs. supine CPR on cerebral oxygenation and cerebral metabolism - a prospective, randomized porcine study.

    Science.gov (United States)

    Putzer, Gabriel; Braun, Patrick; Martini, Judith; Niederstätter, Ines; Abram, Julia; Lindner, Andrea Katharina; Neururer, Sabrina; Mulino, Miriam; Glodny, Bernhard; Helbok, Raimund; Mair, Peter

    2018-05-01

    Recent studies have shown that during cardiopulmonary resuscitation (CPR) head-up position (HUP) as compared to standard supine position (SUP) decreases intracranial pressure (ICP) and increases cerebral perfusion pressure (CPP). The impact of this manoeuvre on brain oxygenation and metabolism is not clear. We therefore investigated HUP as compared to SUP during basic life support (BLS) CPR for their effect on brain oxygenation and metabolism. Twenty pigs were anaesthetized and instrumented. After 8 min of cardiac arrest (CA) pigs were randomized to either HUP or SUP and resuscitated mechanically for 20 min. Mean arterial pressure (MAP), ICP, CPP, cerebral regional oxygen saturation (rSO 2 ) and brain tissue oxygen tension (P bt O 2 ) were measured at baseline, after CA and every 5 min during CPR. Cerebral venous oxygen saturation (S cv O 2 ) was measured at baseline, after CA and after 20 min of CPR. Cerebral microdialysis parameters, e.g. lactate/pyruvate ratio (L/P ratio) were taken at baseline and the end of the experiment. ICP was significantly lower in HUP compared to SUP animals after 5 min (18.0 ± 4.5 vs. 24.1 ± 5.2 mmHg; p = 0.033) and 20 min (12.0 ± 3.4 vs. 17.8 ± 4.3 mmHg; p = 0.023) of CPR. Accordingly, CPP was significantly higher in the HUP group after 5 min (11.2 ± 9.5 vs. 1.0 ± 9.2 mmHg; p = 0.045) and 20 min (3.4 ± 6.4 vs. -3.8 ± 2.8 mmHg; p = 0.023) of CPR. However, no difference was found in rSO 2 , P bt O 2 , S cv O 2 and L/P ratio between groups after 20 min of CPR. In this animal model of BLS CPR, HUP as compared to SUP did not improve cerebral oxygenation or metabolism. Copyright © 2018. Published by Elsevier B.V.

  13. Glucose administration after traumatic brain injury improves cerebral metabolism and reduces secondary neuronal injury.

    Science.gov (United States)

    Moro, Nobuhiro; Ghavim, Sima; Harris, Neil G; Hovda, David A; Sutton, Richard L

    2013-10-16

    Clinical studies have indicated an association between acute hyperglycemia and poor outcomes in patients with traumatic brain injury (TBI), although optimal blood glucose levels needed to maximize outcomes for these patients' remain under investigation. Previous results from experimental animal models suggest that post-TBI hyperglycemia may be harmful, neutral, or beneficial. The current studies determined the effects of single or multiple episodes of acute hyperglycemia on cerebral glucose metabolism and neuronal injury in a rodent model of unilateral controlled cortical impact (CCI) injury. In Experiment 1, a single episode of hyperglycemia (50% glucose at 2 g/kg, i.p.) initiated immediately after CCI was found to significantly attenuate a TBI-induced depression of glucose metabolism in cerebral cortex (4 of 6 regions) and subcortical regions (2 of 7) as well as to significantly reduce the number of dead/dying neurons in cortex and hippocampus at 24 h post-CCI. Experiment 2 examined effects of more prolonged and intermittent hyperglycemia induced by glucose administrations (2 g/kg, i.p.) at 0, 1, 3 and 6h post-CCI. The latter study also found significantly improved cerebral metabolism (in 3 of 6 cortical and 3 of 7 subcortical regions) and significant neuroprotection in cortex and hippocampus 1 day after CCI and glucose administration. These results indicate that acute episodes of post-TBI hyperglycemia can be beneficial and are consistent with other recent studies showing benefits of providing exogenous energy substrates during periods of increased cerebral metabolic demand. © 2013 Elsevier B.V. All rights reserved.

  14. Mechanisms of Acupuncture Therapy for Cerebral Ischemia: an Evidence-Based Review of Clinical and Animal Studies on Cerebral Ischemia.

    Science.gov (United States)

    Zhu, Wen; Ye, Yang; Liu, Yi; Wang, Xue-Rui; Shi, Guang-Xia; Zhang, Shuai; Liu, Cun-Zhi

    2017-12-01

    Ischemic stroke is a major cause of mortality and disability worldwide. As a part of Traditional Chinese Medicine (TCM), acupuncture has been shown to be effective in promoting recovery after stroke. In this article, we review the clinical and experimental studies that demonstrated the mechanisms of acupuncture treatment for cerebral ischemia. Clinical studies indicated that acupuncture activated relevant brain regions, modulated cerebral blood flow and related molecules in stroke patients. Evidence from laboratory indicated that acupuncture regulates cerebral blood flow and metabolism after the interrupt of blood supply. Acupuncture regulates multiple molecules and signaling pathways that lead to excitoxicity, oxidative stress, inflammation, neurons death and survival. Acupuncture also promotes neurogenesis, angiogenesis as well as neuroplasticity after ischemic damage. The evidence provided from clinical and laboratory suggests that acupuncture induces multi-level regulation via complex mechanisms and a single factor may not be enough to explain the beneficial effects against cerebral ischemia.

  15. PET-imaging of cerebral glucose metabolism during sleep and dreaming

    International Nuclear Information System (INIS)

    Heiss, W.D.; Pawlik, G.; Herholz, K.; Wagner, R.; Wienhard, K.

    1985-01-01

    Positron emission tomography (PET) of ( 18 F)-2-fluoro-2-deoxyglucose (FDG) affording non-invasive repeatable quantification of local cerebral glucose utilization was employed to determine possible differential effects of sleep, with and without dreaming, on regional brain metabolism of normal volunteers also measured during wakefulness. (author). 7 refs.; 1 tab

  16. Reduced brain/serum glucose ratios predict cerebral metabolic distress and mortality after severe brain injury.

    Science.gov (United States)

    Kurtz, Pedro; Claassen, Jan; Schmidt, J Michael; Helbok, Raimund; Hanafy, Khalid A; Presciutti, Mary; Lantigua, Hector; Connolly, E Sander; Lee, Kiwon; Badjatia, Neeraj; Mayer, Stephan A

    2013-12-01

    The brain is dependent on glucose to meet its energy demands. We sought to evaluate the potential importance of impaired glucose transport by assessing the relationship between brain/serum glucose ratios, cerebral metabolic distress, and mortality after severe brain injury. We studied 46 consecutive comatose patients with subarachnoid or intracerebral hemorrhage, traumatic brain injury, or cardiac arrest who underwent cerebral microdialysis and intracranial pressure monitoring. Continuous insulin infusion was used to maintain target serum glucose levels of 80-120 mg/dL (4.4-6.7 mmol/L). General linear models of logistic function utilizing generalized estimating equations were used to relate predictors of cerebral metabolic distress (defined as a lactate/pyruvate ratio [LPR] ≥ 40) and mortality. A total of 5,187 neuromonitoring hours over 300 days were analyzed. Mean serum glucose was 133 mg/dL (7.4 mmol/L). The median brain/serum glucose ratio, calculated hourly, was substantially lower (0.12) than the expected normal ratio of 0.40 (brain 2.0 and serum 5.0 mmol/L). In addition to low cerebral perfusion pressure (P = 0.05) and baseline Glasgow Coma Scale score (P brain/serum glucose ratios below the median of 0.12 were independently associated with an increased risk of metabolic distress (adjusted OR = 1.4 [1.2-1.7], P brain/serum glucose ratios were also independently associated with in-hospital mortality (adjusted OR = 6.7 [1.2-38.9], P brain/serum glucose ratios, consistent with impaired glucose transport across the blood brain barrier, are associated with cerebral metabolic distress and increased mortality after severe brain injury.

  17. In vivo analysis of physiological 3D blood flow of cerebral veins

    Energy Technology Data Exchange (ETDEWEB)

    Schuchardt, Florian; Schroeder, Laure; Baeuerle, Jochen; Harloff, Andreas [University Medical Centre, Department of Neurology, Freiburg (Germany); Anastasopoulos, Constantin [University Medical Center, Department of Neuropaediatrics and Muscle Disorders, Freiburg (Germany); University Medical Centre, Department of Neuroradiology, Freiburg (Germany); Markl, Michael [Northwestern University, Department of Radiology, Feinberg School of Medicine and McCormick School of Engineering, Chicago, IL (United States); Hennemuth, Anja; Drexl, Johann [Fraunhofer MEVIS, Bremen (Germany); Valdueza, Jose M. [Neurological Center, Segeberger Kliniken, Bad Segeberg (Germany); Mader, Irina [University Medical Centre, Department of Neuroradiology, Freiburg (Germany)

    2015-08-15

    To visualize and quantify physiological blood flow of intracranial veins in vivo using time-resolved, 3D phase-contrast MRI (4D flow MRI), and to test measurement accuracy. Fifteen healthy volunteers underwent repeated ECG-triggered 4D flow MRI (3 Tesla, 32-channel head coil). Intracranial venous blood flow was analysed using dedicated software allowing for blood flow visualization and quantification in analysis planes at the superior sagittal, straight, and transverse sinuses. MRI was evaluated for intra- and inter-observer agreement and scan-rescan reproducibility. Measurements of the transverse sinuses were compared with transcranial two-dimensional duplex ultrasound. Visualization of 3D blood flow within cerebral sinuses was feasible in 100 % and within at least one deep cerebral vein in 87 % of the volunteers. Blood flow velocity/volume increased along the superior sagittal sinus and was lower in the left compared to the right transverse sinus. Intra- and inter-observer reliability and reproducibility of blood flow velocity (mean difference 0.01/0.02/0.02 m/s) and volume (mean difference 0.0002/-0.0003/0.00003 l/s) were good to excellent. High/low velocities were more pronounced (8 % overestimation/9 % underestimation) in MRI compared to ultrasound. Four-dimensional flow MRI reliably visualizes and quantifies three-dimensional cerebral venous blood flow in vivo and is promising for studies in patients with sinus thrombosis and related diseases. (orig.)

  18. Sex-dependent alterations in resting-state cerebral blood flow, amplitude of low-frequency fluctuations and their coupling relationship in schizophrenia.

    Science.gov (United States)

    Ma, Xiaomei; Wang, Di; Zhou, Yujing; Zhuo, Chuanjun; Qin, Wen; Zhu, Jiajia; Yu, Chunshui

    2016-04-01

    We aimed to investigate sex-dependent alterations in resting-state relative cerebral blood flow, amplitude of low-frequency fluctuations and relative cerebral blood flow-amplitude of low-frequency fluctuations coupling in patients with schizophrenia. Resting-state functional magnetic resonance imaging and three-dimensional pseudo-continuous arterial spin labeling imaging were performed to obtain resting-state amplitude of low-frequency fluctuations and relative cerebral blood flow in 95 schizophrenia patients and 99 healthy controls. Sex differences in relative cerebral blood flow and amplitude of low-frequency fluctuations were compared in both groups. Diagnostic group differences in relative cerebral blood flow, amplitude of low-frequency fluctuations and relative cerebral blood flow-amplitude of low-frequency fluctuations coupling were compared in male and female subjects, respectively. In both healthy controls and schizophrenia patients, the males had higher relative cerebral blood flow in anterior brain regions and lower relative cerebral blood flow in posterior brain regions than did the females. Compared with multiple regions exhibiting sex differences in relative cerebral blood flow, only the left middle frontal gyrus had a significant sex difference in amplitude of low-frequency fluctuations. In the females, schizophrenia patients exhibited increased relative cerebral blood flow and amplitude of low-frequency fluctuations in the basal ganglia, thalamus and hippocampus and reduced relative cerebral blood flow and amplitude of low-frequency fluctuations in the frontal, parietal and occipital regions compared with those of healthy controls. However, there were fewer brain regions with diagnostic group differences in the males than in the females. Brain regions with diagnostic group differences in relative cerebral blood flow and amplitude of low-frequency fluctuations only partially overlapped. Only the female patients exhibited increased relative cerebral

  19. New possibilities for quantitative measurements of regional cerebral blood flow with Au-195 m

    International Nuclear Information System (INIS)

    Lindner, P.; Nickel, O.

    1984-01-01

    A previously reported theory for quantitative cerebral blood flow measurement for nondiffusible radiotracers has been applied on patients after stroke and an volunteers undergoing a mental stimulation exercise. Quantitative measurements of cerebral blood flow patterns not only in p-a. but also in lateral views of the brain are possible by the use of the recently developed generator for the short lived (30 sec) isotope Au-195 m. The energy spectrum of the eluate of the generator shows two strong photon peaks, one at an energy level of 68 KeV and a second at an energy-level of 262 KeV. The low energy peak is suitable for perfusion studies in lateral views of the hemispheres, no ''look through'' effect is seen. The high energy level is good for studies in p-a-positions. The studies last less than 1 minute and can be repeated after 3 minutes. Parametric images for quantitative regional cerebral blood flow can be generated. The area of occluded vessels in the case of stroke can be detected. Quantitative activation patterns of cerebral blood flow during mental stimulation can be generated. The results prove that not only with freely diffusible indicators like Xenon but also with nondiffusible indicators it is possible to measure quantitatively cerebral blood flow patterns. (orig.)

  20. Alterations in cerebral metabolism observed in living rodents using fluorescence lifetime microscopy of intrinsic NADH (Conference Presentation)

    Science.gov (United States)

    Yaseen, Mohammad A.; Sakadžić, Sava; Sutin, Jason; Wu, Weicheng; Fu, Buyin; Boas, David A.

    2017-02-01

    Monitoring cerebral energy metabolism at a cellular level is essential to improve our understanding of healthy brain function and its pathological alterations. In this study, we resolve specific alterations in cerebral metabolism utilizing minimally-invasive 2-Photon fluorescence lifetime imaging (2P-FLIM) measurements of reduced nicotinamide adenine dinucleotide (NADH) fluorescence, collected in vivo from anesthetized rats and mice. Time-resolved lifetime measurements enables distinction of different components contributing to NADH autofluorescence. These components reportedly represent different enzyme-bound formulations of NADH. Our observations from this study confirm the hypothesis that NADH FLIM can identify specific alterations in cerebral metabolism. Using time-correlated single photon counting (TCSPC) equipment and a custom-built multimodal imaging system, 2-photon fluorescence lifetime imaging (FLIM) was performed in cerebral tissue with high spatial and temporal resolution. Multi-exponential fits for NADH fluorescence lifetimes indicate 4 distinct components, or 'species.' We observed distinct variations in the relative proportions of these components before and after pharmacological-induced impairments to several reactions involved in anaerobic glycolysis and aerobic oxidative metabolism. Classification models developed with experimental data correctly predict the metabolic impairments associated with bicuculline-induced focal seizures in separate experiments. Compared to traditional intensity-based NADH measurements, lifetime imaging of NADH is less susceptible to the adverse effects of overlying blood vessels. Evaluating NADH measurements will ultimately lead to a deeper understanding of cerebral energetics and its pathology-related alterations. Such knowledge will likely aid development of therapeutic strategies for neurodegenerative diseases such as Alzheimer's Disease, Parkinson's disease, and stroke.

  1. Dynamic alteration of regional cerebral blood flow during carotid compression and proof of reversibility

    International Nuclear Information System (INIS)

    Asahi, Kouichi; Hori, M; Hamasaki, N; Sato, S; Nakanishi, H; Kuwatsuru, R; Sasai, K; Aoki, S

    2012-01-01

    It is difficult to non-invasively visualize changes in regional cerebral blood flow caused by manual compression of the carotid artery. To visualize dynamic changes in regional cerebral blood flow during and after manual compression of the carotid artery. Two healthy volunteers were recruited. Anatomic features and flow directions in the circle of Willis were evaluated with time-of-flight magnetic resonance angiography (MRA) and two-dimensional phase-contrast (2DPC) MRA, respectively. Regional cerebral blood flow was visualized with territorial arterial spin-labeling magnetic resonance imaging (TASL-MRI). TASL-MRI and 2DPC-MRA were performed in three states: at rest, during manual compression of the right carotid artery, and after decompression. In one volunteer, time-space labeling inversion pulse (Time-SLIP) MRA was performed to confirm collateral flow. During manual carotid compression, in one volunteer, the right thalamus changed to be fed only by the vertebrobasilar system, and the right basal ganglia changed to be fed by the left internal carotid artery. In the other volunteer, the right basal ganglia changed to be fed by the vertebrobasilar system. 2DPC-MRA showed that the flow direction changed in the right A1 segment of the anterior cerebral artery and the right posterior communicating artery. Perfusion patterns and flow directions recovered after decompression. Time-SLIP MRA showed pial vessels and dural collateral circulation when the right carotid artery was manually compressed. Use of TASL-MRI and 2DPC-MRA was successful for non-invasive visualization of the dynamic changes in regional cerebral blood flow during and after manual carotid compression

  2. Neurophysiological Basis of Cerebral Blood Flow Control: An ...

    African Journals Online (AJOL)

    The book describes the current understanding of cerebral blood flow ... metaoolism of the central nervous system. The brain ... in stroke it is a deficiency of the book that the clinical correlates are .... Review of Nutrition and Dietetics. Edited by ...

  3. New possibilities for quantitative measurements of regional cerebral blood flow with gold-195m

    International Nuclear Information System (INIS)

    Lindner, P.; Nickel, O.

    1985-01-01

    A previously reported theory for quantitative cerebral blood flow measurement for nondiffusible radiotracers has been applied to patients after stroke and to volunteers undergoing a mental stimulation exercise. The energy spectrum of gold-195m shows two strong photon peaks, one at an energy level of 68 keV and a second at an energy-level of 262 keV. The low energy peak is suitable for perfusion studies in lateral views of the hemispheres; no look-through effect is seen. The high energy level is good for studies in posterior-anterior positions. Parametric images for quantitative regional cerebral blood flow can be generated. The area of occluded vessels in the case of stroke can be detected. Quantitative activation patterns of cerebral blood flow during mental stimulation can be generated. The results prove that, not only with freely diffusible indicators like xenon but also with nondiffusible indicators, it is possible to measure quantitatively cerebral blood flow patterns

  4. Relationship between cerebral blood flow and later cognitive decline in hypertensive patients with cerebral small vessel disease

    International Nuclear Information System (INIS)

    Kitagawa, Kazuo; Oku, Naohiko; Yagita, Yoshiki; Sakaguchi, Manabu; Sakoda, Saburo; Kimura, Yasuyuku; Hatazawa, Jun

    2009-01-01

    Vascular risk factors are thought to be important for dementia. However, there is little evidence for a prospective association between cerebral blood flow and the risk of cognitive decline. Twenty-seven cognitively intact hypertensive patients aged 55 years and older with lacunar infarction or white matter lesions in magnetic resonance imaging (MRI) underwent positron emission tomography (PET) to measure cerebral blood flow (CBF) and cerebral vascular reactivity (CVR). Cognitive function was assessed at baseline and 3 years later with the mini-mental state examination (MMSE). Patients whose MMSE score fell by more than three points were classified as having cognitive decline. Six patients showed cognitive decline. Baseline CBF in these patients was significantly lower than that of the 21 patients without cognitive decline (31.2±2.4 vs. 42.6±5.9 ml per 100 gmin -1 , respectively; P<0.001). A moderate linear association was found between CBF and change in MMSE score over a 3-year period (r=0.59, P=0.001), not between CBF and baseline MMSE score. In contrast, no association between CVR and later cognitive decline was found. This study suggests that cerebral hypoperfusion is associated with later cognitive decline. (author)

  5. Chronic hydrocephalus-induced changes in cerebral blood flow: mediation through cardiac effects.

    Science.gov (United States)

    Dombrowski, Stephen M; Schenk, Soren; Leichliter, Anna; Leibson, Zack; Fukamachi, Kiyotaka; Luciano, Mark G

    2006-10-01

    Decreased cerebral blood flow (CBF) in hydrocephalus is believed to be related to increased intracranial pressure (ICP), vascular compression as the result of enlarged ventricles, or impaired metabolic activity. Little attention has been given to the relationship between cardiac function and systemic blood flow in chronic hydrocephalus (CH). Using an experimental model of chronic obstructive hydrocephalus developed in our laboratory, we investigated the relationship between the duration and severity of hydrocephalus and cardiac output (CO), CBF, myocardial tissue perfusion (MTP), and peripheral blood flow (PBF). Blood flow measures were obtained using the microsphere injection method under controlled hemodynamic conditions in experimental CH (n=23) and surgical control (n=8) canines at baseline and at 2, 4, 8, 12, and 16 weeks. Cardiac output measures were made using the Swan-Ganz thermodilution method. Intracranial compliance (ICC) via cerebrospinal fluid (CSF) bolus removal and infusion, and oxygen delivery in CSF and prefrontal cortex (PFC) were also investigated. We observed an initial surgical effect relating to 30% CO reduction and approximately 50% decrease in CBF, MTP, and PBF in both groups 2 weeks postoperatively, which recovered in control animals but continued to decline further in CH animals at 16 weeks. Cerebral blood flow, which was positively correlated with CO (P=0.028), showed no significant relationship with either CSF volume or pressure. Decreased CBF correlated with oxygen deprivation in PFC (P=0.006). Cardiac output was inversely related with ventriculomegaly (P=0.019), but did not correlate with ICP. Decreased CO corresponded to increased ICC, as measured by CSF infusion (P=0.04). Our results suggest that CH may have more of an influence on CO and CBF in the chronic stage than in the early condition, which was dominated by surgical effect. The cause of this late deterioration of cardiac function in hydrocephalus is uncertain, but may reflect

  6. Regional cerebral blood flow in status epileptics measured by single photon emission computed tomography (SPECT)

    International Nuclear Information System (INIS)

    Ichiseki, Hajime; Terashi, Akiro; Hamamoto, Makoto; Miyazaki, Tokuzo.

    1995-01-01

    We have performed single photon emission computed tomography (SPECT) with 99m Tc-hexamethylpropylene amineoxime (HM-PAO) to evaluate regional cerebral blood flow (rCBF) in status epileptics (SE) caused by a cerebral vascular accident. In addition, we have discussed the neurophysiology of SE based on the SPECT findings. A total of sixteen patients (5 males and 11 females, average age; 78.2 years old) with SE who were suffering from prolonged consciousness disturbance were investigated. When SPECT was performed in the ictal state, there was a remarkable increase in radio isotope (RI) uptake at the focus which correlated well with EEG findings. However, in other cortical regions, basal ganglia and thalamus, there was a relatively demonstrated decrease in RI uptake compared with that of the focus. Additionally in the interictal state, we found a decrease in RI uptake in the epileptic foci and normal recovery of the RI uptake level in other cerebral regions. We speculate that these characteristic patterns of cerebral blood flow distribution shown by SPECT scans in the ictal state reflect the state of consciousness disturbance due to SE. In general, in the elderly, it is difficult to make a differential diagnosis between prolonged consciousness disturbance due to nonconvulsive SE and other diseases such as cardiovascular diseases, dehydration, metabolic disorder, etc. Nevertheless, nonconvulsive SE causes diffuse cell loss and irreversible brain damage. Therefore the elderly who have suffered from prolonged consciousness disturbance due to SE need an exact diagnosis and immediate medical treatment. When we diagnose a nonconvulsive SE, the characteristic findings of SPECT scans in the ictal state are very clear and useful. In conclusion, SPECT is a very simple and non-invasive method that demonstrates abnormalities of brain function exactly. Therefore, we should perform not only EEC but also SPECT scans when making a diagnosis of SE. (author)

  7. Regional cerebral blood flow in status epileptics measured by single photon emission computed tomography (SPECT)

    Energy Technology Data Exchange (ETDEWEB)

    Ichiseki, Hajime; Terashi, Akiro [Nippon Medical School, Tokyo (Japan); Hamamoto, Makoto; Miyazaki, Tokuzo

    1995-12-01

    We have performed single photon emission computed tomography (SPECT) with {sup 99m}Tc-hexamethylpropylene amineoxime (HM-PAO) to evaluate regional cerebral blood flow (rCBF) in status epileptics (SE) caused by a cerebral vascular accident. In addition, we have discussed the neurophysiology of SE based on the SPECT findings. A total of sixteen patients (5 males and 11 females, average age; 78.2 years old) with SE who were suffering from prolonged consciousness disturbance were investigated. When SPECT was performed in the ictal state, there was a remarkable increase in radio isotope (RI) uptake at the focus which correlated well with EEG findings. However, in other cortical regions, basal ganglia and thalamus, there was a relatively demonstrated decrease in RI uptake compared with that of the focus. Additionally in the interictal state, we found a decrease in RI uptake in the epileptic foci and normal recovery of the RI uptake level in other cerebral regions. We speculate that these characteristic patterns of cerebral blood flow distribution shown by SPECT scans in the ictal state reflect the state of consciousness disturbance due to SE. In general, in the elderly, it is difficult to make a differential diagnosis between prolonged consciousness disturbance due to nonconvulsive SE and other diseases such as cardiovascular diseases, dehydration, metabolic disorder, etc. Nevertheless, nonconvulsive SE causes diffuse cell loss and irreversible brain damage. Therefore the elderly who have suffered from prolonged consciousness disturbance due to SE need an exact diagnosis and immediate medical treatment. When we diagnose a nonconvulsive SE, the characteristic findings of SPECT scans in the ictal state are very clear and useful. In conclusion, SPECT is a very simple and non-invasive method that demonstrates abnormalities of brain function exactly. Therefore, we should perform not only EEC but also SPECT scans when making a diagnosis of SE. (author).

  8. Cerebral blood flow mapping in children with sickle cell disease

    International Nuclear Information System (INIS)

    Numaguchi, Y.; Humbert, J.R.; Robinson, A.E.; Lindstrom, W.W.; Gruenauer, L.M.

    1988-01-01

    A cerebral blood flow mapping system was applied to the evaluation of cerebral blood flow (CBF) in 21 patients with sickle cell cerebrovascular disease, by means of a Picker xenon computed tomographic (CT) scanner. Results indicate that (1) xenon CT is a safe and reliable procedure in children with cerebrovascular diseases; (2) CBF in the gray matter of children seems to be higher than in previously reported data obtained with use of isotopes; and (3) regional CBF can be altered significantly by changing the size of the region of interest (ROI). The term regional CBF probably has to be carefully defined in xenon CT flow mapping. Correlation with anatomy by means of CT or magnetic resonance imaging and comparison with the ROI of the contralateral side and/or adjacent sections is important

  9. Effects of Metformin on the Cerebral Metabolic Changes in Type 2 Diabetic Patients

    Directory of Open Access Journals (Sweden)

    Yung-Cheng Huang

    2014-01-01

    Full Text Available Metformin, a widely used antidiabetic drug, has numerous effects on human metabolism. Based on emerging cellular, animal, and epidemiological studies, we hypothesized that metformin leads to cerebral metabolic changes in diabetic patients. To explore metabolism-influenced foci of brain, we used 2-deoxy-2-[18F]fluoro-D-glucose (FDG positron emission tomography for type 2 diabetic patients taking metformin (MET, n=18, withdrawing from metformin (wdMET, n=13, and not taking metformin (noMET, n=9. Compared with the noMET group, statistical parametric mapping showed that the MET group had clusters with significantly higher metabolism in right temporal, right frontal, and left occipital lobe white matter and lower metabolism in the left parahippocampal gyrus, left fusiform gyrus, and ventromedial prefrontal cortex. In volume of interest (VOI- based group comparisons, the normalized FDG uptake values of both hypermetabolic and hypometabolic clusters were significantly different between groups. The VOI-based correlation analysis across the MET and wdMET groups showed a significant negative correlation between normalized FDG uptake values of hypermetabolic clusters and metformin withdrawal durations and a positive but nonsignificant correlation in the turn of hypometabolic clusters. Conclusively, metformin affects cerebral metabolism in some white matter and semantic memory related sites in patients with type 2 diabetes.

  10. Cerebral blood flow in acute mountain sickness

    DEFF Research Database (Denmark)

    Jensen, J B; Wright, Anne; Lassen, N A

    1990-01-01

    Changes in cerebral blood flow (CBF) were measured using the radioactive xenon technique and were related to the development of acute mountain sickness (AMS). In 12 subjects, ascending from 150 to 3,475 m, CBF was 24% increased at 24 h [45.1 to 55.9 initial slope index (ISI) units] and 4% increased...

  11. Study of cerebral metabolism of glucose in normal human brain correlated with age

    International Nuclear Information System (INIS)

    Si, M.

    2007-01-01

    Full text: The objective was to determine whether cerebral metabolism in various regions of the brain differs with advancing age by using 18F-FDG PET instrument and SPM software. Materials and Methods We reviewed clinical information of 295 healthy normal samples who were examined by a whole body GE Discovery LS PET-CT instrument in our center from Aug. 2004 to Dec. 2005.They (with the age ranging from 21 to 88; mean age+/-SD: 49.77+/-13.51) were selected with: (i)absence of clear focal brain lesions (epilepsy.cerebrovascular diseases etc);(ii) absence of metabolic diseases, such as hyperthyroidism, hypothyroidism and diabetes;(iii) absence of psychiatric disorders and abuse of drugs and alcohol. They were sub grouped into six groups with the interval of 10 years old starting from 21, and the gender, educational background and serum glucose were matched. All subgroups were compared to the control group of 31-40 years old (84 samples; mean age+/-SD: 37.15+/-2.63). All samples were injected with 18F-FDG (5.55MBq/kg), 45-60 minutes later, their brains were scanned for 10min. Pixel-by-pixel t-statistic analysis was applied to all brain images using the Statistical parametric mapping (SPM2) .The hypometabolic areas (p < 0. 01 or p<0.001, uncorrected) were identified in the Stereotaxic coordinate human brain atlas and three-dimensional localized by MNI Space utility (MSU) software. Results:Relative hypometabolic brain areas detected are mainly in the cortical structures such as bilateral prefrontal cortex, superior temporal gyrus(BA22), parietal cortex (inferior parietal lobule and precuneus(BA40, insula(BA13)), parahippocampal gyrus and amygdala (p<0.01).It is especially apparent in the prefrontal cortex (BA9)and sensory-motor cortex(BA5, 7) (p<0.001), while basal ganglia and cerebellum remained metabolically unchanged with advancing age. Conclusions Regional cerebral metabolism of glucose shows a descent tendency with aging, especially in the prefrontal cortex (BA9)and

  12. Cluster headache: transcranial Doppler ultrasound and regional cerebral blood flow studies

    International Nuclear Information System (INIS)

    Dahl, A.; Russell, D.; Nyberg-Hansen, R.; Rootwelt, K.

    1990-01-01

    Transcranial Doppler and rCBF examinations were carried out in 25 cluster headache patients. Spontaneous glyceryl trinitrate (nitroglycerin) provoked attacks were accompanied by a bilateral decrease in middle cerebral artery blood flow velocities. This decrease was more pronounced on the symptomatic side, but the difference did not reach statistical significance. Mean hemispheric blood flow and rCBF were within normal limits during provoked attacks and similar to those found when patients were attack-free. During cluster periods middle cerebral artery velocities were significantly higher on the symptomatic side. Glyceryl trinitrate caused a bilateral middle cerebral artery velocity decrease which was significantly greater on the symptomatic side. Attacks provoked by glyceryl trinitrate appeared to begin when the vasodilatory effect of this substance was received. 17 refs., 2 figs., 5 tabs

  13. Cerebral blood flow response to flavanol-rich cocoa in healthy elderly humans

    Directory of Open Access Journals (Sweden)

    Farzaneh A Sorond

    2008-04-01

    Full Text Available Farzaneh A Sorond1,2, Lewis A Lipsitz2,4, Norman K Hollenberg3,5, Naomi DL Fisher31Department of Neurology, Stroke Division; 2Institute for Aging Research, Hebrew SeniorLife, Boston, MA; 3Department of Medicine, Endocrine-Hypertension Division; 4Department of Medicine, Gerontology, Beth Israel Deaconess Medical Center, Boston, MA, USA; 5Department of Radiology, Brigham and Women’s Hospital, Boston, MABackground and Purpose: Cerebral ischemia is a common, morbid condition accompanied by cognitive decline. Recent reports on the vascular health benefits of flavanol-containing foods signify a promising approach to the treatment of cerebral ischemia. Our study was designed to investigate the effects of flavanol-rich cocoa (FRC consumption on cerebral blood flow in older healthy volunteers.Methods: We used transcranial Doppler (TCD ultrasound to measure mean blood flow velocity (MFV in the middle cerebral artery (MCA in thirty-four healthy elderly volunteers (72 ± 6 years in response to the regular intake of FRC or flavanol-poor cocoa (FPC.Results: In response to two weeks of FRC intake, MFV increased by 8% ± 4% at one week (p = 0.01 and 10% ± 4% (p = 0.04 at two weeks. In response to one week of cocoa, significantly more subjects in the FRC as compared with the FPC group had an increase in their MFV (p < 0.05.Conclusions: In summary, we show that dietary intake of FRC is associated with a significant increase in cerebral blood flow velocity in the MCA as measured by TCD. Our data suggest a promising role for regular cocoa flavanol’s consumption in the treatment of cerebrovascular ischemic syndromes, including dementias and stroke.Keywords: cerebral blood flow, flavanol, cocoa, transcranial Doppler ultrasound

  14. Regional cerebral blood flow in focal cortical epilepsy

    DEFF Research Database (Denmark)

    Hougaard, Kristina Dupont; Oikawa, T; Sveinsdottir, E

    1976-01-01

    Regional cerebral blood flow (rCBF) was studied in ten patients with focal cortical epilepsy. The blood flow was measured by the intra-arterial injection of xenon 133 (133Xe), and the isotope clearance was recorded by a multidetector scintillation camera with 254 detectors. Three patients were....... This finding accords with earlier studies. All nine patients studied in the interictal phase showed, either spontaneously or during activation by intermittent light, focal flow increases in areas presumed to comprise the epileptic focus. These interictal hyperemic foci probably reflect subictal neuronal...

  15. Middle cerebral artery flow velocity and blood flow during exercise and muscle ischemia in humans

    DEFF Research Database (Denmark)

    Jørgensen, L G; Perko, M; Hanel, B

    1992-01-01

    Changes in middle cerebral artery flow velocity (Vmean), measured by transcranial Doppler ultrasound, were used to determine whether increases in mean arterial pressure (MAP) or brain activation enhance cerebral perfusion during exercise. We also evaluated the role of "central command......, they support the hypothesis that cerebral perfusion during exercise reflects an increase in brain activation that is independent of MAP, central command, and muscle metaboreceptors but is likely to depend on influence of mechanoreceptors.......," mechanoreceptors, and/or muscle "metaboreceptors" on cerebral perfusion. Ten healthy subjects performed two levels of dynamic exercise corresponding to a heart rate of 110 (range 89-134) and 148 (129-170) beats/min, respectively, and exhaustive one-legged static knee extension. Measurements were continued during 2...

  16. Program for PET image alignment: Effects on calculated differences in cerebral metabolic rates for glucose

    International Nuclear Information System (INIS)

    Phillips, R.L.; London, E.D.; Links, J.M.; Cascella, N.G.

    1990-01-01

    A program was developed to align positron emission tomography images from multiple studies on the same subject. The program allowed alignment of two images with a fineness of one-tenth the width of a pixel. The indications and effects of misalignment were assessed in eight subjects from a placebo-controlled double-blind crossover study on the effects of cocaine on regional cerebral metabolic rates for glucose. Visual examination of a difference image provided a sensitive and accurate tool for assessing image alignment. Image alignment within 2.8 mm was essential to reduce variability of measured cerebral metabolic rates for glucose. Misalignment by this amount introduced errors on the order of 20% in the computed metabolic rate for glucose. These errors propagate to the difference between metabolic rates for a subject measured in basal versus perturbed states

  17. Cerebral blood flow changes in response to elevated intracranial pressure in rabbits and bluefish: a comparative study.

    Science.gov (United States)

    Beiner, J M; Olgivy, C S; DuBois, A B

    1997-03-01

    In mammals, the cerebrovascular response to increases in intracranial pressure may take the form of the Cushing response, which includes increased mean systemic arterial pressure, bradycardia and diminished respirations. The mechanism, effect and value of these responses are debated. Using laser-Doppler flowmetry to measure cerebral blood flow, we analyzed the cardiovascular responses to intracranial pressure raised by epidural infusion of mock cerebrospinal fluid in the bluefish and in the rabbit, and compare the results. A decline in cerebral blood flow preceding a rise in mean systemic arterial pressure was observed in both species. Unlike bluefish, rabbits exhibit a threshold of intracranial pressure below which cerebral blood flow was maintained and no cardiovascular changes were observed. The difference in response between the two species was due to the presence of an active autoregulatory system in the cerebral tissue of rabbits and its absence in bluefish. For both species studied, the stimulus for the Cushing response seems to be a decrement in cerebral blood flow. The resulting increase in the mean systemic arterial pressure restores cerebral blood flow to levels approaching controls.

  18. Subcortical aphasia and cerebral blood flow using SPECT

    International Nuclear Information System (INIS)

    Celsis, P.; Puel, M.; Demonet, J.P.; Bonafe, A.; Cardebat, D.; Viallard, G.; Pujol, T.; Marc-Vergnes, J.P.; Rascol, A.

    1985-01-01

    Possible cerebral blood flow (CBF) alteration in subcortical aphasia was investigated by single-photon emission tomography (SPECT). The results confirm the capsulo-striatal lesions and also point to the high rate of ipsilateral thalamic and cortical dysfunction. (author). 8 refs.; 1 fig.; 1 tab

  19. A New Technology for Detecting Cerebral Blood Flow

    DEFF Research Database (Denmark)

    Schytz, Henrik W; Guo, Song; Jensen, Lars T

    2012-01-01

    There is a need for real-time non-invasive, continuous monitoring of cerebral blood flow (CBF) during surgery, in intensive care units and clinical research. We investigated a new non-invasive hybrid technology employing ultrasound tagged near infrared spectroscopy (UT-NIRS) that may estimate...

  20. Regional cerebral blood flow and oxygen metabolism in patients with ischemic stroke studied with high resolution pet and the O-15 labelled gas steady-state method

    International Nuclear Information System (INIS)

    Uemura, K.; Shishido, F.; Inugami, A.; Yamaguchi, T.; Ogawa, T.; Murakami, M.; Kanno, I.; Tagawa, K.; Yasui, N.

    1986-01-01

    Although regional cerebral blood flow (rCBF) studies have considerably increased pathophysiological knowledge in ischemic cerebrovascular disease, sometimes the results of such studies do not correlate with neurological abnormalities observed in the subjects being examined. Because regional neuronal activities always couple to the regional energy metabolism of brain tissue, simultaneous observation of rCBF and regional energy metabolism, such as regional oxygen consumption (rCMRO/sub 2/) and regional glucose consumption (rCMRG1), will provide greater understanding of the pathophysiology of the disease than rCBF study alone. Positron emission tomography (PET) using the 0-15 labelled gas steady-state method offers simultaneous measurement of rCBF and rCMRO/sub 2/ in vivo, and demonstrates imbalance between rCBF and rCMRO/sub 2/ in an ischemic lesion in a human brain. However, clinical PET studies in ischemic cerebrovascular disease reported previously, have been carried out using low resolution (more than 15 mm in the full width at half maximum; FWHM) PET. This report presents preliminary results using a high resolution tomograph; Headtome III and 0-15 labelled gas steady state method to investigate ischemic cerebrovascular disease

  1. Intraventricular hemorrhage in the preterm neonate: timing and cerebral blood flow changes

    International Nuclear Information System (INIS)

    Ment, L.R.; Duncan, C.C.; Ehrenkranz, R.A.; Lange, R.C.; Taylor, K.J.; Kleinman, C.S.; Scott, D.T.; Sivo, J.; Gettner, P.

    1984-01-01

    Serial cranial ultrasound studies, 133xenon inhalation cerebral blood flow determinations, and risk factor analyses were performed in 31 preterm neonates. Contrast echocardiographic studies were additionally performed in 16 of these 31 infants. Sixty-one percent were found to have germinal matrix or intraventricular hemorrhage. Seventy-four percent of all hemorrhages were detected by the thirtieth postnatal hour. The patients were divided into three groups: early GMH/IVH by the sixth postnatal hour (eight infants) interval GMH/IVH from 6 hours through 5 days (10), and no GMH/IVH (12). Cerebral blood flow values at 6 postnatal hours were significantly lower for the early GMH/IVH group than for the no GMH/IVH group (P less than 0.01). Progression of GMH/IVH was observed only in those infants with early hemorrhage, and these infants had a significantly higher incidence of neonatal mortality. Ventriculomegaly as determined by ultrasound studies was noted equally in infants with and without GMH/IVH (50%) and was not found to correlate with low cerebral blood flow. The patients with early hemorrhage were distinguishable by their need for more vigorous resuscitation at the time of birth and significantly higher ventilator settings during the first 36 postnatal hours, during which time they also had higher values of PCO2. An equal incidence of patent ductus arteriosus was found across all of the groups. We propose that early GMH/IVH may be related to perinatal events and that the significant decrease in cerebral blood flow found in infants with early GMH/IVH is secondary to the presence of the hemorrhage itself. Progression of early GMH/IVH and new interval GMH/IVH may be related to later neonatal events known to alter cerebral blood flow

  2. Regional cerebral glucose metabolism in patients with alcoholic Korsakoff's syndrome

    Energy Technology Data Exchange (ETDEWEB)

    Kessler, R.M.; Parker, E.S.; Clark, C.M.; Martin, P.R.; George, D.T.; Weingartner, H.; Sokoloff, L.; Ebert, M.H.; Mishkin, M.

