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Sample records for altered cerebral blood

  1. Alterations of Regional Cerebral Blood Flow in Major Depressive Disorder

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Won Hyoung; Chung, Yong An; Seo, Ye Young; Yoo, Ik Dong; Na, Sae Jung; Jung, Hyun Suk; Kim, Ki Jun [College of Medicine, The Catholic University of Korea, Seoul (Korea, Republic of)

    2009-04-15

    The authors analyzed how the regional cerebral blood flow (rCBF) findings of patients with major depression differ from the normal control, and our results were compared to previous reports. Twelve patients fulfilling DSM-IV criteria for major depression who were off all psychotropic medications for > 4 weeks (male: 7, female: 5, age range: 19approx52 years, average age: 29.3+-9.9 years) and 14 normal volunteers (male: 8, female: 6, age range: 19approx53 years, average age: 31.4+-9.2 years) were recruited. Images of brain perfusion SPECT were obtained using Tc-99m ECD and patterns of the rCBF were compared between patients with major depression and the healthy control subjects. The patients with major depression showed increase of the r-CBF in right lingual gyrus, right fusiform gyrus, left lingual gyrus, left precuneus, and left superior temporal gyrus, and showed decrease of r-CBF in right pons, left medial frontal gyrus, cingulate gyrus of left limbic lobe, cingulate gyrus of right frontal lobe, and cingulate gyrus of right limbic lobe compared to the normal control. The Tc-99m ECD brain perfusion SPECT findings in our study did not differ from the previously reported regional cerebral blood flow pattern of patients with major depression. Especially, decreased rCBF pattern typical to major depression patients in the right pons, left medial frontal gyrus, and cingulate regions was clearly demonstrated

  2. Altered Regional Cerebral Blood Flow in Chronic Whiplash Associated Disorders

    NARCIS (Netherlands)

    Vállez García, David; Doorduin, Janine; Willemsen, Antoon T.M.; Dierckx, Rudi A.j.o.; Otte, Andreas

    2016-01-01

    There is increasing evidence of central hyperexcitability in chronic whiplash-associated disorders (cWAD). However, little is known about how an apparently simple cervical spine injury can induce changes in cerebral processes. The present study was designed (1) to validate previous results showing a

  3. 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.

  4. Altered free radical metabolism in acute mountain sickness: implications for dynamic cerebral autoregulation and blood-brain barrier function

    DEFF Research Database (Denmark)

    Bailey, D M; Evans, K A; James, P E

    2008-01-01

    (2)) and following 6 h passive exposure to hypoxia (12% O(2)). Blood flow velocity in the middle cerebral artery (MCAv) and mean arterial blood pressure (MAP) were measured for determination of CA following calculation of transfer function analysis and rate of regulation (RoR). Nine subjects......We tested the hypothesis that dynamic cerebral autoregulation (CA) and blood-brain barrier (BBB) function would be compromised in acute mountain sickness (AMS) subsequent to a hypoxia-mediated alteration in systemic free radical metabolism. Eighteen male lowlanders were examined in normoxia (21% O...

  5. Disodium cromoglycate, a mast-cell stabilizer, alters postradiation regional cerebral blood flow in primates

    Energy Technology Data Exchange (ETDEWEB)

    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.

  6. Regional cerebral blood flow alterations remote from the site of intracranial tumors

    DEFF Research Database (Denmark)

    Endo, H; Larsen, B; Lassen, N A

    1977-01-01

    Regional cerebral blood flow (rCBF) was investigated in 12 patients with brain tumors, using a 254-channel dynamic gamma camera. In nine of the 12 cases, hyperemic regions with loss of autoregulation were seen in sites remote from the tumor (the area around the tumor was in most cases also...... hyperemic). These remote rCBF abnormalities were found in the lower posterior part of the hemisphere in six cases, and in the frontal region in three. The location of the remote rCBF abnormality seemed to depend on the site of the tumor: cases with frontal and posterior fossa mass lesions had hyperemia...

  7. Blood Pressure is Associated With Cerebral Blood Flow Alterations in Patients With T2DM as Revealed by Perfusion Functional MRI.