    1985-05-01

    Seven alcoholic male subjects diagnosed as having Korsakoff's syndrome and eight age-matched male normal volunteers were studied with /sup 18/F 2-fluoro-2-deoxy-D-glucose (2/sup 18/FDG). All subjects were examined at rest with eyes covered in a quiet, darkened room. Serial plasma samples were obtained following injection of 4 to 5 mCi of 2/sup 18/FDG. Tomographic slices spaced at 10mm axial increments were obtained (in-plane resolution = 1.75 cm, axial resolution = 1.78 cm). Four planes were selected from each subject, and a total of 46 regions of interest were sampled and glucose metabolic rates for each region calculated. The mean glucose metalbolic rate for the 46 regions in the Korsakoff subjects was significantly lower than that in the normal controls (5.17 +- .43 versus 6.6 +- 1.31). A Q-component analysis, which examined each subject's regional rates relative to his mean rate, revealed two distinct patterns in the Korsakoff group. Glucose metabolism was significantly reduced in 37 of the 46 regions sampled. Reduced cerebral glucose metabolism in a nondemented group of subjects has not previously been reported. The reduction in cortical metabolism may be the result of damage to sub-cortical projecting systems. The differing patterns of cerebral metabolism in Korsakoff's syndrome suggests subgroups with differing neuropathology. Regions implicated in memory function, medial temporal, thalamic and medial prefrontal were among the regions reduced in metabolism.

  3. Middle cerebral artery flow velocity waveforms in fetal hypoxaemia.

    Science.gov (United States)

    Vyas, S; Nicolaides, K H; Bower, S; Campbell, S

    1990-09-01

    In 81 small-for-gestational age fetuses (SGA) colour flow imaging was used to identify the fetal middle cerebral artery for subsequent pulsed Doppler studies. Impedence to flow (pulsatility index; PI) was significantly lower, and mean blood velocity was significantly higher, than the respective reference ranges with gestation. Fetal blood sampling by cordocentesis was performed in all SGA fetuses and a significant quadratic relation was found between fetal hypoxaemia and the degree of reduction in the PI of FVWs from the fetal middle cerebral artery. Thus, maximum reduction in PI is reached when the fetal PO2 is 2-4 SD below the normal mean for gestation. When the oxygen deficit is greater there is a tendency for the PI to rise, and this presumably reflects the development of brain oedema.

  4. Quantitative measurement of total cerebral blood flow using 2D phase-contrast MRI and doppler ultrasound

    Energy Technology Data Exchange (ETDEWEB)

    Seo, Keum Soo; Choi, Sun Seob; Lee, Young Il [Dong-A Univ., College of Medicine, Busan (Korea, Republic of)

    2001-12-01

    To compare of quantitative measurement of the total cerebral blood flow using two-dimensional phase-contrast MR imaging and Doppler ultrasound. In 16 volunteers (mean age, 26 years; mean body weight, 66 kg) without abnormal medical histories, two-dimensional phase-contrast MR imaging was performed at the level of the C2-3 inter vertebral disc for flow measurement of the internal carotid arteries and the vertebral arteries. Volume flow measurements using Doppler ultrasound were also performed at the internal carotid arteries 2cm above the carotid bifurcation, and at the vertebral arteries at the level of the upper pole of the thyroid gland. Flows in the four vessels measured by the two methods were compared using Wilcoxon's correlation analysis and the median score. Total cerebral blood flows were calculated by summing these four vessel flows, and mean values for the 16 volunteers were calculated. Cerebral blood flows measured by 2-D phase-contrast MR imaging and Doppler ultrasounds were 233 and 239 ml/min in the right internal carotid artery, 250 and 248 ml/min in the left internal carotid artery, 62 and 56 ml/min in the right vertebral artery, and 83 and 68 ml/min in the left vertebral artery. Correlation coefficients of the blood flows determined by the two methods were 0.48, 0.54, 0.49, and 0.62 in each vessel, while total cerebral blood flows were 628{+-}68 (range, 517 to 779) ml/min and 612{+-}79 (range, 482 to 804)ml/min, respectively. Total cerebral blood flow was easily measured using 2-D phase-contrast MR imaging and Doppler ultrasound, and the two noninvasive methods can therefore be used clinically for the measurement of total cerebral blood flow.

  5. Gender differences in regional cerebral blood flow

    International Nuclear Information System (INIS)

    Gur, R.E.; Gur, R.C.

    1990-01-01

    Gender differences have been noted in neurobehavioral studies. The 133xenon inhalation method for measuring regional cerebral blood flow (rCBF) can contribute to the understanding of the neural basis of gender differences in brain function. Few studies have examined gender differences in rCBF. In studies of normal subjects, women have higher rates of CBF than men, and this is related to age. Usually by the sixth decade men and women have similar flow rates. Fewer studies on rCBF in schizophrenia have examined sex differences. The pattern of higher flows for females maintains, but its correlates with gender differences in clinical as well as other parameters of brain function remain to be examined

  6. Dynamic Cerebral Autoregulation Changes during Sub-Maximal Handgrip Maneuver

    Science.gov (United States)

    Nogueira, Ricardo C.; Bor-Seng-Shu, Edson; Santos, Marcelo R.; Negrão, Carlos E.; Teixeira, Manoel J.; Panerai, Ronney B.

    2013-01-01

    Purpose We investigated the effect of handgrip (HG) maneuver on time-varying estimates of dynamic cerebral autoregulation (CA) using the autoregressive moving average technique. Methods Twelve healthy subjects were recruited to perform HG maneuver during 3 minutes with 30% of maximum contraction force. Cerebral blood flow velocity, end-tidal CO2 pressure (PETCO2), and noninvasive arterial blood pressure (ABP) were continuously recorded during baseline, HG and recovery. Critical closing pressure (CrCP), resistance area-product (RAP), and time-varying autoregulation index (ARI) were obtained. Results PETCO2 did not show significant changes during HG maneuver. Whilst ABP increased continuously during the maneuver, to 27% above its baseline value, CBFV raised to a plateau approximately 15% above baseline. This was sustained by a parallel increase in RAP, suggestive of myogenic vasoconstriction, and a reduction in CrCP that could be associated with metabolic vasodilation. The time-varying ARI index dropped at the beginning and end of the maneuver (p<0.005), which could be related to corresponding alert reactions or to different time constants of the myogenic, metabolic and/or neurogenic mechanisms. Conclusion Changes in dynamic CA during HG suggest a complex interplay of regulatory mechanisms during static exercise that should be considered when assessing the determinants of cerebral blood flow and metabolism. PMID:23967113

  7. Dynamic cerebral autoregulation changes during sub-maximal handgrip maneuver.

    Directory of Open Access Journals (Sweden)

    Ricardo C Nogueira

    Full Text Available PURPOSE: We investigated the effect of handgrip (HG maneuver on time-varying estimates of dynamic cerebral autoregulation (CA using the autoregressive moving average technique. METHODS: Twelve healthy subjects were recruited to perform HG maneuver during 3 minutes with 30% of maximum contraction force. Cerebral blood flow velocity, end-tidal CO₂ pressure (PETCO₂, and noninvasive arterial blood pressure (ABP were continuously recorded during baseline, HG and recovery. Critical closing pressure (CrCP, resistance area-product (RAP, and time-varying autoregulation index (ARI were obtained. RESULTS: PETCO₂ did not show significant changes during HG maneuver. Whilst ABP increased continuously during the maneuver, to 27% above its baseline value, CBFV raised to a plateau approximately 15% above baseline. This was sustained by a parallel increase in RAP, suggestive of myogenic vasoconstriction, and a reduction in CrCP that could be associated with metabolic vasodilation. The time-varying ARI index dropped at the beginning and end of the maneuver (p<0.005, which could be related to corresponding alert reactions or to different time constants of the myogenic, metabolic and/or neurogenic mechanisms. CONCLUSION: Changes in dynamic CA during HG suggest a complex interplay of regulatory mechanisms during static exercise that should be considered when assessing the determinants of cerebral blood flow and metabolism.

  8. Multichannel optical brain imaging to separate cerebral vascular, tissue metabolic, and neuronal effects of cocaine

    Science.gov (United States)

    Ren, Hugang; Luo, Zhongchi; Yuan, Zhijia; Pan, Yingtian; Du, Congwu

    2012-02-01

    Characterization of cerebral hemodynamic and oxygenation metabolic changes, as well neuronal function is of great importance to study of brain functions and the relevant brain disorders such as drug addiction. Compared with other neuroimaging modalities, optical imaging techniques have the potential for high spatiotemporal resolution and dissection of the changes in cerebral blood flow (CBF), blood volume (CBV), and hemoglobing oxygenation and intracellular Ca ([Ca2+]i), which serves as markers of vascular function, tissue metabolism and neuronal activity, respectively. Recently, we developed a multiwavelength imaging system and integrated it into a surgical microscope. Three LEDs of λ1=530nm, λ2=570nm and λ3=630nm were used for exciting [Ca2+]i fluorescence labeled by Rhod2 (AM) and sensitizing total hemoglobin (i.e., CBV), and deoxygenated-hemoglobin, whereas one LD of λ1=830nm was used for laser speckle imaging to form a CBF mapping of the brain. These light sources were time-sharing for illumination on the brain and synchronized with the exposure of CCD camera for multichannel images of the brain. Our animal studies indicated that this optical approach enabled simultaneous mapping of cocaine-induced changes in CBF, CBV and oxygenated- and deoxygenated hemoglobin as well as [Ca2+]i in the cortical brain. Its high spatiotemporal resolution (30μm, 10Hz) and large field of view (4x5 mm2) are advanced as a neuroimaging tool for brain functional study.

  9. Propofol Compared to Isoflurane Inhibits Mitochondrial Metabolism in Immature Swine Cerebral Cortex

    Energy Technology Data Exchange (ETDEWEB)

    Kajimoto, Masaki; Atkinson, D. B.; Ledee, Dolena R.; Kayser, Ernst-Bernhard; Morgan, Phil G.; Sedensky, Margaret M.; Isern, Nancy G.; Des Rosiers, Christine; Portman, Michael A.

    2014-01-08

    Anesthetics used in infants and children are implicated in development of neurocognitive disorders. Although propofol induces neuroapoptosis in developing brain, the underlying mechanisms require elucidation and may have an energetic basis. We studied substrate utilization in an immature swine model anesthetized with either propofol or isoflurane for 4 hours. Piglets were infused with 13-Carbon labeled glucose and leucine in the common carotid artery in order to assess citric acid cycle (CAC) metabolism in the parietal cortex. The anesthetics produced similar systemic hemodynamics and cerebral oxygen saturation by near-infrared-spectroscopy. Compared to isoflurane, propofol depleted ATP and glycogen stores. Propofol also decreased pools of the CAC intermediates, citrate and α-ketoglutarate, while markedly increasing succinate along with decreasing mitochondrial complex II activity. Propofol also inhibited acetyl-CoA entry into the CAC through pyruvate dehydrogenase, while promoting glycolytic flux with marked accumulation of lactate. Although oxygen supply appeared similar between the anesthetic groups, propofol yielded a metabolic phenotype which resembled a hypoxic state. Propofol impairs substrate flux through the CAC in the immature cerebral cortex. These impairments occurred without systemic metabolic perturbations which typically accompany propofol infusion syndrome. These metabolic abnormalities may play a role in neurotoxity observed with propofol in the vulnerable immature brain.

  10. Arterial blood gas management in retrograde cerebral perfusion: the importance of carbon dioxide.

    Science.gov (United States)

    Ueno, K; Takamoto, S; Miyairi, T; Morota, T; Shibata, K; Murakami, A; Kotsuka, Y

    2001-11-01

    Many interventional physiological assessments for retrograde cerebral perfusion (RCP) have been explored. However, the appropriate arterial gas management of carbon dioxide (CO2) remains controversial. The aim of this study is to determine whether alpha-stat or pH-stat could be used for effective brain protection under RCP in terms of cortical cerebral blood flow (CBF), cerebral metabolic rate for oxygen (CMRO2), and distribution of regional cerebral blood flow. Fifteen anesthetized dogs (25.1+/-1.1 kg) on cardiopulmonary bypass (CPB) were cooled to 18 degrees C under alpha-stat management and had RCP for 90 min under: (1), alpha-stat; (2), pH-stat; or (3), deep hypothermic (18 degrees C) antegrade CPB (antegrade). RCP flow was regulated for a sagittal sinus pressure of around 25 mmHg. CBF was monitored by a laser tissue flowmeter. Serial analyses of blood gas were made. The regional cerebral blood flow was measured with colored microspheres before discontinuation of RCP. CBF and CMRO2 were evaluated as the percentage of the baseline level (%CBF, %CMRO2). The oxygen content of arterial inflow and oxygen extraction was not significantly different between the RCP groups. The %CBF and %CMRO2 were significantly higher for pH-stat RCP than for alpha-stat RCP. The regional cerebral blood flow, measured with colored microspheres, tended to be higher for pH-stat RCP than for alpha-stat RCP, at every site in the brain. Irrespective of CO2 management, regional differences were not significant among any site in the brain. CO2 management is crucial for brain protection under deep hypothermic RCP. This study revealed that pH-stat was considered to be better than alpha-stat in terms of CBF and oxygen metabolism in the brain. The regional blood flow distribution was considered to be unchanged irrespective of CO2 management.

  11. Vertigo-related cerebral blood flow changes on magnetic resonance imaging.

    Science.gov (United States)

    Chang, Feiyan; Li, Zhongshi; Xie, Sheng; Liu, Hui; Wang, Wu

    2014-11-01

    A prospective study using magnetic resonance imaging on a consecutive cohort of patients with cervical vertigo. To quantitatively investigate the cerebral blood flow (CBF) changes associated with cervical vertigo by using 3-dimensional pseudocontinuous arterial spin labeling. Previous studies reported blood flow velocity reduction in posterior circulation during vertigo. However, the detailed information of CBF related to cervical vertigo has not been provided. A total of 33 patients with cervical vertigo and 14 healthy volunteers were recruited in this study. Three-dimensional pseudocontinuous arterial spin labeling was performed on each subject to evaluate the CBF before and after the cervical hyperextension-hyperflexion movement tests, which was used to induce cervical vertigo. Repeated-measures analysis of variance was conducted to assess the effect of subjects and tests. There were time effects of CBF in the territory of bilateral superior cerebellar artery, bilateral posterior cerebral artery, bilateral middle cerebral artery, and right anterior cerebral artery, but no group effect was observed. The analysis of CBF revealed a significant main effect of tests (P=0.024) and participants (P=0.038) in the dorsal pons. Cervical vertigo onset may be related to CBF reduction in the dorsal pons, which sequentially evokes the vestibular nuclei. 2.

  12. The Dual Role of Cerebral Autoregulation and Collateral Flow in the Circle of Willis After Major Vessel Occlusion.

    Science.gov (United States)

    Kennedy McConnell, Flora; Payne, Stephen

    2017-08-01

    Ischaemic stroke is a leading cause of death and disability. Autoregulation and collateral blood flow through the circle of Willis both play a role in preventing tissue infarction. To investigate the interaction of these mechanisms a one-dimensional steady-state model of the cerebral arterial network was created. Structural variants of the circle of Willis that present particular risk of stroke were recreated by using a network model coupled with: 1) a steady-state physiological model of cerebral autoregulation; and 2) one wherein the cerebral vascular bed was modeled as a passive resistance. Simulations were performed in various conditions of internal carotid and vertebral artery occlusion. Collateral flow alone is unable to ensure adequate blood flow ([Formula: see text] normal flow) to the cerebral arteries in several common variants during internal carotid artery occlusion. However, compared to a passive model, cerebral autoregulation is better able to exploit available collateral flow and maintain flows within [Formula: see text] of baseline. This is true for nearly all configurations. Hence, autoregulation is a crucial facilitator of collateral flow through the circle of Willis. Impairment of this response during ischemia will severely impact cerebral blood flows and tissue survival, and hence, autoregulation should be monitored in this situation.

  13. Depressed cerebral oxygen metabolism in patients with chronic renal failure. A positron emission tomography study

    International Nuclear Information System (INIS)

    Hirakata, Hideki; Kanai, Hidetoshi; Nakane, Hiroshi; Fujii, Ken-ichiro; Hirakata, Eriko; Ibayashi, Setsuro; Kuwabara, Yasuo; Deenitchna, S.S.; Fujishima, Masatoshi

    2001-01-01

    In order to elucidate brain oxygen metabolism in uremic patients, the regional cerebral blood flow (rCBF), oxygen extraction (rOEF) and oxygen metabolism (rCMRO 2 ) were measured by positron emission tomography (PET) in both 10 hemodialysis patients (HD: male [m]/female [f]=2/8, age of 49±3 [SEM] years old, HD duration of 113±26 months) and 13 pre-dialysis renal failure patients (CRF: m/f=10/3, age of 61±2 years old, serum creatinine (SCr) of 6.3±1.0 mg/dl). Data were compared with 20 non-uremic subjects (Control: m/f=7/13, age of 62±2 years old, SCr of 0.9±0.1 mg/dl). They had no neurological abnormalities, congestive heart failure, history of cerebrovascular accident, diabetes mellitus, or symptomatic brain lesion on magnetic resonance imaging. The age of HD was significantly younger than the other groups (p 2 in both HD (1.82±0.10 ml/min/100 g) and CRF (1.95±0.09) showed significantly lower values as compared to Control (2.23±0.05) (p<0.01, respectively). Hemispheric rCBF in HD (35.6±2.1 ml/100 g/min) and in CRF (36.1±2.1) were not different from that in Control (31.8±1.4). Hemispheric rOEF in CRF (45.7±1.6%) was significantly higher than that in Control (40.5±1.2%) (p<0.02), but that in HD (43.7±1.9%) did not increase significantly. These tendencies were similar in all regions of interest, especially in the cerebral cortices, but not in the cerebellum. All PET parameters in the frontal cortices tended to show the lowest value in renal failure patients. For all HD patients, rCBF in both the frontal cortex and the white matter correlated inversely with HD duration (frontal cortex: r=-0.649, p<0.05; white matter: r=-0.706, p<0.02). Based on these data, it is concluded that brain oxygen metabolism is depressed in renal failure patients on or before hemodialysis treatment. The cause for the depressed brain oxygen metabolism is considered to be due either to the dysregulation of cerebral circulation or to lower brain cell activity. (author)

  14. Acquisition and Processing of Cerebral Blood Flow Data with a M ...

    African Journals Online (AJOL)

    1974-12-07

    Dec 7, 1974 ... anaesthetic agent is described, as well as the use of a ... anaesthetic agents cerebral blood flow has therefore to .... AlO = area under clearance curve after 10 min. .... weighted flow was 0,54, and the percentage standard.

  15. Regional cerebral flows in hypertensive patients

    International Nuclear Information System (INIS)

    Britton, K.E.; Granowska, M.; Lee, T.Y.; Nimmon, C.C.; Rutland, M.

    1978-01-01

    The aim of this study is to develop a method for assessing the natural history of cerebrovascular disease in patients with hypertension in order that the effects of controlling hypertension may be judged. By developing a quantitative noninvasive method for measuring regional cerebral flow and internal carotid appearance times it is hoped that drugs intended to inhibit the continued formation of atheroma and drugs intended to aid the dissolution of atheroma, may be objectively evaluated. (Auth.)

  16. Effect of the acquisition enhancing drug piracetam on rat cerebral energy metabolism. Comparison with naftidrofuryl and methamphetamine

    NARCIS (Netherlands)

    Nickolson, V.J.; Wolthuis, O.L.

    1976-01-01

    The effects of Piracetam, Naftidrofuryl and methamphetamine on several parameters of cerebral energy metabolism have been studied. At variance with some reports in the literature neither Piracetam nor Naftidrofuryl affected the cerebral contents of adenine nucleotides and, accordingly, both

  17. How Energy Metabolism Supports Cerebral Function: Insights from 13C Magnetic Resonance Studies In vivo

    Directory of Open Access Journals (Sweden)

    Sarah Sonnay

    2017-05-01

    Full Text Available Cerebral function is associated with exceptionally high metabolic activity, and requires continuous supply of oxygen and nutrients from the blood stream. Since the mid-twentieth century the idea that brain energy metabolism is coupled to neuronal activity has emerged, and a number of studies supported this hypothesis. Moreover, brain energy metabolism was demonstrated to be compartmentalized in neurons and astrocytes, and astrocytic glycolysis was proposed to serve the energetic demands of glutamatergic activity. Shedding light on the role of astrocytes in brain metabolism, the earlier picture of astrocytes being restricted to a scaffold-associated function in the brain is now out of date. With the development and optimization of non-invasive techniques, such as nuclear magnetic resonance spectroscopy (MRS, several groups have worked on assessing cerebral metabolism in vivo. In this context, 1H MRS has allowed the measurements of energy metabolism-related compounds, whose concentrations can vary under different brain activation states. 1H-[13C] MRS, i.e., indirect detection of signals from 13C-coupled 1H, together with infusion of 13C-enriched glucose has provided insights into the coupling between neurotransmission and glucose oxidation. Although these techniques tackle the coupling between neuronal activity and metabolism, they lack chemical specificity and fail in providing information on neuronal and glial metabolic pathways underlying those processes. Currently, the improvement of detection modalities (i.e., direct detection of 13C isotopomers, the progress in building adequate mathematical models along with the increase in magnetic field strength now available render possible detailed compartmentalized metabolic flux characterization. In particular, direct 13C MRS offers more detailed dataset acquisitions and provides information on metabolic interactions between neurons and astrocytes, and their role in supporting neurotransmission. Here

  18. A study of the cerebral blood flow pattern and cognitive deficit in Parkinson's disease

    International Nuclear Information System (INIS)

    Tamaru, Fuyuhiko

    1997-01-01

    Cerebral blood flow pattern in Parkinson's disease was examined by 123 I-IMP SPECT to determine whether the deficit in cognitive function is reflected in it. The patient group with Parkinson's disease showed deterioration in intelligence (Minimental state examination, Raven's Colored Progressive Matrices) and frontal lobe test (the Wisconsin Card Sorting Test). Though the uptake ratio of prefrontal area/occipital area in 123 I-IMP SPECT study varied widely in the Parkinson's disease group compared to the normal control group, there was no significant difference in the mean. Selective depletion of frontal lobe blood flow was not confirmed in this study. There was no correlation between cerebral blood flow pattern and cognitive functions including frontal lobe function and intelligence. We concluded that the deficit in cognitive function was not reflected in the cerebral blood flow pattern in Parkinson's disease. (author)

  19. Regional Cerebral Glucose Metabolism in Novelty Seeking and Antisocial Personality: A Positron Emission Tomography Study.

    Science.gov (United States)

    Park, So Hyeon; Park, Hyun Soo; Kim, Sang Eun

    2016-08-01

    Novelty seeking (NS) and antisocial personality (ASP) are commonly exhibited by those who suffer from addictions, such as substance abuse. NS has been suggested to be a fundamental aspect of ASP. To investigate the neurobiological substrate of NS and ASP, we tested the relationship between regional cerebral glucose metabolism and the level of NS, determining the differences between individuals with and without ASP. Seventy-two healthy adults (43 males, mean age±SD=38.8±16.6 years, range=20~70 years; 29 females, 44.2±20.1 years, range=19~72 years) underwent resting-state brain positron emission tomography (PET) 40 minutes after (18)F-fluorodeoxyglucose (FDG) injection. Within 10 days of the FDG PET study, participants completed Cloninger's 240-item Temperament and Character Inventory (TCI) to determine NS scores. Participants with and without ASP were grouped according to their TCI profiles. Statistical parametric mapping analysis was performed using the FDG PET and TCI profile data. NS scores positively correlated with metabolism in the left anterior cingulate gyrus and the insula on both sides of the brain and negatively correlated with metabolism in the right pallidum and putamen. Participants with ASP showed differences in cerebral glucose metabolism across various cortical and subcortical regions, mainly in the frontal and prefrontal areas. These data demonstrate altered regional cerebral glucose metabolism in individuals with NS and ASP and inform our understanding of the neurobiological substrates of problematic behaviors and personality disorders.

  20. Effects of Insulin on Brain Glucose Metabolism in Impaired Glucose Tolerance

    Science.gov (United States)

    Hirvonen, Jussi; Virtanen, Kirsi A.; Nummenmaa, Lauri; Hannukainen, Jarna C.; Honka, Miikka-Juhani; Bucci, Marco; Nesterov, Sergey V.; Parkkola, Riitta; Rinne, Juha; Iozzo, Patricia; Nuutila, Pirjo

    2011-01-01

    OBJECTIVE Insulin stimulates brain glucose metabolism, but this effect of insulin is already maximal at fasting concentrations in healthy subjects. It is not known whether insulin is able to stimulate glucose metabolism above fasting concentrations in patients with impaired glucose tolerance. RESEARCH DESIGN AND METHODS We studied the effects of insulin on brain glucose metabolism and cerebral blood flow in 13 patients with impaired glucose tolerance and nine healthy subjects using positron emission tomography (PET). All subjects underwent PET with both [18F]fluorodeoxyglucose (for brain glucose metabolism) and [15O]H2O (for cerebral blood flow) in two separate conditions (in the fasting state and during a euglycemic-hyperinsulinemic clamp). Arterial blood samples were acquired during the PET scans to allow fully quantitative modeling. RESULTS The hyperinsulinemic clamp increased brain glucose metabolism only in patients with impaired glucose tolerance (whole brain: +18%, P = 0.001) but not in healthy subjects (whole brain: +3.9%, P = 0.373). The hyperinsulinemic clamp did not alter cerebral blood flow in either group. CONCLUSIONS We found that insulin stimulates brain glucose metabolism at physiological postprandial levels in patients with impaired glucose tolerance but not in healthy subjects. These results suggest that insulin stimulation of brain glucose metabolism is maximal at fasting concentrations in healthy subjects but not in patients with impaired glucose tolerance. PMID:21270256

  1. Acute effects of electroconvulsive therapy on regional cerebral blood flow (rCBF) in psychiatric disorders

    International Nuclear Information System (INIS)

    Prohovnik, I.; Alderson, P.O.; Sackheim, H.A.; Decina, P.; Kahn, D.

    1984-01-01

    Electroconvulsive therapy (ECT) is frequently used in the treatment of major depression and other psychiatric disorders; its mechanism of action is not established, but previous evidence suggests that it is associated with postictal metabolic suppression. The authors have used measurements of rCBF as an index of cortical metabolic activity to study the acute effects of ECT. Measurements of rCBF were made in 32 cortical regions in 10 patients (pts) following one minute breathing of Xe-133 (5mCi/L); the measurements were performed 30min before and 50min after ECT. Bilateral ECT was administered to six pts (five diagnosed as major depressives and one schizophrenic) and unilateral ECT to four (all diagnosed as unipolar or bipolar affective disorder). The total rCBF material consists of 52 measurements in these pts, made before and after 16 bilateral and 10 unilateral treatments. ECT was found to cause significant reduction of rCBF. Mean hemispheric flows (using the Initial Slope Index to measure grey-matter flow) were reduced by about 5% in both hemispheres following bilateral treatment. Unilateral treatment caused a 9% reduction of flow in the treated hemisphere, but only 2% contralaterally. Regional patterns of flow decreases also differed between the two treatment modes: bilateral frontal reductions were found after bilateral treatment, whereas unilateral ECT caused a widespread flow reduction in the treated hemisphere, and almost no effect contralaterally. These results suggest that rCBF studies are useful for assessing ECT, and indicate that the acute cerebral effects of ECT vary with the mode of treatment

  2. Cerebral ischemia produced by four-vessel occlusion in the rat: a quantitative evaluation of cerebral blood flow

    International Nuclear Information System (INIS)

    Furlow, T.W. Jr.

    1982-01-01

    Cerebral ischemia was produced in the rat by simultaneous occlusion of the vertebral and carotid arteries according to the method of Pulsinelli and Brierley (Stroke 10: 267, 1979). Local cerebral blood flow (CBF) was determined by polarographic and autoradiographic techniques. Hydrogen-clearance measurements showed that mean CBF fell in four monitored regions of the hemispheres to between 0.11 and 0.18 ml/g/min, being least in deep rostal gray, intermediate in superficial gray, and greatest in deep caudal gray. However, individual animals had local CBF in excess of 0.20 and even 0.30 ml/g/min, and no animal showed zero CBF. When animals were rendered hypotensive (MABP of 50 Torr) during vascular occlusion, mean CBF ranged between 0.03 and 0.10 ml/g/min in the same regional order. With hypotension, total arrest of flow occurred. Autoradiographic data confirmed the above findings and indicated adequate CBF to the lower brainstem. During vascular occlusion, sufficient CBF may be present ot sustain cerebral tissue as in animals with a well developed spinal circulation or an inadvertently patent vertebral artery

  3. Cerebral blood flow in normal pressure hydrocephalus

    International Nuclear Information System (INIS)

    Mamo, H.L.; Meric, P.C.; Ponsin, J.C.; Rey, A.C.; Luft, A.G.; Seylaz, J.A.

    1987-01-01

    A xenon-133 method was used to measure cerebral blood flow (CBF) before and after cerebrospinal fluid (CSF) removal in patients with normal pressure hydrocephalus (NPH). Preliminary results suggested that shunting should be performed on patients whose CBF increased after CSF removal. There was a significant increase in CBF in patients with NPH, which was confirmed by the favorable outcome of 88% of patients shunted. The majority of patients with senile and presenile dementia showed a decrease or no change in CBF after CSF removal. It is suggested that although changes in CBF and clinical symptoms of NPH may have the same cause, i.e., changes in the cerebral intraparenchymal pressure, there is no simple direct relation between these two events. The mechanism underlying the loss of autoregulation observed in NPH is also discussed

  4. Cardiorespiratory fitness modifies the relationship between myocardial function and cerebral blood flow in older adults.

    Science.gov (United States)

    Johnson, Nathan F; Gold, Brian T; Bailey, Alison L; Clasey, Jody L; Hakun, Jonathan G; White, Matthew; Long, Doug E; Powell, David K

    2016-05-01

    A growing body of evidence indicates that cardiorespiratory fitness attenuates some age-related cerebral declines. However, little is known about the role that myocardial function plays in this relationship. Brain regions with high resting metabolic rates, such as the default mode network (DMN), may be especially vulnerable to age-related declines in myocardial functions affecting cerebral blood flow (CBF). This study explored the relationship between a measure of myocardial mechanics, global longitudinal strain (GLS), and CBF to the DMN. In addition, we explored how cardiorespiratory affects this relationship. Participants were 30 older adults between the ages of 59 and 69 (mean age=63.73years, SD=2.8). Results indicated that superior cardiorespiratory fitness and myocardial mechanics were positively associated with DMN CBF. Moreover, results of a mediation analysis revealed that the relationship between GLS and DMN CBF was accounted for by individual differences in fitness. Findings suggest that benefits of healthy heart function to brain function are modified by fitness. Copyright © 2015 Elsevier Inc. All rights reserved.

  5. Can the cerebral metabolic rate of oxygen be estimated with near-infrared spectroscopy?

    International Nuclear Information System (INIS)

    Boas, D A; Strangman, G; Culver, J P; Hoge, R D; Jasdzewski, G; Poldrack, R A; Rosen, B R; Mandeville, J B

    2003-01-01

    We have measured the changes in oxy-haemoglobin and deoxy-haemoglobin in the adult human brain during a brief finger tapping exercise using near-infrared spectroscopy (NIRS). The cerebral metabolic rate of oxygen (CMRO 2 ) can be estimated from these NIRS data provided certain model assumptions. The change in CMRO 2 is related to changes in the total haemoglobin concentration, deoxy-haemoglobin concentration and blood flow. As NIRS does not provide a measure of dynamic changes in blood flow during brain activation, we relied on a Windkessel model that relates dynamic blood volume and flow changes, which has been used previously for estimating CMRO 2 from functional magnetic resonance imaging (fMRI) data. Because of the partial volume effect we are unable to quantify the absolute changes in the local brain haemoglobin concentrations with NIRS and thus are unable to obtain an estimate of the absolute CMRO 2 change. An absolute estimate is also confounded by uncertainty in the flow-volume relationship. However, the ratio of the flow change to the CMRO 2 change is relatively insensitive to these uncertainties. For the finger tapping task, we estimate a most probable flow-consumption ratio ranging from 1.5 to 3 in agreement with previous findings presented in the literature, although we cannot exclude the possibility that there is no CMRO 2 change. The large range in the ratio arises from the large number of model parameters that must be estimated from the data. A more precise estimate of the flow-consumption ratio will require better estimates of the model parameters or flow information, as can be provided by combining NIRS with fMRI

  6. Differential Systolic and Diastolic Regulation of the Cerebral Pressure-Flow Relationship During Squat-Stand Manoeuvres.

    Science.gov (United States)

    Smirl, Jonathan D; Wright, Alexander D; Ainslie, Philip N; Tzeng, Yu-Chieh; van Donkelaar, Paul

    2018-01-01

    Cerebral pressure-flow dynamics are typically reported between mean arterial pressure and mean cerebral blood velocity. However, by reporting only mean responses, potential differential regulatory properties associated with systole and diastole may have been overlooked. Twenty young adults (16 male, age: 26.7 ± 6.6 years, BMI: 24.9 ± 3.0 kg/m 2 ) were recruited for this study. Middle cerebral artery velocity was indexed via transcranial Doppler. Cerebral pressure-flow dynamics were assessed using transfer function analysis at both 0.05 and 0.10 Hz using squat-stand manoeuvres. This method provides robust and reliable measures for coherence (correlation index), phase (timing buffer) and gain (amplitude buffer) metrics. There were main effects for both cardiac cycle and frequency for phase and gain metrics (p flow relationship. The oscillations associated with systole are extensively buffered within the cerebrovasculature, whereas diastolic oscillations are relatively unaltered. This indicates that the brain is adapted to protect itself against large increases in systolic blood pressure, likely as a mechanism to prevent cerebral haemorrhages.

  7. Cerebral blood flow autoregulation during intracranial hypertension in hypoxic lambs

    International Nuclear Information System (INIS)

    Borel, C.O.; Backofen, J.E.; Koehler, R.C.; Jones, M.D. Jr.; Traystman, R.J.

    1987-01-01

    The authors tested the hypothesis that hypoxic hypoxia interferes with cerebral blood flow (CBF) autoregulation when intracranial pressure (ICP) is elevated in pentobarbital-anesthetized lambs (3 to 9 days old). Cerebral perfusion pressure (CPP) was lowered stepwise from 73 to 23 mmHg in eight normoxic lambs and from 65 to 31 mmHg in eight other hypoxic lambs by ventricular infusion of artificial cerebrospinal fluid. In normoxic lambs, CBF measured by microspheres labeled with six different radioisotopes was not significantly changed over this range of CPP. In animals made hypoxic, base-line CBF was twice that of normoxic lambs. CBF was unchanged as CPP was reduced to 31 mmHg. Lower levels of CPP were not attained because a pressor response occurred with further elevations of ICP. No regional decrements in blood flow to cortical arterial watershed areas or to more caudal regions, such as cerebellum, brain stem, or thalamus, were detected with elevated ICP. Cerebral O 2 uptake was similar in both groups and did not decrease when CPP was reduced. These results demonstrate that normoxic lambs have a considerable capacity for effective autoregulation of CBF when ICP is elevated. Moreover, cerebral vasodilation in response to a level of hypoxia approximating that normally seen prenatally does not abolish CBF autoregulation when ICP is elevated during the first postnatal week

  8. Regional cerebral blood flow in SPECT pattern in Parkinson's disease

    International Nuclear Information System (INIS)

    Lenart-Jankowska, D.; Junik, R.; Sowinski, J.; Gembicki, M.; Wender, M.

    1997-01-01

    The purpose of our work was to compare the regional cerebral blood flow (rCBF) in SPECT examination in Parkinson's disease with (17 cases) and without (7 cases) dementia and in various clinical stages of the disease. The patients underwent SPECT examination 5-40 min after intravenous application of HMPAO (Ceretec, Amersham) with 740 Mbq (20 mCi) pertechnate 99m Tc. SPECT was performed with a Siemens Diacam single-head rotating gamma camera coupled to a high resolution collimator and Icon computer system provided by the manufacturer. The results were defined in relative values of ROI in relation to cerebellum. Patients with Parkinson's disease showed hypoperfusion in cerebral lobes and in deep cerebral structures including the basal ganglia. Regional perfusion deficit in SPECT was seen with and without associated dementia and already in early stage of the disease. Parkinson's disease is provoked by the lesions of dopaminergic neurons of the central nervous system leading to domination of extrapyramidal symptoms. There are many indications that also the neurotransmitters associated with cognitive functions as acetylcholine demonstrate some abnormalities. However, only in some cases of Parkinson's disease dementia is the dominating symptom. Our results of regional cerebral blood flow testify that in Parkinson's disease the dysfunction of the central nervous system is more diffuse than has previously been suggested. (author)

  9. Cerebral pressure-flow relationship in lowlanders and natives at high altitude.

    Science.gov (United States)

    Smirl, Jonathan D; Lucas, Samuel J E; Lewis, Nia C S; duManoir, Gregory R; Dumanior, Gregory R; Smith, Kurt J; Bakker, Akke; Basnyat, Aperna S; Ainslie, Philip N

    2014-02-01

    We investigated if dynamic cerebral pressure-flow relationships in lowlanders are altered at high altitude (HA), differ in HA natives and after return to sea level (SL). Lowlanders were tested at SL (n=16), arrival to 5,050 m, after 2-week acclimatization (with and without end-tidal PO2 normalization), and upon SL return. High-altitude natives (n=16) were tested at 5,050 m. Testing sessions involved resting spontaneous and driven (squat-stand maneuvers at very low (VLF, 0.05 Hz) and low (LF, 0.10 Hz) frequencies) measures to maximize blood pressure (BP) variability and improve assessment of the pressure-flow relationship using transfer function analysis (TFA). Blood flow velocity was assessed in the middle (MCAv) and posterior (PCAv) cerebral arteries. Spontaneous VLF and LF phases were reduced and coherence was elevated with acclimatization to HA (Pflow coupling. However, when BP was driven, both the frequency- and time-domain metrics were unaltered and comparable with HA natives. Acute mountain sickness was unrelated to TFA metrics. In conclusion, the driven cerebral pressure-flow relationship (in both frequency and time domains) is unaltered at 5,050 m in lowlanders and HA natives. Our findings indicate that spontaneous changes in TFA metrics do not necessarily reflect physiologically important alterations in the capacity of the brain to regulate BP.

  10. Metabolic response of the cerebral cortex following gentle sleep deprivation and modafinil administration.

    OpenAIRE

    Petit Jean-Marie; Tobler Irene; Kopp Caroline; Morgenthaler Florence; Borbély Alexander A; Magistretti Pierre J

    2010-01-01

    STUDY OBJECTIVES The main energy reserve of the brain is glycogen which is almost exclusively localized in astrocytes. We previously reported that cerebral expression of certain genes related to glycogen metabolism changed following instrumental sleep deprivation in mice. Here we extended our investigations to another set of genes related to glycogen and glucose metabolism. We also compared the effect of instrumentally and pharmacologically induced prolonged wakefulness followed (or not) by 3...

  11. Cerebral blood flow velocity changes during upright positioning in bed after acute stroke : An observational study

    NARCIS (Netherlands)

    Aries, Marcel J; Elting, Jan Willem; Stewart, Roy; De Keyser, Jacques; Kremer, Berry; Vroomen, Patrick

    2013-01-01

    Objectives: National guidelines recommend mobilisation in bed as early as possible after acute stroke. Little is known about the influence of upright positioning on real-time cerebral flow variables in patients with stroke. We aimed to assess whether cerebral blood flow velocity (CBFV) changes

  12. On the effect of dihydroergocristin-methansulfonate on human cerebral blood flow in an acute test

    International Nuclear Information System (INIS)

    Kohlmeyer, K.; Blessing, J.

    1978-01-01

    In 20 patients suffering from acute cerebrovascular diseases, cerebral trauma, cerebral atrophy and an apallic syndrome due to heart arrest, studies of regional cerebral blood flow (rCBF) were performed by means of the intracaroticial 133 xenon clearance method using 35 scintillation detectors to test the effect of dihydroegocristin-methansulfonate (DHEC) on the cerebral circulation. 0.6 mg and 0.9 mg, resp., DHEC dissolved in 200 mg levulose 5% were administered by a slow i.v. infusion during 20 min. Taking into consideration both the administered dosage of DHEC and the clinical diagnoses of the material, the results are the following: 0.6 mg DHEC lead to a significant increase of mean hemispheric flow in the average of 10 patients. On the other hand, 0.9 mg DHEC does not effect a significant change of mean hemispheric flow in the average of 10 patients. The highest increase of mean hemispheric flow was observed in the group of cases with cerebrovascular diseases receiving 0.6 mg DHEC. (orig./AJ) [de

  13. Assessing regional cerebral blood flow in depression using 320-slice computed tomography.

    Directory of Open Access Journals (Sweden)

    Yiming Wang

    Full Text Available While there is evidence that the development and course of major depressive disorder (MDD symptomatology is associated with vascular disease, and that there are changes in energy utilization in the disorder, the extent to which cerebral blood flow is changed in this condition is not clear. This study utilized a novel imaging technique previously used in coronary and stroke patients, 320-slice Computed-Tomography (CT, to assess regional cerebral blood flow (rCBF in those with MDD and examine the pattern of regional cerebral perfusion. Thirty nine participants with depressive symptoms (Hamilton Depression Rating Scale 24 (HAMD24 score > 20, and Self-Rating Depression Scale (SDS score > 53 and 41 healthy volunteers were studied. For all subjects, 3 ml of venous blood was collected to assess hematological parameters. Transcranial Doppler (TCD ultrasound was utilized to measure parameters of cerebral artery rCBFV and analyse the Pulsatility Index (PI. 16 subjects (8 =  MDD; 8 =  healthy also had rCBF measured in different cerebral artery regions using 320-slice CT. Differences among groups were analyzed using ANOVA and Pearson's tests were employed in our statistical analyses. Compared with the control group, whole blood viscosity (including high\\middle\\low shear rateand hematocrit (HCT were significantly increased in the MDD group. PI values in different cerebral artery regions and parameters of rCBFV in the cerebral arteries were decreased in depressive participants, and there was a positive relationship between rCBFV and the corresponding vascular rCBF in both gray and white matter. rCBF of the left gray matter was lower than that of the right in MDD. Major depression is characterized by a wide range of CBF impairments and prominent changes in gray matter blood flow. 320-slice CT appears to be a valid and promising tool for measuring rCBF, and could thus be employed in psychiatric settings for biomarker and treatment response purposes.