    Science.gov (United States)

    Xia, Wenqing; Rao, Hengyi; Spaeth, Andrea M; Huang, Rong; Tian, Sai; Cai, Rongrong; Sun, Jie; Wang, Shaohua

    2015-12-01

    Type 2 diabetes mellitus (T2DM) and hypertension are both associated with cognitive impairment and brain function abnormalities. We investigated whether abnormal cerebral blood flow (CBF) patterns exists in T2DM patients and possible relationships between aberrant CBF and cognitive performance. Furthermore, we examined the influence of hypertension on CBF alterations in T2DM patients. T2DM patients (n = 38) and non-T2DM subjects (n = 40) were recruited from clinics, hospitals, and normal community health screenings. Cerebral blood flow images were collected and analyzed using arterial spin labeling perfusion functional magnetic resonance imaging (fMRI). Regions with major CBF differences between T2DM patients and non-T2DM controls were detected via 1-way ANOVA. The interaction effects between hypertension and T2DM for CBF alterations were also examined. Correlation analyses illustrated the association between CBF values and cognitive performance and between CBF and blood pressure. Compared with non-T2DM controls, T2DM patients exhibited decreased CBF, primarily in the visual area and the default mode network (DMN); decreased CBF in these regions was correlated with cognitive performance. There was a significant interaction effect between hypertension and diabetes for CBF in the precuneus and the middle occipital gyrus. Additionally, blood pressure correlated negatively with CBF in T2DM patients.T2DM patients exhibited reduced CBF in the visual area and DMN. Hypertension may facilitate a CBF decrease in the setting of diabetes. T2DM patients may benefit from blood pressure control to maintain their brain perfusion through CBF preservation.

  8. Primary Somatosensory Cortices Contain Altered Patterns of Regional Cerebral Blood Flow in the Interictal Phase of Migraine

    Science.gov (United States)

    Hodkinson, Duncan J.; Veggeberg, Rosanna; Wilcox, Sophie L.; Scrivani, Steven; Burstein, Rami; Becerra, Lino; Borsook, David

    2015-01-01

    The regulation of cerebral blood flow (CBF) is a complex integrated process that is critical for supporting healthy brain function. Studies have demonstrated a high incidence of alterations in CBF in patients suffering from migraine with and without aura during different phases of attacks. However, the CBF data collected interictally has failed to show any distinguishing features or clues as to the underlying pathophysiology of the disease. In this study we used the magnetic resonance imaging (MRI) technique—arterial spin labeling (ASL)—to non-invasively and quantitatively measure regional CBF (rCBF) in a case-controlled study of interictal migraine. We examined both the regional and global CBF differences between the groups, and found a significant increase in rCBF in the primary somatosensory cortex (S1) of migraine patients. The CBF values in S1 were positively correlated with the headache attack frequency, but were unrelated to the duration of illness or age of the patients. Additionally, 82% of patients reported skin hypersensitivity (cutaneous allodynia) during migraine, suggesting atypical processing of somatosensory stimuli. Our results demonstrate the presence of a disease-specific functional deficit in a known region of the trigemino-cortical pathway, which may be driven by adaptive or maladaptive functional plasticity. These findings may in part explain the altered sensory experiences reported between migraine attacks. PMID:26372461

  9. Primary Somatosensory Cortices Contain Altered Patterns of Regional Cerebral Blood Flow in the Interictal Phase of Migraine.

    Directory of Open Access Journals (Sweden)

    Duncan J Hodkinson

    Full Text Available The regulation of cerebral blood flow (CBF is a complex integrated process that is critical for supporting healthy brain function. Studies have demonstrated a high incidence of alterations in CBF in patients suffering from migraine with and without aura during different phases of attacks. However, the CBF data collected interictally has failed to show any distinguishing features or clues as to the underlying pathophysiology of the disease. In this study we used the magnetic resonance imaging (MRI technique-arterial spin labeling (ASL-to non-invasively and quantitatively measure regional CBF (rCBF in a case-controlled study of interictal migraine. We examined both the regional and global CBF differences between the groups, and found a significant increase in rCBF in the primary somatosensory cortex (S1 of migraine patients. The CBF values in S1 were positively correlated with the headache attack frequency, but were unrelated to the duration of illness or age of the patients. Additionally, 82% of patients reported skin hypersensitivity (cutaneous allodynia during migraine, suggesting atypical processing of somatosensory stimuli. Our results demonstrate the presence of a disease-specific functional deficit in a known region of the trigemino-cortical pathway, which may be driven by adaptive or maladaptive functional plasticity. These findings may in part explain the altered sensory experiences reported between migraine attacks.

  10. Disodium Cromoglycate, A Mast-Cell Stabilizer, Alters Postradiation Regional Cerebral Blood Flow in Primates

    Science.gov (United States)

    1986-01-01

    ranD RISEARCH INSTITUTI SCIENTIFIC REPORTTC SR86-14 ELECTE JUL0186_ _ ~D DISODIUM CROMOGLYCATE , A MAST-CELL STABILIZER, ALTERS POSTRADIATION...were given the mast-cell stabilizers disodium cromoglycate (DSCC) or BRL 22321 (Beecham Phar- maceuticals, Research Division) before exposure to 100 Gy...flow could be mitigated by the pre- radiation administration of either disodium cromoglycate (DSCG) (Fisons Corporation, ledford, Mass.) or BRL 22321

  11. Resting cerebral blood flow

    Science.gov (United States)

    Ances, B M.; Sisti, D; Vaida, F; Liang, C L.; Leontiev, O; Perthen, J E.; Buxton, R B.; Benson, D; Smith, D M.; Little, S J.; Richman, D D.; Moore, D J.; Ellis, R J.