  14. Imaging of cerebral blood flow in patients with severe traumatic brain injury in the neurointensive care.

    Directory of Open Access Journals (Sweden)

    Elham eRostami

    2014-07-01

    Full Text Available Ischemia is a common and deleterious secondary injury following traumatic brain injury (TBI. A great challenge for the treatment of TBI patients in the neurointensive care unit (NICU is to detect early signs of ischemia in order to prevent further advancement and deterioration of the brain tissue. Today, several imaging techniques are available to monitor cerebral blood flow (CBF in the injured brain such as Positron emission tomography (PET, Single-photon emission computed tomography (SPECT, Xenon-CT, perfusion weighted magnetic resonance imaging (MRI and CT perfusion scan. An ideal imaging technique would enable continuous noninvasive measurement of blood flow and metabolism across the whole brain. Unfortunately, no current imaging method meets all these criteria. These techniques offer snapshots of the CBF. MRI may also provide some information about the metabolic state of the brain. PET provides images with high resolution and quantitative measurements of CBF and metabolism however it is a complex and costly method limited to few TBI centres. All of these methods except mobile Xenon-CT require transfer of TBI patients to the radiological department. Mobile Xenon-CT emerges as a feasible technique to monitor CBF in the NICU, with lower risk of adverse effects. Promising results have been demonstrated with Xenon-CT in predicting outcome in TBI patients. This review covers available imaging methods used to monitor CBF in patients with severe TBI.

  15. Impaired autoregulation of cerebral blood flow in long-term type I (insulin-dependent) diabetic patients with nephropathy and retinopathy

    DEFF Research Database (Denmark)

    Kastrup, J; Rørsgaard, S; Parving, H H

    1986-01-01

    Autoregulation of cerebral blood flow, i.e., the maintenance of cerebral blood flow within narrow limits during changes in arterial perfusion pressure, was studied in nine healthy control subjects and in 12 long-term Type I (insulin-dependent) diabetic patients with clinical microangiopathy...... the previous findings suggesting that autoregulation of cerebral blood flow is impaired in some long-term Type I diabetic patients with clinical microangiopathy (arteriolar hyalinosis)........ Cerebral blood flow was measured by the intravenous 133Xenon method. Mean arterial blood pressure was elevated approximately 30 mmHg by intravenous infusion of angiotensin amide II and lowered about 10 mmHg by intravenous infusion of trimethaphan camsylate. In the control subjects the flow/pressure curve...

  16. Regional cerebral blood flow during comprehension and speech (in cerebrally healthy subjects)

    International Nuclear Information System (INIS)

    Lechevalier, B.; Petit, M.C.; Eustache, F.; Lambert, J.; Chapon, F.; Viader, F.

    1989-01-01

    Regional cerebral blood flow (rCBF) was measured by the xenon-133 inhalation method in 10 cerebrally healthy subjects at rest and during linguistic activation tests. These consisted of a comprehension test (binaural listening to a narrative text) and a speech test (making sentences from a list of words presented orally at 30-s intervals). The comprehension task induced a moderate increase in the mean right CBF and in both inferior parietal areas, whereas the speech test resulted in a diffuse increase in the mean CBF of both hemispheres, predominating regionally in both inferior parietal, left operculary, and right upper motor and premotor areas. It is proposed that the activation pattern induced by linguistic stimulation depends on not only specific factors, such as syntactic and semantic aspects of language, but also the contents of the material proposed and the attention required by the test situation

  17. Quantitative activation patterns of cerebral blood flow during mental stimulation after intravenous injection of sup(195m)Au

    International Nuclear Information System (INIS)

    Lindner, P.; Nickel, O.

    1983-01-01

    A previously reported theory for quantitative cerebral blood flow measurement for nondiffusible radiotracers has been applied to patients after stroke and to volunteers undergoing a mental stimulation exercise. Quantitative measurements of cerebral blood flow pattern in p-a and lateral projections of the brain are obtained using the short lived (30s) isotope sup(195m)Au from the recently developed generator. The energy spectrum of the eluate from the generator shows two strong photon peaks, one at an energy level of 68 KeV and a second at 262 KeV. The low-energy peak is suitable for perfusion studies of the cerebral hemispheres in lateral projection, being without ''look through'' effect. The high-energy level is good for studies in p-a-projection. Studies last less than 1 min and can be repeated after 3 min. Parametric images for quantitative regional cerebral blood flow can be generated, in which the avascular region following stroke can be detected. Quantitative activation patterns of cerebral blood flow during mental stimulation can be generated. The results show that it is possible to measure cerebral blood-flow patterns not only with freely diffusible indicators like Xenon but also with nondiffusible indicators. (orig.)

  18. Cerebral blood flow imaging with thallium-201 diethyldithiocarbamate SPECT

    NARCIS (Netherlands)

    van Royen, E. A.; de Bruïne, J. F.; Hill, T. C.; Vyth, A.; Limburg, M.; Byse, B. L.; O'Leary, D. H.; de Jong, J. M.; Hijdra, A.; van der Schoot, J. B.

    1987-01-01

    Thallium-201 diethyldithiocarbamate ([201TI]DDC) was studied in humans as an agent for cerebral blood flow imaging. Brain uptake proved to be complete 90 sec after injection with no appreciable washout or redistribution for hours. Intracarotid injection suggested an almost 100% extraction during the

  19. Monitoring of cerebral blood flow autoregulation in adults undergoing sevoflurane anesthesia: a prospective cohort study of two age groups.

    Science.gov (United States)

    Goettel, Nicolai; Patet, Camille; Rossi, Ariane; Burkhart, Christoph S; Czosnyka, Marek; Strebel, Stephan P; Steiner, Luzius A

    2016-06-01

    Autoregulation of blood flow is a key feature of the human cerebral vascular system to assure adequate oxygenation and metabolism of the brain under changing physiological conditions. The impact of advanced age and anesthesia on cerebral autoregulation remains unclear. The primary objective of this study was to determine the effect of sevoflurane anesthesia on cerebral autoregulation in two different age groups. This is a follow-up analysis of data acquired in a prospective observational cohort study. One hundred thirty-three patients aged 18-40 and ≥65 years scheduled for major noncardiac surgery under general anesthesia were included. Cerebral autoregulation indices, limits, and ranges were compared in young and elderly patient groups. Forty-nine patients (37 %) aged 18-40 years and 84 patients (63 %) aged ≥65 years were included in the study. Age-adjusted minimum alveolar concentrations of sevoflurane were 0.89 ± 0.07 in young and 0.99 ± 0.14 in older subjects (P blood pressure range of 13.8 ± 9.8 mmHg in young and 10.2 ± 8.6 mmHg in older patients (P = 0.079). The lower limit of autoregulation was 66 ± 12 mmHg and 73 ± 14 mmHg in young and older patients, respectively (P = 0.075). The association between sevoflurane concentrations and autoregulatory capacity was similar in both age groups. Our data suggests that the autoregulatory plateau is shortened in both young and older patients under sevoflurane anesthesia with approximately 1 MAC. Lower and upper limits of cerebral blood flow autoregulation, as well as the autoregulatory range, are not influenced by the age of anesthetized patients. Trial registration ClinicalTrials.gov (NCT00512200).

  20. Anxiety and cerebral blood flow during behavioral challenge. Dissociation of central from peripheral and subjective measures

    International Nuclear Information System (INIS)

    Zohar, J.; Insel, T.R.; Berman, K.F.; Foa, E.B.; Hill, J.L.; Weinberger, D.R.

    1989-01-01

    To investigate the relationship between anxiety and regional cerebral blood flow, we administered behavioral challenges to 10 patients with obsessive-compulsive disorder while measuring regional cerebral blood flow with the xenon 133 inhalation technique. Each patient was studied under three conditions: relaxation, imaginal flooding, and in vivo (actual) exposure to the phobic stimulus. Subjective anxiety, obsessive-compulsive ratings, and autonomic measures (heart rate, blood pressure) increased significantly, but respiratory rate and PCO 2 did not change across the three conditions. Regional cerebral blood flow increased slightly (in the temporal region) during imaginal flooding, but decreased markedly in several cortical regions during in vivo exposure, when anxiety was highest by subjective and peripheral autonomic measures. These results demonstrate that intense anxiety can be associated with decreased rather than increased cortical perfusion and that ostensibly related states of anxiety (eg, anticipatory and obsessional anxiety) may be associated with opposite effects on regional cerebral blood flow

  1. Postnatal changes in local cerebral blood flow measured by the quantitative autoradiographic [14C]iodoantipyrine technique in freely moving rats

    International Nuclear Information System (INIS)

    Nehlig, A.; Pereira de Vasconcelos, A.; Boyet, S.

    1989-01-01

    The postnatal changes in local cerebral blood flow in freely moving rats were measured by means of the quantitative autoradiographic [ 14 C]iodoantipyrine method. The animals were studied at 10, 14, 17, 21 and 35 days and at the adult stage. At 10 days after birth, rates of blood flow were very low and quite homogeneous in most cerebral structures except in a few posterior areas. From these relatively uniform levels, values of local cerebral blood flow rose notably to reach a peak at 17 days in all brain regions studied. Rates of blood flow decreased between 17 and 21 days after birth and then increased from weaning time to reach the known characteristic distribution of the adult rat. The postnatal evolution of local cerebral blood in the rat is in good agreement with previous studies in other species such as dog and humans that also show higher rates of cerebral blood flow and glucose utilization at immature stages. However, in the rat, local cerebral blood flow and local cerebral glucose utilization are not coupled over the whole postnatal period studied, since blood flow rates reach peak values at 17 days whereas glucose utilization remains still quite low at that stage. The high rate of cerebral blood flow in the 17-day-old rat may reflect the energetic and biosynthetic needs of the actively developing brain that are completed by the summation of glucose and ketone body utilization

  2. Changes in glutamate concentration, glucose metabolism, and cerebral blood flow during focal brain cooling of the epileptogenic cortex in humans.

    Science.gov (United States)

    Nomura, Sadahiro; Fujii, Masami; Inoue, Takao; He, Yeting; Maruta, Yuichi; Koizumi, Hiroyasu; Suehiro, Eiichi; Imoto, Hirochika; Ishihara, Hideyuki; Oka, Fumiaki; Matsumoto, Mishiya; Owada, Yuji; Yamakawa, Takeshi; Suzuki, Michiyasu

    2014-05-01

    Recently, focal brain cooling (FBC) was proposed as a method for treating refractory epilepsy. However, the precise influence of cooling on the molecular basis of epilepsy has not been elucidated. Thus the aim of this study was to assess the effect of FBC on glutamate (Glu) concentration, cerebral blood flow (CBF), and glucose metabolism in patients with intractable epilepsy. Nine patients underwent FBC at 15°C for 30 min prior to cortical resection (n = 6) or hippocampectomy (n = 3). Measurement of metabolites and CBF, as well as electrocorticography (ECoG), was performed. Epileptic discharge (ED), as observed by ECoG, disappeared in the cooling period and reappeared in the rewarming period. Glu concentrations were high during the precooling period and were reduced to 51.2% during the cooling period (p = 0.025). Glycerol levels showed a similar decrease (p = 0.028). Lactate concentration was high during the precooling period and was reduced during the cooling period (21.3% decrease; p = 0.005). Glucose and pyruvate levels were maintained throughout the procedure. Changes in CBF were parallel to those observed by ECoG. FBC reduced EDs and concentrations of Glu and glycerol. This demonstrates the neuroprotective effect of FBC. Our findings confirm that FBC is a reasonable and optimal treatment option for patients with intractable epilepsy. Wiley Periodicals, Inc. © 2014 International League Against Epilepsy.

  3. Quantitative Analysis of Regional Cerebral Blood Flow using 99mTc-HMPAO SPECT in Parkinson's Disease

    International Nuclear Information System (INIS)

    Lee, Myung Chul; Bae, Sang Kyun; Chung, June Key; Koh, Chang Soon; Roh, Jae Kyu; Myung, Ho Jin; Lee, Myung Hae

    1992-01-01

    Regional cerebral blood flow were measured in 10 patients with Parkinson's disease and 12 normal persons using 99m Tc-HMPAO SPECT. Reconstructed images were interpreted qualitatively and were compared with those findings of CT. For the quantitative analysis, six pairs of region of interest matched with the perfusion territories of large cerebral arteries and cerebellar hemisphere were determined. From the count values, indices showing the degree of asymmetry between right and left cerebral or cerebellar hemisphere, cerebral asymmetry index (ASI) and percent index of cerebellar asymmetry (PIA), and an index showing change of each region, region to cerebellum ratio (RCR) were obtained. ASI of normal persons and patients were 0.082 ± 0.033 and 0.108 ± 0.062, respectively and PIA were -0.4 ± 0.7% and -0.7 ± 1.0%, respectively, which showed no statistically significant difference between normal persons and patients. Among 10 RCR's, those of both regions of basal ganglia and both regions of anterior cerebral artery were significantly reduced. We concluded that the most significant reduction of regional cerebral blood flow in patients with Parkinson's disease was observed in the regions of basal ganglia and in the regions of anterior cerebral artery, and the degree of change in hemispheric blood flow was similar in both hemisphere.

  4. Tomographic images of cerebral blood flow using a slant hole collimator

    International Nuclear Information System (INIS)

    Wraight, E.P.; Barber, R.W.; Crossland, P.; Maltby, P.

    1983-01-01

    The feasibility of using a rotating slant hole (RSH) collimator on simple tomographic equipment such as a standard gamma camera interfaced to a general purpose Nuclear Medicine computer is reported for producing images of cerebral blood flow following the administration of 123 I-iodoamphetamine to patients. Initial studies produced satisfactory images, thus opening the possibility of tomographic cerebral blood flow imaging to centres not possessing sophisticated tomographic equipment. Planar resolution is superior to that reported for a 25 0 RSH collimator. Axial resolution is not as good at small source distances but is comparable at distances beyond 10 cm. Sensitivity is comparable to other RSH collimators and is similar to Technicare's parallel hole general all purpose collimator. (UK)

  5. A study of the acute effect of smoking on cerebral blood flow using 99mTc-ECD SPET

    International Nuclear Information System (INIS)

    Yamamoto, Yuka; Nishiyama, Yoshihiro; Monden, Toshihide; Satoh, Katashi; Ohkawa, Motoomi

    2003-01-01

    Cigarette smoking is known to be associated with atherosclerosis, is an important risk factor for stroke and has other serious effects. The aim of this study was to evaluate the acute effect of cigarette smoking on cerebral blood flow using statistical parametric mapping (SPM). Ten healthy volunteers with a smoking habit were studied using technetium-99m-labelled ethylcysteinate dimer single-photon emission tomography (SPET). We evaluated the regional cerebral blood flow under the smoking and resting states. The regional cerebral blood flow on smoking-activated SPET was significantly decreased in the whole brain as compared with that on resting SPET. Our findings therefore suggest that one of the acute effects of cigarette smoking is to induce a diffuse decrease in cerebral blood flow. (orig.)

  6. pCO2 And pH regulation of cerebral blood flow

    Directory of Open Access Journals (Sweden)

    SeongHun eYoon

    2012-09-01

    Full Text Available CO2 Serves as one of the fundamental regulators of cerebral blood flow. It is widely considered that this regulation occurs through pCO2-driven changes in pH of the cerebral spinal fluid, with elevated and lowered pH causing direct relaxation and contraction of the smooth muscle, respectively. However, some findings also suggest that pCO2 acts independently of and/or in conjunction with altered pH. This action may be due to a direct effect of cerebral spinal fluid pCO2 on the smooth muscle as well as on the endothelium, nerves, and astrocytes. Findings may also point to an action of arterial pCO2 on the endothelium to regulate smooth muscle contractility. Thus, the effects of pH and pCO2 may be influenced by the absence/presence of different cell types in the various experimental preparations. Results may also be influenced by experimental parameters including myogenic tone as well as solutions containing significantly altered HCO3- concentrations, i.e., solutions routinely employed to differentiate the effects of pH from pCO2. In sum, it appears that pCO2, independently and in conjunction with pH, may regulate cerebral blood flow.

  7. Correlations between cerebral glucose metabolism and neuropsychological test performance in nonalcoholic cirrhotics.

    Science.gov (United States)

    Lockwood, Alan H; Weissenborn, Karin; Bokemeyer, Martin; Tietge, U; Burchert, Wolfgang

    2002-03-01

    Many cirrhotics have abnormal neuropsychological test scores. To define the anatomical-physiological basis for encephalopathy in nonalcoholic cirrhotics, we performed resting-state fluorodeoxyglucose positron emission tomographic scans and administered a neuropsychological test battery to 18 patients and 10 controls. Statistical parametric mapping correlated changes in regional glucose metabolism with performance on the individual tests and a composite battery score. In patients without overt encephalopathy, poor performance correlated with reductions in metabolism in the anterior cingulate. In all patients, poor performance on the battery was positively correlated (p glucose metabolism in bifrontal and biparietal regions of the cerebral cortex and negatively correlated with metabolism in hippocampal, lingual, and fusiform gyri and the posterior putamen. Similar patterns of abnormal metabolism were found when comparing the patients to 10 controls. Metabolic abnormalities in the anterior attention system and association cortices mediating executive and integrative function form the pathophysiological basis for mild hepatic encephalopathy.

  8. Positron emission tomography in the newborn: extensive impairment of regional cerebral blood flow with intraventricular hemorrhage and hemorrhagic intracerebral involvement

    International Nuclear Information System (INIS)

    Volpe, J.J.; Herscovitch, P.; Perlman, J.M.; Raichle, M.E.

    1983-01-01

    Positron emission tomography (PET) now provides the capability of measuring regional cerebral blood flow with high resolution and little risk. In this study, we utilized PET in six premature infants (920 to 1,200 g) with major intraventricular hemorrhage and hemorrhagic intracerebral involvement to measure regional cerebral blood flow during the acute period (5 to 17 days of age). Cerebral blood flow was determined after intravenous injection of H 2 O, labeled with the positron-emitting isotope, 15 O. Findings were similar and dramatic in all six infants. In the area of hemorrhagic intracerebral involvement, little or no cerebral blood flow was detected. However, in addition, surprisingly, a marked two- to fourfold reduction in cerebral blood flow was observed throughout the affected hemisphere, well posterior and lateral to the intracerebral hematoma, including cerebral white matter and, to a lesser extent, frontal, temporal, and parietal cortex. In the one infant studied a second time, ie, at 3 months of age, the extent and severity of the decreased cerebral blood flows in the affected hemisphere were similar to those observed on the study during the neonatal period. At the three autopsies, the affected left hemisphere showed extensive infarction, corroborating the PET scans. These observations, the first demonstration of the use of PET in the determination of regional cerebral blood flow in the newborn, show marked impairments in regional cerebral blood flow in the hemisphere containing an apparently restricted intracerebral hematoma, indicating that the hemorrhagic intracerebral involvement is only a component of a much larger lesion, ischemic in basic nature, ie, an infarction. This large ischemic lesion explains the poor neurologic outcome in infants with intraventricular hemorrhage and hemorrhagic intracerebral involvement

  9. A neutral lipophilic technetium-99m complex for regional cerebral blood flow imaging

    International Nuclear Information System (INIS)

    Narra, R.K.; Nunn, A.D.; Kuczynski, B.L.; DiRocco, R.J.; Feld, T.; Silva, D.A.; Eckelman, W.C.

    1990-01-01

    Technetium-99m-DMG-2MP (Chloro[bis[2,3-butanedionedioxime(1-)-0][2,3- butanedionedioximato (2-)-N,N',N double-prime,N'double-prime,N double-prime double-prime,N'double-prime double-prime] (2-methylpropyl borato (2-))technetium]), also known as SQ 32097 is a member of a family of neutral lipophilic compounds generally known as boronic acid adducts of technetium dioxime complexes (BATOs). After i.v. administration, the concentration of [ 99m Tc]DMG-2MP in various regions of the brain appears to be proportional to blood flow. In rats, 1.1% ID was in the brain at 5 min postinjection when the blood contained less than 3% ID. Over 24 hr excretion was 59% in the feces and 23% in the urine. The activity in monkey brain at 5 min was 2.8% ID and it cleared with a t1/2 of 86 min. Autoradiographs of monkey brain sections showed excellent regional detail with a gray/white ratio of 3.6 at 10 min. The distribution of [ 99m Tc]DMG-2MP in the monkey brain corresponds to the known cytoarchitectural pattern of cerebral glucose metabolism. The properties of [ 99m Tc]DMG-2MP make it a potentially useful agent for cerebral perfusion imaging in man

  10. Cerebral blood flow response to hypoglycemia is altered in patients with type 1 diabetes and impaired awareness of hypoglycemia.

    Science.gov (United States)

    Wiegers, Evita C; Becker, Kirsten M; Rooijackers, Hanne M; von Samson-Himmelstjerna, Federico C; Tack, Cees J; Heerschap, Arend; de Galan, Bastiaan E; van der Graaf, Marinette

    2017-06-01

    It is unclear whether cerebral blood flow responses to hypoglycemia are altered in people with type 1 diabetes and impaired awareness of hypoglycemia. The aim of this study was to investigate the effect of hypoglycemia on both global and regional cerebral blood flow in type 1 diabetes patients with impaired awareness of hypoglycemia, type 1 diabetes patients with normal awareness of hypoglycemia and healthy controls ( n = 7 per group). The subjects underwent a hyperinsulinemic euglycemic-hypoglycemic glucose clamp in a 3 T MR system. Global and regional changes in cerebral blood flow were determined by arterial spin labeling magnetic resonance imaging, at the end of both glycemic phases. Hypoglycemia generated typical symptoms in patients with type 1 diabetes and normal awareness of hypoglycemia and healthy controls, but not in patients with impaired awareness of hypoglycemia. Conversely, hypoglycemia increased global cerebral blood flow in patients with impaired awareness of hypoglycemia, which was not observed in the other two groups. Regionally, hypoglycemia caused a redistribution of cerebral blood flow towards the thalamus of both patients with normal awareness of hypoglycemia and healthy controls, consistent with activation of brain regions associated with the autonomic response to hypoglycemia. No such redistribution was found in the patients with impaired awareness of hypoglycemia. An increase in global cerebral blood flow may enhance nutrient supply to the brain, hence suppressing symptomatic awareness of hypoglycemia. Altogether these results suggest that changes in cerebral blood flow during hypoglycemia contribute to impaired awareness of hypoglycemia.

  11. Depressed cerebral oxygen metabolism in patients with chronic renal failure. A positron emission tomography study

    Energy Technology Data Exchange (ETDEWEB)

    Hirakata, Hideki; Kanai, Hidetoshi; Nakane, Hiroshi; Fujii, Ken-ichiro; Hirakata, Eriko; Ibayashi, Setsuro; Kuwabara, Yasuo; Deenitchna, S.S.; Fujishima, Masatoshi [Kyushu Univ., Fukuoka (Japan). Graduate School of Medical Sciences

    2001-07-01

    In order to elucidate brain oxygen metabolism in uremic patients, the regional cerebral blood flow (rCBF), oxygen extraction (rOEF) and oxygen metabolism (rCMRO{sub 2}) were measured by positron emission tomography (PET) in both 10 hemodialysis patients (HD: male [m]/female [f]=2/8, age of 49{+-}3 [SEM] years old, HD duration of 113{+-}26 months) and 13 pre-dialysis renal failure patients (CRF: m/f=10/3, age of 61{+-}2 years old, serum creatinine (SCr) of 6.3{+-}1.0 mg/dl). Data were compared with 20 non-uremic subjects (Control: m/f=7/13, age of 62{+-}2 years old, SCr of 0.9{+-}0.1 mg/dl). They had no neurological abnormalities, congestive heart failure, history of cerebrovascular accident, diabetes mellitus, or symptomatic brain lesion on magnetic resonance imaging. The age of HD was significantly younger than the other groups (p<0.02) and the hemoglobin (Hb) levels in both HD (10.5{+-}0.5 g/dl) and CRF (9.8{+-}0.9) were significantly lower than that in Control (13.3{+-}0.3) (p<0.02). In the hemisphere, rCMRO{sub 2} in both HD (1.82{+-}0.10 ml/min/100 g) and CRF (1.95{+-}0.09) showed significantly lower values as compared to Control (2.23{+-}0.05) (p<0.01, respectively). Hemispheric rCBF in HD (35.6{+-}2.1 ml/100 g/min) and in CRF (36.1{+-}2.1) were not different from that in Control (31.8{+-}1.4). Hemispheric rOEF in CRF (45.7{+-}1.6%) was significantly higher than that in Control (40.5{+-}1.2%) (p<0.02), but that in HD (43.7{+-}1.9%) did not increase significantly. These tendencies were similar in all regions of interest, especially in the cerebral cortices, but not in the cerebellum. All PET parameters in the frontal cortices tended to show the lowest value in renal failure patients. For all HD patients, rCBF in both the frontal cortex and the white matter correlated inversely with HD duration (frontal cortex: r=-0.649, p<0.05; white matter: r=-0.706, p<0.02). Based on these data, it is concluded that brain oxygen metabolism is depressed in renal failure

  12. Changes in cerebral glucose metabolism in patients with posttraumatic cognitive impairment after memantine therapy. A preliminary study

    International Nuclear Information System (INIS)

    Kim, Yong-Wook; Shin, Ji-Cheol; An, Young-Sil

    2010-01-01

    The objective of this study was to investigate the changes in cerebral glucose metabolism in patients with posttraumatic cognitive impairment after memantine therapy. We performed serial F-18 fluorodeoxyglucose positron emission tomography studies before and after memantine therapy (20 mg per day) on 17 patients with posttraumatic cognitive impairment using statistical parametric mapping analysis. In addition, covariance analysis was performed to identify regions, where changes in regional cerebral glucose metabolism correlated significantly with increased Mini-Mental Status Examination scores. Statistical parametric mapping analysis demonstrated that, compared with baseline, significantly increased cerebral glucose metabolism occurred in both inferior, middle and superior frontal gyri, both angular gyri, both precuneus, the right middle cingulum, the left inferior parietal lobule, the left fusiform gyrus, the left precentral gyrus, the left paracentral lobule, and the left lingual gyrus after memantine therapy (P uncorrected uncorrected corrected <0.0001). Our findings indicate that the prefrontal and the parietal association cortices may be the relevant structures for the pharmacological response to memantine therapy in patients with posttraumatic cognitive impairment. (author)

  13. Patterns of regional cerebral blood flow in acute stroke

    DEFF Research Database (Denmark)

    Olsen, T S; Skriver, E B

    1981-01-01

    In a consecutive group of 56 stroke patients the regional cerebral blood flow was measured within 84 hours after stroke. A 254 multidetector scintillation camera and the intracarotid Xenon-133 injection method was used to study rCBF. Typical rCBF-patterns are described and compared to the findings...

  14. Relationship between cardiac function and resting cerebral blood flow

    DEFF Research Database (Denmark)

    Henriksen, Otto M; Jensen, Lars T; Krabbe, Katja

    2014-01-01

    ) and 2.4 l min(-1) m(-2), respectively, in females. No effects of cardiac output or cardiac index on CBF or structural signs of brain ageing were observed. However, fractional brain flow defined as the ratio of total brain flow to cardiac output was inversely correlated with cardiac index (r(2) = 0.22, P...... = 0.008) and furthermore lower in males than in females (8.6% versus 12.5%, P = 0.003). Fractional brain flow was also inversely correlated with cerebral white matter lesion grade, although this effect was not significant when adjusted for age. Frequency analysis of heart rate variability showed...

  15. Regional cerebral blood flow in primary degenerative dementia

    International Nuclear Information System (INIS)

    Kawakatsu, Shinobu; Totsuka, Shiro; Shinohara, Masao; Koyama, Hideki; Sagawa, Katsuo; Morinobu, Shigeru; Oiji, Arata; Komatani, Akio

    1991-01-01

    Regional cerebral blood flow (rCBF) was examined, using SPECT by Xe-133 inhalation, in patients with primary degenerative dementia who were subgrouped according to predominant symptoms with respect to amnesia, apraxia, agnosia, aphasia, and personality changes. Also the effect of sex and age at dementia onset on the rCBF patterns was assessed. (author). 26 refs.; 1 fig.; 7 tabs

  16. Factors which affect cerebral uptake and retention of 13NH3

    International Nuclear Information System (INIS)

    Phelps, M.E.; Raichle, M.E.; Hoffman, E.J.; Raybaud, C.

    1977-01-01

    The single pass extraction of ammonia (E) by cerebral capillaries was studied in vivo in Rhesus monkeys with 13 N. The value of E for 13 N-ammonia was found to be less than 100%, inversely related to cerebral blood flow and to be limited by the permeability of the blood brain barrier for ammonia. A vaue of the permeability surface area product was determined to be 0.0040 x 10 -4 cm 3 /sec/gm. The single pass extraction fraction, E, for 13 N-ammonia was found to be independent of arterial blood pH (in the range of 7.2 to 7.6) and of arterial blood ammonia concentration (in the range of 80-1400 μgms/100 cc). An insulin induced hypoglycemic reduction in the cerebral metabolic rate for glucose and oxygen of 54% produced a reduction in E of about 24%. When a condition of elevated arterial blood ammonia was added to hypoglycemia, the value of E and cerebral metabolic rate for oxygen remained low while the cerebral metabolic rate for glucose increased by a factor of 2.5 indicating the presence of a detoxification shunt for ammonia. Positron tomographic images of the equilibrium cross section distribution of 13 N-ammonia appeared to reflect regional differences in capillary density of the cerebral tissue

  17. Protein metabolism in the rat cerebral cortex in vivo and in vitro as affected by the acquisition enhancing drug piracetam

    NARCIS (Netherlands)

    Nickolson, V.J.; Wolthuis, O.L.

    1976-01-01

    The effect of Piracetam on rat cerebral protein metabolism in vivo and in vitro was studied. It was found that the drug stimulates the uptake of labelled leucine by cerebral cortex slices, has no effect on the incorporation of leucine into cerebral protein, neither in slices nor in vivo, but

  18. Impact of Cardiac Contractility during Cerebral Blood Flow in Ischemia

    Directory of Open Access Journals (Sweden)

    Silver, Brian

    2011-05-01

    Full Text Available Objective: In cerebral regions affected by ischemia, intrinsic vascular autoregulation is often lost. Blood flow delivery depends upon cardiac function and may be influenced by neuro-endocrine mediated myocardial suppression. Our objective is to evaluate the relation between ejection fraction (EF and transcranial doppler (TCD peak systolic velocities (PSV in patients with cerebral ischemic events.Methods: We conducted a retrospective cohort study from an existing TCD registry. We evaluated patients admitted within 24 hours of onset of a focal neurological deficit who had an echocardiogram and TCD performed within 72 hours of admission.Results: We identified 58 patients from March to October 2003. Eighty-one percent (n=47 had a hospital discharge diagnosis of ischemic stroke and 18.9% (n=11 had a diagnosis of transient ischemic attack. Fourteen patients had systolic dysfunction (EF50% compared to those with systolic dysfunction (EF<50% was as follows: middle cerebral artery 62.0 + 28.6 cm/s vs. 51.0 + 23.3 cm/s, p=0.11; anterior cerebral artery 52.1 + 21.6 cm/s vs. 45.9 + 22.7 cm/s, p=0.28; internal carotid artery 56.5 + 20.1 cm/s vs. 46.4 + 18.4 cm/s, p=0.04; ophthalmic artery 18.6 + 7.2 cm/s vs. 15.3 + 5.2 cm/s, p=0.11; vertebral artery 34.0 + 13.9 cm/s vs. 31.6 + 15.0 cm/s, p=0.44.Conclusion: Cerebral blood flow in the internal carotid artery territory appears to be higher in cerebral ischemia patients with preserved left ventricular contractility. Our study was unable to differentiate pre-existing cardiac dysfunction from neuro-endocrine mediated myocardial stunning. Future research is necessary to better understand heart-brain interactions in this setting and to further explore the underlying mechanisms and consequences of neuro-endocrine mediated cardiac dysfunction. [West J Emerg Med. 2011;12(2:227-232.

  19. Multimodal quantitation of the effects of endovascular therapy for vasospasm on cerebral blood flow, transcranial doppler ultrasonographic velocities, and cerebral artery diameters.

    Science.gov (United States)

    Oskouian, Rod J; Martin, Neil A; Lee, Jae Hong; Glenn, Thomas C; Guthrie, Donald; Gonzalez, Nestor R; Afari, Arash; Viñuela, Fernando

    2002-07-01

    The goal of this study was to quantify the effects of endovascular therapy on vasospastic cerebral vessels. We reviewed the medical records for 387 patients with ruptured intracranial aneurysms who were treated at a single institution (University of California, Los Angeles) between May 1, 1993, and March 31, 2001. Patients who developed cerebral vasospasm and underwent cerebral arteriographic, transcranial Doppler ultrasonographic, and cerebral blood flow (CBF) studies before and after endovascular therapy for cerebral arterial spasm (vasospasm) were included in this study. Forty-five patients fulfilled the aforementioned criteria and were treated with either papaverine infusion, papaverine infusion with angioplasty, or angioplasty alone. After balloon angioplasty (12 patients), CBF increased from 27.8 +/- 2.8 ml/100 g/min to 28.4 +/- 3.0 ml/100 g/min (P = 0.87); the middle cerebral artery blood flow velocity was 1 57.6 +/- 9.4 cm/s and decreased to 76.3 +/- 9.3 cm/s (P < 0.05), with a mean increase in cerebral artery diameters of 24.4%. Papaverine infusion (20 patients) transiently increased the CBF from 27.5 +/- 2.1 ml/100 g/min to 38.7 +/- 2.8 ml/100 g/min (P < 0.05) and decreased the middle cerebral artery blood flow velocity from 109.9 +/- 9.1 cm/s to 82.8 +/- 8.6 cm/s (P < 0.05). There was a mean increase in vessel diameters of 30.1% after papaverine infusion. Combined treatment (13 patients) significantly increased the CBF from 33.3 +/- 3.2 ml/100 g/min to 41.7 +/- 2.8 ml/100 g/min (P< 0.05) and decreased the transcranial Doppler velocities from 148.9 +/- 12.7 cm/s to 111.4 +/- 10.6 cm/s (P < 0.05), with a mean increase in vessel diameters of 42.2%. Balloon angioplasty increased proximal vessel diameters, whereas papaverine treatment effectively dilated distal cerebral vessels. In our small series, we observed no correlation between early clinical improvement or clinical outcomes and any of our quantitative or physiological data (CBF, transcranial Doppler

  20. Effect of hypoxia on cerebral blood flow regulation during rest and exercise : role of cerebral oxygen delivery on performance

    OpenAIRE

    Fan, J.-L.

    2014-01-01

    Adequate supply of oxygen to the brain is critical for maintaining normal brain function. Severe hypoxia, such as that experienced during high altitude ascent, presents a unique challenge to brain oxygen (O2) supply. During high-intensity exercise, hyperventilation-induced hypocapnia leads to cerebral vasoconstriction, followed by reductions in cerebral blood flow (CBF), oxygen delivery (DO2), and tissue oxygenation. This reduced O2 supply to the brain could potentially account for the reduce...

  1. Evaluation of regional cerebral circulation and metabolism in moyamoya disease using positron emission computed tomography

    International Nuclear Information System (INIS)

    Kuwabara, Yasuo

    1986-01-01

    Regional cerebral blood flow, oxygen extraction fraction, metabolic rate of oxygen, blood volume and transit time were evaluated in 11 patients with moyamoya disease and 3 with suspected moyamoya disease using positron emission computed tomography. Eight of them were examined before and after EC-IC bypass surgery. Moyamoya patients were classified into four groups, namely, pediatric bilateral chronic type (over 5 years from onset), pediatric bilateral early type (within 5 years from onset), pediatric unilateral early type and adult type, according to age, duration of disease from onset and angiographic findings. These four groups showed different patterns on PET images; diffusely decreased CBF and CMRO2 in pediatric bilateral chronic type, decreased CBF and increased OEF in the frontal or temporoparietal region in pediatric bilateral early type, diffusely decreased CBF and increased OEF in the unilateral cerebral hemisphere in pediatric unilateral cerebral hemisphere in pediatric unilateral early type, and decreased CBF and CMRO2 in adult type. An increase of rCBV was demonstrated in frontal regions or basal ganglia in all groups, more prominently in pediatric patients. This was thought to be a common finding in moyamoya disease, corresponding to moyamoya vessels. Staging of moyamoya disease by PET was presented and compared to the angiographic staging. They were significantly correlated, and the stage 3 on PET image with decreased CMRO2 corresponded to the stage 3 or 4 on angiography, the most active stage of moyamoya disease. PET revealed increased CBF in the cortical area around EC-IC bypass but no remarkable changes in mean values of rCBF, OEF, CMRO2 and CBV in cerebral hemisphere. Some patients showed decreased rCBV in the basal ganglia. (J.P.N.)

  2. Cerebral blood flow study with 3D-SSP and neuropsychological evaluation by mini-mental state examination (MMSE) before and after clipping of unruptured cerebral aneurysm

    International Nuclear Information System (INIS)

    Takada, Hidekazu; Sasaki, Takehiko; Osato, Toshiaki

    2006-01-01

    We evaluate the influence of surgery for unruptured aneurysms on cerebral blood flow and neuropsychological estimate. We evaluated the cases of 28 consecutive patients with unruptured cerebral aneurysm treated with direct surgery accompanied by craniotomy. Before and after surgery, MRI, 123 I-IMP-SPECT with 3D-SSP analysis and MMSE were performed. There was not a significant decrease in MMSE. In 123 I-IMP-SPECT, it was recognized that the cerebral blood flow was decreased at the frontal operculum of operative site. These results indicate that careful neuropsychological evaluation is essential to make a favorable treatment plan for unruptured aneulysms. (author)

  3. Patient state index and cerebral blood flow changes during shoulder arthroscopy in beach chair position.

    Science.gov (United States)

    Buget, Mehmet Ilke; Atalar, Ata Can; Edipoglu, Ipek Saadet; Sungur, Zerrin; Sivrikoz, Nukhet; Karadeniz, Meltem; Saka, Esra; Kucukay, Suleyman; Senturk, Mert N

    2016-01-01

    The aim of the study were to demonstrate the possible hemodynamic changes and cerebral blood flow alterations in patients who were positioned from supine to beach chair position; and to detect if the position change causes any cortical activity alteration as measured by the 4-channeled electroencephalography monitor. 35 patients were included. Before the induction, mean arterial pressure and patient state index values were recorded (T0). After the intubation, doppler-ultrasonography of the patients' internal carotid and vertebral arteries were evaluated to acquire cerebral blood flow values from the formula. In supine position, mean arterial pressure, patient state index and cerebral blood flow values were recorded (T1) and the patient was positioned to beach chair position. After 5min all measurements were repeated (T2). Measurements of patient state index and mean arterial pressure were repeated after 20 (T3), and 40 (T4)min. There was a significant decrease between T0 and T1 in heart rate (80.5±11.6 vs. 75.9±14.4beats/min), MAP (105.8±21.9 vs. 78.9±18.4mmHg) and PSI (88.5±8.3 vs. 30.3±9.7) (all pstate index values (T1-T4) showed no significant change; however, comparing only T1 and T2 resulted in a statically significant decrease in patient state index. There was a significant decrease in cerebral blood flow after beach chair position. Beach chair position was associated with a decrease in cerebral blood flow and patient state index values. Patient state index was affected by the gravitational change of the cerebral blood flow; however, both factors were not directly correlated to each other. Moreover, the decrease in patient state index value was transient and returned to normal values within 20min. Copyright © 2015 Sociedade Brasileira de Anestesiologia. Published by Elsevier Editora Ltda. All rights reserved.

  4. [Patient state index and cerebral blood flow changes during shoulder arthroscopy in beach chair position].

    Science.gov (United States)

    Buget, Mehmet Ilke; Atalar, Ata Can; Edipoglu, Ipek Saadet; Sungur, Zerrin; Sivrikoz, Nukhet; Karadeniz, Meltem; Saka, Esra; Kucukay, Suleyman; Senturk, Mert N

    2016-01-01

    The aim of the study were to demonstrate the possible hemodynamic changes and cerebral blood flow alterations in patients who were positioned from supine to beach chair position; and to detect if the position change causes any cortical activity alteration as measured by the 4-channeled electroencephalography monitor. 35 patients were included. Before the induction, mean arterial pressure and patient state index values were recorded (T0). After the intubation, doppler-ultrasonography of the patients' internal carotid and vertebral arteries were evaluated to acquire cerebral blood flow values from the formula. In supine position, mean arterial pressure, patient state index and cerebral blood flow values were recorded (T1) and the patient was positioned to beach chair position. After 5min all measurements were repeated (T2). Measurements of patient state index and mean arterial pressure were repeated after 20 (T3), and 40 (T4)min. There was a significant decrease between T0 and T1 in heart rate (80.5±11.6 vs. 75.9±14.4beats/min), MAP (105.8±21.9 vs. 78.9±18.4mmHg) and PSI (88.5±8.3 vs. 30.3±9.7) (all pstate index values (T1-T4) showed no significant change; however, comparing only T1 and T2 resulted in a statically significant decrease in patient state index. There was a significant decrease in cerebral blood flow after beach chair position. Beach chair position was associated with a decrease in cerebral blood flow and patient state index values. Patient state index was affected by the gravitational change of the cerebral blood flow; however, both factors were not directly correlated to each other. Moreover, the decrease in patient state index value was transient and returned to normal values within 20min. Copyright © 2015 Sociedade Brasileira de Anestesiologia. Publicado por Elsevier Editora Ltda. All rights reserved.

  5. Neurological Injury and Cerebral Blood Flow in Single Ventricles Throughout Staged Surgical Reconstruction.

    Science.gov (United States)

    Fogel, Mark A; Li, Christine; Elci, Okan U; Pawlowski, Tom; Schwab, Peter J; Wilson, Felice; Nicolson, Susan C; Montenegro, Lisa M; Diaz, Laura; Spray, Thomas L; Gaynor, J William; Fuller, Stephanie; Mascio, Christopher; Keller, Marc S; Harris, Matthew A; Whitehead, Kevin K; Bethel, Jim; Vossough, Arastoo; Licht, Daniel J

    2017-02-14

    Patients with a single ventricle experience a high rate of brain injury and adverse neurodevelopmental outcome; however, the incidence of brain abnormalities throughout surgical reconstruction and their relationship with cerebral blood flow, oxygen delivery, and carbon dioxide reactivity remain unknown. Patients with a single ventricle were studied with magnetic resonance imaging scans immediately prior to bidirectional Glenn (pre-BDG), before Fontan (BDG), and then 3 to 9 months after Fontan reconstruction. One hundred sixty-eight consecutive subjects recruited into the project underwent 235 scans: 63 pre-BDG (mean age, 4.8±1.7 months), 118 BDG (2.9±1.4 years), and 54 after Fontan (2.4±1.0 years). Nonacute ischemic white matter changes on T2-weighted imaging, focal tissue loss, and ventriculomegaly were all more commonly detected in BDG and Fontan compared with pre-BDG patients ( P <0.05). BDG patients had significantly higher cerebral blood flow than did Fontan patients. The odds of discovering brain injury with adjustment for surgical stage as well as ≥2 coexisting lesions within a patient decreased (63%-75% and 44%, respectively) with increasing amount of cerebral blood flow ( P <0.05). In general, there was no association of oxygen delivery (except for ventriculomegaly in the BDG group) or carbon dioxide reactivity with neurological injury. Significant brain abnormalities are commonly present in patients with a single ventricle, and detection of these lesions increases as children progress through staged surgical reconstruction, with multiple coexisting lesions more common earlier than later. In addition, this study demonstrated that BDG patients had greater cerebral blood flow than did Fontan patients and that an inverse association exists of various indexes of cerebral blood flow with these brain lesions. However, CO 2 reactivity and oxygen delivery (with 1 exception) were not associated with brain lesion development. URL: http

  6. Measurement of local blood flow and oxygen consumption in evolving irreversible cerebral infarction: an in vivo study in man

    International Nuclear Information System (INIS)

    Baron, J.C.; Rougemont, D.; Lebrun-Grandie, P.; Bousser, M.G.; Cabanis, E.; Bories, J.; Comar, D.; Castaigne, P.

    1982-09-01

    Positron emission tomography (PET) allows in vivo measurement of local cerebral blood flow (1CBF), oxygen consumption rate (1CMRO 2 ) and glucose utilisation (1CMRG1c) in man. Although 1CMRG1c is accessible in animals, this is not the case for 1CMRO 2 , an excellent index of local functional state. PET imaging of the local interrelationship of CBF and metabolism in completed ischemic stroke has attracted considerable interest because of its potential to differentiate irreversibly damaged from viable tissue on the basis of the CBF- metabolism patterns. Several qualitative or semi-quantitative pioneering studies provided a limited insight into this question, while the single truly quantitative study was only briefly reported. We report here a detailed study of the local CBF-CMRO 2 quantitative patterns in irreversibly infarcted brain regions

  7. Altered phase interactions between spontaneous blood pressure and flow fluctuations in type 2 diabetes mellitus: Nonlinear assessment of cerebral autoregulation

    Science.gov (United States)

    Hu, Kun; Peng, C. K.; Huang, Norden E.; Wu, Zhaohua; Lipsitz, Lewis A.; Cavallerano, Jerry; Novak, Vera

    2008-04-01

    Cerebral autoregulation is an important mechanism that involves dilatation and constriction in arterioles to maintain relatively stable cerebral blood flow in response to changes of systemic blood pressure. Traditional assessments of autoregulation focus on the changes of cerebral blood flow velocity in response to large blood pressure fluctuations induced by interventions. This approach is not feasible for patients with impaired autoregulation or cardiovascular regulation. Here we propose a newly developed technique-the multimodal pressure-flow (MMPF) analysis, which assesses autoregulation by quantifying nonlinear phase interactions between spontaneous oscillations in blood pressure and flow velocity during resting conditions. We show that cerebral autoregulation in healthy subjects can be characterized by specific phase shifts between spontaneous blood pressure and flow velocity oscillations, and the phase shifts are significantly reduced in diabetic subjects. Smaller phase shifts between oscillations in the two variables indicate more passive dependence of blood flow velocity on blood pressure, thus suggesting impaired cerebral autoregulation. Moreover, the reduction of the phase shifts in diabetes is observed not only in previously-recognized effective region of cerebral autoregulation (type 2 diabetes mellitus alters cerebral blood flow regulation over a wide frequency range and that this alteration can be reliably assessed from spontaneous oscillations in blood pressure and blood flow velocity during resting conditions. We also show that the MMPF method has better performance than traditional approaches based on Fourier transform, and is more suitable for the quantification of nonlinear phase interactions between nonstationary biological signals such as blood pressure and blood flow.

  8. Detection of misery perfusion in the cerebral hemisphere with chronic unilateral major cerebral artery steno-occlusive disease using crossed cerebellar hypoperfusion: comparison of brain SPECT and PET imaging

    Energy Technology Data Exchange (ETDEWEB)

    Matsumoto, Yoshiyasu; Ogasawara, Kuniaki; Saito, Hideo; Takahashi, Yoshihiro; Ogasawara, Yasushi; Kobayashi, Masakazu; Ogawa, Akira [Iwate Medical University, Department of Neurosurgery, Morioka (Japan); Iwate Medical University, Cyclotron Research Center, Morioka (Japan); Terasaki, Kazunori [Iwate Medical University, Cyclotron Research Center, Morioka (Japan); Yoshida, Kenji; Beppu, Takaaki; Kubo, Yoshitaka; Fujiwara, Shunrou [Iwate Medical University, Department of Neurosurgery, Morioka (Japan); Tsushima, Eiki [Hirosaki University, Graduate School of Health Sciences, Hirosaki (Japan)

    2013-10-15

    In patients with unilateral internal carotid or middle cerebral artery (ICA or MCA) occlusive disease, the degree of crossed cerebellar hypoperfusion that is evident within a few months after the onset of stroke may reflect cerebral metabolic rate of oxygen in the affected cerebral hemisphere relative to that in the contralateral cerebral hemisphere. The aim of the present study was to determine whether the ratio of blood flow asymmetry in the cerebellar hemisphere to blood flow asymmetry in the cerebral hemisphere on positron emission tomography (PET) and single photon emission computed tomography (SPECT) correlates with oxygen extraction fraction (OEF) asymmetry in the cerebral hemisphere on PET in patients with chronic unilateral ICA or MCA occlusive disease and whether this blood flow ratio on SPECT detects misery perfusion in the affected cerebral hemisphere in such patients. Brain blood flow and OEF were assessed using {sup 15}O-PET and N-isopropyl-p-[{sup 123}I]iodoamphetamine ({sup 123}I-IMP) SPECT, respectively. All images were anatomically standardized using SPM2. A region of interest (ROI) was automatically placed in the bilateral MCA territories and in the bilateral cerebellar hemispheres using a three-dimensional stereotaxic ROI template, and affected-to-contralateral asymmetry in the MCA territory or contralateral-to-affected asymmetry in the cerebellar hemisphere was calculated. Sixty-three patients with reduced blood flow in the affected cerebral hemisphere on {sup 123}I-IMP SPECT were enrolled in this study. A significant correlation was observed between MCA ROI asymmetry of PET OEF and the ratio of cerebellar hemisphere asymmetry of blood flow to MCA ROI asymmetry of blood flow on PET (r = 0.381, p = 0.0019) or SPECT (r = 0.459, p = 0.0001). The correlation coefficient was higher when reanalyzed in a subgroup of 43 patients undergoing a PET study within 3 months after the last ischemic event (r = 0.541, p = 0.0001 for PET; r = 0.609, p < 0

  9. Imaging of Neuronal Activity in Awake Mice by Measurements of Flavoprotein Autofluorescence Corrected for Cerebral Blood Flow.

    Science.gov (United States)

    Takahashi, Manami; Urushihata, Takuya; Takuwa, Hiroyuki; Sakata, Kazumi; Takado, Yuhei; Shimizu, Eiji; Suhara, Tetsuya; Higuchi, Makoto; Ito, Hiroshi

    2017-01-01

    Green fluorescence imaging (e.g., flavoprotein autofluorescence imaging, FAI) can be used to measure neuronal activity and oxygen metabolism in living brains without expressing fluorescence proteins. It is useful for understanding the mechanism of various brain functions and their abnormalities in age-related brain diseases. However, hemoglobin in cerebral blood vessels absorbs green fluorescence, hampering accurate assessments of brain function in animal models with cerebral blood vessel dysfunctions and subsequent cerebral blood flow (CBF) alterations. In the present study, we developed a new method to correct FAI signals for hemoglobin-dependent green fluorescence reductions by simultaneous measurements of green fluorescence and intrinsic optical signals. Intrinsic optical imaging enabled evaluations of light absorption and scatters by hemoglobin, which could then be applied to corrections of green fluorescence intensities. Using this method, enhanced flavoprotein autofluorescence by sensory stimuli was successfully detected in the brains of awake mice, despite increases of CBF, and hemoglobin interference. Moreover, flavoprotein autofluorescence could be properly quantified in a resting state and during sensory stimulation by a CO 2 inhalation challenge, which modified vascular responses without overtly affecting neuronal activities. The flavoprotein autofluorescence signal data obtained here were in good agreement with the previous findings from a condition with drug-induced blockade of cerebral vasodilation, justifying the current assaying methodology. Application of this technology to studies on animal models of brain diseases with possible changes of CBF, including age-related neurological disorders, would provide better understanding of the mechanisms of neurovascular coupling in pathological circumstances.

  10. Regional cerebral glucose metabolism during sevoflurane anaesthesia in healthy subjects studied with positron emission tomography

    DEFF Research Database (Denmark)

    Schlünzen, L; Juul, N; Hansen, K V

    2010-01-01

    BACKGROUND: The precise mechanism by which sevoflurane exerts its effects in the human brain remains unknown. In the present study, we quantified the effects of sevoflurane on regional cerebral glucose metabolism (rGMR) in the human brain measured with positron emission tomography. METHODS: Eight...... areas by 48-71% of the baseline (Pbrain metabolic reduction of GMR in all regions...... of the human brain, with the most marked metabolic suppression in the lingual gyrus, thalamus and occipital lobe....

  11. Role of cerebral blood flow in extreme breath holding.

    Science.gov (United States)

    Bain, Anthony R; Ainslie, Philip N; Hoiland, Ryan L; Willie, Chris K; MacLeod, David B; Madden, Dennis; Maslov, Petra Zubin; Drviš, Ivan; Dujić, Željko

    2016-01-01

    The role of cerebral blood flow (CBF) on a maximal breath-hold (BH) in ultra-elite divers was examined. Divers (n = 7) performed one control BH, and one BH following oral administration of the non-selective cyclooxygenase inhibitor indomethacin (1.2 mg/kg). Arterial blood gases and CBF were measured prior to (baseline), and at BH termination. Compared to control, indomethacin reduced baseline CBF and cerebral delivery of oxygen (CDO 2 ) by about 26% (p tension was higher following oral administration of indomethacin compared to control (4.05 ± 0.45 vs. 3.44 ± 0.32 kPa). The absolute increase in CBF from baseline to the termination of apnea was lower with indomethacin (p = 0.01). These findings indicate that the impact of CBF on maximal BH time is likely attributable to its influence on cerebral H + washout, and therefore central chemoreceptive drive to breathe, rather than to CDO 2 .

  12. Aging, regional cerebral blood flow, and neuropsychological functioning

    International Nuclear Information System (INIS)

    MacInnes, W.D.; Golden, C.J.; Gillen, R.W.; Sawicki, R.F.; Quaife, M.; Uhl, H.S.; Greenhouse, A.J.

    1984-01-01

    Previous studies found changes in regional cerebral blood flow (rCBF) patterns related to both age and various cognitive tasks. However, no study has yet demonstrated a relationship between rCBF and performance on the Luria-Nebraska Neuropsychological Battery (LNNB) in an elderly group. Seventy-nine elderly volunteers (56-88 years old), both healthy and demented, underwent the 133 xenon inhalation rCBF procedure and were given the LNNB. The decrements in the gray-matter blood flow paralleled decrements in performance on the LNNB. Using partial correlations, a significant proportion of shared variance was observed between gray-matter blood flow and the LNNB scales. However, there was much less of a relationship between white-matter blood flow and performance on the LNNB. This study suggests that even within a restricted age sample rCBF is related in a global way to neuropsychological functioning

  13. Type of aphasia and regional cerebral blood flow

    International Nuclear Information System (INIS)

    Tagawa, Koichi; Sugimoto, Keiko; Minematsu, Kazuo; Yamaguchi, Takenori; Naritomi, Hiroaki; Sawada, Tohru

    1982-01-01

    In 40 patients with aphasia due to cerebral infarction, regional cerebral blood flow (rCBF) was measured after 2 months of ictus with 133 Xe inhalation method. There were 18 cases with motor aphasia and 22 with sensory aphasia. On the measurements of rCBF, 3 detectors were placed over frontal region (group F), 3 over temporal region (group T), and remaining 3 over parietal region (group P), of the dominant hemisphere. The flow values were compared with the rCBF values obtained from 21 control subjects who had no abnormality in CT scan and on neurological examinations. The control subjects revealed the hyperfrontal pattern of flow distribution; rCBF values in groups F, T and P, which were expressed as an initial slope index, were 50.0 +- 4.8, 48.0 +- 5.1 and 47.4 +- 4.5, respectively. The hyperfrontal pattern was absent in cases with motor aphasia. In this group, rCBF in groups F, T and P were 42.0 +- 8.3, 44.7 +- 8.4 and 41.0 +- 8.5, respectively, and rCBF in frontal region was significantly reduced compared with that in the control group. In sensory aphasia, rCBF values in groups F, T and P were all significantly reduced compared to the controls showing 44.0 +- 5.7, 42.8 +- 5.1 and 40.6 +- 5.4, respectively. In this group, the hyperfrontal pattern was maintained at a low flow level. When absolute rCBF values were compared between motor and sensory aphasia, there was no significant difference between these 2 groups. However, regional flow distribution in motor aphasia was significantly different from that of sensory aphasia, and the cases having the lowest value in group F were more frequently found in the former than in the latter. (J.P.N.)

  14. Scintigraphy of cerebral blood flow with N-isopropyl-p-[123I]-iodoamphetamine in cerebrovascular accident

    International Nuclear Information System (INIS)

    Sone, Teruki; Fukunaga, Masao; Otsuka, Nobuaki

    1985-01-01

    In 20 patients with cerebrovascular accident, cerebral blood flow was estimated with N-isopropyl-p-[ 123 I]-iodoamphetamine ( 123 I-IMP) using a rotating gamma camera, and the findings were compared with those of X-CT or angiography. 123 I-IMP study demonstrated the areas of diminished cerebral blood flow in 14 cases. X-CT also demonstrated lesions in 14 cases, however, 123 I-IMP study delineated the lesions more precisely corresponding to the neurological findings. In cases with cerebellar hemorrhage or reversible ischemic neurological deficit (RIND), the lesion could be established only by 123 I-IMP study. It was demonstrated by 123 I-IMP study that vascular stenosis or abnormal vessels seen on angiography in patients with vertebro-basilar insufficiency or venous angioma was not necessarily accompanied by diminished blood flow. It was shown that scintigraphy with 123 I-IMP was a non-invasive, safe and extremely useful method to estimate the regional cerebral blood flow. (author)

  15. A study of the acute effect of smoking on cerebral blood flow using {sup 99m}Tc-ECD SPET

    Energy Technology Data Exchange (ETDEWEB)

    Yamamoto, Yuka; Nishiyama, Yoshihiro; Monden, Toshihide; Satoh, Katashi; Ohkawa, Motoomi [Department of Radiology, Faculty of Medicine, Kagawa Medical University, 1750-1 Ikenobe, Miki-cho, Kita-gun, Kagawa, 761-0793 (Japan)

    2003-04-01

    Cigarette smoking is known to be associated with atherosclerosis, is an important risk factor for stroke and has other serious effects. The aim of this study was to evaluate the acute effect of cigarette smoking on cerebral blood flow using statistical parametric mapping (SPM). Ten healthy volunteers with a smoking habit were studied using technetium-99m-labelled ethylcysteinate dimer single-photon emission tomography (SPET). We evaluated the regional cerebral blood flow under the smoking and resting states. The regional cerebral blood flow on smoking-activated SPET was significantly decreased in the whole brain as compared with that on resting SPET. Our findings therefore suggest that one of the acute effects of cigarette smoking is to induce a diffuse decrease in cerebral blood flow. (orig.)

  16. Quantitative Analysis of Regional Cerebral Blood Flow using {sup 99m}Tc-HMPAO SPECT in Parkinson's Disease

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Myung Chul; Bae, Sang Kyun; Chung, June Key; Koh, Chang Soon; Roh, Jae Kyu; Myung, Ho Jin [Seoul National University College of Medicine, Seoul (Korea, Republic of); Lee, Myung Hae [Asan Medical Center, Seoul (Korea, Republic of)

    1992-07-15

    Regional cerebral blood flow were measured in 10 patients with Parkinson's disease and 12 normal persons using {sup 99m}Tc-HMPAO SPECT. Reconstructed images were interpreted qualitatively and were compared with those findings of CT. For the quantitative analysis, six pairs of region of interest matched with the perfusion territories of large cerebral arteries and cerebellar hemisphere were determined. From the count values, indices showing the degree of asymmetry between right and left cerebral or cerebellar hemisphere, cerebral asymmetry index (ASI) and percent index of cerebellar asymmetry (PIA), and an index showing change of each region, region to cerebellum ratio (RCR) were obtained. ASI of normal persons and patients were 0.082 +- 0.033 and 0.108 +- 0.062, respectively and PIA were -0.4 +- 0.7% and -0.7 +- 1.0%, respectively, which showed no statistically significant difference between normal persons and patients. Among 10 RCR's, those of both regions of basal ganglia and both regions of anterior cerebral artery were significantly reduced. We concluded that the most significant reduction of regional cerebral blood flow in patients with Parkinson's disease was observed in the regions of basal ganglia and in the regions of anterior cerebral artery, and the degree of change in hemispheric blood flow was similar in both hemisphere.

  17. Cerebral blood flow and brain shrinkage seen on CT during ACTH therapy

    International Nuclear Information System (INIS)

    Futagi, Yasuyuki; Abe, Jiro; Kawahigashi, Kenji

    1986-01-01

    By means of the Doppler ultrasound method, the cerebral blood flow (CBF) was assessed in 21 children with epilepsy undergoing treatment with adrenocorticotrophic hormone (ACTH). The maximum reduction in the internal carotid velocity, as an index of CBF during therapy, was about 35 percent compared with the values before therapy. Furthermore, sequential computed tomography (CT) examinations of the same subjects were performed to evaluate the change in the area of the intracranial brain parenchyma during therapy. The maximum reduction in the parenchymal area during therapy was about 10 percent. This corresponds to a 20 percent reduction in CBF according to Poiseuille's law, however, the remaining reduction in CBF demonstrated by velocity measurement cannot be explained only by that mechanical vascular factor. From these findings, it is concluded that in order to elucidate the mechanism of the CBF reduction, physiological factors such as changes in metabolism during therapy should also be evaluated in addition to the mechanical and physical causes. (author)

  18. Similarities of cerebral glucose metabolism in Alzheimer's and Parkinsonian dementia

    International Nuclear Information System (INIS)

    Kuhl, D.E.; Metter, E.J.; Benson, D.F.; Ashford, J.W.; Riege, W.H.; Fujikawa, D.G.; Markham, C.H.; Maltese, A.

    1985-01-01

    In the dementia of probable Alzheimer's Disease (AD), there is a decrease in the metabolic ratio of parietal cortex/caudate-thalamus which relates measures in the most and in the least severely affected locations. Since some demented patients with Parkinson's Disease (PDD) are known to share pathological and neurochemical features with AD patients, the authors evaluated if the distribution of cerebral hypometabolism in PDD and AD were the same. Local cerebral metabolic rates were determined using the FDG method and positron tomography in subjects with AD (N=23), and PDD (N=7), multiple infarct dementia (MID)(N=6), and controls (N=10). In MID, the mean par/caudthal ratio was normal (0.79 +- 0.9, N=6). In AD and PDD patients, this ratio correlated negatively with both the severity (r=-0.624, rho=0.001) and duration (r=-0.657, rho=0.001) of dementia. The ratio was markedly decreased in subjects with mild to severe dementia (0.46 +- 0.09, N=21) and with dementia duration greater than two years (0.44 +- 0.08, N=18), but the ratio was also significantly decreased in patients with less advanced disease, i.e., when dementia was only questionable (0.64 +- 0.14, N=9) (t=2.27, rho<0.037) and when duration was two years or less (0.62 +- 0.13, N=12)(t=2.88, rho<0.009). This similarity of hypometabolism in AD and PDD is additional evidence that a common mechanism may operate in both disorders. The par/caud-thal metabolic ratio may be an index useful in the differential diagnosis of early dementia

  19. Impairment of neuropsychological function in patients with hemodynamic cerebral ischemia and efficacy of bypass surgery

    International Nuclear Information System (INIS)

    Sasoh, Masayuki

    1999-01-01

    In order to evaluate the relation between neuropsychological functions and hemodynamic cerebral ischemia, the author analyzed neuropsychological examination and the cerebral blood flow and metabolism of patients before and after bypass surgery. Twenty-five patients were defined by clinical and laboratory criteria as suffering from hemodynamic cerebral ischemia. All patients had one or more episodes of focal cerebral ischemia due to unilateral internal carotid or middle cerebral artery occlusion. Computerized tomography scans either were normal or showed evidence of watershed infarction. Based on these criteria, superficial temporal artery-proximal middle cerebral artery anastomosis was performed. The baseline cerebral blood flow (CBF), oxygen extraction fraction (OEF), cerebral metabolic rate of oxygen (CMRO 2 ) and cerebrovascular reserve capacity (CVRC) were studied using positron emission computerized tomography (PET) and the acetazolamide test. Neuropsychological evaluations including Hasegawa Dementia Scale-Revised, Mini-Mental State and Wechsler Adult Intelligence Scale-Revised (WAIS-R), and PET study were completed one month after the last ischemic event and 3-6 months after the operation. A significant negative correlation was observed between OEF and neuropsychological functions. Postoperative neuropsychological functions showed significant improvement. Significant correlations were observed for ΔWAIS-R (preoperative WAIS-R postoperative WAIS-R) versus preoperative CMRO 2 (r=0.52), for ΔWAIS-R versus preoperative OEF (r=0.47). In view of these findings, the author concludes that elevation of OEF impairs neuropsychological functions and bypass surgery improves neuropsychological functions in patients with normal CMRO 2 and elevated OEF. (author)

  20. Sodium bicarbonate causes dose-dependent increases in cerebral blood flow in infants and children with single ventricle physiology

    Science.gov (United States)

    Buckley, Erin M.; Naim, Maryam Y.; Lynch, Jennifer M.; Goff, Donna A.; Schwab, Peter J.; Diaz, Laura K.; Nicolson, Susan C.; Montenegro, Lisa M.; Lavin, Natasha A.; Durduran, Turgut; Spray, Thomas L.; Gaynor, J. William; Putt, Mary E.; Yodh, A.G.; Fogel, Mark A.; Licht, Daniel J.

    2013-01-01

    Background Sodium bicarbonate (NaHCO3) is a common treatment for metabolic acidemia, however little definitive information exists regarding its treatment efficacy and cerebral hemodynamic effects. This pilot observational study quantifies relative changes in cerebral blood flow (rCBF) and oxy and deoxy-hemoglobin concentrations (ΔHbO2 and ΔHb) due to bolus administration of NaHCO3 in patients with mild base deficits. Methods Infants and children with hypoplastic left heart syndrome (HLHS) were recruited prior to cardiac surgery. NaHCO3 was given as needed for treatment of base deficit. Diffuse optical spectroscopies were employed for 15 minutes post-injection to non-invasively monitor ΔHb, ΔHbO2 and rCBF relative to baseline prior to NaHCO3 administration. Results Twenty-two anesthetized and mechanically ventilated HLHS patients (1 day to 4 years old) received a median (interquartile range) dose of 1.1 (0.8, 1.8) mEq/kg NaHCO3 administered intravenously over 10–20 seconds to treat a base deficit of −4 (−6, −3) mEq/l. NaHCO3 caused significant dose-dependent increases in rCBF, however population averaged ΔHb or Δ4HbO2 compared to controls were not significant. Conclusions Dose-dependent increases in cerebral blood flow (CBF) caused by bolus NaHCO3 are an important consideration in vulnerable populations wherein risk of rapid CBF fluctuations does not outweigh the benefit of treating a base deficit. PMID:23403802

  1. Regional cerebral blood flow in older patients with chronic subdural hematoma

    International Nuclear Information System (INIS)

    Hoshi, Yutaka; Fuse, Masaaki; Iio, Masahiro; Fuziwara, Keigo; Kawaguchi, Shinichiro

    1978-01-01

    Regional cerebral blood flow (rCBF) was measured in 4 regions (frontal, parietal, occipital, and temporal) over the entire hemisphere using modified 133 Xe clearance method in 5 patients with chronic subdural hematoma. In 5 patients, rCBF was measured both pre- and postoperation and those values were compared. CBF (average cerebral blood flow) measurements were compared. CBF measurements were carried out in each patients respectively, that is before the operation and 3 weeks after the operation. Before the operation, the presence of chronic subdural hematoma, but brought about only slight or moderate generalized decrease in rCBF. The older patients presented subnormal values of 31.5 - 45.1 ml/100 g/min. Mean f sub(g) (the flow in the grey matter) of 5 patients was 66.8 +- 5.0 ml/100 g/min on the hematoma site, 58.1 +- 2.8 ml/100 g/min on the non-hematoma site before operation. Three weeks after operation mean f sub(g) was 65.5 +- 7.6 ml/100 g/min on the non-hematoma site, 64.2 +- 3.5 ml/100 g/min on the hematoma site, and CBFr of non-hematoma site was 40.2 +- 5.7 ml/100 g/min and that of hematoma site, 38.5 +- 8.8 ml/100 g/min. These figures are moderately smaller than that of the normal values. A comparison between regional flow values noted in patients of pre- and post-operation who has a removal of hematomas indicated that the flow values of non-hematoma site increased slightly 3 weeks after operation, inspite of the only slight or no improvement in neurological features. But the flow values (f sub(g), CBFr) of hematoma site decreased 3 weeks after operation. It seems that post-operative follow up of mean cerebral blood flow change might be of help in the assessment of prognosis of operation. (auth.)

  2. Regional cerebral blood flow in older patients with chronic subdural hematoma

    Energy Technology Data Exchange (ETDEWEB)

    Hoshi, Y; Fuse, M; Iio, M; Fuziwara, K; Kawaguchi, S [Tokyo Metropolitan Geriatric Medical Center (Japan)

    1978-02-01

    Regional cerebral blood flow (rCBF) was measured in 4 regions (frontal, parietal, occipital, and temporal) over the entire hemisphere using modified /sup 133/Xe clearance method in 5 patients with chronic subdural hematoma. In 5 patients, rCBF was measured both pre- and postoperation and those values were compared. CBF (average cerebral blood flow) measurements were compared. CBF measurements were carried out in each patients respectively, that is before the operation and 3 weeks after the operation. Before the operation, the presence of chronic subdural hematoma, but brought about only slight or moderate generalized decrease in rCBF. The older patients presented subnormal values of 31.5 - 45.1 ml/100 g/min. Mean f sub(g) (the flow in the grey matter) of 5 patients was 66.8 +- 5.0 ml/100 g/min on the hematoma site, 58.1 +- 2.8 ml/100 g/min on the non-hematoma site before operation. Three weeks after operation mean f sub(g) was 65.5 +- 7.6 ml/100 g/min on the non-hematoma site, 64.2 +- 3.5 ml/100 g/min on the hematoma site, and CBFr of non-hematoma site was 40.2 +- 5.7 ml/100 g/min and that of hematoma site, 38.5 +- 8.8 ml/100 g/min. These figures are moderately smaller than that of the normal values. A comparison between regional flow values noted in patients of pre- and post-operation who has a removal of hematomas indicated that the flow values of non-hematoma site increased slightly 3 weeks after operation, inspite of the only slight or no improvement in neurological features. But the flow values (f sub(g), CBFr) of hematoma site decreased 3 weeks after operation. It seems that post-operative follow up of mean cerebral blood flow change might be of help in the assessment of prognosis of operation.

  3. Changes of regional cerebral glucose metabolism in normal aging process : A study with FDG PET

    Energy Technology Data Exchange (ETDEWEB)

    Yoon, Joon Kee; Kim, Sang Eun; Lee, Kyung Han; Choi, Yong; Choe, Yearn Seong; Kim, Byung Tae [Sungkyunkwan Univ., School of Medicine, Seoul (Korea, Republic of)

    2001-08-01

    Normal aging results in detectable changes in the brain structure and function. We evaluated the changes of regional cerebral glucose metabolism in the normal aging process with FDG PET. Brain PET images were obtained in 44 healthy volunteers (age range 20-69'y'; M:F = 29:15) who had no history of neuropsychiatric disorders. On 6 representative transaxial images, ROls were drawn in the cortical and subcortical areas. Regional FDG uptake was normalized using whole brain uptake to adjust for the injection dose and correct for nonspecific declines of glucose metabolism affecting all brain areas equally. In the prefrontal, temporoparietal and primary sensorimotor cortex, the normalized FDG uptake (NFU) reached a peak In subjects in their 30s. The NFU in the prefrontal and primary sensorimotor cortex declined with age after 30s at a rate of 3.15%/decade and 1.93%/decade, respectively. However, the NFU in the lernporoparietal cortex did not change significantly with age after 30s. The anterior (prefrontal) posterior (temporoparietal) gradient peaked in subjects in their 30s and declined with age the reafter at a rate of 35%/decade. The NFU in the caudate nucleus was decreased with age after 20s at a rate of 2.39%/decade. In the primary visual cortex, putamen, and thalamus, the NFU values did not change significantly throughout the ages covered. These patterns were not significantly different between right and left cerebral hemispheres. Of interest was that the NFU in the left cerebellar cortex was increased with age after 20s at a rate of 2.86%/decade. These data demonstrate regional variation of the age-related changes in the cerebral glucose metabolism, with the most prominent age-related decline of metabolism in the prefrontal cortex. The increase in the cerebellar metabolism with age might reflect a process of neuronal plasticity associated with aging.

  4. Changes of regional cerebral glucose metabolism in normal aging process : A study with FDG PET

    International Nuclear Information System (INIS)

    Yoon, Joon Kee; Kim, Sang Eun; Lee, Kyung Han; Choi, Yong; Choe, Yearn Seong; Kim, Byung Tae

    2001-01-01

    Normal aging results in detectable changes in the brain structure and function. We evaluated the changes of regional cerebral glucose metabolism in the normal aging process with FDG PET. Brain PET images were obtained in 44 healthy volunteers (age range 20-69'y'; M:F = 29:15) who had no history of neuropsychiatric disorders. On 6 representative transaxial images, ROls were drawn in the cortical and subcortical areas. Regional FDG uptake was normalized using whole brain uptake to adjust for the injection dose and correct for nonspecific declines of glucose metabolism affecting all brain areas equally. In the prefrontal, temporoparietal and primary sensorimotor cortex, the normalized FDG uptake (NFU) reached a peak In subjects in their 30s. The NFU in the prefrontal and primary sensorimotor cortex declined with age after 30s at a rate of 3.15%/decade and 1.93%/decade, respectively. However, the NFU in the lernporoparietal cortex did not change significantly with age after 30s. The anterior (prefrontal) posterior (temporoparietal) gradient peaked in subjects in their 30s and declined with age the reafter at a rate of 35%/decade. The NFU in the caudate nucleus was decreased with age after 20s at a rate of 2.39%/decade. In the primary visual cortex, putamen, and thalamus, the NFU values did not change significantly throughout the ages covered. These patterns were not significantly different between right and left cerebral hemispheres. Of interest was that the NFU in the left cerebellar cortex was increased with age after 20s at a rate of 2.86%/decade. These data demonstrate regional variation of the age-related changes in the cerebral glucose metabolism, with the most prominent age-related decline of metabolism in the prefrontal cortex. The increase in the cerebellar metabolism with age might reflect a process of neuronal plasticity associated with aging

  5. Brain Size and Cerebral Glucose Metabolic Rate in Nonspecific Retardation and Down Syndrome.

    Science.gov (United States)

    Haier, Richard J.; And Others

    1995-01-01

    Brain size and cerebral glucose metabolic rate were determined for 10 individuals with mild mental retardation (MR), 7 individuals with Down syndrome (DS), and 10 matched controls. MR and DS groups both had brain volumes of about 80% compared to controls, with variance greatest within the MR group. (SLD)

  6. [Characteristics of cerebral glucose metabolism in patients with cognitive impairment in Parkinson's disease].

    Science.gov (United States)

    Homenko, Ju G; Susin, D S; Kataeva, G V; Irishina, Ju A; Zavolokov, I G

    To study the relationship between early cognitive impairment symptoms and cerebral glucose metabolism in different brain regions (according to the positron emission tomography (PET) data) in Parkinson's disease (PD) in order to increase the diagnostic and treatment efficacy. Two groups of patients with PD (stage I-III), including 11 patients without cognitive disorders and 13 with mild cognitive impairment (MCI), were examined. The control group included 10 age-matched people with normal cognition. To evaluate cognitive state, the Mini mental state examination (MMSE), the Frontal assessment battery (FAB) and the 'clock drawing test' were used. The regional cerebral glucose metabolism rate (CMRglu) was assessed using PET with 18F-fluorodeoxyglucose (FDG). In PD patients, CMRglu were decreased in the frontal (Brodmann areas (BA) 9, 10, 11, 46, 47), occipital (BA 19) and parietal (BA 39), temporal (BA 20, 37), and cingulate cortex (BA 32) compared to the control group. Cerebral glucose metabolism was decreased in the frontal (BA 8, 9, 10, 45, 46, 47), parietal (BA 7, 39, 40) and cingulate cortex (BA 23, 24, 31, 32) in the group of PD patients with MCI compared to PD patients with normal cognition. Hypometabolism in BA 7, 8, 23, 24, 31, 40 was revealed only in comparison of PD and PD-MCI groups, and did not appear in case of comparison of cognitively normal PD patients with the control group. It is possible to suggest that the mentioned above brain areas were associated with cognitive impairment. The revealed glucose hypometabolism pattern possibly has the diagnostic value for the early and preclinical diagnosis of MCI in PD and control of treatment efficacy.

  7. Assessment of resting-state blood flow through anterior cerebral arteries using trans-cranial doppler recordings.

    Science.gov (United States)

    Huang, Hanrui; Sejdić, Ervin

    2013-12-01

    Trans-cranial Doppler (TCD) recordings are used to monitor cerebral blood flow in the main cerebral arteries. The resting state is usually characterized by the mean velocity or the maximum Doppler shift frequency (an envelope signal) by insonating the middle cerebral arteries. In this study, we characterized cerebral blood flow in the anterior cerebral arteries. We analyzed both envelope signals and raw signals obtained from bilateral insonation. We recruited 20 healthy patients and conducted the data acquisition for 15 min. Features were extracted from the time domain, the frequency domain and the time-frequency domain. The results indicate that a gender-based statistical difference exists in the frequency and time-frequency domains. However, no handedness effect was found. In the time domain, information-theoretic features indicated that mutual dependence is higher in raw signals than in envelope signals. Finally, we concluded that insonation of the anterior cerebral arteries serves as a complement to middle cerebral artery studies. Additionally, investigation of the raw signals provided us with additional information that is not otherwise available from envelope signals. Use of direct trans-cranial Doppler raw data is therefore validated as a valuable method for characterizing the resting state. Copyright © 2013 World Federation for Ultrasound in Medicine & Biology. Published by Elsevier Inc. All rights reserved.

  8. Decreased cerebral blood flow in renal transplant recipients

    International Nuclear Information System (INIS)

    Kamano, Chisako; Komaba, Yuichi; Sakayori, Osamu; Iino, Yasuhiko; Katayama, Yasuo

    2002-01-01

    We performed single-photon emission computed tomography (SPECT) to investigate the influence of renal transplantation on cerebral blood flow (CBF). Fifteen renal transplant recipients and twelve normal subjects underwent cerebral SPECT with N-isopropyl-p-[ 123 I] iodoamphetamine ( 123 I-IMP). All transplant recipients received prednisolone and cyclosporine (CyA). Regional CBF (rCBF) was measured by defining regions of interest in the cerebral cortex, deep white matter, striatum, thalamus, and cerebellum. In transplant recipients, correlations to the mean overall cortical CBF were assessed using the interval from transplantation to measurement of SPECT, as well as the serum creatinine concentration. Moreover, to investigate the influence of CyA on CBF, the correlation between mean overall cortical CBF and CyA trough concentrations was assessed. In all regions, CBF in renal transplant recipients was significantly lower than in normal subjects. No significant correlation was seen between serum creatinine, interval from transplantation, or CyA trough concentrations and mean overall cortical CBF. Renal transplant recipients demonstrated a decrease in CBF, that can have an associated secondary pathology. Therefore, renal transplant recipients may benefit from post-operative MRI or CT. (author)

  9. In vivo measurements of cerebral metabolic abnormalities by proton spectroscopy after a transient ischemic attack revealing an internal carotid stenosis > 70%

    International Nuclear Information System (INIS)

    Giroud, M.; Becker, F.; Lemesle, M.; Walker, P.; Guy, F.; Martin, D.; Baudouin, N.; Brunotte, F.; Dumas, R.

    1996-01-01

    Aims: The aim of this work is to look for cerebral metabolic abnormalities within the first 3 days after a transient ischemic attack revealing an internal carotid stenosis > 70 %. Methods: Five patients with a transient ischemic attack lasting between 30 and 180 minutes, affecting sensory and motor brachio-facial territory, with or without aphasia. Were studied. A CT-scan, an EEG, a cervical Doppler ultrasound, a standard arteriography, a magnetic resonance imaging and a proton spectroscopy were performed within the cerebral area affected by the transient ischemic attack. We measured 2 markers: N-acetyl-aspartate, the marker of the neuronal mass, and lactate, the marker of anaerobe metabolism. In each case, a contralateral internal stenosis was diagnosed by cervical Doppler ultrasound and standard arteriography. No cerebral infarction was observed. Results: With the affected cerebral area defined according to clinical and EEG features, proton spectroscopy showed a significant rise of lactate, without any change in N-acetyl-aspartate levels. Conclusions: Within the first 3 days after a transient ischemic attack, there is a significant risk of lactate inside the affected cerebral area. This change may reflect a localized and transient hypoperfusion, but long enough to induce a rise of lactate but not sufficient to produce a cerebral infarct. This area is probably at risk to induce cerebral infarct. This data lead us to study the metabolic change induced by the asymptomatic internal carotid stenosis. (authors). 18 refs

  10. Comparative studies of D2 receptors and cerebral blood flow in hemi-Parkinsonism rats

    International Nuclear Information System (INIS)

    Lin Yansong; Lin Xiangtong

    2000-01-01

    Objective: To study the relationship between dopamine D 2 receptors and cerebral blood flow in hemi-Parkinsonism rats. Methods: Hemi-Parkinsonism rats were made by stereotaxic 6-hydroxy dopamine (6-OH-DA) lesions in substantia nigra and ventral tegmental area, apomorphine (Apo) which could induce the successful model rat to rotate toward the intact side was used to select the rat models, 125 I-IBZM in vivo autoradiography and 99 Tc m -HMPAO regional cerebral biodistribution analysis were used to study D 2 receptors and cerebral blood flow. The HPLC-ECD was used to measure striatum DA and its metabolite content . Results: the lesioned side striatum DA and its metabolites homovanillic acid (HVA) 3,4-dihyroxy-phenylacetic acid (DOPAC) reduced significantly than that of the intact side and pseudo-operated group, striatum/cerebellum 125 I-IBZM uptake ratio was 8.04 +- 0.71 in lesioned side of hemi-Parkinsonism rats, significantly increased compared with the intact side and the pseudo-operated group (P 0.05). Conclusions: the 6-OH-DA lesioned side DA content decreased significantly and thus induced a compensative up-regulation of striatum D 2 receptor binding sites in hemi-Parkinsonism rats, which show good correlation with rotation behavior induced by Apo. Comparing with cerebral blood flow, D 2 receptor reflected by IBZM seems to be more specific and earlier to detect the cerebral functional impairment in experimental hemi-Parkinsonism

  11. Cerebral glucose metabolism in Wernicke's, Broca's, and conduction aphasia

    Energy Technology Data Exchange (ETDEWEB)

    Metter, E.J.; Kempler, D.; Jackson, C.; Hanson, W.R.; Mazziotta, J.C.; Phelps, M.E.

    1989-01-01

    Cerebral glucose metabolism was evaluated in patients with either Wernicke's (N = 7), Broca's (N = 11), or conduction (N = 10) aphasia using /sup 18/F-2-fluoro-2-deoxy-D-glucose with positron emission tomography. The three aphasic syndromes differed in the degree of left-to-right frontal metabolic asymmetry, with Broca's aphasia showing severe asymmetry and Wernicke's aphasia mild-to-moderate metabolic asymmetry, while patients with conduction aphasia were metabolically symmetric. On the other hand, the three syndromes showed the same degree of metabolic decline in the left temporal region. The parietal region appeared to separate conduction aphasia from both Broca's and Wernicke's aphasias. Common aphasic features in the three syndromes appear to be due to common changes in the temporal region, while unique features were associated with frontal and parietal metabolic differences.