    2009-01-01

    Objective: HIV enters the brain soon after infection causing neuronal damage and microglial/astrocyte dysfunction leading to neuropsychological impairment. We examined the impact of HIV on resting cerebral blood flow (rCBF) within the lenticular nuclei (LN) and visual cortex (VC). Methods: This cross-sectional study used arterial spin labeling MRI (ASL-MRI) to measure rCBF within 33 HIV+ and 26 HIV− subjects. Nonparametric Wilcoxon rank sum test assessed rCBF differences due to HIV serostatus. Classification and regression tree (CART) analysis determined optimal rCBF cutoffs for differentiating HIV serostatus. The effects of neuropsychological impairment and infection duration on rCBF were evaluated. Results: rCBF within the LN and VC were significantly reduced for HIV+ compared to HIV− subjects. A 2-tiered CART approach using either LN rCBF ≤50.09 mL/100 mL/min or LN rCBF >50.09 mL/100 mL/min but VC rCBF ≤37.05 mL/100 mL/min yielded an 88% (29/33) sensitivity and an 88% (23/26) specificity for differentiating by HIV serostatus. HIV+ subjects, including neuropsychologically unimpaired, had reduced rCBF within the LN (p = 0.02) and VC (p = 0.001) compared to HIV− controls. A temporal progression of brain involvement occurred with LN rCBF significantly reduced for both acute/early (<1 year of seroconversion) and chronic HIV-infected subjects, whereas rCBF in the VC was diminished for only chronic HIV-infected subjects. Conclusion: Resting cerebral blood flow (rCBF) using arterial spin labeling MRI has the potential to be a noninvasive neuroimaging biomarker for assessing HIV in the brain. rCBF reductions that occur soon after seroconversion possibly reflect neuronal or vascular injury among HIV+ individuals not yet expressing neuropsychological impairment. GLOSSARY AEH = acute/early HIV infection; ANOVA = analysis of variance; ASL-MRI = arterial spin labeling MRI; CART = classification and regression tree; CBF = cerebral blood flow; CH = chronic HIV

  12. Middle cerebral artery blood velocity during rowing

    DEFF Research Database (Denmark)

    Secher, Niels Henry; Pott, F; Knudsen, L.;

    1997-01-01

    original,arterial blood pressure,central venous pressure,cerebral blood flow, exercise, transcranial Doppler......original,arterial blood pressure,central venous pressure,cerebral blood flow, exercise, transcranial Doppler...

  13. Neuromodulation of cerebral blood flow

    NARCIS (Netherlands)

    ter Laan, Mark

    2014-01-01

    Dit proefschrift behandelt de modulatie van de cerebrale doorbloeding (cerebral blood flow, CBF) door cervicale elektrische stimulatie en de aanname dat het sympathisch zenuwstelsel hierin een specifieke rol speelt. Enkele resultaten met cervicale ruggenmergsstimulatie (spinal cord stimulation, SCS)

  14. Alterations of Regional Cerebral Blood Flow in Tinnitus Patients as Assessed Using Single-Photon Emission Computed Tomography.

    Directory of Open Access Journals (Sweden)

    Takashi Ueyama

    Full Text Available Tinnitus is the perception of phantom sound without an external auditory stimulus. Using neuroimaging techniques, such as positron emission tomography, electroencephalography, magnetoencephalography, and functional magnetic resonance imaging (fMRI, many studies have demonstrated that abnormal functions of the central nervous system are closely associated with tinnitus. In our previous research, we reported using resting-state fMRI that several brain regions, including the rectus gyrus, cingulate gyrus, thalamus, hippocampus, caudate, inferior temporal gyrus, cerebellar hemisphere, and medial superior frontal gyrus, were associated with tinnitus distress and loudness. To reconfirm these results and probe target regions for repetitive transcranial magnetic stimulation (rTMS, we investigated the regional cerebral blood flow (rCBF between younger tinnitus patients (<60 years old and the age-matched controls using single-photon emission computed tomography and easy Z-score imaging system. Compared with that of controls, the rCBF of tinnitus patients was significantly lower in the bilateral medial superior frontal gyri, left middle occipital gyrus and significantly higher in the bilateral cerebellar hemispheres and vermis, bilateral middle temporal gyri, right fusiform gyrus. No clear differences were observed between tinnitus patients with normal and impaired hearing. Regardless of the assessment modality, similar brain regions were identified as characteristic in tinnitus patients. These regions are potentially involved in the pathophysiology of chronic subjective tinnitus.

  15. Cerebral blood-flow tomography

    DEFF Research Database (Denmark)

    Lassen, N A; Henriksen, L; Holm, S;

    1983-01-01

    Tomographic maps of local cerebral blood flow (CBF) were obtained with xenon-133 and with isopropyl-amphetamine-iodine-123 (IMP) in 11 subjects: one normal, two tumor cases, and eight cerebrovascular cases. A highly sensitive four-face, rapidly rotating, single-photon emission tomograph was used......., and with low radiation exposure to patient and personnel. On the other hand, IMP gives an image of slightly higher resolution. It also introduces a new class of iodinated brain-seeking compounds allowing, perhaps, imaging of other functions more important than mere blood flow.......Tomographic maps of local cerebral blood flow (CBF) were obtained with xenon-133 and with isopropyl-amphetamine-iodine-123 (IMP) in 11 subjects: one normal, two tumor cases, and eight cerebrovascular cases. A highly sensitive four-face, rapidly rotating, single-photon emission tomograph was used...

  16. Brief Report: Alterations in Cerebral Blood Flow as Assessed by PET/CT in Adults with Autism Spectrum Disorder with Normal IQ

    Science.gov (United States)

    Pagani, Marco; Manouilenko, Irina; Stone-Elander, Sharon; Odh, Richard; Salmaso, Dario; Hatherly, Robert; Brolin, Fredrik; Jacobsson, Hans; Larsson, Stig A.; Bejerot, Susanne

    2012-01-01

    Specific biological markers for Autism Spectrum Disorder (ASD) have not yet been established. Functional studies have shown abnormalities in the anatomo-functional connectivity of the limbic-striatal "social" brain. This study aimed to investigate regional cerebral blood flow (rCBF) at rest. Thirteen patients with ASD of normal intelligence and…

  17. Quantitative Cerebral Blood Flow Measurements Using MRI

    OpenAIRE

    Muir, Eric R; Watts, Lora Talley; Tiwari, Yash Vardhan; Bresnen, Andrew; Timothy Q Duong

    2014-01-01

    Magnetic resonance imaging utilized as a quantitative and noninvasive method to image cerebral blood flow. The two most common techniques used to detect cerebral blood flow are dynamic susceptibility contrast (DSC) perfusion MRI and arterial spin labeling perfusion MRI. Herein we describe the use of these two techniques to measure cerebral blood flow in rodents, including methods, analysis, and important considerations when utilizing these techniques.

  18. Middle cerebral artery blood velocity during running

    DEFF Research Database (Denmark)

    Lyngeraa, Tobias; Pedersen, Lars Møller; Mantoni, T;

    2013-01-01

    Running induces characteristic fluctuations in blood pressure (BP) of unknown consequence for organ blood flow. We hypothesized that running-induced BP oscillations are transferred to the cerebral vasculature. In 15 healthy volunteers, transcranial Doppler-determined middle cerebral artery (MCA....... During running, rhythmic oscillations in arterial BP induced by interference between HR and step frequency impact on cerebral blood velocity. For the exercise as a whole, average MCA velocity becomes elevated. These results suggest that running not only induces an increase in regional cerebral blood flow...

  19. Methods for measurement of cerebral blood flow in man

    DEFF Research Database (Denmark)

    Lassen, N A

    1976-01-01

    A survey of the currently available methods for the measurement of cerebral blood flow in man is given. Many of the clinically important brain diseases such as tumors, stroke, brain trauma or epilepsy entail focal or regional flow alterations. Therefore a special emphasis is placed on methods all...

  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...

  1. Cerebral blood flow in the neonate.

    Science.gov (United States)

    Vutskits, Laszlo

    2014-01-01

    Ensuring adequate oxygenation of the developing brain is the cornerstone of neonatal critical care. Despite decades of clinical research dedicated to this issue of paramount importance, our knowledge and understanding regarding the physiology and pathophysiology of neonatal cerebral blood flow are still rudimentary. This review primarily focuses on currently available human clinical and experimental data on cerebral blood flow and autoregulation in the preterm and term infant. Limitations of systemic blood pressure values as surrogates for monitoring adequate cerebral oxygen delivery are discussed. Particular emphasis is placed on the high interindividual variability in cerebral blood flow values, vasoreactivity, and autoregulatory thresholds making the applications of normative values highly questionable. Technical and ethical difficulties to conduct such trials leave us with a near complete lack of knowledge on how pharmacological and surgical interventions impact on cerebral autoregulation. The ensemble of these works argues for the necessity of highly individualized care by taking advantage of continuous bedside monitoring of cerebral circulation. They also point to the urgent need for further studies addressing the exciting but difficult issue of cerebral blood flow autoregulation in the neonate.