  12. Diabetic patients have abnormal cerebral autoregulation during cardiopulmonary bypass

    International Nuclear Information System (INIS)

    Croughwell, N.; Lyth, M.; Quill, T.J.; Newman, M.; Greeley, W.J.; Smith, L.R.; Reves, J.G.

    1990-01-01

    We tested the hypothesis that insulin-dependent diabetic patients with coronary artery bypass graft surgery experience altered coupling of cerebral blood flow and oxygen consumption. In a study of 23 patients (11 diabetics and 12 age-matched controls), cerebral blood flow was measured using 133Xe clearance during nonpulsatile, alpha-stat blood gas managed cardiopulmonary bypass at the conditions of hypothermia and normothermia. In diabetic patients, the cerebral blood flow at 26.6 +/- 2.42 degrees C was 25.3 +/- 14.34 ml/100 g/min and at 36.9 +/- 0.58 degrees C it was 27.3 +/- 7.40 ml/100 g/min (p = NS). The control patients increased cerebral blood flow from 20.7 +/- 6.78 ml/100 g/min at 28.4 +/- 2.81 degrees C to 37.6 +/- 8.81 ml/100 g/min at 36.5 +/- 0.45 degrees C (p less than or equal to 0.005). The oxygen consumption was calculated from jugular bulb effluent and increased from hypothermic values of 0.52 +/- 0.20 ml/100 g/min in diabetics to 1.26 +/- 0.28 ml/100 g/min (p = 0.001) at normothermia and rose from 0.60 +/- 0.27 to 1.49 +/- 0.35 ml/100 g/min (p = 0.0005) in the controls. Thus, despite temperature-mediated changes in oxygen consumption, diabetic patients did not increase cerebral blood flow as metabolism increased. Arteriovenous oxygen saturation gradients and oxygen extraction across the brain were calculated from arterial and jugular bulb blood samples. The increase in arteriovenous oxygen difference between temperature conditions in diabetic patients and controls was significantly different (p = 0.01). These data reveal that diabetic patients lose cerebral autoregulation during cardiopulmonary bypass and compensate for an imbalance in adequate oxygen delivery by increasing oxygen extraction

  13. Long-term follow-up of cerebral blood flow in patients with ruptured cerebral aneurysm

    Energy Technology Data Exchange (ETDEWEB)

    Yamakami, Iwao; Tanno, Hirokazu; Isobe, Katsumi [Kimitsu Central Hospital, Kisarazu, Chiba (Japan); Yamaura, Akira

    1992-03-01

    The xenon-133 inhalation technique was used to make three measurements of regional cerebral blood flow (CBF) in 34 patients with ruptured cerebral aneurysm: in the acute period (<14 days) after subarachnoid hemorrhage, in the subacute period (15-30 days), and in the chronic period (12-24 months). The hemispheric mean value of initial slope index was used as the mean CBF. The clinical outcomes were classified into good recovery (GR)(24 cases), moderate disability (MD)(5), and severe disability (SD)(5) on the Glasgow Outcome Scale. In all periods, the mean CBF significantly correlated with the outcome. GR patients had the highest mean CBF, MD patients the intermediate mean CBF, and SD patients the lower mean CBF. GR patients had a near-normal mean CBF by the chronic period, while SD patients showed no significant CBF recovery throughout the course. (author).

  14. Low regional cerebral blood flow in burning mouth syndrome patients with depression.

    Science.gov (United States)

    Liu, B-L; Yao, H; Zheng, X-J; Du, G-H; Shen, X-M; Zhou, Y-M; Tang, G-Y

    2015-07-01

    The main aims of this study were to (i) investigate the emotional disorder status of patients with burning mouth syndrome (BMS) and (ii) detect regional cerebral blood flow in BMS patients with the application of combined single-photon emission computed tomography and computed tomography (SPECT/CT). The degree of pain was measured using the visual analysis scale, and emotional disorder with the self-rating anxiety scale, self-rating depression scale, and Hamilton depression rating scale in 29 patients with BMS and 10 healthy controls. SPECT/CT was performed in 29 patients with BMS and 10 healthy controls, and statistical parametric mapping method was used for between-group analyses. The incidence rate of depression in patients with BMS was 31.0%. Compared to the control group, patients with BMS displayed significantly different depression and anxiety scales (P < 0.05). Significantly lower regional cerebral blood flow in the left parietal and left temporal lobes was recorded for BMS patients with depression (P < 0.05). Patients with BMS experience more depression and anxious emotion. Moreover, depression in patients with BMS may be associated with lower regional cerebral blood flow in the left temporal and left parietal lobes. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  15. Comparison Between Cerebral Tissue Oxygen Tension and Energy Metabolism in Experimental Subdural Hematoma

    DEFF Research Database (Denmark)

    Nielsen, Troels Halfeld; Engell, Susanne I; Johnsen, Rikke Aagaard

    2011-01-01

    BACKGROUND: An experimental swine model (n = 7) simulating an acute subdural hematoma (ASDH) was employed (1) to explore the relation between the brain tissue oxygenation (PbtO(2)) and the regional cerebral energy metabolism as obtained by microdialysis, and (2) to define the lowest level of PbtO(2...

  16. Effect of short-term hyperventilation on cerebral blood flow autoregulation in patients with acute bacterial meningitis

    DEFF Research Database (Denmark)

    Møller, Kirsten

    2000-01-01

    BACKGROUND AND PURPOSE: Cerebral blood flow (CBF) autoregulation is impaired in patients with acute bacterial meningitis: this may be caused by cerebral arteriolar dilatation. We tested the hypothesis that CBF autoregulation is recovered by acute mechanical hyperventilation in 9 adult patients...... with acute bacterial meningitis. METHODS: Norepinephrine was infused to increase mean arterial pressure (MAP) 30 mm Hg from baseline. Relative changes in CBF were concomitantly recorded by transcranial Doppler ultrasonography of the middle cerebral artery, measuring mean flow velocity (V...... completely during hyperventilation. The slope of the autoregulation curve decreased during hyperventilation compared with normoventilation (Pmeningitis, indicating...

  17. Cerebral glucose metabolic differences in patients with panic disorder

    Energy Technology Data Exchange (ETDEWEB)

    Nordahl, T.E.; Semple, W.E.; Gross, M.; Mellman, T.A.; Stein, M.B.; Goyer, P.; King, A.C.; Uhde, T.W.; Cohen, R.M. (NIMH, Bethesda, MD (USA))

    1990-08-01

    Regional glucose metabolic rates were measured in patients with panic disorder during the performance of auditory discrimination. Those regions examined by Reiman and colleagues in their blood flow study of panic disorder were examined with a higher resolution positron emission tomography (PET) scanner and with the tracer (F-18)-2-fluoro-2-deoxyglucose (FDG). In contrast to the blood flow findings of Reiman et al., we did not find global gray metabolic differences between patients with panic disorder and normal controls. Consistent with the findings of Reiman et al., we found hippocampal region asymmetry. We also found metabolic decreases in the left inferior parietal lobule and in the anterior cingulate (trend), as well as an increase in the metabolic rate of the medial orbital frontal cortex (trend) of panic disorder patients. It is unclear whether the continuous performance task (CPT) enhanced or diminished findings that would have been noted in a study performed without task.

  18. Cerebral glucose metabolic differences in patients with panic disorder

    International Nuclear Information System (INIS)

    Nordahl, T.E.; Semple, W.E.; Gross, M.; Mellman, T.A.; Stein, M.B.; Goyer, P.; King, A.C.; Uhde, T.W.; Cohen, R.M.

    1990-01-01

    Regional glucose metabolic rates were measured in patients with panic disorder during the performance of auditory discrimination. Those regions examined by Reiman and colleagues in their blood flow study of panic disorder were examined with a higher resolution positron emission tomography (PET) scanner and with the tracer [F-18]-2-fluoro-2-deoxyglucose (FDG). In contrast to the blood flow findings of Reiman et al., we did not find global gray metabolic differences between patients with panic disorder and normal controls. Consistent with the findings of Reiman et al., we found hippocampal region asymmetry. We also found metabolic decreases in the left inferior parietal lobule and in the anterior cingulate (trend), as well as an increase in the metabolic rate of the medial orbital frontal cortex (trend) of panic disorder patients. It is unclear whether the continuous performance task (CPT) enhanced or diminished findings that would have been noted in a study performed without task

  19. Determinants of resting cerebral blood flow in sickle cell disease

    NARCIS (Netherlands)

    Bush, Adam M.; Borzage, Matthew T.; Choi, Soyoung; Václavů, Lena; Tamrazi, Benita; Nederveen, Aart J.; Coates, Thomas D.; Wood, John C.

    2016-01-01

    Stroke is common in children with sickle cell disease and results from an imbalance in oxygen supply and demand. Cerebral blood flow (CBF) is increased in patients with sickle cell disease to compensate for their anemia, but adequacy of their oxygen delivery has not been systematically demonstrated.

  20. Global reduction of cerebral glucose metabolism in persons with symptomatic as well as asymptomatic lacunar infarction

    International Nuclear Information System (INIS)

    Takahashi, Wakoh; Takagi, Shigeharu; Shinohara, Yukito; Ide, Michiru; Shohtsu, Akira

    2000-01-01

    To clarify the hemodynamic changes in lacunar infarction, we evaluated cerebral glucose metabolism by using positron emission tomography with 18 F-fluorodeoxyglucose (FDG-PET) in patients with asymptomatic and symptomatic lacunar infarction and in persons without cerebral infarction on MRI. Subjects in this study were 27 patients with symptomatic lacunar infarction (SCI group), 73 subjects with asymptomatic lacunar infarction (ACI group), and 134 persons without infarction (NC group). CMRgI in the ACI group was significantly lower than that in the NC group in the cerebral cortex (P<0.05) and thalamus (P<0.05). CMRgI in the SCI group was significantly reduced from that in the NC group in the cerebral cortex (P<0.005), basal ganglia (P<0.001), thalamus (P<0.05) and white matter (P<0.005). The reduction in CMRgI in the SCI group was more severe than that in the ACI group in basal ganglia (P<0.05) and thalamus (P<0.05). Our results indicated that glucose metabolism in patients with asymptomatic lacunar infarction is reduced throughout the whole brain as compared with non-infarcted elderly persons. Follow-up and treatment of risk factors if present, may be necessary in such patients. (author)

  1. Psychiatric and subjective symptoms and cerebral blood flow in patients with chronic cerebral infarction after treatment with Ca antagonist (nilvadipine). Quantitative measurement of cerebral blood flow by the 123IMP-SPECT ARG method

    International Nuclear Information System (INIS)

    Sakayori, Osamu; Kitamura, Shin; Mishina, Masahiro; Yamazaki, Mineo; Terashi, Akirou

    1997-01-01

    Psychiatric and subjective symptoms such as headache, dizziness, lack of spontaneity, anxiety, and a depressive state are often found in patients with chronic cerebral infarction. Some Ca antagonists are reported to relieve such symptoms. The purpose of the present study was to investigate the relationship between psychiatric and subjective symptoms and cerebral blood flow (CBF) in cerebral infarction and to evaluate the clinical effects of Ca antagonists from the standpoint of the cerebral circulation. Nilvadipine was administered to is patients with chronic cerebral infarction and their CBF was measured by the 123 IMP-SPECT ARG method before and at 8 weeks after the nilvadipine treatment. The CBF in patients with hypertension was increased by 11% after giving nilvadipine. Patients without hypertension showed no tendency for elevation of their CBF. Patients who were relieved from some psychiatric symptoms revealed a 14% increase of CBF in all cortical regions, and a significant increase was noted in the frontal and temporal regions. In other patients without changes in psychiatric symptoms, the CBF did not increase in any of the cortical regions. No relationship between symptoms and CBF was observed in any of the patients with subjective symptoms. Our study demonstrated a close correlation between psychiatric symptoms and CBF. We speculate that psychiatric symptoms in chronic cerebral infarction may reflect diffuse brain dysfunctions. We also conclude that nilvadipine is more effective in relieving psychiatric symptoms in patients with hypertensive cerebral infarction. It is inferred that nilvadipine may be more effective in relieving psychiatric symptoms in patients with hypertension. (author)

  2. Regional cerebral blood flow and periventricular hyperintensity in silent cerebral infarction. Comparison with multi-infarct dementia

    International Nuclear Information System (INIS)

    Koshi, Yasuhiko; Kitamura, Shin; Nagazumi, Atushi; Tsuganesawa, Toshikazu; Terashi, Akiro

    1996-01-01

    In order to investigate relationship between regional cerebral blood flow (rCBF) and the white matter lesions on MRI in silent cerebral infarction, we quantitatively measured rCBF by 123 I-IMP autoradiography method (IMP ARG method) and single photon emission tomography (SPECT) in 36 patients with silent cerebral infarction (SCI group), 22 patients with multi-infarct dementia (MID group), and 16 control subjects without periventricular hyperintensity (PVH) and lacunar infarction on MRI (CL group). Regions of interest (ROIs) on rCBF images were set in the frontal (F), temporal (T), parietal (P), occipital (O) cortex, and the cerebral white matter (W). The severity of PVH on MRI T 2 -weighted image was divided into four grades (grade 0-3). Though the frequency of hypertension was significantly higher in SCI group and MID group compared with CL group, no significant difference was seen in the mean age among these three groups. rCBF in the white matter and cerebral cortices except the occipital cortex in SCI group was significantly low compared with CL group (rCBF SCI /rCBF CL : W 0.87, F 0.87, T 0.87, P 0.88, O 0.92). rCBF in the white matter and cerebral cortices, especially in the white matter and frontal cortex, in MID group was significantly low compared with SCI group (rCBF MID /rCBF CL : W 0.69, F 0.71, T 0.74, P 0.75, O 0.81). The mean grade of PVH in MID group was significantly higher than that in SCI group (SCI 1.1 vs MID 2.5). The severity of PVH was significantly correlated with each rCBF in the white matter and cerebral cortices, especially in the white matter and frontal cortex. Our findings suggest that the quantitative measurement of rCBF by IMP ARG method is useful for the follow-up study in the patients with silent cerebral infarction as well as the evaluation of the severity of PVH on MRI. (author)

  3. Cerebral blood flow in acute and chronic ischemic stroke using xenon-133 inhalation tomography

    DEFF Research Database (Denmark)

    Vorstrup, S; Paulson, O B; Lassen, N A

    1986-01-01

    . They showed in the acute phase (Days 1-3) very large low-flow areas, larger than the hypodense areas seen on the CT scan. The cerebral vasoconstrictor and vasodilator capacity was tested in the acute phase following aminophylline and acetazolamide, respectively. A preserved but reduced reactivity was seen......Serial measurements of cerebral blood flow (CBF) were performed in 12 patients with acute symptoms of ischemic cerebrovascular disease. CBF was measured by xenon-133 inhalation and single photon emission computer tomography. Six patients had severe strokes and large infarcts on the CT scan...

  4. Cerebral oxygen metabolism in patients with early Parkinson's disease

    DEFF Research Database (Denmark)

    Borghammer, Per; Cumming, Paul; Østergaard, Karen

    2012-01-01

    ) and cerebral blood flow (CBF) PET scans from PD patients and healthy controls. MATERIALS AND METHODS: Nine early-stage PD patients and 15 healthy age-matched controls underwent PET scans for quantitative mapping of CMRO(2) and CBF. Between-group differences were evaluated for absolute data and intensity...... in spatially contiguous cortical regions in early PD, and support the hypothesis that ETC dysfunction could be a primary pathogenic mechanism in early PD....

  5. Timing of potential and metabolic brain energy

    DEFF Research Database (Denmark)

    Korf, Jakob; Gramsbergen, Jan Bert

    2007-01-01

    functions. We introduce the concepts of potential and metabolic brain energy to distinguish trans-membrane gradients of ions or neurotransmitters and the capacity to generate energy from intra- or extra-cerebral substrates, respectively. Higher brain functions, such as memory retrieval, speaking......The temporal relationship between cerebral electro-physiological activities, higher brain functions and brain energy metabolism is reviewed. The duration of action potentials and transmission through glutamate and GABA are most often less than 5 ms. Subjects may perform complex psycho......-physiological tasks within 50 to 200 ms, and perception of conscious experience requires 0.5 to 2 s. Activation of cerebral oxygen consumption starts after at least 100 ms and increases of local blood flow become maximal after about 1 s. Current imaging technologies are unable to detect rapid physiological brain...

  6. Comparative studies of D2 receptors and cerebral blood flow in hemi-parkinsonism rats

    International Nuclear Information System (INIS)

    Lin, Y.; Lin, X.

    2000-01-01

    To study the relationship between dopamine (DA) D 2 receptors and cerebral blood flow in hemiparkinsonism rats. Hemi-parkinsonism rats were made by stereotaxic 6-hydroxy dopamine (6-OH-DA) lesions in substantia nigra and ventral tegmental area, apomorphine (Apo) which could induce the successful model rat rotates toward the intact side was used to screen that rats, 125 I-IBZM in vivo autoradiography and 99m Tc-HM-PAO regional brain biodistribution were used to study D 2 receptors and cerebral blood flow. The HPLC-ECD were used to measure the concentration of DA and it metabolites homovanillic acid (HVA), 3,4-dehydroxyphenyl acetic acid (DOPAC) in bilateral striatum (ST). The lesioned side ST DA and its metabolites HVA DOPAC reduced significantly than that of the intact side and pseudo-operated control group, ST/cerebellum (CB) 125 I-IBZM uptake ratio was 8.04 ±0.71 in lesioned side of hemi-parkinsonism rats, significantly increased compared with the intact side and the pseudo-operated group (p 99m Tc 30.1±4.53% enhancement as compared to the intact side, and also show good correlation with 30 min Apo induced rotation numbers (r=0.98), the regional cerebral blood flow study didn't show significant difference between bilateral brain cortex area (p>0.05). The DA content decreased significantly and induced an up-regulation of ST D 2 receptor binding sites in 6-OH-DA lesioned side in hemi-parkinsonism rats, the increased percentage of lesioned-intact side ST/CB 125 I-IBZM uptake ratio showed good correlation with rotation behavior induced by Apo. Compare with cerebral blood flow, D 2 receptor reflected by IBZM seems to be more specific and earlier to detect the cerebral functional impairment in experimental hemi-parkinsonism

  7. Persistent resetting of the cerebral oxygen/glucose uptake ratio by brain activation

    DEFF Research Database (Denmark)

    Madsen, P L; Hasselbalch, S G; Hagemann, L P

    1995-01-01

    fraction of the activation-induced excess glucose uptake. These data confirm earlier reports that brain activation can induce resetting of the cerebral oxygen/glucose consumption ratio, and indicate that the resetting persists for a long period after cerebral activation has been terminated and physiologic......Global cerebral blood flow (CBF), global cerebral metabolic rates for oxygen (CMRO2), and for glucose (CMRglc), and lactate efflux were measured during rest and during cerebral activation induced by the Wisconsin card sorting test. Measurements were performed in healthy volunteers using the Kety......-Schmidt technique. Global CMRO2 was unchanged during cerebral activation, whereas global CBF and global CMRglc both increased by 12%, reducing the molar ratio of oxygen to glucose consumption from 6.0 during baseline conditions to 5.4 during activation. Data obtained in the period following cerebral activation...

  8. Regional cerebral blood flow and oxygen consumption during normal human sleep

    International Nuclear Information System (INIS)

    Takahashi, Ken

    1989-01-01

    Regional cerebral blood flow (rCBF), regional oxygen extraction fraction (rCEF) and regional cerebral metabolic rate for oxygen (rCMRO 2 ) were measured using the continuous inhalation technique for 15 O with positron emission tomography (PET) during both wakefulness and sleep. Ten paid volunteers, with a mean age of 21.6 yrs., were deprived of sleep for a period of approximately 20 hours, and the experiments were performed mostly in the morning. 15 O activity of both whole blood and the plasma, pixel count of PET, total arterial blood oxygen content were used for analysis of rCBF, rOEF and rCMRO 2 . PET scannings were carried out mostly during the very light non-rapid eye movement (NREM) sleep, i.e. stage 1 and/or 2, and wakefulness. About 10 minutes after the start of continuous inhalation of 15 O gas, the 15 O activity of the brain was found to be in a steady-state condition. During this steady-state condition, PET scannings were performed for about 10 minutes. Regions of interest, square in shape and having an area of 2.8 cm 3 , were set in each cortex on PET images of a horizontal cross-section of the brain, set at 45 mm above the orbitomeatal line. The rCBF and rCMRO 2 were analysed in 5 of 10 male subjects during both wakefulness and NREM sleep, and only 3 were done during three sleep stages, including REM sleep. Levels of rCBF and rCMRO 2 were found to be decreased in NREM sleep, and the decreasing rates were calculated at 10.2% and 7.6% from the level of wakefulness, respectively. There was no significant difference in the mean value of rOEF between wakefulness and NREM sleep. There were no significant regional differences found in the rate of decrease among the frontal, temporal and occipital cortices. It was considered that the decrease of rCBF and rCMRO 2 during NREM sleep suggested a decrease of the activity levels in the cerebral functions. (author)

  9. The study of regional cerebral glucose metabolic change in human being normal aging process by using PET scanner

    International Nuclear Information System (INIS)

    Si Mingjue; Huang Gang

    2008-01-01

    Objective: With the technique development, PET has been more and more applied in brain function research. The aim of this study was to investigate the tendency of regional cerebral glucose metabolism changes in human being normal aging process by using 18 F-fluorodeoxyglucose (FDG) PET/CT and statistical parametric mapping (SPM) software. Methods: 18 F-FDG PET/CT brain imaging data acquired from 252 healthy normal subjects (age ranging: 21 to 88 years old) were divided into 6 groups according to their age: 21-30, 31-40, 41-50, 51-60, 61-70, 71-88. All 5 groups with age ≥31 years old were compared to the control group of 21-30 years old, and pixel-by-pixel t-statistic analysis was applied using the SPM2. The hypo-metabolic areas were identified by MNI space utility (MSU) software and the voxel value of each brain areas were calculated (P 60 years old showed significant metabolic decreases with aging mainly involved bilateral frontal lobe (pre-motto cortex, dorsolateral prefrontal cortex, frontal pole), temporal lobe (temporal pole), insula, anterior cingulate cortex and cerebellum. The most significant metabolic decrease area with aging was the frontal lobe , followed by the anterior cingulate cortex, temporal lobe, insula and cerebellum at predominance right hemisphere (P<0.0001). Parietal lobe, parahippocampal gyrus, basal ganglia and thalamus remain metabolically unchanged with advancing aging. Conclusions: Cerebral metabolic function decrease with normal aging shows an inconstant and unsymmetrical process. The regional cerebral metabolic decrease much more significantly in older than 60 years old healthy volunteers, mainly involving bilateral frontal lobe, temporal lobe, insula, anterior cingulate cortex and cerebellum at right predominance hemisphere. (authors)

  10. Is there any influence of breastfeeding on the cerebral blood flow? A review of 256 healthy newborns

    Directory of Open Access Journals (Sweden)

    Alexandra Maria Vieira Monteiro

    2012-10-01

    Full Text Available OBJECTIVE: To investigate whether breastfeeding influence the cerebral blood-flow velocity. MATERIALS AND METHODS: The present study included 256 healthy term neonates, all of them with appropriate weight for gestational age, 50.8% being female. Pulsatility index, resistance index and mean velocity were measured during breastfeeding or resting in the anterior cerebral artery, in the left middle cerebral artery, and in the right middle cerebral artery of the neonates between their first 10 and 48 hours of life. The data were analyzed by means of a paired t-test, Brieger's f-test for analysis of variance and linear regression, with p < 0.01 being accepted as statistically significant. RESULTS: Mean resistance index decreased as the mean velocity increased significantly during breastfeeding. Pulsatility index values decreased as much as the resistance index, but in the right middle cerebral artery it was not statistically significant. CONCLUSION: Breastfeeding influences the cerebral blood flow velocities.

  11. Quantification of cerebral blood flow and its clinical usefulness. Application of SPECT to psychiatry

    Energy Technology Data Exchange (ETDEWEB)

    Matsuda, Hiroshi; Uema, Takeshi; Kogure, Daisuke; Takano, Harumasa; Terada, Tomo [National Center Hospital for Mental, Nervous and Muscular Disorders, Kodaira, Tokyo (Japan)

    1998-10-01

    Brain perfusion SPECT using {sup 99m}Tc-ethyl-cysteinate dimer ({sup 99m}Tc-ECD) was applied to psychiatric diseases with aid of statistical parametric mapping (SPM) for analysis of data. To evaluate influence of aging on brain perfusion, noninvasive measurements of cerebral blood flow using {sup 99m}Tc-ECD were performed in 53 normal volunteers, aged 18 to 87 years old. Mean cerebral blood flow (mCBF) was 43.9{+-}5.0 ml/100 g/min and showed weak negative correlation with aging (r=-0.451). Perisylvian cerebral cortices and medial frontal areas including anterior cingulate gyri showed greater negative correlation than other areas. These findings suggest the necessity of age-matched control regional CBF (rCBF) data to investigate rCBF abnormality in patients. Four drug-naive schizophrenic patients showed flow decrease in bilateral frontal and superior temporal areas and a left infero-posterior temporal area. Haloperidol administration induced flow decrease in bilateral frontal and left parietal areas, while flow increase in bilateral striatal and right hippocampal areas. Ten aged depressive patients showed flow decrease in bilateral frontal and left temporo-parietal areas. Even after remission patients showed flow decrease in the left frontal area as compared with normal subjects. Remission induced flow increase in the right frontal, right parietal, and right orbitofrontal areas compared with depression. These results suggest that CBF measurements using {sup 99m}Tc-ECD are useful for objective evaluation of regional abnormality in brain function in psychiatric diseases. (author)

  12. Correlation of glucose metabolism in brain cells and brain morphological changes with clinical typing in children with cerebral palsy

    Institute of Scientific and Technical Information of China (English)

    Qiongxiang Zhai; Huixian Qiao; Jiqing Liu

    2006-01-01

    BACKGROUND:It is widely known that fluorino-18-fluorodeoxyglucose positron emission tomography(18F-FDG PET)is commonly used to evaluate and diagnose epilepsy;however,whether it is beneficial to understand functional metabolism of bra in cells so as to reflect injured site and degree of brain cells or not should be studied further.OBJECTIVE:To evaluate the correlation between glucose metabolism and clinical typling as well as the conelation between active function of brain cells and degree of brain injury among children with cerbral palsy with 18F-FDG PET and MRI and compare the results of them.DESIGN:Case analysis.SETTING:Department of Pediatrics,People's Hospital of Guangdong Province.PARTICIPANTS:A total of 31 children with cerebral palsy were selected from Out-patient Clinic and In-patient Department of People's Hospital of Guangdong Province from July 2001 to August 2004.Based on clinical criteria of cerebral palsy,patients were classified into spasm(n=10),gradual movement(n=4),mixed type(n =13)and ataxia(n=4).There were 18 boys and 13 girls aged from 10 months to 4 years.All of them were met the diagnostic criteria of cerebral palsy and all parents of them were told the facts.Exclusion cdteria:Patients who had cerebral palsy caused by genetic metabolism disease were excluded.METHODS:①All children accepted MRI examination after hospitalization with Philips Acs NT 15T superconductling magnetic resonance scanner.②All children were fasted for 4 hours.And then,PET image of brain was collected based on T+EID type.If obvious hypermetabolism or hypometabolism region successively occurred on two layers, the image was regarded as abnormality. ③Different correlations of various abnormal greups of MRI and vadous types of cerebral palsy with PET image were compared and analyzed with Erusal-Willas rank sum test.MAIN OUTCOME MEASURES:①Results of 18F-FDG PET;②Results of MRI examination;③Correlation of variously abnormal groups of MRI and various types of cerebral

  13. Central Pulsatile Pressure and Flow Relationship in the Time and Frequency Domain to Characterise Hydraulic Input to the Brain and Cerebral Vascular Impedance.

    Science.gov (United States)

    Kim, Mi Ok; O'Rourke, Michael F; Adji, Audrey; Avolio, Alberto P

    2016-01-01

    In the time domain, pulsatile flow and pressure can be characterised as the ratio of the late systolic boost of flow or pressure to the pulse amplitude so as to estimate the hydraulic input to the brain. While vascular impedance has been widely used to represent the load presented to the heart by the systemic circulation, it has not been applied to the cerebral circulation.We set out to study the relationship between the pressure and the flow augmentation index (AIx) in the time domain and to determine cerebral vascular impedance using aortic blood pressure and cerebral blood flow waveforms in the frequency domain. Twenty-four young subjects (aged 21-39 years) were recruited; aortic pressure was derived using SphygmoCor from radial pressure. Flow waveforms were recorded from the middle cerebral artery. In three subjects, we performed the Valsalva manoeuvre to investigate their response to physiological intervention. There was a linear relationship between flow and pressure AIx, and cerebral impedance values were similar to those estimated for low resistance vascular beds. Substantial change in pressure and flow wave contour was observed during the Valsalva manoeuvre; however, the relationship in both the time and the frequency domains were unchanged. This confirms that aortic pressure and cerebral flow waveform can be used to study cerebral impedance.

  14. Sources of variability of resting cerebral blood flow in healthy subjects

    DEFF Research Database (Denmark)

    Henriksen, Otto Mølby; Kruuse, Christina Rostrup; Olesen, Jes

    2013-01-01

    Measurements of cerebral blood flow (CBF) show large variability among healthy subjects. The aim of the present study was to investigate the relative effect of established factors influencing CBF on the variability of resting CBF. We retrospectively analyzed spontaneous variability in 430 CBF...... measurements acquired in 152 healthy, young subjects using (133)Xe single-photon emission computed tomography. Cerebral blood flow was correlated positively with both end-tidal expiratory PCO2 (PETCO2) and female gender and inversely with hematocrit (Hct). Between- and within-subject CO2 reactivity...... when Hct was also accounted for. The present study confirms large between-subject variability in CBF measurements and that gender, Hct, and PETCO2 explain only a small part of this variability. This implies that a large fraction of CBF variability may be due to unknown factors such as differences...

  15. Enhanced cerebrovascular expression of matrix metalloproteinase-9 and tissue inhibitor of metalloproteinase-1 via the MEK/ERK pathway during cerebral ischemia in the rat

    DEFF Research Database (Denmark)

    Maddahi, Aida; Chen, Qingwen; Edvinsson, Lars

    2009-01-01

    BACKGROUND: Cerebral ischemia is usually characterized by a reduction in local blood flow and metabolism and by disruption of the blood-brain barrier in the infarct region. The formation of oedema and opening of the blood-brain barrier in stroke is associated with enhanced expression of metallopr......BACKGROUND: Cerebral ischemia is usually characterized by a reduction in local blood flow and metabolism and by disruption of the blood-brain barrier in the infarct region. The formation of oedema and opening of the blood-brain barrier in stroke is associated with enhanced expression...

  16. Oxygen consumption and blood flow coupling in human motor cortex during intense finger tapping

    DEFF Research Database (Denmark)

    Seyedi Vafaee, Manouchehr; Vang, Kim; Bergersen, Linda H

    2012-01-01

    Rates of cerebral blood flow (CBF) and glucose consumption (CMR(glc)) rise in cerebral cortex during continuous stimulation, while the oxygen-glucose index (OGI) declines as an index of mismatched coupling of oxygen consumption (cerebral metabolic rate of oxygen-CMRO(2)) to CBF and CMR(glc). To t...

  17. Regional cerebral glucose metabolic rate in human sleep assessed by positron emission tomography

    International Nuclear Information System (INIS)

    Buchsbaum, M.S.; Wu, J.; Hazlett, E.; Sicotte, N.; Bunney, W.E. Jr.; Gillin, J.C.

    1989-01-01

    The cerebral metabolic rate of glucose was measured during nighttime sleep in 36 normal volunteers using positron emission tomography and fluorine-18-labeled 2-deoxyglucose (FDG). In comparison to waking controls, subjects given FDG during non-rapid eye movement (NREM) sleep showed about a 23% reduction in metabolic rate across the entire brain. This decrease was greater for the frontal than temporal or occipital lobes, and greater for basal ganglia and thalamus than cortex. Subjects in rapid eye movement (REM) sleep tended to have higher cortical metabolic rates than walking subjects. The cingulate gyrus was the only cortical structure to show a significant increase in glucose metabolic rate in REM sleep in comparison to waking. The basal ganglia were relatively more active on the right in REM sleep and symmetrical in NREM sleep

  18. Dose-Dependent Effects of Radiation Therapy on Cerebral Blood Flow, Metabolism, and Neurocognitive Dysfunction

    International Nuclear Information System (INIS)

    Hahn, Carol A.; Zhou Sumin; Raynor, Renee; Tisch, Andrea; Light, Kim; Shafman, Timothy; Wong, Terence; Kirkpatrick, John; Turkington, Timothy; Hollis, Donna; Marks, Lawrence B.

    2009-01-01

    Purpose: A prospective study was performed to formally relate dose-dependent radiologically defined changes in normal brain induced by radiotherapy (RT) to neurocognitive dysfunction in subjects with primary brain tumors. Methods and Materials: Adult patients receiving three-dimensional RT for central nervous system (CNS) tumors were enrolled. Positron emission tomography (PET) scanning and neuropsychological testing were performed before RT and 3 weeks and 6 months after treatment. Analyses were performed for correlations between changes in 2-deoxy-2-[ 18 F]-fluoro-D-glucose (FDG)-PET (metabolism), 15 O-PET (relative blood flow), regional radiation dose, follow-up time, and neuropsychological test scores. Results: Eleven subjects were enrolled and 6 completed follow-up studies. The PET data showed reduced FDG uptake, with average decreases of 2-6% in regions of the brain receiving greater than 40 Gy at 3 weeks' and 6 months' follow-up. The 15 O-H 2 O PET showed increases (<10%) at 3 weeks in relative regional blood flow in brain receiving greater than 30 Gy, but less at the 6-month follow-up studies. There were significant correlations between decreases in FDG uptake and increased scores from the Symptom Checklist-90-R, with an average increase in T score of 2 (p < 0.0001). The Wisconsin Card Sorting Test showed a significant correlation of decreased FDG uptake with increased errors and perseveration in test performance, with an average decrease in T score of 11 (p = 0.037). Conclusions: A dose-dependent response of CNS tissue was detected using FDG PET in this small number of patients. Decreases in CNS metabolism correlated with decreased performance on neuropsychological tests for problem solving, cognitive flexibility, and global measures of psychopathology. Additional research is needed to verify and define these findings

  19. Imaging of Neuronal Activity in Awake Mice by Measurements of Flavoprotein Autofluorescence Corrected for Cerebral Blood Flow

    Directory of Open Access Journals (Sweden)

    Manami Takahashi

    2018-01-01

    Full Text Available Green fluorescence imaging (e.g., flavoprotein autofluorescence imaging, FAI can be used to measure neuronal activity and oxygen metabolism in living brains without expressing fluorescence proteins. It is useful for understanding the mechanism of various brain functions and their abnormalities in age-related brain diseases. However, hemoglobin in cerebral blood vessels absorbs green fluorescence, hampering accurate assessments of brain function in animal models with cerebral blood vessel dysfunctions and subsequent cerebral blood flow (CBF alterations. In the present study, we developed a new method to correct FAI signals for hemoglobin-dependent green fluorescence reductions by simultaneous measurements of green fluorescence and intrinsic optical signals. Intrinsic optical imaging enabled evaluations of light absorption and scatters by hemoglobin, which could then be applied to corrections of green fluorescence intensities. Using this method, enhanced flavoprotein autofluorescence by sensory stimuli was successfully detected in the brains of awake mice, despite increases of CBF, and hemoglobin interference. Moreover, flavoprotein autofluorescence could be properly quantified in a resting state and during sensory stimulation by a CO2 inhalation challenge, which modified vascular responses without overtly affecting neuronal activities. The flavoprotein autofluorescence signal data obtained here were in good agreement with the previous findings from a condition with drug-induced blockade of cerebral vasodilation, justifying the current assaying methodology. Application of this technology to studies on animal models of brain diseases with possible changes of CBF, including age-related neurological disorders, would provide better understanding of the mechanisms of neurovascular coupling in pathological circumstances.

  20. The effect of phosphodiesterase-5 inhibitors on cerebral blood flow in humans

    DEFF Research Database (Denmark)

    Pauls, Mathilde Mh; Moynihan, Barry; Barrick, Thomas R

    2018-01-01

    , ED, type 2 diabetes, stroke, pulmonary hypertension, Becker muscular dystrophy and subarachnoid haemorrhage. Most studies used middle cerebral artery flow velocity to estimate CBF. Few studies employed direct measurements of tissue perfusion. Resting CBF velocity was unaffected by phosphodiesterase-5...... inhibitors, but cerebrovascular regulation was improved in ED, pulmonary hypertension, diabetes, Becker's and a group of healthy volunteers. This evidence suggests that phosphodiesterase-5 inhibitors improve responsiveness of the cerebral vasculature, particularly in disease states associated...

  1. Elevated global cerebral blood flow, oxygen extraction fraction and unchanged metabolic rate of oxygen in young adults with end-stage renal disease: an MRI study

    International Nuclear Information System (INIS)

    Zheng, Gang; Lou, Yaxian; Pan, Zhiying; Liu, Ya; Wen, Jiqiu; Li, Xue; Zhang, Zhe; Lu, Hanzhang; Liu, Wei; Liu, Hui; Chen, Huijuan; Kong, Xiang; Luo, Song; Jiang, Xiaolu; Zhang, Zongjun; Zhang, Long Jiang; Lu, Guang Ming

    2016-01-01

    To noninvasively assess global cerebral blood flow (CBF), oxygen extraction fraction (OEF) and cerebral metabolic rate of oxygen (CMRO 2 ) in young adults with end-stage renal disease (ESRD). Thirty-six patients and 38 healthy volunteers were included and took part in MR examinations, blood and neuropsychological tests. CBF and OEF were measured by phase-contrast and T2-relaxation-under-spin-tagging MRI techniques, respectively. CMRO 2 was computed from CBF, OEF and hematocrit according to Fick's principle. Correlations were performed between MR measurements, blood biochemistry measurements and neuropsychological test scores. Compared with controls, ESRD patients had elevated CBF (72.9 ± 12.5 vs. 63.8 ± 8.5 ml min -1 100 g -1 , P < 0.001), elevated OEF (47.2 ± 10.2 vs. 35.8 ± 5.4 %, P < 0.001), but unaffected CMRO 2 (199.5 ± 36.4 vs. 193.8 ± 28.6 μmol O 2 min -1 100 g -1 , P = 0.879). Hematocrit negatively correlated with CBF (r = -0.640, P < 0.001) and OEF (r = -0.701, P < 0.001), but not with CMRO 2 . Altered neuropsychological test scores of ESRD patients were associated with OEF and CBF, but not with CMRO 2 . There were weak relationships between eGFR and hematocrit (r = 0.308, P = 0.068) or CBF (r = 0.318, P = 0.059). Our findings suggested that anaemic young adults with ESRD may afford higher CBF and OEF to maintain a normal CMRO 2 . Despite this compensatory process, however, cognitive function was still impaired and its severity was correlated with their CBF and OEF abnormality. (orig.)

  2. Cerebral blood flow during delirium tremens and related clinical states studied with xenon-133 inhalation tomography

    International Nuclear Information System (INIS)

    Hemmingsen, R.; Vorstrup, S.; Clemmesen, L.; Holm, S.; Tfelt-Hansen, P.; Sorensen, A.S.; Hansen, C.; Sommer, W.; Bolwig, T.G.

    1988-01-01

    The regional cerebral blood flow of 12 patients with severe alcohol withdrawal reactions (delirium tremens or impending delirium tremens) was measured during the acute state before treatment and after recovery. Greater cerebral blood flow was significantly correlated with visual hallucinations and agitation during the acute withdrawal reaction. The results suggest that delirium tremens and related clinical states represent a type of acute brain syndrome mainly characterized by CNS hyperexcitability

  3. Impairment of neuropsychological function in patients with hemodynamic cerebral ischemia and efficacy of bypass surgery

    Energy Technology Data Exchange (ETDEWEB)

    Sasoh, Masayuki [Iwate Medical Univ., Morioka (Japan). School of Medicine

    1999-08-01

    In order to evaluate the relation between neuropsychological functions and hemodynamic cerebral ischemia, the author analyzed neuropsychological examination and the cerebral blood flow and metabolism of patients before and after bypass surgery. Twenty-five patients were defined by clinical and laboratory criteria as suffering from hemodynamic cerebral ischemia. All patients had one or more episodes of focal cerebral ischemia due to unilateral internal carotid or middle cerebral artery occlusion. Computerized tomography scans either were normal or showed evidence of watershed infarction. Based on these criteria, superficial temporal artery-proximal middle cerebral artery anastomosis was performed. The baseline cerebral blood flow (CBF), oxygen extraction fraction (OEF), cerebral metabolic rate of oxygen (CMRO{sub 2}) and cerebrovascular reserve capacity (CVRC) were studied using positron emission computerized tomography (PET) and the acetazolamide test. Neuropsychological evaluations including Hasegawa Dementia Scale-Revised, Mini-Mental State and Wechsler Adult Intelligence Scale-Revised (WAIS-R), and PET study were completed one month after the last ischemic event and 3-6 months after the operation. A significant negative correlation was observed between OEF and neuropsychological functions. Postoperative neuropsychological functions showed significant improvement. Significant correlations were observed for {delta}WAIS-R (preoperative WAIS-R postoperative WAIS-R) versus preoperative CMRO{sub 2} (r=0.52), for {delta}WAIS-R versus preoperative OEF (r=0.47). In view of these findings, the author concludes that elevation of OEF impairs neuropsychological functions and bypass surgery improves neuropsychological functions in patients with normal CMRO{sub 2} and elevated OEF. (author)

  4. Correlation between quantitative EEG and cerebral blood flow and oxygen metabolism in patients with dementia of Alzheimer type

    International Nuclear Information System (INIS)

    Kudoh, Masako; Takahashi, Satoshi; Yonezawa, Hisashi

    1997-01-01

    Quantitative scalp EEG and cerebral blood flow (CBF) and oxygen metabolism (CMRO 2 ) measured by the steady-state 15 O technique and positron emission tomography were studied in 19 patients with mild to moderate dementia of Alzheimer type (DAT) and age-matched controls (EEG=19, PET=6). Scalp electrodes were placed according to the international 10-20 method except for Cz, T3, and T4. To evaluate the relative changes in power for each frequency band between the two groups, the percentage power fraction (percentage power for each frequency band at a site compared to the total power at that site; %delta for 2.0-3.8 Hz, %theta for 4.0-7.8 Hz, %alpha for 8.0-12.8 Hz, %beta for 13.0-25.4 Hz) was calculated. Compared with controls, DAT patients showed a significant decrease in %alpha, while significant increases in %theta at all electrodes, and significant increases in %delta at the temporal, parietal and occipital electrodes were observed. The patient group displayed a significant decrease in rCBF and rCMRO 2 in the parietal, temporal and frontal cortices, but the reduction in rCMRO 2 was less remarkable than that of rCBF. %Theta at P3, O1 and O2 showed a significant negative correlation with rCBF, and %theta at P3, O1showed a significant negative correlation with rCMRO 2 . %Delta at P3, P4 and T5 was significantly negatively correlated with rCBF in the corresponding regions, and %alpha at almost all the electrodes (except O1, F3, P3) was significantly positively correlated with rCBF in the corresponding regions. %Delta and %alpha did not show any significant correlation with rCMRO 2 . (author)

  5. Non-selective beta-adrenergic blockade prevents reduction of the cerebral metabolic ratio during exhaustive exercise in humans

    DEFF Research Database (Denmark)

    Larsen, T.S.; Rasmussen, P.; Overgaard, M.