  2. Ventilatory response in metabolic acidosis and cerebral blood volume in humans.

    NARCIS (Netherlands)

    Ven, M.T.P. van de; Colier, W.N.J.M.; Sluijs, M.C. van der; Oeseburg, B.; Folgering, H.T.M.

    2001-01-01

    The relationship between alterations in cerebral blood volume (CBV) and central chemosensitivity regulation was studied under neutral metabolic conditions and during metabolic acidosis. Fifteen healthy subjects (5610 years) were investigated. To induce metabolic acidosis, ammonium chloride (NH(4)Cl)

  3. 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.

  4. Regional cerebral blood flow in aphasia

    DEFF Research Database (Denmark)

    Soh, K; Larsen, B; Skinhøj, E

    1978-01-01

    Regional cerebral blood flow (rCBF) was studied in 13 aphasic patients with left hemisphere lesions, using the intracarotid xenon 133 injection method and a 254-detector gamma camera system. The rCBF was measured during rest and during various function tests, including a simple speech test...

  5. 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...

  6. 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...

  7. Transfer function analysis for the assessment of cerebral autoregulation using spontaneous oscillations in blood pressure and cerebral blood flow

    NARCIS (Netherlands)

    Abeelen, A.S.S. van den; Beek, A.H. van; Slump, C.H.; Panerai, R.B.; Claassen, J.A.H.R.

    2014-01-01

    Cerebral autoregulation (CA) is a key mechanism to protect the brain against excessive fluctuations in blood pressure (BP) and maintain cerebral blood flow. Analyzing the relationship between spontaneous BP and cerebral blood flow velocity (CBFV) using transfer function analysis is a widely used tec

  8. 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.

  9. Altered modulation of prefrontal and subcortical brain activity in newly diagnosed schizophrenia and schizophreniform disorder. A regional cerebral blood flow study

    DEFF Research Database (Denmark)

    Rubin, P; Holm, S; Friberg, L;

    1991-01-01

    To measure prefrontal and subcortical activity during a cognitive task, we examined 19 newly diagnosed schizophrenics and patients with schizophreniform psychosis. Seven healthy volunteers served as controls. The patients were drug naive or had received neuroleptics for a few days only. Cerebral ...

  10. Altered cerebral vascular volumes and solute transport at the blood-brain barriers of two transgenic mouse models of Alzheimer's disease.

    Science.gov (United States)

    Do, Tuan Minh; Alata, Wael; Dodacki, Agnès; Traversy, Marie-Thérèse; Chacun, Hélène; Pradier, Laurent; Scherrmann, Jean-Michel; Farinotti, Robert; Calon, Frédéric; Bourasset, Fanchon

    2014-06-01

    We evaluated the integrity and function of the blood-brain barrier in 3xTg-AD mice aged 3-18 months and in APP/PS1 mice aged 8-months to determine the impacts of changes in amyloid and tau proteins on the brain vascular changes. The vascular volume (Vvasc) was sub-normal in 3xTg-AD mice aged from 6 to 18 months, but not in the APP/PS1 mice. The uptakes of [(3)H]-diazepam by the brains of 3xTg-AD, APP/PS1 and their age-matched control mice were similar at all the times studied, suggesting that the simple diffusion of small solutes is unchanged in transgenic animals. The uptake of d-glucose by the brains of 18-month old 3xTg-AD mice, but not by those of 8-month old APP/PS1 mice, was reduced compared to their age-matched controls. Accordingly, the amount of Glut-1 protein was 1.4 times lower in the brain capillaries of 18 month-old 3xTg-AD mice than in those of age-matched control mice. We conclude that the brain vascular volume is reduced early in 3xTg-AD mice, 6 months before the appearance of pathological lesions, and that this reduction persists until they are at least 18 months old. The absence of alterations in the BBB of APP/PS1 mice suggests that hyperphosphorylated tau proteins contribute to the vascular changes that occur in AD.

  11. Cerebral hemodynamics in aging : the interplay between blood pressure, cerebral perfusion, and dementia

    NARCIS (Netherlands)

    Claassen, J.A.H.R.

    2008-01-01

    Advances in measurement techniques have made it possible to study dynamic changes in brain blood flow. Transcranial Doppler ultrasonography measures changes in cerebral blood flow-velocity in the larger cerebral arteries (e.g. the middle cerebral artery). Near infrared spectroscopy records changes i

  12. Intraoperative cerebral blood flow imaging of rodents

    Science.gov (United States)

    Li, Hangdao; Li, Yao; Yuan, Lu; Wu, Caihong; Lu, Hongyang; Tong, Shanbao

    2014-09-01

    Intraoperative monitoring of cerebral blood flow (CBF) is of interest to neuroscience researchers, which offers the assessment of hemodynamic responses throughout the process of neurosurgery and provides an early biomarker for surgical guidance. However, intraoperative CBF imaging has been challenging due to animal's motion and position change during the surgery. In this paper, we presented a design of an operation bench integrated with laser speckle contrast imager which enables monitoring of the CBF intraoperatively. With a specially designed stereotaxic frame and imager, we were able to monitor the CBF changes in both hemispheres during the rodent surgery. The rotatable design of the operation plate and implementation of online image registration allow the technician to move the animal without disturbing the CBF imaging during surgery. The performance of the system was tested by middle cerebral artery occlusion model of rats.

  13. Cerebral blood flow and metabolism during sleep.

    Science.gov (United States)

    Madsen, P L; 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 levels of sleep into consideration, show that light sleep (stage II) is characterized by global levels of CBF and CMR only slightly reduced by 3-10% below the level associated with wakefulness, whereas CBF and CMR during deep sleep (stage III-IV) is dramatically reduced by 25-44%. Furthermore, recent data indicate that global levels of CBF and CMR are about the same during REM sleep as in wakefulness. On the regional level, deep sleep seems to be associated with a uniform decrease in regional CBF and CMR. Investigations concerning regional CBF and CMR during REM sleep are few but data from recent investigations seem to identify site-specific changes in regional CBF and CMR during REM sleep. CBF and CMR are reflections of cerebral synaptic activity and the magnitude of reduction in these variables associated with deep sleep indicates that overall cerebral synaptic activity is reduced to approximately one-half the level associated with wakefulness, while cerebral synaptic activity levels during REM sleep are similar to wakefulness. However, even though the new understanding of CBF and CMR during sleep provides significant and important information of the brain's mode of working during sleep, it does not at its current state identify the physiological processes involved in sleep or the physiological role of sleep.

  14. Phase-Contrast Magnetic Resonance Angiography Measurements of Global Cerebral Blood Flow in the Neonate

    NARCIS (Netherlands)

    Benders, Manon J. N. L.; Hendrikse, Jeroen; de Vries, Linda S.; van Bel, Frank; Groenendaal, Floris

    2011-01-01

    Cerebral blood flow (CBF) alterations are important in pathogenesis of neonatal ischemic/hemorrhagic brain damage. In clinical practice, estimation of neonatal CBF is mostly based on Doppler-measured blood flow velocities in major intracranial arteries. Using phase-contrast magnetic resonance angiog

  15. Correlation between cerebral oxygen metabolism and cerebral blood flow simultaneously measured before and after acetazolamide administration

    Science.gov (United States)

    Yamaguchi, Hiroichiro; Yamauchi, Hideto; Hazama, Shiro; Hamamoto, Hirotsugu; Inoue, Nobuhiro

    1999-10-01

    The cerebral circulation and metabolism of ten preoperative cardiac surgery patients were assessed. Alterations in regional cerebral blood flow (rCBF), measured by 123I-N- isopropyl-p-iodo-amphetamine single-photon emission computed tomography, and in cerebral oxygen metabolism, simultaneously detected by near-infrared spectroscopy (NIRS) before and after acetazolamide administration, were investigated. The rCBF (ml/min/100 g) increased significantly from 40.21 +/- 7.65 to 56.24 +/- 13.69 (p equals 0.001), and a significant increase in oxyhemoglobin (Oxy-Hb) of 13.9% (p equals 0.0022) and total hemoglobin (Total-Hb) of 5.7% (0.0047) along with a significant decrease in deoxyhemoglobin (Deoxy-Hb) of 8.9% (p equals 0.0414) were observed concomitantly. Thus, the Oxy-Hb/Total- Hb ratio (%Oxy-Hb) rose significantly from 67.26 +/- 9.82% to 72.98 +/- 8.09% (p equals 0.0022). Examination of the relationships between individual parameters showed that the percentage changes in rCBF and Oxy-Hb were significantly correlated (r equals 0.758, p equals 0.011). The percentage changes in rCBF and %Oxy-Hb were also correlated significantly (r equals 0.740, p equals 0.014). In conclusion, this evidence suggested that NIRS is able to detect relative changes in cerebral hemodynamics and reflect luxury perfusion induced by acetazolamide.