    2008-01-01

    Intense exercise decreases the cerebral metabolic ratio of oxygen to carbohydrates [O(2)/(glucose + (1/2)lactate)], but whether this ratio is influenced by adrenergic stimulation is not known. In eight males, incremental cycle ergometry increased arterial lactate to 15.3 +/- 4.2 mm (mean +/- s.......d.) and the arterial-jugular venous (a-v) difference from -0.02 +/- 0.03 mm at rest to 1.0 +/- 0.5 mm (P cerebral metabolic ratio decreased from 5.5 +/- 1.4 to 3.0 +/- 0.3 (P ... of a non-selective beta-adrenergic (beta(1) + beta(2)) receptor antagonist (propranolol) reduced heart rate (69 +/- 8 to 58 +/- 6 beats min(-1)) and exercise capacity (239 +/- 42 to 209 +/- 31 W; P

  6. Influence of cerebrovascular resistance on the dynamic relationship between blood pressure and cerebral blood flow in humans.

    Science.gov (United States)

    Smirl, J D; Tzeng, Y C; Monteleone, B J; Ainslie, P N

    2014-06-15

    We examined the hypothesis that changes in the cerebrovascular resistance index (CVRi), independent of blood pressure (BP), will influence the dynamic relationship between BP and cerebral blood flow in humans. We altered CVRi with (via controlled hyperventilation) and without [via indomethacin (INDO, 1.2 mg/kg)] changes in PaCO2. Sixteen subjects (12 men, 27 ± 7 yr) were tested on two occasions (INDO and hypocapnia) separated by >48 h. Each test incorporated seated rest (5 min), followed by squat-stand maneuvers to increase BP variability and improve assessment of the pressure-flow dynamics using linear transfer function analysis (TFA). Beat-to-beat BP, middle cerebral artery velocity (MCAv), posterior cerebral artery velocity (PCAv), and end-tidal Pco2 were monitored. Dynamic pressure-flow relations were quantified using TFA between BP and MCAv/PCAv in the very low and low frequencies through the driven squat-stand maneuvers at 0.05 and 0.10 Hz. MCAv and PCAv reductions by INDO and hypocapnia were well matched, and CVRi was comparably elevated (P flow dynamics. These findings are consistent with the concept of CVRi being a key factor that should be considered in the correct interpretation of cerebral pressure-flow dynamics as indexed using TFA metrics. Copyright © 2014 the American Physiological Society.

  7. Effect of Acute Resistance Exercise on Carotid Artery Stiffness and Cerebral Blood Flow Pulsatility

    Directory of Open Access Journals (Sweden)

    Wesley K Lefferts

    2014-03-01

    Full Text Available Arterial stiffness is associated with cerebral flow pulsatility. Arterial stiffness increases following acute resistance exercise (RE. Whether this acute RE-induced vascular stiffening affects cerebral pulsatility remains unknown. Purpose: To investigate the effects of acute RE on common carotid artery (CCA stiffness and cerebral blood flow velocity (CBFv pulsatility. Methods: Eighteen healthy men (22 ± 1 yr; 23.7 ± 0.5 kg∙m-2 underwent acute RE (5 sets, 5-RM bench press, 5 sets 10-RM bicep curls with 90 s rest intervals or a time control condition (seated rest in a randomized order. CCA stiffness (β-stiffness, Elastic Modulus (Ep and hemodynamics (pulsatility index, forward wave intensity and reflected wave intensity were assessed using a combination of Doppler ultrasound, wave intensity analysis and applanation tonometry at baseline and 3 times post-RE. CBFv pulsatility index was measured with transcranial Doppler at the middle cerebral artery (MCA. Results: CCA β-stiffness, Ep and CCA pulse pressure significantly increased post-RE and remained elevated throughout post-testing (p 0.05. There were significant increases in forward wave intensity post-RE (p0.05. Conclusion: Although acute RE increases CCA stiffness and pressure pulsatility, it may not affect CCA or MCA flow pulsatility. Increases in pressure pulsatility may be due to increased forward wave intensity and not pressure from wave reflections.

  8. The Role of Exercise – Rehabilitation on Energy Cost and Metabolic Efficiency in Dipelegic Spastic Cerebral Palsy Children

    Directory of Open Access Journals (Sweden)

    M. Izadi

    2005-07-01

    Full Text Available Introduction & Objective: The aim of this study was to compare the resting energy expenditure and metabolic efficiency before and after of aerobic exercise in spastic cerebral palsy children (mean age of 11 years and also to compare with those of normal children. Materials & Methods : Fifteen dipelegia spastic cerebral palsy children (experimental group participated in exercise–rehabilitation program by voluntarily and the peers eighteen able body children(control group were selected randomly. The experimental group(cp performed rehabilitation program for 3 months,3 session in week with work intensity(%HRR=462.5equal to144bpm of heart rate. The values were measured on tantory cycle ergometer according to Macmaster protocol.Results: Rest and exercise heart rate and exercise intensity(%HRR in patients decreased after rehabilitation program(P<0.05. The resting energy expenditure was similar in cp and normal groups. The rate of oxygen cost of patients decreased in post test(P<0.05 that showed increasing in metabolic efficiency.Conclusion: cerebral palsy children have greater exercise energy cost and lower cardiovascular fitness than normal children and exercise–rehabilitation leads to enhance of metabolic efficiency in this patients that is remarkable from clinical perception.

  9. Effect of pregnancy on regional cerebral blood flow

    International Nuclear Information System (INIS)

    Nagamachi, Shigeki; Hoshi, Hiroaki; Jinnouchi, Seishi; Ohnishi, Takashi; Futami, Shigemi; Watanabe, Katsushi; Ikeda, Tomoaki; Mori, Norimasa

    1993-01-01

    Regional cerebral blood flow (r-CBF) of 10 pregnant women were quantified by 133 Xe SPECT study with inhalation method before and after artificial abortion. During pregnancy, value of r-CBF in each region except occipital lobe was significantly higher than that of the post abortion. Arterial blood gas was analyzed after SPECT procedure. P co2 concentration increased significantly after artificial abortion. Although its mechanism is unknown, our preliminary work demonstrates that r-CBF increased by pregnancy. (author)

  10. A study on measurement of the regional cerebral blood flow using autoradiographic method in moyamoya disease

    International Nuclear Information System (INIS)

    Sasaki, Tomohiro; Kiya, Katsuzo; Yuki, Kiyoshi; Kawamoto, Hitoshi; Mizoue, Tatsuya; Kiura, Yoshihiro; Uozumi, Tohru; Ikawa, Fusao

    1997-01-01

    Development of Autoradiographic method (ARG) has provided measurement of cerebral blood flow in moyamoya disease. We evaluate a cerebral vasodilatory capacity (CVC) for moyamoya disease using ARG method. We used 5 patients with moyamoya disease as a candidate for measurement of the cerebral blood flow (CBF) who admitted to Hiroshima Prefectural Hospital during the past one year. There were 3 patients in an adult age and 2 patients in a young age. We tried to measure the regional CBF (rCBF) using ARG method which was a easy way to estimate the rCBF on SPECT. The CVC was calculated from the difference of the rCBF between resting SPECT and Diamox-loading SPECT. Results were as follows; Reactivity of cerebral vessels to CO 2 loading and CVC weakened in moyamoya disease. The rCBF and CVC in the territories of anterior and middle cerebral arteries reduced in comparison with those in the area supplied by the posterior cerebral artery. The CVC at the treated side with surgical reconstruction recovered somewhat in an adult type. From these results, measurement of CBF using ARG method seems to be useful for evaluation of the CVC in moyamoya disease. (author)

  11. Relationship of cerebral blood flow to aortic-to-pulmonary collateral/shunt flow in single ventricles

    Science.gov (United States)

    Fogel, Mark A; Li, Christine; Wilson, Felice; Pawlowski, Tom; Nicolson, Susan C; Montenegro, Lisa M; Berenstein, Laura Diaz; Spray, Thomas L; Gaynor, J William; Fuller, Stephanie; Keller, Marc S; Harris, Matthew A; Whitehead, Kevin K; Clancy, Robert; Elci, Okan; Bethel, Jim; Vossough, Arastoo; Licht, Daniel J

    2016-01-01

    Objective Patients with single ventricle can develop aortic-to-pulmonary collaterals (APCs). Along with systemic-to-pulmonary artery shunts, these structures represent a direct pathway from systemic to pulmonary circulations, and may limit cerebral blood flow (CBF). This study investigated the relationship between CBF and APC flow on room air and in hypercarbia, which increases CBF in patients with single ventricle. Methods 106 consecutive patients with single ventricle underwent 118 cardiac magnetic resonance (CMR) scans in this cross-sectional study; 34 prior to bidirectional Glenn (BDG) (0.50±0.30 years old), 50 prior to Fontan (3.19±1.03 years old) and 34 3–9 months after Fontan (3.98±1.39 years old). Velocity mapping measured flows in the aorta, cavae and jugular veins. Analysis of variance (ANOVA) and multiple linear regression were used. Significance was p<0.05. Results A strong inverse correlation was noted between CBF and APC/shunt both on room air and with hypercarbia whether CBF was indexed to aortic flow or body surface area, independent of age, cardiopulmonary bypass time, Po2 and Pco2 (R=−0.67–−0.70 for all patients on room air, p<0.01 and R=−0.49–−0.90 in hypercarbia, p<0.01). Correlations were not different between surgical stages. CBF was lower, and APCs/shunt flow was higher prior to BDG than in other stages. Conclusions There is a strong inverse relationship between CBF and APC/shunt flow in patients with single ventricle throughout surgical reconstruction on room air and in hypercarbia independent of other factors. We speculate that APC/shunt flow may have a negative impact on cerebral development and neurodevelopmental outcome. Interventions on APC may modify CBF, holding out the prospect for improving neurodevelopmental trajectory. Trial Registration Number NCT02135081. PMID:26048877

  12. Quantitative determination of the regional cerebral blood flow with 133Xe

    International Nuclear Information System (INIS)

    Otto, H.J.; Abraham, K.; Freitag, J.; Koch, R.D.; Freitag, G.; Hoefs, R.

    1982-01-01

    After injection of 133 Xe into the A. carotis interna, the regional blood flow in the brain was determined with a 10-channel measuring unit. From the first clinical evaluation of the findings in 35 patients, the following conclusions can be drawn: 1. In epileptics, a localized hyperemia indicates very probably a latent increased convulsive activity. 2. The measurement of the cerebral blood flow does not yield a contribution to the diagnosis of the type of cerebral tumors. 3. As consequence of mass shifting of space occupying processes particularly endangered brain sections, also remote from the focus proper, show a localized pathological hyeperemia (morbid 'luxus perfusion'). 4. Of greatest importance is the method with regard to the elucidation of pathophysiological relations, as well as of questions in connection with the blood/brain barrier function, and concerning the indication for and the estimation of the results of vascular interventions. (author)

  13. The coupling of cerebral blood flow and oxygen metabolism with brain activation is similar for simple and complex stimuli in human primary visual cortex.

    Science.gov (United States)

    Griffeth, Valerie E M; Simon, Aaron B; Buxton, Richard B

    2015-01-01

    Quantitative functional MRI (fMRI) experiments to measure blood flow and oxygen metabolism coupling in the brain typically rely on simple repetitive stimuli. Here we compared such stimuli with a more naturalistic stimulus. Previous work on the primary visual cortex showed that direct attentional modulation evokes a blood flow (CBF) response with a relatively large oxygen metabolism (CMRO2) response in comparison to an unattended stimulus, which evokes a much smaller metabolic response relative to the flow response. We hypothesized that a similar effect would be associated with a more engaging stimulus, and tested this by measuring the primary human visual cortex response to two contrast levels of a radial flickering checkerboard in comparison to the response to free viewing of brief movie clips. We did not find a significant difference in the blood flow-metabolism coupling (n=%ΔCBF/%ΔCMRO2) between the movie stimulus and the flickering checkerboards employing two different analysis methods: a standard analysis using the Davis model and a new analysis using a heuristic model dependent only on measured quantities. This finding suggests that in the primary visual cortex a naturalistic stimulus (in comparison to a simple repetitive stimulus) is either not sufficient to provoke a change in flow-metabolism coupling by attentional modulation as hypothesized, that the experimental design disrupted the cognitive processes underlying the response to a more natural stimulus, or that the technique used is not sensitive enough to detect a small difference. Copyright © 2014 Elsevier Inc. All rights reserved.

  14. Quantitative evaluation of regional cerebral blood flow by visual stimulation in 99mTc-HMPAO brain SPECT

    International Nuclear Information System (INIS)

    Juh, R. H.; Suh, T. S.; Chung, Y. A.

    2002-01-01

    The purpose of this study is to investigate the effects of visual activation and quantitative analysis of regional cerebral blood flow. Visual activation was known to increase regional cerebral blood flow in the visual cortex in occipital lobe. We evaluated that change in the distribution of 99mTc-HMPAO (Hexamethyl propylene amine oxime) to reflect in regional cerebral blood flow. The six volunteers were injected with 925 MBq (mean ages: 26.75 years, n=6, 3men, 3women) underwent MRI and 99mTc- HMPAO SPECT during a rest state with closed eyes and visual stimulated with 8 Hz LED. We delineate the region of interest and calculated the mean count per voxel in each of the fifteen slices to quantitative analysis. The ROI to whole brain ratio and regional index was calculated pixel to pixel subtraction visual non-activation image from visual activation image and constructed brain map using a statistical parameter map (SPM99). The mean regional cerebral blood flow was increased due to visual stimulation. The increase rate of the mean regional cerebral blood flow which of the activation region in primary visual cortex of occipital lobe was 32.50±5.67%. The significant activation sites using a statistical parameter of brain constructed a rendering image and image fusion with SPECT and MRI. Visual activation was revealed significant increase through quantitative analysis in visual cortex. Activation region was certified in Talairach coordinate and primary visual cortex (Ba17),visual association area (Ba18,19) of Brodmann

  15. Quantitative evaluation of regional cerebral blood flow by visual stimulation in 99mTc- HMPAO brain SPECT

    International Nuclear Information System (INIS)

    Juh, Ra Hyeong; Suh, Tae Suk; Kwark, Chul Eun; Choe, Bo Young; Lee, Hyoung Koo; Chung, Yong An; Kim, Sung Hoon; Chung, Soo Kyo

    2002-01-01

    The purpose of this study is to investigate the effects of visual activation and quantitative analysis of regional cerebral blood flow. Visual activation was known to increase regional cerebral blood flow in the visual cortex in occipital lobe. We evaluated that change in the distribution of '9 9m Tc-HMPAO (Hexamethyl propylene amine oxime) to reflect in regional cerebral blood flow. The six volunteers were injected with 925 MBq (mean ages: 26.75 years, n=6, 3men, 3women) underwent MRI and 99m Tc-HMPAO SPECT during a rest state with closed eyes and visual stimulated with 8 Hz LED. We delineate the region of interest and calculated the mean count per voxel in each of the fifteen slices to quantitative analysis. The ROI to whole brain ratio and regional index was calculated pixel to pixel subtraction visual non-activation image from visual activation image and constructed brain map using a statistical parameter map(SPM99). The mean regional cerebral blood flow was increased due to visual stimulation. The increase rate of the mean regional cerebral blood flow which of the activation region in primary visual cortex of occipital lobe was 32.50±5.67%. The significant activation sites using a statistical parameter of brain constructed a rendering image and image fusion with SPECT and MRI. Visual activation was revealed significant increase through quantitative analysis in visual cortex. Activation region was certified in Talairach coordinate and primary visual cortex (Ba17),visual association area (Ba18,19) of Brodmann

  16. Modelling Blood Flow and Metabolism in the Preclinical Neonatal Brain during and Following Hypoxic-Ischaemia.

    Directory of Open Access Journals (Sweden)

    Matthew Caldwell

    Full Text Available Hypoxia-ischaemia (HI is a major cause of neonatal brain injury, often leading to long-term damage or death. In order to improve understanding and test new treatments, piglets are used as preclinical models for human neonates. We have extended an earlier computational model of piglet cerebral physiology for application to multimodal experimental data recorded during episodes of induced HI. The data include monitoring with near-infrared spectroscopy (NIRS and magnetic resonance spectroscopy (MRS, and the model simulates the circulatory and metabolic processes that give rise to the measured signals. Model extensions include simulation of the carotid arterial occlusion used to induce HI, inclusion of cytoplasmic pH, and loss of metabolic function due to cell death. Model behaviour is compared to data from two piglets, one of which recovered following HI while the other did not. Behaviourally-important model parameters are identified via sensitivity analysis, and these are optimised to simulate the experimental data. For the non-recovering piglet, we investigate several state changes that might explain why some MRS and NIRS signals do not return to their baseline values following the HI insult. We discover that the model can explain this failure better when we include, among other factors such as mitochondrial uncoupling and poor cerebral blood flow restoration, the death of around 40% of the brain tissue.

  17. Characterisation of cerebral blood flow via determining the vascular mean transit time

    International Nuclear Information System (INIS)

    Lindner, P.; Thelen, M.

    1987-01-01

    By using a recently developed algorithm it is possible to quantify the dynamic information of a DSA sequence of the brain. The theory of algorithm allows to calculate vascular mean transit from time density curves. The algorithm minimizes the problems of densitometry with regard to 'quantitative DSA'. There is a strong correlation between vascular mean transit times and cerebral blood flow values, and therefore the results for mean transit times also correspond to the results obtained for cerebral blood flow. By computerized postprocessing of DSA-images it is possible to generate functional images of the brain with a spatial resolution that had not been attainable so far. The images represent the distribution pattern of reverse vascular mean transit times. The results from 36 patients with proven stenoses of the cervical vessels are reported. (orig.) [de

  18. Cerebral small-resistance artery structure and cerebral blood flow in normotensive subjects and hypertensive patients

    Energy Technology Data Exchange (ETDEWEB)

    De Ciuceis, Carolina; Porteri, Enzo; Rizzoni, Damiano; Boari, Gianluca E.M.; Rosei, Enrico Agabiti [University of Brescia, Clinica Medica, Department of Clinical and Experimental Sciences, Brescia (Italy); Cornali, Claudio; Mardighian, Dikran; Fontanella, Marco M. [University of Brescia, Section of Neurosurgery, Department of Medical and Surgical Specialties, Radiological Sciences and Public Health, Brescia (Italy); Pinardi, Chiara [Spedali Civili, Medical Physics Unit, Brescia (Italy); University of Brescia, Section of Neuroradiology, Department of Medical and Surgical Specialties, Radiological Sciences and Public Health, Brescia (Italy); Rodella, Luigi F.; Rezzani, Rita [University of Brescia, Section of Anatomy, Department of Clinical and Experimental Sciences, Brescia (Italy); Gasparotti, Roberto [University of Brescia, Section of Neurosurgery, Department of Medical and Surgical Specialties, Radiological Sciences and Public Health, Brescia (Italy); University of Brescia, Section of Neuroradiology, Department of Medical and Surgical Specialties, Radiological Sciences and Public Health, Brescia (Italy)

    2014-12-15

    The aim of this study was to prospectively investigate whether the structure of cerebral small-resistance arteries is related to cerebral perfusion parameters as measured with dynamic susceptibility-weighted contrast magnetic resonance imaging (DSC-MRI) in a selected cohort of hypertensive and normotensive patients. Ten hypertensive and 10 normotensive patients were included in the study. All patients underwent neurosurgical intervention for an intracranial tumor and were investigated with DSC-MRI at 1.5 T. Cerebral small-resistance arteries were dissected from a small portion of morphologically normal cerebral tissue and mounted on an isometric myograph for the measurement of the media-to-lumen (M/L) ratio. A quantitative assessment of cerebral blood flow (CBF) and volume (CBV) was performed with a region-of-interest approach. Correlation coefficients were calculated for normally distributed variables. The institutional review board approved the study, and informed consent was obtained from all patients. Compared with normotensive subjects, hypertensive patients had significantly lower regional CBF (mL/100 g/min) in the cortical grey matter (55.63 ± 1.90 vs 58.37 ± 2.19, p < 0.05), basal ganglia (53.34 ± 4.39 vs 58.22. ± 4.33, p < 0.05), thalami (50.65 ± 3.23 vs 57.56 ± 4.45, p < 0.01), subcortical white matter (19.32 ± 2.54 vs 22.24 ± 1.9, p < 0.05), greater M/L ratio (0.099 ± 0.013 vs 0.085 ± 0.012, p < 0.05), and lower microvessel density (1.66 ± 0.67 vs 2.52 ± 1.28, p < 0.05). A statistically significant negative correlation was observed between M/L ratio of cerebral arteries and CBF in the cortical grey matter (r = -0.516, p < 0.05), basal ganglia (r = -0.521, p < 0.05), thalami (r = -0.527 p < 0.05), and subcortical white matter (r = -0.612, p < 0.01). Our results indicate that microvascular structure might play a role in controlling CBF, with possible clinical consequences. (orig.)

  19. Daily consumption of white tea (Camellia sinensis (L.)) improves the cerebral cortex metabolic and oxidative profile in prediabetic Wistar rats.

    Science.gov (United States)

    Nunes, Ana R; Alves, Marco G; Tomás, Gonçalo D; Conde, Vanessa R; Cristóvão, Ana C; Moreira, Paula I; Oliveira, Pedro F; Silva, Branca M

    2015-03-14

    Diabetes mellitus (DM) is a major public health problem and its incidence is rising dramatically. The brain, particularly the cerebral cortex, is very susceptible to glucose fluctuations and hyperglycaemia-induced oxidative stress. Tea (Camellia sinensis (L.)) is widely consumed; however, the antidiabetic properties of white tea remain largely unexplored. In the present study, we investigated the effects of daily consumption of white tea on the cerebral cortex of prediabetic rats. The cerebral cortex metabolic profile was evaluated, and the expression levels of GLUT, phosphofructokinase-1, lactate dehydrogenase (LDH) and monocarboxylate transporter 4 were assessed. LDH activity was also determined. The cerebral cortex oxidative profile was determined by evaluating its antioxidant power, lipid peroxidation and protein oxidation levels. Catalase, glutathione, glutamate, N-acetylaspartate, aspartate, choline, γ-aminobutyric acid, taurine and valine contents were determined. Daily consumption of white tea ameliorated glucose tolerance and insulin sensitivity. Moreover, white tea altered the cortex glycolytic profile, modulating GLUT expression and lactate and alanine contents. Finally, white tea consumption restored protein oxidation and lipid peroxidation levels and catalase expression, and improved antioxidant capacity. In conclusion, daily consumption of white tea improved the cerebral cortex metabolic and oxidative profile in prediabetic rats, suggesting it as a good, safe and inexpensive strategy to prevent DM-related effects in the cerebral cortex.

  20. Radiotracer transit measurements as an index of regional cerebral blood flow. Pt. 1. Methodological and clinical results in chronic alcoholics cortical blood flow

    International Nuclear Information System (INIS)

    Dobrzanski, T.

    1975-01-01

    The numerical mean values of the cerebral radiorheographic index in healthy control subjects and in patients with cerebrovascular disease were not significantly different from the values of regional cerebral blood flow reported, respectively, by other authors using a modification of the Xe-133 method. In the group of chronic alcoholics there was a significant correlation between the duration of alcoholism and certain numerical values of the cerebral radiorheographic index. (author)

  1. Effects of ethamsylate on cerebral blood flow velocity in premature babies.

    OpenAIRE

    Rennie, J M; Lam, P K

    1989-01-01

    Cerebral blood flow velocity and cardiac output were measured with ultrasound before and 30 minutes after the administration of ethamsylate in a double blind placebo controlled study of 19 very low birthweight infants. No differences were found before or after treatment in either group.

  2. Resting state cerebral blood flow with arterial spin labeling MRI in developing human brains.

    Science.gov (United States)

    Liu, Feng; Duan, Yunsuo; Peterson, Bradley S; Asllani, Iris; Zelaya, Fernando; Lythgoe, David; Kangarlu, Alayar

    2018-07-01

    The development of brain circuits is coupled with changes in neurovascular coupling, which refers to the close relationship between neural activity and cerebral blood flow (CBF). Studying the characteristics of CBF during resting state in developing brain can be a complementary way to understand the functional connectivity of the developing brain. Arterial spin labeling (ASL), as a noninvasive MR technique, is particularly attractive for studying cerebral perfusion in children and even newborns. We have collected pulsed ASL data in resting state for 47 healthy subjects from young children to adolescence (aged from 6 to 20 years old). In addition to studying the developmental change of static CBF maps during resting state, we also analyzed the CBF time series to reveal the dynamic characteristics of CBF in differing age groups. We used the seed-based correlation analysis to examine the temporal relationship of CBF time series between the selected ROIs and other brain regions. We have shown the developmental patterns in both static CBF maps and dynamic characteristics of CBF. While higher CBF of default mode network (DMN) in all age groups supports that DMN is the prominent active network during the resting state, the CBF connectivity patterns of some typical resting state networks show distinct patterns of metabolic activity during the resting state in the developing brains. Copyright © 2018 European Paediatric Neurology Society. All rights reserved.

  3. In vivo neuro MR spectroscopy: a non-invasive insight into cerebral metabolism

    International Nuclear Information System (INIS)

    Rose, S.; De Zubicaray, G.; Wang, D.; Galloway, G.; Doddrell, D.; Chalk, J.; University of Queensland, Brisbane, QLD; Eagle, S.; Semple, J.

    1999-01-01

    In addition to conventional magnetic resonance imaging (MRI) for examining anatomical structure, in vivo proton magnetic resonance spectroscopy (MRS) is currently being used as a non-invasive clinical tool for monitoring altered brain metabolism. Conditions such as head injury, dementia, multiple sclerosis, tumour, stroke, epilepsy and inborn errors of metabolism are all presently being investigated with MRS. At the Centre for Magnetic Resonance, we are currently undertaking a longitudinal study of dementia progression in Alzheimer's disease (AD) utilising both MRS and volumetric MRI techniques. The aim is to identify metabolic differences between this patient group and normal older adults and to correlate these measures with cognitive function. Cerebral artrophy, or loss of brain matter, together with ventricular enlargement , or enlargement of normally occuring cavities, is clearly present on MRI exams in patients with moderate and severe AD

  4. Metabolic and hemodynamic evaluation of brain metastases from small cell lung cancer with positron emission tomography

    DEFF Research Database (Denmark)

    Lassen, U; Andersen, P; Daugaard, G

    1998-01-01

    for studies of metabolic and hemodynamic features. This study was performed to determine regional cerebral metabolic rate of glucose (rCMRglu), regional cerebral blood flow (rCBF), and regional cerebral blood volume (rCBV) in brain metastases from small cell lung cancer and the surrounding brain. Tumor r......Brain metastases from small cell lung cancer respond to chemotherapy, but response duration is short and the intracerebral concentration of chemotherapy may be too low because of the characteristics of the blood-brain barrier. Positron emission tomography has been applied in a variety of tumors...

  5. Significance of preoperative cerebral blood flow measurements in endovascular occlusion of the internal carotid and middle cerebral arteries

    International Nuclear Information System (INIS)

    Laurent, A.; Weitzner, I.; Luft, A.; Merland, J.J.

    1988-01-01

    Cerebral blood flow (CBF) measurements during 12 endovascular balloon occlusions (ten internal carotid and two middle cerebral arteries) with good clinical and angiographic tolerance were done with repeated boluses of Xe-133 injected directly into the ipsi- and contralateral carotid systems, during the occlusion and repeated measurements with detectors on both sides (before occlusion and 5-30 minutes after occlusion). In two cases of unchanged and four of increased CBF, one reversible deficit was probably due to an embolus. In six cases of decreased CBF, two deficits occurred, characterized by a greater than 25% decrease. It seems to represent a good predictive value for intolerance to occlusion

  6. Quantitative Rates of Brain Glucose Metabolism Distinguish Minimally Conscious from Vegetative State Patients

    DEFF Research Database (Denmark)

    Stender, Johan; Kupers, Ron; Rodell, Anders

    2015-01-01

    of these patients. However, no quantitative comparisons of cerebral glucose metabolism in VS/UWS and MCS have yet been reported. We calculated the regional and whole-brain CMRglc of 41 patients in the states of VS/UWS (n=14), MCS (n=21) or emergence from MCS (EMCS, n=6), and healthy volunteers (n=29). Global......The differentiation of the vegetative or unresponsive wakefulness syndrome (VS/UWS) from the minimally conscious state (MCS) is an important clinical issue. The cerebral metabolic rate of glucose (CMRglc) declines when consciousness is lost, and may reveal the residual cognitive function...... these results reveal a significant correlation between whole-brain energy metabolism and level of consciousness, suggesting that quantitative values of CMRglc reveal consciousness in severely brain-injured patients.Journal of Cerebral Blood Flow & Metabolism advance online publication, 8 October 2014; doi:10...

  7. Metabolic Characterization of Acutely Isolated Hippocampal and Cerebral Cortical Slices Using [U-13C]Glucose and [1,2-13C]Acetate as Substrates.

    Science.gov (United States)

    McNair, Laura F; Kornfelt, Rasmus; Walls, Anne B; Andersen, Jens V; Aldana, Blanca I; Nissen, Jakob D; Schousboe, Arne; Waagepetersen, Helle S

    2017-03-01

    Brain slice preparations from rats, mice and guinea pigs have served as important tools for studies of neurotransmission and metabolism. While hippocampal slices routinely have been used for electrophysiology studies, metabolic processes have mostly been studied in cerebral cortical slices. Few comparative characterization studies exist for acute hippocampal and cerebral cortical slices, hence, the aim of the current study was to characterize and compare glucose and acetate metabolism in these slice preparations in a newly established incubation design. Cerebral cortical and hippocampal slices prepared from 16 to 18-week-old mice were incubated for 15-90 min with unlabeled glucose in combination with [U- 13 C]glucose or [1,2- 13 C]acetate. Our newly developed incubation apparatus allows accurate control of temperature and is designed to avoid evaporation of the incubation medium. Subsequent to incubation, slices were extracted and extracts analyzed for 13 C-labeling (%) and total amino acid contents (µmol/mg protein) using gas chromatography-mass spectrometry and high performance liquid chromatography, respectively. Release of lactate from the slices was quantified by analysis of the incubation media. Based on the measured 13 C-labeling (%), total amino acid contents and relative activity of metabolic enzymes/pathways, we conclude that the slice preparations in the current incubation apparatus exhibited a high degree of metabolic integrity. Comparison of 13 C-labeling observed with [U- 13 C]glucose in slices from cerebral cortex and hippocampus revealed no significant regional differences regarding glycolytic or total TCA cycle activities. On the contrary, results from the incubations with [1,2- 13 C]acetate suggest a higher capacity of the astrocytic TCA cycle in hippocampus compared to cerebral cortex. Finally, we propose a new approach for assessing compartmentation of metabolite pools between astrocytes and neurons using 13 C-labeling (%) data obtained from

  8. Near-infrared spectroscopy assessed cerebral oxygenation during open abdominal aortic aneurysm repair

    DEFF Research Database (Denmark)

    Sørensen, H.; Nielsen, Henning Morris Bay; Secher, N H

    2016-01-01

    During open abdominal aortic aneurism (AAA) repair cerebral blood flow is challenged. Clamping of the aorta may lead to unintended hyperventilation as metabolism is reduced by perfusion of a smaller part of the body and reperfusion of the aorta releases vasodilatory substances including CO2. We i...

  9. Quantitative assessment of cerebral blood flow by 123I-IMP SPECT

    International Nuclear Information System (INIS)

    Moriwaki, Hiroshi; Matsumoto, Masayasu; Hashikawa, Kazuo

    1993-01-01

    To establish a noninvasive, quantitative method for measuring regional cerebral blood flow (rCBF) by N-isopropyl-p-[ 123 I]iodoamphetamine ( 123 I-IMP) SPECT, we attempted to employ continuous venous sampling instead of arterial sampling. Forty two patients with cerebrovascular disease were classified into two groups, with (group II: n=35) and without (group I: n=7) hand warming. In group II, either hand was warmed, wrapping in a hot blanket (group IIA) or immersed in a 44degC water bath (group IIB). Immediately after intravenous bolus injection of 222 MBq IMP, arterial and venous blood samples were collected continuously for 5 min from the radial artery and the cubital vein, respectively. By octanol extraction, IMP was divided into the unmetabolized and metabolized fractions. The ratio of 123 I-IMP of venous blood to arterial blood (pass ratio, referred to as %PR) was calculated in the whole blood, unmetabolized, and metabolized fractions. Using these parameters, we assessed the possibility to estimate the amount of unmetabolized IMP fraction of arterial blood, usually used as an input function, from venous samples. In group I, %PR demonstrated a considerable variation between individuals (whole IMP, 47.5±24.6%; unmetabolized IMP, 46.0±24.5%; metabolized IMP, 51.8±27.4%). In group II, especially in group IIB, both increase of %PR value and the decrease in variation (whole, 77.9±5.6%; unmetabolized, 75.7±5.7%; metabolized, 86.7±8.7%) were observed, permitting the further calculation based on the assumption that %PR value was constant in each IMP fraction. The coefficient of variation of the difference between estimated arterial IMP radioactivity from venous samples and actual arterial IMP was 9.0% and 7.5%. The use of venous sampling coupled with a hand warming technique allowed the estimation of the arterial unmetabolized IMP radioactivity from venous samples with a reliability of 90% or more. (author)

  10. Role of cerebral blood flow in extreme breath holding

    Directory of Open Access Journals (Sweden)

    Bain Anthony R.

    2016-01-01

    Full Text Available The role of cerebral blood flow (CBF on a maximal breath-hold (BH in ultra-elite divers was examined. Divers (n = 7 performed one control BH, and one BH following oral administration of the non-selective cyclooxygenase inhibitor indomethacin (1.2 mg/kg. Arterial blood gases and CBF were measured prior to (baseline, and at BH termination. Compared to control, indomethacin reduced baseline CBF and cerebral delivery of oxygen (CDO2 by about 26% (p < 0.01. Indomethacin reduced maximal BH time from 339 ± 51 to 319 ± 57 seconds (p = 0.04. In both conditions, the CDO2 remained unchanged from baseline to the termination of apnea. At BH termination, arterial oxygen tension was higher following oral administration of indomethacin compared to control (4.05 ± 0.45 vs. 3.44 ± 0.32 kPa. The absolute increase in CBF from baseline to the termination of apnea was lower with indomethacin (p = 0.01. These findings indicate that the impact of CBF on maximal BH time is likely attributable to its influence on cerebral H+ washout, and therefore central chemoreceptive drive to breathe, rather than to CDO2.

  11. Delayed decrease in hemispheric cerebral blood flow during Wada test demonstrated by 99mTc-HMPAO single photon emission computer tomography

    International Nuclear Information System (INIS)

    Ryding, E.; Sjoeholm, H.; Skeidsvoll, H.; Elmqvist, D.

    1989-01-01

    We describe how brain regions with a flow (and metabolism) decrease can be visualized after an injection of short-acting barbiturate in one of the internal carotid arteries during a Wada test. An intravenous administration of 99mTc-HMPAO was used to mark the relative flow distribution. The 99mTc-HMPAO distribution in the brain was recorded three-dimensionally about 1 h later, by means of a single photon emission computer tomograph. We show that the timing of the intravenous 99mTc-HMPAO administration during the Wada test is important for the visualization of the low-flow regions. The administration of the tracer substance should be delayed at least 30 s after the first signs of the barbiturate effect. The rCBF decrease in the barbiturate-injected cerebral hemisphere was associated with a simultaneous decrease in the contralateral, pharmacologically not directly affected, cerebellar hemisphere (crossed cerebellar diaschisis). (author)

  12. Cerebral metabolic changes in neurologically presymptomatic patients undergoing haemodialysis: in vivo proton MR spectroscopic findings

    International Nuclear Information System (INIS)

    Chiu, Ming-Lun; Chiang, I. Chan; Li, Chun-Wei; Chang, Jer-Ming; Ko, Chih-Hung; Chuang, Hung-Yi; Sheu, Reu-Sheng; Lee, Chen-Chang; Hsieh, Tsyh-Jyi

    2010-01-01

    To prospectively investigate and detect early cerebral metabolic changes in patients with end-stage renal disease (ESRD) by using in vivo proton MR spectroscopy (MRS). We enrolled 32 patients with ESRD and 32 healthy controls between the ages of 26 and 50 years. Short echo time single-voxel proton MRS was acquired from volumes of interest (VOIs) located in the frontal grey and white matter, temporal white matter and basal ganglia. The choline/phospatidylcholine (Cho), myo-inositol (mI), N-acetylaspartate (NAA) and total creatine (tCr) peaks were measured and the metabolic ratios with respect to tCr were calculated. In the ESRD group, significant elevations of the Cho/tCr and mI/tCr ratios were observed for the frontal grey matter, frontal white matter, temporal white matter and basal ganglia as compared with controls. There was no significant difference in the NAA/tCr ratios at all VOIs between the ESRD patients and the healthy controls. Proton MRS is a useful and non-invasive imaging tool for the detection of early cerebral metabolic changes in neurologically presymptomatic ESRD patients. (orig.)

  13. Cerebral metabolism, anatomy, and cognition in monozygotic twins discordant for dementia of the Alzheimer type.

    Science.gov (United States)

    Luxenberg, J S; May, C; Haxby, J V; Grady, C; Moore, A; Berg, G; White, B J; Robinette, D; Rapoport, S I

    1987-03-01

    One pair of monozygotic twins discordant for dementia of the Alzheimer type (DAT) was studied using neuropsychological testing, quantitative x-ray computed tomography (QCT) and magnetic resonance imaging (MRI) of the brain. Cerebral glucose metabolism was measured using positron emission tomography (PET) and 2-[18-F]fluoro-2-deoxy-D-glucose (FDG). The affected twin had a seven year history of progressive cognitive impairment and was severely demented. Neuropsychological testing of the affected twin demonstrated marked deficits in all areas of cognitive function. The asymptomatic twin showed some impairment on tests of perceptual organisation and delayed recall. The affected twin had loss of gray matter and ventricular enlargement on QCT and MRI compared with healthy controls (p less than 0.05). He also had frontal and parietal lobe hypometabolism and increased asymmetry of metabolism on PET compared to both his twin and healthy age-matched controls (p less than 0.05). PET, QCT, and MRI distinguished changes in the twin with DAT compared with his brother and healthy controls. Although the subtle neuropsychological abnormalities of the asymptomatic twin may be signs of early DAT, they were not accompanied by any changes in regional cerebral metabolism or brain structure.

  14. Cerebral metabolic changes in neurologically presymptomatic patients undergoing haemodialysis: in vivo proton MR spectroscopic findings

    Energy Technology Data Exchange (ETDEWEB)

    Chiu, Ming-Lun; Chiang, I. Chan [Kaohsiung Medical University Hospital, Department of Medical Imaging (China); Li, Chun-Wei [Kaohsiung Medical University, Department of Medical Imaging and Radiological Sciences, College of Health Science (China); Chang, Jer-Ming [Kaohsiung Medical University, Department of Internal Medicine, Kaohsiung Hsiao-Kang Municipal Hospital (China); Kaohsiung Medical University, Department of Nephrology, School of Medicine, College of Medicine (China); Ko, Chih-Hung [Kaohsiung Medical University, Department of Psychiatry, School of Medicine, College of Medicine (China); Kaohsiung Medical University Hospital, Department of Psychiatry (China); Chuang, Hung-Yi [Kaohsiung Medical University, Faculty of Public Health, College of Health Science (China); Kaohsiung Medical University Hospital, Department of Environmental and Occupational Medicine (China); Sheu, Reu-Sheng [Kaohsiung Medical University, Department of Radiology, Kaohsiung Municipal Hsiao-Kang Hospital (China); Kaohsiung Medical University, Department of Radiology, Faculty of Medicine, College of Medicine (China); Lee, Chen-Chang [Kaohsiung Medical University, Department of Medical Imaging and Radiological Sciences, College of Health Science (China); Kaohsiung Medical Centre, Department of Radiology, Chang Gung Memorial Hospital (China); Hsieh, Tsyh-Jyi [Kaohsiung Medical University Hospital, Department of Medical Imaging (China); Kaohsiung Medical University, Department of Radiology, Faculty of Medicine, College of Medicine (China); Kaohsiung Municipal Ta-Tung Hospital, Department of Medical Imaging (China)

    2010-06-15

    To prospectively investigate and detect early cerebral metabolic changes in patients with end-stage renal disease (ESRD) by using in vivo proton MR spectroscopy (MRS). We enrolled 32 patients with ESRD and 32 healthy controls between the ages of 26 and 50 years. Short echo time single-voxel proton MRS was acquired from volumes of interest (VOIs) located in the frontal grey and white matter, temporal white matter and basal ganglia. The choline/phospatidylcholine (Cho), myo-inositol (mI), N-acetylaspartate (NAA) and total creatine (tCr) peaks were measured and the metabolic ratios with respect to tCr were calculated. In the ESRD group, significant elevations of the Cho/tCr and mI/tCr ratios were observed for the frontal grey matter, frontal white matter, temporal white matter and basal ganglia as compared with controls. There was no significant difference in the NAA/tCr ratios at all VOIs between the ESRD patients and the healthy controls. Proton MRS is a useful and non-invasive imaging tool for the detection of early cerebral metabolic changes in neurologically presymptomatic ESRD patients. (orig.)