  16. Investigation of the cerebral blood flow of an Omani man with supposed ‘spirit possession’ associated with an altered mental state : a case report

    Directory of Open Access Journals (Sweden)

    Al-Azri Faisal

    2009-12-01

    Full Text Available Abstract Introduction The view that spirits may possess humans is found in 90% of the world population, including Arab/Islamic societies. Despite the association between possessive states and various neurological and psychiatric disorders, the available literature has yet to correlate possessive states with functional brain imaging modalities such as single-photon-emission computed tomography. Case presentation This paper describes the clinical case of a 22-year-old male Omani patient who presented to us with an altered state of consciousness that his caregiver attributed to possession. We examined whether the patient's mental state correlated with neuro-imaging data. The patient's distress was invariably associated with specific perfusion in the left temporal lobe and structural abnormality in the left basal ganglia. Conclusion We discuss the case in the context of possession as a culturally sanctioned idiom of distress, and highlight the importance of studying cross-cultural presentations of altered states of consciousness within biomedical models.

  17. 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

  18. Middle cerebral artery blood velocity and plasma catecholamines during exercise

    DEFF Research Database (Denmark)

    Pott, F; Jensen, K; Hansen, H;

    1996-01-01

    During dynamic exercise, mean blood velocity (Vmean) in the middle cerebral artery (MCA) demonstrates a graded increase to work rate and reflects regional cerebral blood flow. At a high work rate, however, vasoactive levels of plasma catecholamines could mediate vasoconstriction of the MCA...

  19. Cerebral oxygen extraction, oxygen consumption, and regional cerebral blood flow during the aura phase of migraine

    DEFF Research Database (Denmark)

    Friberg, L; Olesen, Jes; Lassen, N A

    1994-01-01

    The aura phase of migraine is associated with focal blood flow changes, but it has been largely unknown whether these changes are correlated to changes in the cerebral metabolism.......The aura phase of migraine is associated with focal blood flow changes, but it has been largely unknown whether these changes are correlated to changes in the cerebral metabolism....

  20. Effect of labetalol on cerebral blood flow and middle cerebral arterial flow velocity in healthy volunteers

    DEFF Research Database (Denmark)

    Schroeder, T; Schierbeck, Jens; Howardy, P;

    1991-01-01

    in normotensive subjects. Neither does it affect CO2 reactivity. The uniform results obtained with the two methods suggest TCD as a usable alternative to conventional CBF technique in the assessment of cerebral vasoactivity of various drugs in subjects with a normal cerebral circulation.......The effect of labetalol, a combined alpha- and beta-adrenoceptor antagonist, on the cerebral circulation was investigated in 7 normotensive subjects. Cerebral blood flow (CBF) was measured with the intravenous 133Xe method and mean flow velocity (Vmean) in the middle cerebral artery was determined...

  1. Cerebral blood flow tomography with xenon-133

    Energy Technology Data Exchange (ETDEWEB)

    Lassen, N.A.

    1985-10-01

    Cerebral blood flow (CBF) can be measured tomographically by inhalation of Xenon-/sup 133/. The calculation is based on taking a sequence of tomograms during the wash-in and wash-out phase of the tracer. Due to the dynamic nature of the process, a highly sensitive and fast moving single photon emission computed tomograph (SPECT) is required. Two brain-dedicated SPECT systems designed for this purpose are mentioned, and the method is described with special reference to the limitations inherent in the soft energy of the 133Xe primary photons. CBF tomography can be used for a multitude of clinical and investigative purposes. This article discusses in particular its use for the selection of patients with carotid occlusion for extracranial/intracranial bypass surgery, for detection of severe arterial spasm after aneurysm bleeding, and for detection of low flow areas during severe migraine attacks. The use of other tracers for CBF tomography using SPECT is summarized with emphasis on the /sup 99m/Tc chelates that freely pass the intact blood-brain barrier. The highly sensitive brain-dedicated SPECT systems described are a prerequisite for achieving high resolution tomograms with such tracers.

  2. Altered sense of agency in children with spastic cerebral palsy

    DEFF Research Database (Denmark)

    Ritterband-Rosenbaum, Anina; Christensen, Mark S; Kliim-Due, Mette;

    2011-01-01

    ABSTRACT: Background Children diagnosed with spastic Cerebral Palsy (CP) often show perceptual and cognitive problems, which may contribute to their functional deficit. Here we investigated if altered ability to determine whether an observed movement is performed by themselves (sense of agency...