  15. Cerebral blood flow single-photon emission tomography with 123I-IMP in vascular dementia

    International Nuclear Information System (INIS)

    Kawahata, Nobuya; Gotoh, Chiharu; Yokoyama, Sakura; Daitoh, Nobuyuki

    2001-01-01

    Cerebral blood flow differences between patients with vascular dementia, patients with multiple lacunar infarction without cognitive dysfunction, and age-matched controls were examined. Thirty four patients with vascular dementia (VD) were selected from consecutive referrals to the Memory Clinic at Narita Memorial Hospital. All the patients had routine assessment including history, physical and neurological examinations, neuropsychological assessment, blood tests, EEG, head MRI, and single photon emission computed tomography (SPECT). All of them fulfilled the NINDS-AIREN diagnostic criteria for vascular dementia. Thirty nine patients with multiple lacunar infarction without cognitive dysfunction and 110 age-matched controls were included in this study. Mean cerebral blood flow (mCBF) and regional cerebral blood flow (rCBF) were measured using N-isopropyl-P- 123 I-iodoamphetamine ( 123 I-IMP) and SPECT imager. The mCBF in VD was 27.6±5.3 ml/100 g/min, while those in the control group and multiple lacunar infarction without cognitive dysfunction were 36.6±6.1 ml/100 g/min and 32.5±5.5 ml/100 g/min, respectively. The patients with VD demonstrated significantly reduced mCBF and rCBF in twenty regions including both cerebellar hemispheres as compared with those of the control group. Although there was no significant rCBF differences in bilateral inferior occipital regions and the right cerebellar hemisphere between patients with VD and multiple lacunar infarction without cognitive dysfunction, we could find significant lower rCBF in the remaining brain areas. In spite of the severity of VD, the diffuse decrease of cerebral blood flow was recognized in all patients with VD. (author)

  16. Disodium cromoglycate, a mast-cell stabilizer, alters postradiation regional cerebral blood flow in primates

    International Nuclear Information System (INIS)

    Cockerham, L.G.; Doyle, T.F.; Pautler, E.L.; Hampton, J.D.

    1986-01-01

    Early transient incapacitation (ETI) is the complete cessation of performance during the first 30 min after radiation exposure, and performance decrement (PD) is a reduction in performance at the same time. Supralethal doses of radiation have been shown to produce a marked decrease in regional cerebral blood flow in primates concurrent with systemic hypotension and a dramatic release of mast-cell histamine. In an attempt to elucidate mechanisms underlying the radiation-induced ETI/PD phenomena and the postradiation decrease in cerebral blood flow, primates were given the mast-cell stabilizers disodium cromoglycate (DSCG) or BRL 22321 before exposure to 100 Gy whole-body gamma radiation. Hypothalamic and cortical blood flows were measured by hydrogen clearance, before and after radiation exposure. Systemic blood pressures were determined simultaneously. The data indicated that DSCG was successful in diminishing postradiation decrease in cerebral blood flow. Irradiated animals pretreated with DSCG, showed only a 10% decrease in hypothalamic blood flow 60 min postradiation, while untreated, irradiated animals showed a 57% decrease. The cortical blood flow of DSCG treated, irradiated animals showed a triphasic response, with a decrease of 38% at 10 min postradiation, then a rise to 1% below baseline at 20 min, followed by a fall to 42% below baseline by 50 min postradiation. In contrast, the untreated, irradiated animals showed a steady decrease in cortical blood flow to 79% below baseline by 50 min postradiation. There was no significant difference in blood-pressure response between the treated and untreated, irradiated animals. Systemic blood pressure showed a 60% decrease at 10 min postradiation, falling to a 71% decrease by 60 min

  17. Ten-minute umbilical cord occlusion markedly reduces cerebral blood flow and heat production in fetal sheep.

    NARCIS (Netherlands)

    Lotgering, F.K.; Bishai, J.M.; Struijk, P.C.; Blood, A.B.; Hunter, C.J.; Power, G.G.; Longo, L.D.

    2003-01-01

    OBJECTIVE: The study was undertaken to determine to what extent a 10-minute total umbilical cord occlusion affects autoregulation of cerebral blood flow and cerebral heat production in the fetus. STUDY DESIGN: In seven chronically catheterized late-gestation fetal sheep (127-131 days' gestation), we

  18. Glucose and fatty acid metabolism in normal and diabetic rabbit cerebral microvessels

    International Nuclear Information System (INIS)

    Hingorani, V.; Brecher, P.

    1987-01-01

    Rabbit cerebral microvessels were used to study fatty acid metabolism and its utilization relative to glucose. Microvessels were incubated with either [6- 14 C]glucose or [1- 14 C]oleic acid and the incorporation of radioactivity into 14 CO 2 , lactate, triglyceride, cholesterol ester, and phospholipid was determined. The inclusion of 5.5 mM glucose in the incubation mixture reduced oleate oxidation by 50% and increased esterification into both phospholipid and triglyceride. Glucose oxidation to CO 2 was reduced by oleate addition, whereas lactate production was unaffected. 2'-Tetradecylglycidic acid, an inhibitor of carnitine acyltransferase I, blocked oleic acid oxidation in the presence and absence of glucose. It did not effect fatty acid esterification when glucose was absent and eliminated the inhibition of oleate on glucose oxidation. Glucose oxidation to 14 CO 2 was markedly suppressed in microvessels from alloxan-treated diabetic rabbits but lactate formation was unchanged. Fatty acid oxidation to CO 2 and incorporation into triglyceride, phospholipid, and cholesterol ester remained unchanged in the diabetic state. The experiments show that both fatty acid and glucose can be used as a fuel source by the cerebral microvessels, and the interactions found between fatty acid and glucose metabolism are similar to the fatty acid-glucose cycle, described previously

  19. Elevated global cerebral blood flow, oxygen extraction fraction and unchanged metabolic rate of oxygen in young adults with end-stage renal disease: an MRI study

    Energy Technology Data Exchange (ETDEWEB)

    Zheng, Gang; Lou, Yaxian; Pan, Zhiying; Liu, Ya [Medical School of Nanjing University, Department of Medical Imaging, Jinling Hospital, Nanjing, Jiangsu (China); Nanjing University of Aeronautics and Astronautics, College of Aivil Aviation, Nanjing, Jiangsu (China); Wen, Jiqiu; Li, Xue; Zhang, Zhe [Medical School of Nanjing University, National Clinical Research Center of Kidney Diseases, Jinling Hospital, Nanjing, Jiangsu (China); Lu, Hanzhang [University of Texas Southwestern Medical Center, Advanced Imaging Research Center, Dallas, TX (United States); Liu, Wei [Siemens Shenzhen Magnetic Resonance Ltd., Shenzhen, Guangdong (China); Liu, Hui [Siemens MR NEA Collaboration, Siemens Ltd., Shanghai (China); Chen, Huijuan; Kong, Xiang; Luo, Song; Jiang, Xiaolu; Zhang, Zongjun; Zhang, Long Jiang; Lu, Guang Ming [Medical School of Nanjing University, Department of Medical Imaging, Jinling Hospital, Nanjing, Jiangsu (China)

    2016-06-15

    To noninvasively assess global cerebral blood flow (CBF), oxygen extraction fraction (OEF) and cerebral metabolic rate of oxygen (CMRO{sub 2}) in young adults with end-stage renal disease (ESRD). Thirty-six patients and 38 healthy volunteers were included and took part in MR examinations, blood and neuropsychological tests. CBF and OEF were measured by phase-contrast and T2-relaxation-under-spin-tagging MRI techniques, respectively. CMRO{sub 2} was computed from CBF, OEF and hematocrit according to Fick's principle. Correlations were performed between MR measurements, blood biochemistry measurements and neuropsychological test scores. Compared with controls, ESRD patients had elevated CBF (72.9 ± 12.5 vs. 63.8 ± 8.5 ml min{sup -1} 100 g{sup -1}, P < 0.001), elevated OEF (47.2 ± 10.2 vs. 35.8 ± 5.4 %, P < 0.001), but unaffected CMRO{sub 2} (199.5 ± 36.4 vs. 193.8 ± 28.6 μmol O{sub 2} min{sup -1} 100 g{sup -1}, P = 0.879). Hematocrit negatively correlated with CBF (r = -0.640, P < 0.001) and OEF (r = -0.701, P < 0.001), but not with CMRO{sub 2}. Altered neuropsychological test scores of ESRD patients were associated with OEF and CBF, but not with CMRO{sub 2}. There were weak relationships between eGFR and hematocrit (r = 0.308, P = 0.068) or CBF (r = 0.318, P = 0.059). Our findings suggested that anaemic young adults with ESRD may afford higher CBF and OEF to maintain a normal CMRO{sub 2}. Despite this compensatory process, however, cognitive function was still impaired and its severity was correlated with their CBF and OEF abnormality. (orig.)

  20. Heterogeneity of cerebral blood flow: a fractal approach

    International Nuclear Information System (INIS)

    Kuikka, J.T.; Hartikainen, P.

    2000-01-01

    Aim: We demonstrate the heterogeneity of regional cerebral blood flow using a fractal approach and single-photon emission computed tomography (SPECT). Method: Tc-99m-labelled ethylcysteine dimer was injected intravenously in 10 healthy controls and in 10 patients with dementia of frontal lobe type. The head was imaged with a gamma camera and transaxial, sagittal and coronal slices were reconstructed. Two hundred fifty-six symmetrical regions of interest (ROIs) were drawn onto each hemisphere of functioning brain matter. Fractal analysis was used to examine the spatial heterogeneity of blood flow as a function of the number of ROIs. Results: Relative dispersion (=coefficient of variation of the regional flows) was fractal-like in healthy subjects and could be characterized by a fractal dimension of 1.17±0.05 (mean±SD) for the left hemisphere and 1.15±0.04 for the right hemisphere, respectively. The fractal dimension of 1.0 reflects completely homogeneous blood flow and 1.5 indicates a random blood flow distribution. Patients with dementia of frontal lobe type had a significantly lower fractal dimension of 1.04±0.03 than in healthy controls. (orig.) [de

  1. Computational model of cerebral blood flow redistribution during cortical spreading depression

    Science.gov (United States)

    Verisokin, Andrey Y.; Verveyko, Darya V.; Postnov, Dmitry E.

    2016-04-01

    In recent decades modelling studies on cortical spreading depression (CSD) and migraine waves successfully contributed to formation of modern view on these fundamental phenomena of brain physiology. However, due to the extreme complexity of object under study (brain cortex) and the diversity of involved physiological pathways, the development of new mathematical models of CSD is still a very relevant and challenging research problem. In our study we follow the functional modelling approach aimed to map the action of known physiological pathways to the specific nonlinear mechanisms that govern formation and evolution of CSD wave patterns. Specifically, we address the role of cerebral blood flow (CBF) redistribution that is caused by excessive neuronal activity by means of neurovascular coupling and mediates a spatial pattern of oxygen and glucose delivery. This in turn changes the local metabolic status of neural tissue. To build the model we simplify the web of known cell-to-cell interactions within a neurovascular unit by selecting the most relevant ones, such as local neuron-induced elevation of extracellular potassium concentration and biphasic response of arteriole radius. We propose the lumped description of distance-dependent hemodynamic coupling that fits the most recent experimental findings.

  2. Relationship of cerebral blood flow to aortic-to-pulmonary collateral/shunt flow in single ventricles.

    Science.gov (United States)

    Fogel, Mark A; Li, Christine; Wilson, Felice; Pawlowski, Tom; Nicolson, Susan C; Montenegro, Lisa M; Diaz Berenstein, Laura; Spray, Thomas L; Gaynor, J William; Fuller, Stephanie; Keller, Marc S; Harris, Matthew A; Whitehead, Kevin K; Clancy, Robert; Elci, Okan; Bethel, Jim; Vossough, Arastoo; Licht, Daniel J

    2015-08-01

    Patients with single ventricle can develop aortic-to-pulmonary collaterals (APCs). Along with systemic-to-pulmonary artery shunts, these structures represent a direct pathway from systemic to pulmonary circulations, and may limit cerebral blood flow (CBF). This study investigated the relationship between CBF and APC flow on room air and in hypercarbia, which increases CBF in patients with single ventricle. 106 consecutive patients with single ventricle underwent 118 cardiac magnetic resonance (CMR) scans in this cross-sectional study; 34 prior to bidirectional Glenn (BDG) (0.50±0.30 years old), 50 prior to Fontan (3.19±1.03 years old) and 34 3-9 months after Fontan (3.98±1.39 years old). Velocity mapping measured flows in the aorta, cavae and jugular veins. Analysis of variance (ANOVA) and multiple linear regression were used. Significance was pflow or body surface area, independent of age, cardiopulmonary bypass time, Po2 and Pco2 (R=-0.67--0.70 for all patients on room air, pflow was higher prior to BDG than in other stages. There is a strong inverse relationship between CBF and APC/shunt flow in patients with single ventricle throughout surgical reconstruction on room air and in hypercarbia independent of other factors. We speculate that APC/shunt flow may have a negative impact on cerebral development and neurodevelopmental outcome. Interventions on APC may modify CBF, holding out the prospect for improving neurodevelopmental trajectory. NCT02135081. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

  3. No effect of angiotensin II AT(2)-receptor antagonist PD 123319 on cerebral blood flow autoregulation

    DEFF Research Database (Denmark)

    Estrup, T M; Paulson, O B; Strandgaard, S

    2001-01-01

    Blockade of the renin-angiotensin system with angiotensin-converting enzyme inhibitors (ACE-I) or angiotensin AT1-receptor antagonists shift the limits of autoregulation of cerebral blood flow (CBF) towards lower blood pressure (BP). The role of AT2-receptors in the regulation of the cerebral cir...

  4. Intensive blood pressure control affects cerebral blood flow in type 2 diabetes mellitus patients

    DEFF Research Database (Denmark)

    Kim, Yu-Sok; Davis, Shyrin C A T; Truijen, Jasper

    2011-01-01

    Type 2 diabetes mellitus is associated with microvascular complications, hypertension, and impaired dynamic cerebral autoregulation. Intensive blood pressure (BP) control in hypertensive type 2 diabetic patients reduces their risk of stroke but may affect cerebral perfusion. Systemic hemodynamic...... variables and transcranial Doppler-determined cerebral blood flow velocity (CBFV), cerebral CO2 responsiveness, and cognitive function were determined after 3 and 6 months of intensive BP control in 17 type 2 diabetic patients with microvascular complications (T2DM+), in 18 diabetic patients without (T2DM......-) microvascular complications, and in 16 nondiabetic hypertensive patients. Cerebrovascular reserve capacity was lower in T2DM+ versus T2DM- and nondiabetic hypertensive patients (4.6±1.1 versus 6.0±1.6 [P

  5. Symptom correlates of cerebral blood flow following acute concussion

    Directory of Open Access Journals (Sweden)

    Nathan W. Churchill

    Full Text Available Concussion is associated with significant symptoms within hours to days post-injury, including disturbances in physical function, cognition, sleep and emotion. However, little is known about how subjective impairments correlate with objective measures of cerebrovascular function following brain injury. This study examined the relationship between symptoms and cerebral blood flow (CBF in individuals following sport-related concussion. Seventy university level athletes had CBF measured using Arterial Spin Labelling (ASL, including 35 with acute concussion and 35 matched controls and their symptoms were assessed using the Sport Concussion Assessment Tool 3 (SCAT3. For concussed athletes, greater total symptom severity was associated with elevated posterior cortical CBF, although mean CBF was not significantly different from matched controls (p=0.46. Examining symptom clusters, athletes reporting greater cognitive symptoms also had lower frontal and subcortical CBF, relative to athletes with greater somatic symptoms. The “cognitive” and “somatic” subgroups also exhibited significant differences in CBF relative to controls (p≤0.026. This study demonstrates objective CBF correlates of symptoms in recently concussed athletes and shows that specific symptom clusters may have distinct patterns of altered CBF, significantly extending our understanding of the neurobiology of concussion and traumatic brain injury. Keywords: Sport concussion, Cerebral blood flow, ASL, Symptoms

  6. Dietary and plant polyphenols exert neuroprotective effects and improve cognitive function in cerebral ischemia

    Science.gov (United States)

    Cerebral ischemia is caused by an interruption of blood flow to the brain which generally leads to irreversible brain damage. Ischemic injury is associated with vascular leakage, inflammation, tissue injury, and cell death. Cellular changes associated with ischemia include impairment of metabolism, ...

  7. Cerebral blood flow and intracranial pulsatility studied with MRI: measurement, physiological and pathophysiological aspects

    International Nuclear Information System (INIS)

    Waahlin, Anders

    2012-01-01

    During each cardiac cycle pulsatile arterial blood inflates the vascular bed of the brain, forcing cerebrospinal fluid (CSF) and venous blood out of the cranium. Excessive arterial pulsatility may be part of a harmful mechanism causing cognitive decline among elderly. Additionally, restricted venous flow from the brain is suggested as the cause of multiple sclerosis. Addressing hypotheses derived from these observations requires accurate and reliable investigational methods. This work focused on assessing the pulsatile waveform of cerebral arterial, venous and CSF flows. The overall aim of this dissertation was to explore cerebral blood flow and intracranial pulsatility using MRI, with respect to measurement, physiological and pathophysiological aspects.Two-dimensional phase contrast magnetic resonance imaging (2D PCMRI) was used to assess the pulsatile waveforms of cerebral arterial, venous and CSF flow. The repeatability was assessed in healthy young subjects. The 2D PCMRI measurements of cerebral arterial, venous and CSF pulsatility were generally repeatable but the pulsatility decreased systematically during the investigation. A method combining 2D PCMRI measurements with invasive CSF infusion tests to determine the magnitude and distribution of compliance within the craniospinal system was developed and applied in a group of healthy elderly. The intracranial space contained approximately two thirds of the total craniospinal compliance. The magnitude of craniospinal compliance was less than suggested in previous studies. The vascular hypothesis for multiple sclerosis was tested. Venous drainage in the internal jugular veins was compared between healthy controls and multiple sclerosis patients using 2D PCMRI. For both groups, a great variability in the internal jugular flow was observed but no pattern specific to multiple sclerosis could be found. Relationships between regional brain volumes and potential biomarkers of intracranial cardiac-related pulsatile

  8. Cerebral blood flow and intracranial pulsatility studied with MRI: measurement, physiological and pathophysiological aspects

    Energy Technology Data Exchange (ETDEWEB)

    Waahlin, Anders

    2012-07-01

    During each cardiac cycle pulsatile arterial blood inflates the vascular bed of the brain, forcing cerebrospinal fluid (CSF) and venous blood out of the cranium. Excessive arterial pulsatility may be part of a harmful mechanism causing cognitive decline among elderly. Additionally, restricted venous flow from the brain is suggested as the cause of multiple sclerosis. Addressing hypotheses derived from these observations requires accurate and reliable investigational methods. This work focused on assessing the pulsatile waveform of cerebral arterial, venous and CSF flows. The overall aim of this dissertation was to explore cerebral blood flow and intracranial pulsatility using MRI, with respect to measurement, physiological and pathophysiological aspects.Two-dimensional phase contrast magnetic resonance imaging (2D PCMRI) was used to assess the pulsatile waveforms of cerebral arterial, venous and CSF flow. The repeatability was assessed in healthy young subjects. The 2D PCMRI measurements of cerebral arterial, venous and CSF pulsatility were generally repeatable but the pulsatility decreased systematically during the investigation. A method combining 2D PCMRI measurements with invasive CSF infusion tests to determine the magnitude and distribution of compliance within the craniospinal system was developed and applied in a group of healthy elderly. The intracranial space contained approximately two thirds of the total craniospinal compliance. The magnitude of craniospinal compliance was less than suggested in previous studies. The vascular hypothesis for multiple sclerosis was tested. Venous drainage in the internal jugular veins was compared between healthy controls and multiple sclerosis patients using 2D PCMRI. For both groups, a great variability in the internal jugular flow was observed but no pattern specific to multiple sclerosis could be found. Relationships between regional brain volumes and potential biomarkers of intracranial cardiac-related pulsatile

  9. Quantitative evaluation of regional cerebral blood flow by visual stimulation in {sup 99m}Tc- HMPAO brain SPECT

    Energy Technology Data Exchange (ETDEWEB)

    Juh, Ra Hyeong; Suh, Tae Suk; Kwark, Chul Eun; Choe, Bo Young; Lee, Hyoung Koo; Chung, Yong An; Kim, Sung Hoon; Chung, Soo Kyo [College of Medicine, The Catholic Univ. of Seoul, Seoul (Korea, Republic of)

    2002-06-01

    The purpose of this study is to investigate the effects of visual activation and quantitative analysis of regional cerebral blood flow. Visual activation was known to increase regional cerebral blood flow in the visual cortex in occipital lobe. We evaluated that change in the distribution of '9{sup 9m}Tc-HMPAO (Hexamethyl propylene amine oxime) to reflect in regional cerebral blood flow. The six volunteers were injected with 925 MBq (mean ages: 26.75 years, n=6, 3men, 3women) underwent MRI and {sup 99m}Tc-HMPAO SPECT during a rest state with closed eyes and visual stimulated with 8 Hz LED. We delineate the region of interest and calculated the mean count per voxel in each of the fifteen slices to quantitative analysis. The ROI to whole brain ratio and regional index was calculated pixel to pixel subtraction visual non-activation image from visual activation image and constructed brain map using a statistical parameter map(SPM99). The mean regional cerebral blood flow was increased due to visual stimulation. The increase rate of the mean regional cerebral blood flow which of the activation region in primary visual cortex of occipital lobe was 32.50{+-}5.67%. The significant activation sites using a statistical parameter of brain constructed a rendering image and image fusion with SPECT and MRI. Visual activation was revealed significant increase through quantitative analysis in visual cortex. Activation region was certified in Talairach coordinate and primary visual cortex (Ba17),visual association area (Ba18,19) of Brodmann.

  10. Quantitative evaluation of regional cerebral blood flow by visual stimulation in {sup 99m}Tc-HMPAO brain SPECT

    Energy Technology Data Exchange (ETDEWEB)

    Juh, R. H.; Suh, T. S.; Chung, Y. A. [The Catholic Univ., of Korea, Seoul (Korea, Republic of)

    2002-07-01

    The purpose of this study is to investigate the effects of visual activation and quantitative analysis of regional cerebral blood flow. Visual activation was known to increase regional cerebral blood flow in the visual cortex in occipital lobe. We evaluated that change in the distribution of 99mTc-HMPAO (Hexamethyl propylene amine oxime) to reflect in regional cerebral blood flow. The six volunteers were injected with 925 MBq (mean ages: 26.75 years, n=6, 3men, 3women) underwent MRI and 99mTc- HMPAO SPECT during a rest state with closed eyes and visual stimulated with 8 Hz LED. We delineate the region of interest and calculated the mean count per voxel in each of the fifteen slices to quantitative analysis. The ROI to whole brain ratio and regional index was calculated pixel to pixel subtraction visual non-activation image from visual activation image and constructed brain map using a statistical parameter map (SPM99). The mean regional cerebral blood flow was increased due to visual stimulation. The increase rate of the mean regional cerebral blood flow which of the activation region in primary visual cortex of occipital lobe was 32.50{+-}5.67%. The significant activation sites using a statistical parameter of brain constructed a rendering image and image fusion with SPECT and MRI. Visual activation was revealed significant increase through quantitative analysis in visual cortex. Activation region was certified in Talairach coordinate and primary visual cortex (Ba17),visual association area (Ba18,19) of Brodmann.

  11. Coupling between arterial and venous cerebral blood flow during postural change

    DEFF Research Database (Denmark)

    Ogoh, Shigehiko; Washio, Takuro; Sasaki, Hiroyuki

    2016-01-01

    In supine humans the main drainage from the brain is through the internal jugular vein (IJV) but the vertebral veins (VV) become important during orthostatic stress because the IJV is partially collapsed. To identify the effect of this shift in venous drainage from the brain on the cerebral...... blood flow (r=0.649, P=0.004) and the two flows were coupled during manipulation of the end-tidal CO2 tension (supine, r=0.551, P=0.004; seated, r=0.612, P

  12. Cerebral blood flow in acute and chronic ischemic stroke using xenon-133 inhalation tomography

    DEFF Research Database (Denmark)

    Vorstrup, S; Paulson, O B; Lassen, N A

    1986-01-01

    Serial measurements of cerebral blood flow (CBF) were performed in 12 patients with acute symptoms of ischemic cerebrovascular disease. CBF was measured by xenon-133 inhalation and single photon emission computer tomography. Six patients had severe strokes and large infarcts on the CT scan....... They showed in the acute phase (Days 1-3) very large low-flow areas, larger than the hypodense areas seen on the CT scan. The cerebral vasoconstrictor and vasodilator capacity was tested in the acute phase following aminophylline and acetazolamide, respectively. A preserved but reduced reactivity was seen...... had occlusion of the relevant internal carotid artery. In all 6 patients, CBF studies at 2 and 6 months resembled the acute phase, showing large areas with reduced flow. At the 6 months follow-up, the vasodilatory stress test was repeated, and all but one showed a preserved but reduced vasoreactivity...

  13. Focal increase of cerebral blood flow during stereognostic testing in man

    DEFF Research Database (Denmark)

    Roland, E; Larsen, B

    1976-01-01

    An attempt was made to study the regional cerebral blood flow (rCBF) pattern during stereognostic discrimination in man. The rCBF was measured in 18 subjects who had no major neurological defects. The clearance from the hemisphere of xenon 133 injected (133Xe) into the carotid artery was measured...

  14. Brain energy metabolism and dopaminergic function in Huntington's disease measured in vivo using positron emission tomography

    International Nuclear Information System (INIS)

    Leenders, K.L.; Frackowiak, R.S.; Quinn, N.; Marsden, C.D.

    1986-01-01

    A 48-year-old man with typical Huntington's disease was investigated with computed tomography (CT) and positron emission tomography. Regional cerebral blood flow, oxygen extraction, oxygen and glucose utilization, L-Dopa uptake, and dopamine (D2) receptor binding were measured using several positron-labelled tracers. CT showed slight atrophy of the head of caudate but no cortical atrophy, although distinct frontal lobe dysfunction was present on psychometric testing. Oxygen and glucose metabolism and cerebral blood flow were decreased in the striata and to a lesser extent in frontal cortex. Cerebral blood flow was in the low normal range throughout the remainder of the brain. A normal metabolic ratio was found in all regions, since the changes in glucose utilization paralleled those in oxygen consumption. The capacity of the striatum to store dopamine as assessed by L-[ 18 F]-fluorodopa uptake was normal, but dopamine (D2) receptor binding was decreased when compared to normal subjects

  15. Physiological activation of the human cerebral cortex during auditory perception and speech revealed by regional increases in cerebral blood flow

    DEFF Research Database (Denmark)

    Lassen, N A; Friberg, L

    1988-01-01

    by measuring regional cerebral blood flow CBF after intracarotid Xenon-133 injection are reviewed with emphasis on tests involving auditory perception and speech, and approach allowing to visualize Wernicke and Broca's areas and their contralateral homologues in vivo. The completely atraumatic tomographic CBF...

  16. Simultaneous imaging of cerebral partial pressure of oxygen and blood flow during functional activation and cortical spreading depression

    Science.gov (United States)

    Sakadžić, Sava; Yuan, Shuai; Dilekoz, Ergin; Ruvinskaya, Svetlana; Vinogradov, Sergei A.; Ayata, Cenk; Boas, David A.

    2009-01-01

    We developed a novel imaging technique that provides real-time two-dimensional maps of the absolute partial pressure of oxygen and relative cerebral blood flow in rats by combining phosphorescence lifetime imaging with laser speckle contrast imaging. Direct measurement of blood oxygenation based on phosphorescence lifetime is not significantly affected by changes in the optical parameters of the tissue during the experiment. The potential of the system as a novel tool for quantitative analysis of the dynamic delivery of oxygen to support brain metabolism was demonstrated in rats by imaging cortical responses to forepaw stimulation and the propagation of cortical spreading depression waves. This new instrument will enable further study of neurovascular coupling in normal and diseased brain. PMID:19340106

  17. Brain metabolism in autism. Resting cerebral glucose utilization rates as measured with positron emission tomography

    Energy Technology Data Exchange (ETDEWEB)

    Rumsey, J.M.; Duara, R.; Grady, C.; Rapoport, J.L.; Margolin, R.A.; Rapoport, S.I.; Cutler, N.R.

    1985-05-01

    The cerebral metabolic rate for glucose was studied in ten men (mean age = 26 years) with well-documented histories of infantile autism and in 15 age-matched normal male controls using positron emission tomography and (F-18) 2-fluoro-2-deoxy-D-glucose. Positron emission tomography was completed during rest, with reduced visual and auditory stimulation. While the autistic group as a whole showed significantly elevated glucose utilization in widespread regions of the brain, there was considerable overlap between the two groups. No brain region showed a reduced metabolic rate in the autistic group. Significantly more autistic, as compared with control, subjects showed extreme relative metabolic rates (ratios of regional metabolic rates to whole brain rates and asymmetries) in one or more brain regions.

  18. Brain metabolism in autism. Resting cerebral glucose utilization rates as measured with positron emission tomography

    International Nuclear Information System (INIS)

    Rumsey, J.M.; Duara, R.; Grady, C.; Rapoport, J.L.; Margolin, R.A.; Rapoport, S.I.; Cutler, N.R.

    1985-01-01

    The cerebral metabolic rate for glucose was studied in ten men (mean age = 26 years) with well-documented histories of infantile autism and in 15 age-matched normal male controls using positron emission tomography and (F-18) 2-fluoro-2-deoxy-D-glucose. Positron emission tomography was completed during rest, with reduced visual and auditory stimulation. While the autistic group as a whole showed significantly elevated glucose utilization in widespread regions of the brain, there was considerable overlap between the two groups. No brain region showed a reduced metabolic rate in the autistic group. Significantly more autistic, as compared with control, subjects showed extreme relative metabolic rates (ratios of regional metabolic rates to whole brain rates and asymmetries) in one or more brain regions

  19. Regional cerebral blood flow and oxygen consumption during normal human sleep

    Energy Technology Data Exchange (ETDEWEB)

    Takahashi, Ken [Toho Univ., Tokyo (Japan). School of Medicine

    1989-09-01

    Regional cerebral blood flow (rCBF), regional oxygen extraction fraction (rCEF) and regional cerebral metabolic rate for oxygen (rCMRO{sub 2}) were measured using the continuous inhalation technique for {sup 15}O with positron emission tomography (PET) during both wakefulness and sleep. Ten paid volunteers, with a mean age of 21.6 yrs., were deprived of sleep for a period of approximately 20 hours, and the experiments were performed mostly in the morning. {sup 15}O activity of both whole blood and the plasma, pixel count of PET, total arterial blood oxygen content were used for analysis of rCBF, rOEF and rCMRO{sub 2}. PET scannings were carried out mostly during the very light non-rapid eye movement (NREM) sleep, i.e. stage 1 and/or 2, and wakefulness. About 10 minutes after the start of continuous inhalation of {sup 15}O gas, the {sup 15}O activity of the brain was found to be in a steady-state condition. During this steady-state condition, PET scannings were performed for about 10 minutes. Regions of interest, square in shape and having an area of 2.8 cm{sup 3}, were set in each cortex on PET images of a horizontal cross-section of the brain, set at 45 mm above the orbitomeatal line. The rCBF and rCMRO{sub 2} were analysed in 5 of 10 male subjects during both wakefulness and NREM sleep, and only 3 were done during three sleep stages, including REM sleep. Levels of rCBF and rCMRO{sub 2} were found to be decreased in NREM sleep, and the decreasing rates were calculated at 10.2% and 7.6% from the level of wakefulness, respectively. There was no significant difference in the mean value of rOEF between wakefulness and NREM sleep. There were no significant regional differences found in the rate of decrease among the frontal, temporal and occipital cortices. It was considered that the decrease of rCBF and rCMRO{sub 2} during NREM sleep suggested a decrease of the activity levels in the cerebral functions. (author).

  20. Alterations in Cerebral Cortical Glucose and Glutamine Metabolism Precedes Amyloid Plaques in the APPswe/PSEN1dE9 Mouse Model of Alzheimer's Disease

    DEFF Research Database (Denmark)

    Andersen, Jens V; Christensen, Sofie K; Aldana, Blanca I

    2017-01-01

    slices of APPswe/PSEN1dE9 mice incubated in media containing [U-(13)C]glucose. No changes in glial [1,2-(13)C]acetate metabolism were observed. Cerebral cortical slices from APPswe/PSEN1dE9 mice exhibited a reduced capacity for uptake and oxidative metabolism of glutamine. Furthermore, the ATP synthesis......Alterations in brain energy metabolism have been suggested to be of fundamental importance for the development of Alzheimer's disease (AD). However, specific changes in brain energetics in the early stages of AD are poorly known. The aim of this study was to investigate cerebral energy metabolism...... in the APPswe/PSEN1dE9 mouse prior to amyloid plaque formation. Acutely isolated cerebral cortical and hippocampal slices of 3-month-old APPswe/PSEN1dE9 and wild-type control mice were incubated in media containing [U-(13)C]glucose, [1,2-(13)C]acetate or [U-(13)C]glutamine, and tissue extracts were analyzed...

  1. Regional cerebral blood flow in schizophrenia

    International Nuclear Information System (INIS)

    Kanoh, Masayuki

    1989-01-01

    Regional cerebral blood flow (rCBF) was measured at rest using the 133 Xe inhalation technique in 40 DSM-III-diagnosed schizophrenics (22 males, 18 females: mean age 35.0 years, range 20-49 years) and 31 age-and sex-matched normal controls (16 males, 15 females: mean age 34.3 years, range 21-49 years). The absolute value (AV) and the percent value (PV) of the rCBF in schizophrenics were compared with those in controls. Correlations between rCBF and the Brief Psychiatric Rating Scale (BPRS) scores or the performance of Wisconsin Card Sorting Test (WCST) were examined in schizophrenics. Schizophrenics showed significantly lower AVs in all brain regions examined and a significantly lower PV in the left superior frontal region than controls. The hyperfrontal rCBF distribution which was found in both hemispheres in controls, was absent in the left hemisphere in schizophrenics. In schizophrenics, superior frontal blood flows were significantly negatively correlated with the negative symptom scores of the BPRS but not with the total scores and the positive symptom scores of the BPRS. In schizophrenics, inferior frontal blood flows were significantly correlated with the number of sorting categories achieved. These results indicate that rCBF in schizophrenia is reduced in the whole brain and especially in the left superior frontal region. These findings suggest a frontal lobe dysfunction in schizophrenia. (author)

  2. The deep cerebral stimulation of the under thalamic nucleus modifies the cerebral metabolism in {sup 18}FDG-Tep of obsessive compulsive patients; La stimulation cerebrale profonde du noyau sous thalamique modifie le metabolisme cerebral en 18FDG-TEP des patients obsessionnels compulsifs

    Energy Technology Data Exchange (ETDEWEB)

    Le Jeune, F.; Garin, E. [Service de medecine nucleaire, centre Eugene-Marquis, Rennes, (France); Verin, M.; Peron, J. [service de neurologie, CHU Pontchaillou, Rennes, (France); Mallet, L.; Yelnik, J. [Inserm, Avenir Team, Behavior, Emotion and Basal Ganglia, IFR 70, Pitie-Salpetriere, Paris, (France); Kreps, M.O. [Inserm U796, service de psychiatrie, hopital Sainte-Anne, Paris, (France); Drapier, D.; Millet, B. [service de psychiatrie adulte, centre hospitalier Guillaume-Regnier, Rennes, (France)

    2009-05-15

    The aim of this work was to find again this orbito-frontal hyper metabolism among the resistant obsessive compulsive disorder patients that are going to benefit of a deep cerebral stimulation of the under thalamus nucleus and to demonstrate that this new therapy approach leads a reduction of the metabolism in this area in correlation with the clinical improvement. It is about the first study realized in isotopic functional imaging on ten resistant compulsive disorder patients treated by bilateral deep cerebral stimulation of the under thalamus nucleus. It shows that the treatment efficiency is in relation with a reduction of the glucide metabolism in the right orbito-frontal cortex. It suggests equally that the under thalamus nucleus would be functionally linked to the orbito-frontal cortex. (N.C.)

  3. Regional cerebral blood flow during mechanical hyperventilation in patients with acute bacterial meningitis

    DEFF Research Database (Denmark)

    Møller, Kirsten; Høgh, Peter; Larsen, Fin Stolze

    2000-01-01

    Mechanical hyperventilation is often instituted in patients with acute bacterial meningitis when increased intracranial pressure is suspected. However, the effect on regional cerebral blood flow (CBF) is unknown. In this study, we measured regional CBF (rCBF) in patients with acute bacterial...... meningitis before and during short-term hyperventilation. In 17 patients with acute bacterial meningitis, absolute rCBF (in ml/100 g min-1) was measured during baseline ventilation and hyperventilation by single-photon emission computed tomography (SPECT) using intravenous 133Xe bolus injection. Intravenous...... in the frontal and parietal cortex as well as in the basal ganglia. Focal perfusion abnormalities were present in 10 of 12 patients. Regional cerebral blood flow abnormalities are frequent in patients with acute bacterial meningitis. Short-term hyperventilation does not enhance these abnormalities....

  4. Cerebral blood flow and oximetry response to blood transfusion in relation to chronological age in preterm infants.

    Science.gov (United States)

    Banerjee, J; Leung, T S; Aladangady, N

    2016-06-01

    Preterm infants frequently receive blood transfusion (BT) and the aim of this study was to measure the effect of BT on cerebral blood flow and oxygenation in preterm infants in relation to chronological age. Preterm infants undergoing intensive care recruited to three chronological age groups: 1 to 7 (Group 1; n=20), 8 to 28 (Group 2; n=21) & ≥29days of life (Group 3; n=18). Pre and post-BT anterior cerebral artery (ACA) time averaged mean velocity (TAMV) and superior vena cava (SVC) flow were measured. Cerebral Tissue Haemoglobin Index (cTHI) and Oxygenation Index (cTOI) were measured from 15-20min before to 15-20min post-BT using NIRS. Vital parameters and blood pressure were measured continuously. Mean BP increased significantly, and there was no significant change in vital parameters following BT. Pre-BT ACA TAMV was higher in Group 2 and 3 compared to Group 1 (pBlood transfusion increased cTOI and cTHI and decreased ACA TAMV in all groups. PDA had no impact on the baseline cerebral oximetry and blood flow as well as changes following blood transfusion. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

  5. Regional cerebral blood flow in pure dysarthria. A 3D-SSP study

    International Nuclear Information System (INIS)

    Okamoto, Kensho; Kamogawa, Kenji; Okuda, Bungo; Kawabata, Keita; Tachibana, Hisao

    2007-01-01

    Pure dysarthria from brain infarction is a rare condition, and its pathophysiology remains unclear. To clarify the underlying mechanism of pure dysarthria, we investigated the lesion sites and regional cerebral blood flow in patients with pure dysarthria. We examined 18 consecutive patients with pure dysarthria (9 men and 9 women; mean age, 71 years) who underwent MRI and cerebral blood flow studies. To visualize the regional cerebral blood flow, we generated Z score images using the three-dimensional stereotactic surface projection (3D-SSP) method with single-photon emission computed tomography (SPECT) and N-isopropyl-p [ 123 I]iodoamphetamine. Data on the brain surface perfusion extracted by the 3D-SSP analysis were compared between the pure dysarthria (PD) patients and 9 control subjects. MRI revealed multiple lacunar infarctions involving the internal capsule and/or corona radiata in 11 patients, left internal capsule-corona radiata infarction in 4 patients, and pontine infarction in 3 patients. SPECT with 3D-SSP demonstrated bilateral frontal cortical hypoperfusion in all patients, particularly in the anterior opercular region. Based on intergroup comparisons, the PD group exhibited pronounced cortical hypoperfusion in the opercular and medial frontal regions, left more than right. In conclusion, pure dysarthria is considered to originate from frontal cortical hypoperfusion, mainly in the anterior opercular and medial frontal regions, which is probably due to interruption of the corticosubcortical neural networks relevant to speech expression and articulation. In addition, it is suggested that left hemispheric lesions may make a greater contribution to the development of pure dysarthria than do right ones. (author)

  6. Investigations on the effects of ''Ecstasy'' on cerebral glucose metabolism: an 18-FDG PET study

    International Nuclear Information System (INIS)

    Schreckenberger, M.; Sabri, O.; Arning, C.; Tuttass, T.; Schulz, G.; Kaiser, H.J.; Wagenknecht, G.; Buell, U.; Gouzoulis-Mayfrank, E.; Sass, H.

    1998-01-01

    Purpose: The aim of the present study was to determine the acute effects of the 'Ecstasy' analogue MDE (3,4-methylendioxyethamphetamine) on the cerebral glucose metabolism (rMRGlu) of healthy volunteers. Method: In a randomised double-blind trial, 16 healthy volunteers without a history of drug abuse were examined with 18-FDG PET 110-120 minutes after oral administration of 2 mg/kg MDE (n=8) or placebo (n=8). Beginning two minutes prior to radiotracer injection, a constant cognitive stimulation was maintained for 32 minutes using a word repetition paradigm in order to ensure constant and comparable mental conditions during cerebral 18-FDG uptake. Individual brain anatomy was represented using T1-weighted 3D flash MRI, followed by manual regionalisation into 108 regions-of-interest and PET/MRI overlay. Absolute quantification of rMRGlu and comparison of glucose metabolism under MDE versus placebo were performed using Mann-Whitney U-test. Results: Absolute global MRGlu was not significantly changed under MDE versus placebo (MDE: 41,8±11,1 μmol/min/100 g, placebo: 50,1±18,1 μmol/min/100 g, p=0,298). The normalised regional metabolic data showed a significantly decreased rMRGlu in the bilateral frontal cortex: Left frontal posterior (-7.1%, p [de

  7. Effects of vasoactive and metabolic active substances (measurement of RCBF)

    Energy Technology Data Exchange (ETDEWEB)

    Herrschaft, H.

    1986-09-29

    Methods, principles, normal values, reproducibility and clinical indications of rCBF-measurements, using the intraartrial 133-Xenon-clearance-technique, are presented. The effect of vaso- and metabolically active drugs on cerebral blood flow was examined in 215 patients, suffering from cerebral ischemia. Significant increase of rCBF was ascertained after intravenous injection of centrophenoxine, pyrithioxine, extractum sanguis deproteinatus, piracetam and solutions of low molecular dextran. All the other drugs tested proved to be either without any effect or caused decrease of rCBF. In 130 patients with obstructive disease of internal carotid artery after surgery at an interval of 6 - 8 weeks and 1 year a significant increase of CBF could be stated. The rank of psychological tests and quantitative EEF-investigations relating to evidence of efficacy of metabolically active drugs is discussed critically. Therapeutic efficacy and clinical relevance of vaso- and metabolically active drugs in cerebral ischemia of man are to be substantiated only by double-blind controlled studies.

  8. Effects of vasoactive and metabolic active substances (measurement of RCBF)

    International Nuclear Information System (INIS)

    Herrschaft, H.

    1986-01-01

    Methods, principles, normal values, reproducibility and clinical indications of rCBF-measurements, using the intraartrial 133-Xenon-clearance-technique, are presented. The effect of vaso- and metabolically active drugs on cerebral blood flow was examined in 215 patients, suffering from cerebral ischemia. Significant increase of rCBF was ascertained after intravenous injection of centrophenoxine, pyrithioxine, extractum sanguis deproteinatus, piracetam and solutions of low molecular dextran. All the other drugs tested proved to be either without any effect or caused decrease of rCBF. In 130 patients with obstructive disease of internal carotid artery after surgery at an interval of 6 - 8 weeks and 1 year a significant increase of CBF could be stated. The rank of psychological tests and quantitative EEF-investigations relating to evidence of efficacy of metabolically active drugs is discussed critically. Therapeutic efficacy and clinical relevance of vaso- and metabolically active drugs in cerebral ischemia of man are to be substantiated only by double-blind controlled studies. (orig.) [de

  9. Differences in lateral hemispheric asymmetries of cerebral blood flow measured by SPECT in dementia of Alzheimer type

    Energy Technology Data Exchange (ETDEWEB)

    Yoshimura, Nahoko [Niigata Univ. (Japan). School of Medicine

    1993-12-01

    We studied 21 right-handed patients clinically diagnosed as dementia of Alzheimer type (8 men, 13 women; aged 53-85, mean 71.1 years). The average duration of symptoms was 2.7 years. Dementia ranged from mild to moderately severe. None had clinical or laboratory evidence of cerebro-vascular disease (Hachinski ischemic scores for all patients were 4 or below). All received the Wechsler Adult Intelligence Scale (WAIS), Mini-mental State Test (MMS) and Western Aphasia Battery (WAB, First Japanese edition, 1986). Regional cerebral blood flow was evaluated by single photon emission CT (SPECT) with [sup 123]I-N-isopropyl-p-iodoamphetamine ([sup 123]I-IMP), using the Matsuda's quantitative method. The subjects were divided into three groups on the basis of right-left hemispheric asymmetry of cerebral blood flow (leftcerebral blood flow. Verbal IQ in patients with predominant hypoperfusion of left temporal and parietal lobe were significantly lower than in other groups, while performance IQ and WAB constructive scores were lower in those with right hemispheric hypoperfusion (p<0.05). We concluded that cerebral blood flow asymmetry detected by SPECT was related significantly to the deficit of language and constructive function in patients with dementia of Alzheimer type. (author).

  10. Differences in lateral hemispheric asymmetries of cerebral blood flow measured by SPECT in dementia of Alzheimer type

    Energy Technology Data Exchange (ETDEWEB)

    Yoshimura, Nahoko (Niigata Univ. (Japan). School of Medicine)

    1993-12-01

    We studied 21 right-handed patients clinically diagnosed as dementia of Alzheimer type (8 men, 13 women; aged 53-85, mean 71.1 years). The average duration of symptoms was 2.7 years. Dementia ranged from mild to moderately severe. None had clinical or laboratory evidence of cerebro-vascular disease (Hachinski ischemic scores for all patients were 4 or below). All received the Wechsler Adult Intelligence Scale (WAIS), Mini-mental State Test (MMS) and Western Aphasia Battery (WAB, First Japanese edition, 1986). Regional cerebral blood flow was evaluated by single photon emission CT (SPECT) with [sup 123]I-N-isopropyl-p-iodoamphetamine ([sup 123]I-IMP), using the Matsuda's quantitative method. The subjects were divided into three groups on the basis of right-left hemispheric asymmetry of cerebral blood flow (leftcerebral blood flow. Verbal IQ in patients with predominant hypoperfusion of left temporal and parietal lobe were significantly lower than in other groups, while performance IQ and WAB constructive scores were lower in those with right hemispheric hypoperfusion (p<0.05). We concluded that cerebral blood flow asymmetry detected by SPECT was related significantly to the deficit of language and constructive function in patients with dementia of Alzheimer type. (author).

  11. Differences in lateral hemispheric asymmetries of cerebral blood flow measured by SPECT in dementia of Alzheimer type

    International Nuclear Information System (INIS)

    Yoshimura, Nahoko

    1993-01-01

    We studied 21 right-handed patients clinically diagnosed as dementia of Alzheimer type (8 men, 13 women; aged 53-85, mean 71.1 years). The average duration of symptoms was 2.7 years. Dementia ranged from mild to moderately severe. None had clinical or laboratory evidence of cerebro-vascular disease (Hachinski ischemic scores for all patients were 4 or below). All received the Wechsler Adult Intelligence Scale (WAIS), Mini-mental State Test (MMS) and Western Aphasia Battery (WAB, First Japanese edition, 1986). Regional cerebral blood flow was evaluated by single photon emission CT (SPECT) with 123 I-N-isopropyl-p-iodoamphetamine ( 123 I-IMP), using the Matsuda's quantitative method. The subjects were divided into three groups on the basis of right-left hemispheric asymmetry of cerebral blood flow (left< right, n=6; right< left, n=3; left=right, n=12). General scores (MMS, T-IQ) were not correlated with asymmetry of cerebral blood flow. Verbal IQ in patients with predominant hypoperfusion of left temporal and parietal lobe were significantly lower than in other groups, while performance IQ and WAB constructive scores were lower in those with right hemispheric hypoperfusion (p<0.05). We concluded that cerebral blood flow asymmetry detected by SPECT was related significantly to the deficit of language and constructive function in patients with dementia of Alzheimer type. (author)

  12. Cerebral blood flow mapping using stable xenon-enhanced CT in sickle cell cerebrovascular disease

    International Nuclear Information System (INIS)

    Numaguchi, Y.; Robinson, A.E.; Carey, J.E.

    1990-01-01

    The cerebral blood flow (CBF) of 25 patients with sickle cell cerebrovascular disease (SCCVD) was examined using a xenon-CT flow mapping method. Brain CT and MR findings were correlated with those of the xenon-CT flow studies. CBF defects on xenon-CT correlated reasonably well with the areas of cortical infarctions on the MR images, but in 27% of the cases, flow defects were slightly larger than the areas of infarctions on the MR images. In deep watershed or basal ganglia infarctions, abnormal CBF was noted about the cerebral cortex near infarctions in 72% of the patients, regardless of infarction sizes on the MR images. However, decreased CBF was recognized in 4 of the 9 children whose MR images were virtually normal. Thus, the extent of flow depletion cannot be predicted accurately by MR imaging alone. Xenon-CT flow mapping proved a safe and reliable procedure for evaluation of the CBF of patients with SCCVD. Although this study is preliminary, it may have a potential in selecting patients for hypertransfusion therapy, as a noninvasive test and for following children with SCCVD during their therapy. Careful correlation of results of CBF with those of MR imaging or of CT is important for objective interpretations of flow mapping images. (orig.)

  13. Investigation of cerebral metabolism by positron CT in Japanese following musical stimulation

    Energy Technology Data Exchange (ETDEWEB)

    Wakasugi, Naotoshi (Nihon Univ., Tokyo (Japan). School of Medicine)

    1994-02-01

    Cerebral metabolic responses to Japanese and Western instrumental music were examined using [sup 11]C-glucose and positron CT. Eight right-handed subjects were studied in both Japanese and Western music-stimulated states. Biaural musical stimulation with a Japanese instrument, the 'shakuhachi', produced diffuse metabolic changes in the left temporal lobe in all subjects. Biaural musical stimulation with a Western instrument, the 'violin', produced metabolic changes in the right temporal lobe in 3 subjects, changes in the left in 4, and changes on both sides in one. It was considered previously that all musical stimulation led to hypermetabolism in the right hemisphere of human beings. However, the present results indicated that Japanese music produced activation of the left hemisphere in Japanese. On the other hand, Western music produced right hemispheric hypermetabolism in Japanese with no emotion. The laterality of the hemisphere stimulated by Western music was apparently incidentally changed according to the state of mind the Japanese subjects. (author).

  14. Investigation of cerebral metabolism by positron CT in Japanese following musical stimulation

    International Nuclear Information System (INIS)

    Wakasugi, Naotoshi

    1994-01-01

    Cerebral metabolic responses to Japanese and Western instrumental music were examined using 11 C-glucose and positron CT. Eight right-handed subjects were studied in both Japanese and Western music-stimulated states. Biaural musical stimulation with a Japanese instrument, the 'shakuhachi', produced diffuse metabolic changes in the left temporal lobe in all subjects. Biaural musical stimulation with a Western instrument, the 'violin', produced metabolic changes in the right temporal lobe in 3 subjects, changes in the left in 4, and changes on both sides in one. It was considered previously that all musical stimulation led to hypermetabolism in the right hemisphere of human beings. However, the present results indicated that Japanese music produced activation of the left hemisphere in Japanese. On the other hand, Western music produced right hemispheric hypermetabolism in Japanese with no emotion. The laterality of the hemisphere stimulated by Western music was apparently incidentally changed according to the state of mind the Japanese subjects. (author)

  15. Single-photon tomographic determination of regional cerebral blood flow in epilepsy

    International Nuclear Information System (INIS)

    Bonte, F.J.; Devous, M.D. Sr.; Stokely, E.M.; Homan, R.W.

    1983-01-01

    Using a single-photon emission computed tomographic scanner (SPECT) the authors determined regional cerebral blood flow (rCBF) with inhaled xenon-133, a noninvasive procedure. Studies were performed in 40 normal individuals, and these were compared with rCBF determinations in 51 patients with seizure disorders. Although positive results were obtained in 15 of 16 patients with mass lesions, the group of principal interest comprised 25 patients suffering from ''temporal lobe'' epilepsy. Only one of these had a positive x-ray computed tomogram, but 16 had positive findings on rCBF study. These findings included increased local blood flow in the ictal state and reduced flow interictally

  16. Local cerebral glucose utilization in the beagle puppy model of intraventricular hemorrhage

    International Nuclear Information System (INIS)

    Ment, L.R.; Stewart, W.B.; Duncan, C.C.

    1982-01-01

    Local cerebral glucose utilization has been measured by means of carbon-14( 14 C)-autoradiography with 2-deoxyglucose in the newborn beagle puppy model of intraventricular hemorrhage. Our studies demonstrate gray matter/white matter differentiation of uptake of 14 C-2-deoxyglucose in the control pups, as would be expected from adult animal studies. However, there is a marked homogeneity of 14 C-2-deoxyglucose uptake in all brain regions in the puppies with intraventricular hemorrhage, possibly indicating a loss of the known coupling between cerebral blood flow and metabolism in this neuropathological condition

  17. Botulinum toxin effect on salivary flow rate in children with cerebral palsy.

    NARCIS (Netherlands)

    Jongerius, P.H.; Rotteveel, J.J.; Limbeek, J. van; Gabreëls, F.J.M.; Hulst, K. van; Hoogen, F.J.A. van den

    2004-01-01

    OBJECTIVE: To investigate the effectiveness of botulinum neurotoxin (BoNT) type A in reducing salivary flow rate in children with cerebral palsy (CP) with severe drooling. METHODS: During a controlled clinical trial, single-dose BoNT injections into the submandibular salivary glands were compared

  18. Cerebral blood flow in hypothyroidism: Response to therapy and associated cognitive performance

    International Nuclear Information System (INIS)

    Ilgin, N.; Akdemir, U.O.; Yetkin, I.; Eroglu, A.

    2002-01-01

    Hypothyroidism is often associated with defective memory, psychomotor slowing and depression. However, the relationship between thyroid status, related cognitive state and associated cerebral circulatory and/or metabolic abnormalities have not been elucidated. Purpose: The aim of this study was to evaluate pre-and post-therapy brain perfusion patterns in 9 hypothyroid patients presenting with Hashimoto thyroiditis. Method: Patients were referred on the basis of abnormal levels of anti-thyroglobulin and anti-microsomal antibodies, hypothyroidism and symptoms of cognitive dysfunction. Cognitive performance was tested using Raven's Coloured Progressive Matrices and Bender Gestalt Test. Functional evaluation of the brain was also performed via the methods of electroencephalography (EEG) and single photon emission tomography (SPECT). An initial SPECT study was carried out after I.V. injection of Tc99m-HMPAO and semiquantitative rCBF analysis was performed by drawing irregular regions of interest (ROIs) in three slices. A total number of 12 sector regions of interest placed on the two hemispheres and regional cerebral blood flow (rCBF) was determined using cortical region/cerebellum ratios obtained in each hemisphere. A repeat SPECT study was undertaken in 5 subjects 3-6 months after the initiation of medical therapy. Results: Pre-therapy perfusion data in four patients showed that the cortical ratios were globally depressed at the levels of 0.65-0.85 where these ratios improved quickly to the near normal-above normal levels (range of rCBF improvement as % difference from baseline 25%-45%) within 3-4 months of therapy. Conclusion: These results indicate that brain activity was globally decreased in severe hypothyroidism of short duration which normalized steadily as the hypothyroid state is corrected

  19. Cerebral blood flow single-photon emission tomography with {sup 123}I-IMP in vascular dementia

    Energy Technology Data Exchange (ETDEWEB)

    Kawahata, Nobuya; Gotoh, Chiharu; Yokoyama, Sakura; Daitoh, Nobuyuki [Narita Memorial Hospital, Toyohashi, Aichi (Japan)

    2001-06-01

    Cerebral blood flow differences between patients with vascular dementia, patients with multiple lacunar infarction without cognitive dysfunction, and age-matched controls were examined. Thirty four patients with vascular dementia (VD) were selected from consecutive referrals to the Memory Clinic at Narita Memorial Hospital. All the patients had routine assessment including history, physical and neurological examinations, neuropsychological assessment, blood tests, EEG, head MRI, and single photon emission computed tomography (SPECT). All of them fulfilled the NINDS-AIREN diagnostic criteria for vascular dementia. Thirty nine patients with multiple lacunar infarction without cognitive dysfunction and 110 age-matched controls were included in this study. Mean cerebral blood flow (mCBF) and regional cerebral blood flow (rCBF) were measured using N-isopropyl-P-{sup 123}I-iodoamphetamine ({sup 123}I-IMP) and SPECT imager. The mCBF in VD was 27.6{+-}5.3 ml/100 g/min, while those in the control group and multiple lacunar infarction without cognitive dysfunction were 36.6{+-}6.1 ml/100 g/min and 32.5{+-}5.5 ml/100 g/min, respectively. The patients with VD demonstrated significantly reduced mCBF and rCBF in twenty regions including both cerebellar hemispheres as compared with those of the control group. Although there was no significant rCBF differences in bilateral inferior occipital regions and the right cerebellar hemisphere between patients with VD and multiple lacunar infarction without cognitive dysfunction, we could find significant lower rCBF in the remaining brain areas. In spite of the severity of VD, the diffuse decrease of cerebral blood flow was recognized in all patients with VD. (author)

  20. Interactive handling of regional cerebral blood flow data using a macrolanguage

    International Nuclear Information System (INIS)

    Sveinsdottir, E.; Schomacker, T.; Lassen, N.A.

    1976-01-01

    A general image handling software system has been developed for on-line collection, processing and display of gamma camera images (IMAGE system). The most distinguishable feature of the system is the ability for the user to interactively specify sequences, called macros, of basic functions to be performed. Information about a specified sequence is retained in the system, thus enabling new sequences or macros to be defined using already specified sequences. Facilities for parameter setting and parameter transfer between functions, as well as facilities for repetition of a function, are included. Finally, functions, be it basic or macro, can be specified to be iteratively activated using a physiological trigger signal as f.ex. the ECG. In addition, a special program system was developed for handling the dynamic data, from Xenon-133 studies of regional cerebral blood flow (CBF system). Parametric or functional images derived from the CBF system and depicting estimates of regional cerebral blood flow, relative weights of grey matter or other parameters can after computation be handled in the IMAGE system

  1. UBC-Nepal expedition: markedly lower cerebral blood flow in high-altitude Sherpa children compared with children residing at sea level.

    Science.gov (United States)

    Flück, Daniela; Morris, Laura E; Niroula, Shailesh; Tallon, Christine M; Sherpa, Kami T; Stembridge, Mike; Ainslie, Philip N; McManus, Ali M

    2017-10-01

    Developmental cerebral hemodynamic adaptations to chronic high-altitude exposure, such as in the Sherpa population, are largely unknown. To examine hemodynamic adaptations in the developing human brain, we assessed common carotid (CCA), internal carotid (ICA), and vertebral artery (VA) flow and middle cerebral artery (MCA) velocity in 25 (9.6 ± 1.0 yr old, 129 ± 9 cm, 27 ± 8 kg, 14 girls) Sherpa children (3,800 m, Nepal) and 25 (9.9 ± 0.7 yr old, 143 ± 7 cm, 34 ± 6 kg, 14 girls) age-matched sea level children (344 m, Canada) during supine rest. Resting gas exchange, blood pressure, oxygen saturation and heart rate were assessed. Despite comparable age, height and weight were lower (both P sea level children. Mean arterial pressure, heart rate, and ventilation were similar, whereas oxygen saturation (95 ± 2 vs. 99 ± 1%, P sea level children. This was reflected in a lower ICA flow (283 ± 108 vs. 333 ± 56 ml/min, P = 0.05), VA flow (78 ± 26 vs. 118 ± 35 ml/min, P sea level children (425 ± 92 vs. 441 ± 81 ml/min, P = 0.52). Scaling flow and oxygen uptake for differences in vessel diameter and body size, respectively, led to the same findings. A lower cerebral blood flow in Sherpa children may reflect specific cerebral hemodynamic adaptations to chronic hypoxia. NEW & NOTEWORTHY Cerebral blood flow is lower in Sherpa children compared with children residing at sea level; this may reflect a cerebral hemodynamic pattern, potentially due to adaptation to a hypoxic environment. Copyright © 2017 the American Physiological Society.

  2. Attacks of common migraine or hortons headache may not be accompanied by changes in regional cerebral blood flow

    International Nuclear Information System (INIS)

    Henriksen, L.; Aebelholt Krabbe, A.; Tfelt-Hansen, P.; Olesen, J.

    1982-01-01

    Vasospasm and cerebral ischemia, followed by cerebral and extracerebral vasodilation and hyperemia, are generally believed to form the common pathophysiology of the various subtypes of migraine. Mild forms of reactions are thought to result in common migraine (no neurological prodromes or accompaniments), and more severe reactions are thought to induce classical migraine. 8 induced common migraine attacks in 6 patients do not support this unitarian view, as no regional cerebral blood flow changes was found, but suggests a different pathophysiology in common migraine compaired to classical migraine. There are few features in Hortons headache to incriminate the cerebral vessels, and generally patients do not have symptoms attributable to cerebral involvement. In 6 out of 14 patients with known Hortons headache we succesfully induced an attack after alcohol alone or in combination with sublingual nitroglycerine. A slight hyperventilation occurred during the attack, correcting cerebral blood flow for these changes left mean CBF totally unchanged. No regional abnormalities occurred in any of the about 700 regions measured from during each investigation in neither the group with common migraine, nor in the patients with Hortons headache. (Author)

  3. Control of cerebral cortical blood flow by stimulation of basal forebrain cholinergic areas in mice.

    Science.gov (United States)

    Hotta, Harumi; Uchida, Sae; Kagitani, Fusako; Maruyama, Naoki

    2011-05-01

    We examined whether activity of the nucleus basalis of Meynert (NBM) regulates regional cerebral cortical blood flow (rCBF) in mice, using laser speckle and laser Doppler flowmetry. In anesthetized mice, unilateral focal stimulation, either electrical or chemical, of the NBM increased rCBF of the ipsilateral cerebral cortex in the frontal, parietal and occipital lobes, independent of changes in systemic blood pressure. Most of vasodilative responses to low intensity stimuli (2 times threshold intensity: 2T) were abolished by atropine (a muscarinic cholinergic blocker), whereas responses to higher intensity stimuli (3T) were abolished by atropine and mecamylamine (a nicotinic cholinergic blocker). Blood flow changes were largest when the tip of the electrode was located within the area containing cholinergic neurons shown by choline acetyltransferase-immunocytochemistry. These results suggest that cholinergic projections from basal forebrain neurons in mice cause vasodilation in the ipsilateral cerebral cortex by a combination of muscarinic and nicotinic mechanisms, as previously found in rats and cats.

  4. Changes in cerebral artery blood flow velocity after intermittent cerebrospinal fluid drainage.

    OpenAIRE

    Kempley, S T; Gamsu, H R

    1993-01-01

    Doppler ultrasound was used to measure blood flow velocity in the anterior cerebral artery of six premature infants with posthaemorrhagic hydrocephalus, before and after intermittent cerebrospinal fluid (CSF) drainage, on 23 occasions. There was a significant increase in mean blood flow velocity after the drainage procedures (+5.6 cm/s, 95% confidence interval +2.9 to +8.3 cm/s), which was accompanied by a decrease in velocity waveform pulsatility. CSF pressure also fell significantly. In pat...

  5. Cerebral Blood Flow Responses to Aquatic Treadmill Exercise.

    Science.gov (United States)

    Parfitt, Rhodri; Hensman, Marianne Y; Lucas, Samuel J E

    2017-07-01

    Aquatic treadmills are used as a rehabilitation method for conditions such as spinal cord injury, osteoarthritis, and stroke, and can facilitate an earlier return to exercise training for athletes. However, their effect on cerebral blood flow (CBF) responses has not been examined. We tested the hypothesis that aquatic treadmill exercise would augment CBF and lower HR compared with land-based treadmill exercise. Eleven participants completed incremental exercise (crossover design) starting from walking pace (4 km·h, immersed to iliac crest [aquatic], 6 km·h [land]) and increasing 1 km·h every 2 min up to 10 km·h for aquatic (maximum belt speed) or 12 km·h for land. After this, participants completed two 2-min bouts of exercise immersed to midthigh and midchest at constant submaximal speed (aquatic), or were ramped to exhaustion (land; increased gradient 2° every min). Middle cerebral artery blood flow velocity (MCAv) and HR were measured throughout, and the initial 10 min of each protocol and responses at each immersion level were compared. Compared with land-based treadmill, MCAvmean increased more from baseline for aquatic exercise (21% vs 12%, P aquatic walking compared with land-based moderate intensity running (~10 cm·s, P = 0.56). Greater water immersion lowered HR (139 vs 178 bpm for midchest vs midthigh), whereas MCAvmean remained constant (P = 0.37). Findings illustrate the potential for aquatic treadmill exercise to enhance exercise-induced elevations in CBF and thus optimize shear stress-mediated adaptation of the cerebrovasculature.

  6. Quantitative measurement of the cerebral blood flow

    International Nuclear Information System (INIS)

    Houdart, R.; Mamo, H.; Meric, P.; Seylaz, J.

    1976-01-01

    The value of the cerebral blood flow measurement (CBF) is outlined, its limits are defined and some future prospects discussed. The xenon 133 brain clearance study is at present the most accurate quantitative method to evaluate the CBF in different regions of the brain simultaneously. The method and the progress it has led to in the physiological, physiopathological and therapeutic fields are described. The major disadvantage of the method is shown to be the need to puncture the internal carotid for each measurement. Prospects are discussed concerning methods derived from the same general principle but using a simpler, non-traumatic way to introduce the radio-tracer, either by breathing into the lungs or intraveinously [fr

  7. Quantitative imaging of cerebral blood flow velocity and intracellular motility using dynamic light scattering-optical coherence tomography.

    Science.gov (United States)

    Lee, Jonghwan; Radhakrishnan, Harsha; Wu, Weicheng; Daneshmand, Ali; Climov, Mihail; Ayata, Cenk; Boas, David A

    2013-06-01

    This paper describes a novel optical method for label-free quantitative imaging of cerebral blood flow (CBF) and intracellular motility (IM) in the rodent cerebral cortex. This method is based on a technique that integrates dynamic light scattering (DLS) and optical coherence tomography (OCT), named DLS-OCT. The technique measures both the axial and transverse velocities of CBF, whereas conventional Doppler OCT measures only the axial one. In addition, the technique produces a three-dimensional map of the diffusion coefficient quantifying nontranslational motions. In the DLS-OCT diffusion map, we observed high-diffusion spots, whose locations highly correspond to neuronal cell bodies and whose diffusion coefficient agreed with that of the motion of intracellular organelles reported in vitro in the literature. Therefore, the present method has enabled, for the first time to our knowledge, label-free imaging of the diffusion-like motion of intracellular organelles in vivo. As an example application, we used the method to monitor CBF and IM during a brief ischemic stroke, where we observed an induced persistent reduction in IM despite the recovery of CBF after stroke. This result supports that the IM measured in this study represent the cellular energy metabolism-related active motion of intracellular organelles rather than free diffusion of intracellular macromolecules.

  8. Cocaine abstinence following chronic treatment alters cerebral metabolism in dopaminergic reward regions. Bromocriptine enhances recovery

    International Nuclear Information System (INIS)

    Clow, D.W.; Hammer, R.P. Jr.

    1991-01-01

    2-[14C]deoxyglucose autoradiography was used to determine local cerebral glucose utilization (lCGU) in rats following chronic cocaine treatment and subsequent abstinence. lCGU was examined in 43 discrete brain regions in animals which had received daily injections of cocaine for 14 days (10 mg/kg) followed by 3 days of saline or bromocriptine (10 mg/kg) treatment. Cocaine abstinence following chronic treatment significantly reduced lCGU in several regions including mesocorticolimbic structures such as ventral tegmental area, medial prefrontal cortex, and nucleus accumbens (NAc). Within the NAc, however, only the rostral pole showed significant reduction. In contrast, when bromocriptine treatment accompanied abstinence, lCGU was no longer reduced in mesocorticolimbic and most other regions, implying that metabolic recovery was enhanced by bromocriptine treatment during early abstinence following chronic cocaine treatment. These data suggest that cerebral metabolism is decreased during cocaine abstinence following chronic treatment in critical brain regions, and that this alteration can be prevented by treatment with direct-acting dopamine agonists such as bromocriptine

  9. Cocaine abstinence following chronic treatment alters cerebral metabolism in dopaminergic reward regions. Bromocriptine enhances recovery

    Energy Technology Data Exchange (ETDEWEB)

    Clow, D.W.; Hammer, R.P. Jr. (Univ. of Hawaii School of Medicine, Honolulu (USA))

    1991-01-01

    2-(14C)deoxyglucose autoradiography was used to determine local cerebral glucose utilization (lCGU) in rats following chronic cocaine treatment and subsequent abstinence. lCGU was examined in 43 discrete brain regions in animals which had received daily injections of cocaine for 14 days (10 mg/kg) followed by 3 days of saline or bromocriptine (10 mg/kg) treatment. Cocaine abstinence following chronic treatment significantly reduced lCGU in several regions including mesocorticolimbic structures such as ventral tegmental area, medial prefrontal cortex, and nucleus accumbens (NAc). Within the NAc, however, only the rostral pole showed significant reduction. In contrast, when bromocriptine treatment accompanied abstinence, lCGU was no longer reduced in mesocorticolimbic and most other regions, implying that metabolic recovery was enhanced by bromocriptine treatment during early abstinence following chronic cocaine treatment. These data suggest that cerebral metabolism is decreased during cocaine abstinence following chronic treatment in critical brain regions, and that this alteration can be prevented by treatment with direct-acting dopamine agonists such as bromocriptine.

  10. Restoration of the contrast of cerebral blood flows by the spatial deconvolution method

    International Nuclear Information System (INIS)

    Compingt, D.L.; Philippon, B.L.

    1982-01-01

    The measurement of regional cerebral blood flows (rCBF) with a gamma camera during xenon-133 inhalation necessitates collimators with high efficiency. Their spatial resolutions are weak: on the images given by a F.W.H.M. collimator (25 mm to 5 cm depth of water), the contrast restoration method by the ponctual dispersion function (P.D.F.) is used. The convolution product (Image)=(Object)*(P.D.F.) is resolved by a bidimensional Fast Fourier Transform treatment. The high frequencies are eliminated by a progressive filtration. The rCBF is calculated with Obrist's method. The Initial Slope Index is only used. A rCBF image with the calculator is also realized. The numerical values are compared with the normal treatment (N) without contrast restoration and after restoration. 22 patients are so treated after severe cerebral strokes. The hemispheric average of the flows according to the 2 treatments is unchanged (difference: 1.1%). The contrast between higher and lower flow areas is increasing by 73% after contrast restoration (significant difference: p [fr

  11. No relationship between cerebral blood flow velocity and cerebrovascular reserve capacity and contemporaneously measured glucose and insulin concentrations in diabetes mellitus

    NARCIS (Netherlands)

    Fülesdi, B.; Limburg, M.; Bereczki, D.; Molnár, C.; Michels, R. P.; Leányvári, Z.; Csiba, L.

    1999-01-01

    Blood glucose and insulin concentrations have been reported to influence cerebral hemodynamics. We studied the relationship between actual blood glucose and insulin concentrations and resting cerebral blood flow velocity in the middle cerebral artery and cerebrovascular reserve capacity after

  12. Cerebral blood flow measured by positron emission tomography during normothermic cardiopulmonary bypass: An experimental porcine study

    DEFF Research Database (Denmark)

    Thomassen, Sisse Anette; Kjaergaard, Benedict; Alstrup, Aage Kristian Olsen

    2018-01-01

    emission tomography (PET) using 15O-labelled water with no pharmacological interventions to maintain the MAP. Methods: Eight pigs (69-71 kg) were connected to normothermic CPB. After 60 minutes (min) with a CPB pump flow of 60 mL/kg/min, the pigs were changed to either 35 mL/kg/min or 47.5 mL/kg/min for 60......Background: Mean arterial blood pressure (MAP) and/or pump flow during normothermic cardiopulmonary bypass (CPB) are the most important factors of cerebral perfusion. The aim of this study was to explore the influence of CPB blood flow on cerebral blood flow (CBF) measured by dynamic positron...... min and, thereafter, all the pigs returned to 60 mL/kg/min for another 60 min. The MAP was measured continuously and the CBF was measured by positron emission tomography (PET) during spontaneous circulation and at each CPB pump flow after 30 min of steady state. Results: Two pigs were excluded due...

  13. Impaired cerebral blood flow and oxygenation during exercise in type 2 diabetic patients

    DEFF Research Database (Denmark)

    Kim, Yu-Sok; Seifert, Thomas; Brassard, Patrice

    2015-01-01

    Endothelial vascular function and capacity to increase cardiac output during exercise are impaired in patients with type 2 diabetes (T2DM). We tested the hypothesis that the increase in cerebral blood flow (CBF) during exercise is also blunted and, therefore, that cerebral oxygenation becomes...... affected and perceived exertion increased in T2DM patients. We quantified cerebrovascular besides systemic hemodynamic responses to incremental ergometer cycling exercise in eight male T2DM and seven control subjects. CBF was assessed from the Fick equation and by transcranial Doppler-determined middle...... at higher workloads in T2DM patients and their work capacity and increase in cardiac output were only ~80% of that established in the control subjects. CBF and cerebral oxygenation were reduced during exercise in T2DM patients (P

  14. Acupuncture regulates the glucose metabolism in cerebral functional regions in chronic stage ischemic stroke patients---a PET-CT cerebral functional imaging study

    Directory of Open Access Journals (Sweden)

    Huang Yong

    2012-06-01

    Full Text Available Abstract Background Acupuncture has been applied to aid in the recovery of post-stroke patients, but its mechanism is unclear. This study aims to analyze the relationship between acupuncture and glucose metabolism in cerebral functional regions in post-stroke patients using 18 FDG PET-CT techniques. Forty-three ischemic stroke patients were randomly divided into 5 groups: the Waiguan (TE5 needling group, the TE5 sham needling group, the sham point needling group, the sham point sham needling group and the non-needling group. Cerebral functional images of all patients were then acquired using PET-CT scans and processed by SPM2 software. Results Compared with the non-needling group, sham needling at TE5 and needling/sham needling at the sham point did not activate cerebral areas. However, needling at TE5 resulted in the activation of Brodmann Area (BA 30. Needling/sham needling at TE5 and needling at the sham point did not deactivate any cerebral areas, whereas sham needling at the sham point led to deactivation in BA6. Compared with sham needling at TE5, needling at TE5 activated BA13, 19 and 47 and did not deactivate any areas. Compared with needling at the sham point, needling at TE5 had no associated activation but a deactivating effect on BA9. Conclusion Needling at TE5 had a regulating effect on cerebral functional areas shown by PET-CT, and this may relate to its impact on the recovery of post-stroke patients.

  15. Clinical application of cerebral dynamic perfusion studies

    International Nuclear Information System (INIS)

    DeLand, F.H.

    1975-01-01

    Radionuclide cerebral perfusion studies are assuming a far greater importance in the detection and differential diagnosis of cerebral lesions. Perfusion studies not only contribute to the differential diagnosis of lesions but in certain cases are the preferred methods by which more accurate clinical interpretations can be made. The characteristic blood flow of arterio-venous malformations readily differentiates this lesion from neoplasms. The decreased perfusion or absent perfusion observed in cerebral infarctions is diagnostic without concurrent evidence from static images. Changes in rates and direction of blood flow contribute fundamental information to the status of stenosis and vascular occlusion and, in addition, offer valuable information on the competency and routes of collateral circulation. The degree of cerebral perfusion after cerebral vascular accidents appears to be directly related to patient recovery, particularly muscular function. Cerebral perfusion adds a new parameter in the diagnosis of subdural haematomas and concussion and in the differentiation of obscuring radioactivity from superficial trauma. Although pictorial displays of perfusion blood flow will offer information in most cerebral vascular problems, the addition of computer analysis better defines temporal relationships of regional blood flow, quantitative changes in flow and the detection of the more subtle increases or decreases in cerebral blood flow. The status of radionuclide cerebral perfusion studies has taken on an importance making it the primary modality for the diagnosis of cerebral lesions. (author)

  16. Reduction of cerebral blood flow in subclinical hepatic encephalopathy and its correlation with plasma-free tryptophan

    International Nuclear Information System (INIS)

    Rodriguez, G.; Testa, R.; Celle, G.; Gris, A.; Marenco, S.; Nobili, F.; Novellone, G.; Rosadini, G.

    1987-01-01

    Cerebral blood flow (CBF), measured by the noninvasive xenon-133 inhalation method, EEG, and plasma levels of ammonia (NH 3 ) and free tryptophan were determined in 18 hospitalized cirrhotic patients affected with subclinical hepatic encephalopathy, as diagnosed by the Kurtz test. CBF results were significantly lower (p less than 0.001) in the patients' group as compared with a sex- and age-matched normal control population, although seven patients had values in the normal range. NH 3 was increased only in six, while free tryptophan was increased in all but two patients. A significant negative correlation (p = 0.02) between CBF and free tryptophan was found, even though it appears to be difficult to interpret. We suggest that CBF impairment in some cirrhotic patients with subclinical hepatic encephalopathy may be related to the systemic metabolic derangement caused by the liver disease; free tryptophan could have some implication in producing CBF reduction

  17. Relationship between cardiac function and resting cerebral blood flow: MRI measurements in healthy elderly subjects.

    Science.gov (United States)

    Henriksen, Otto M; Jensen, Lars T; Krabbe, Katja; Larsson, Henrik B W; Rostrup, Egill

    2014-11-01

    Although both impaired cardiac function and reduced cerebral blood flow are associated with ageing, current knowledge of the influence of cardiac function on resting cerebral blood flow (CBF) is limited. The aim of this study was to investigate the potential effects of cardiac function on CBF. CBF and cardiac output were measured in 31 healthy subjects 50-75 years old using magnetic resonance imaging techniques. Mean values of CBF, cardiac output and cardiac index were 43.6 ml per 100 g min(-1), 5.5 l min(-1) and 2.7 l min(-1) m(-2), respectively, in males, and 53.4 ml per 100 g min(-1), 4.3 l min(-1) and 2.4 l min(-1) m(-2), respectively, in females. No effects of cardiac output or cardiac index on CBF or structural signs of brain ageing were observed. However, fractional brain flow defined as the ratio of total brain flow to cardiac output was inversely correlated with cardiac index (r(2) = 0.22, P = 0.008) and furthermore lower in males than in females (8.6% versus 12.5%, P = 0.003). Fractional brain flow was also inversely correlated with cerebral white matter lesion grade, although this effect was not significant when adjusted for age. Frequency analysis of heart rate variability showed a gender-related inverse association of increased low-to-high-frequency power ratio with CBF and fractional brain flow. The findings do not support a direct effect of cardiac function on CBF, but demonstrates gender-related differences in cardiac output distribution. We propose fractional brain flow as a novel index that may be a useful marker of adequate brain perfusion in the context of ageing as well as cardiovascular disease. © 2013 Scandinavian Society of Clinical Physiology and Nuclear Medicine. Published by John Wiley & Sons Ltd.

  18. Magnetic resonance spectroscopy and imaging in cerebral ischemia

    International Nuclear Information System (INIS)

    Rijen, P.C. van.

    1991-01-01

    In-vivo proton and phosphorus magnetic resonance spectroscopy was used to detect changes in cerebral metabolism during ischemia and other types of metabolic stress. Magnetic resonance imaging was performed in an animal model to observe morphological alterations during focal cerebral ischemia. Spectroscopy was performed in animal models with global ischemia, in volunteers during hyperventilation and pharmaco-logically altered cerebral perfusion, and in patients with acute and prolonged focal cerebral ischemia. (author). 396 refs.; 44 figs.; 14 tabs

  19. GABAA Receptor-Mediated Bidirectional Control of Synaptic Activity, Intracellular Ca2+, Cerebral Blood Flow, and Oxygen Consumption in Mouse Somatosensory Cortex In Vivo

    DEFF Research Database (Denmark)

    Jessen, Sanne Barsballe; Brazhe, Alexey; Lind, Barbara Lykke

    2015-01-01

    Neural activity regulates local increases in cerebral blood flow (ΔCBF) and the cortical metabolic rate of oxygen (ΔCMRO2) that constitutes the basis of BOLD functional neuroimaging signals. Glutamate signaling plays a key role in brain vascular and metabolic control; however, the modulatory effect...... of GABA is incompletely understood. Here we performed in vivo studies in mice to investigate how THIP (which tonically activates extrasynaptic GABAARs) and Zolpidem (a positive allosteric modulator of synaptic GABAARs) impact stimulation-induced ΔCBF, ΔCMRO2, local field potentials (LFPs), and fluorescent...... cytosolic Ca2+ transients in neurons and astrocytes. Low concentrations of THIP increased ΔCBF and ΔCMRO2 at low stimulation frequencies. These responses were coupled to increased synaptic activity as indicated by LFP responses, and to Ca2+ activities in neurons and astrocytes. Intermediate and high...

  20. Hepatic and cerebral energy metabolism after neonatal canine alimentation.

    Science.gov (United States)

    Kliegman, R M; Miettinen, E L; Morton, S K

    1983-04-01

    Intrahepatic and intracerebral metabolic responses to neonatal fasting or enteric carbohydrate alimentation were investigated among newborn dogs. Pups were either fasted or given an intravenous glucose infusion (alimented) before an enteric feeding of physiologic quantities of either glucose or galactose. These pups were also compared to another group which was completely starved throughout the study period. Gastrointestinal carbohydrate feeding resulted in enhanced hepatic glycogen content among pups after a prior state of fasting. Though there were no differences of glycogen content between glucose or galactose feeding in this previously fasted group, combined intravenous glucose and enteric galactose administration produced the greatest effect on hepatic glycogen synthesis. Intrahepatic fructose 1, 6-diphosphate and phosphoenolpyruvate levels were increased among previously fasted pups fed enteric monosaccharides compared to completely starved control pups, whereas intrahepatic phosphoenolpyruvate and pyruvate levels were elevated after combined intravenous and enteric carbohydrate administration. Of greater interest was the observation that hepatic levels of ATP were significantly elevated among all groups given exogenous carbohydrates compared to the completely starved control group. In contrast to the augmented hepatic glycogen and ATP levels, there were no alterations of cerebral glycogen or ATP after alimentation. Nevertheless, cerebral pyruvate and/or phosphoenolpyruvate concentrations were elevated after enteric or combined intravenous and enteric alimentation compared to the totally starved control pups.