  3. Cerebral blood flow simulations in realistic geometries

    Directory of Open Access Journals (Sweden)

    Szopos Marcela

    2012-04-01

    Full Text Available The aim of this work is to perform the computation of the blood flow in all the cerebral network, obtained from medical images as angiographies. We use free finite elements codes as FreeFEM++. We first test the code on analytical solutions in simplified geometries. Then, we study the influence of boundary conditions on the flow and we finally perform first computations on realistic meshes. L’objectif est ici de simuler l’écoulement sanguin dans tout le réseau cérébral (artériel et veineux obtenu à partir d’angiographies cérébrales 3D à l’aide de logiciels d’éléments finis libres, comme FreeFEM++. Nous menons d’abord une étude détaillée des résultats sur des solutions analytiques et l’influence des conditions limites à imposer dans des géométries simplifiées avant de travailler sur les maillages réalistes.

  4. Alteration of blood-brain barrier integrity by retroviral infection.

    Directory of Open Access Journals (Sweden)

    Philippe V Afonso

    2008-11-01

    Full Text Available The blood-brain barrier (BBB, which forms the interface between the blood and the cerebral parenchyma, has been shown to be disrupted during retroviral-associated neuromyelopathies. Human T Lymphotropic Virus (HTLV-1 Associated Myelopathy/Tropical Spastic Paraparesis (HAM/TSP is a slowly progressive neurodegenerative disease associated with BBB breakdown. The BBB is composed of three cell types: endothelial cells, pericytes and astrocytes. Although astrocytes have been shown to be infected by HTLV-1, until now, little was known about the susceptibility of BBB endothelial cells to HTLV-1 infection and the impact of such an infection on BBB function. We first demonstrated that human cerebral endothelial cells express the receptors for HTLV-1 (GLUT-1, Neuropilin-1 and heparan sulfate proteoglycans, both in vitro, in a human cerebral endothelial cell line, and ex vivo, on spinal cord autopsy sections from HAM/TSP and non-infected control cases. In situ hybridization revealed HTLV-1 transcripts associated with the vasculature in HAM/TSP. We were able to confirm that the endothelial cells could be productively infected in vitro by HTLV-1 and that blocking of either HSPGs, Neuropilin 1 or Glut1 inhibits this process. The expression of the tight-junction proteins within the HTLV-1 infected endothelial cells was altered. These cells were no longer able to form a functional barrier, since BBB permeability and lymphocyte passage through the monolayer of endothelial cells were increased. This work constitutes the first report of susceptibility of human cerebral endothelial cells to HTLV-1 infection, with implications for HTLV-1 passage through the BBB and subsequent deregulation of the central nervous system homeostasis. We propose that the susceptibility of cerebral endothelial cells to retroviral infection and subsequent BBB dysfunction is an important aspect of HAM/TSP pathogenesis and should be considered in the design of future therapeutics strategies.

  5. Pre- and postoperative changes of regional cortical cerebral blood flow in patients with cerebral arteriovenous malformation

    Institute of Scientific and Technical Information of China (English)

    石广志; 赵继宗; 王硕; 王永刚; 陆铮

    2003-01-01

    Objective To investigate pre- and postoperative changes of regional cerebral cortical blood flow in patients with cerebral arteriovenous malformation. Method Twenty-two adult patients with arteriovenous malformation(AVM) were recruited into this study at Beijing Tiantan Hospital from September 2001 to May 2002. Eight patients had giant cerebral AVM and the other 14 had a small one. Cortical cerebral blood flow (CBF) was measured by laser Doppler flowmetry (LDF) before and after AVM resections. After surgery, the probe of LDF was implanted adjacent to the area of AVM and monitored for 24 hours.Results CBF increased significantly after the resection in all patients regardless of AVM size. In patients with small AVM, CBF returned to the baseline level within 4 hours, but in patients with giant AVM, CBF remained high even after 24 hours.Conclusions Monitoring CBF is helpful to understand pre- and postoperative changes of regional cortical CBF in patients with cerebral AVM.

  6. Activated oxygen alters cerebral microvascular responses in newborn pigs

    Energy Technology Data Exchange (ETDEWEB)

    Leffler, C.W.; Busiia, D.W.; Armstead, W.M.; Mirro, R.; Thelin, O. (Univ. of Tennessee, Memphis (United States))

    1990-02-26

    In piglets, cerebral ischemia/reperfusion blocks prostanoid dependent cerebral vasodilation to hypercapnia (CO{sub 2}) and hypotension but not prostanoid independent dilation to isoproterenol (Isu) or constriction to norepinephrine (NE). Ischemia/reperfusion increases activated-O{sub 2} production by piglet brains. Using cranial windows in piglets, the authors investigated the hypothesis that activated oxygen can block prostanoid dependent cerebral vasodilator responses to CO{sub 2} and hypotension without altering responses to Isu and NE. Exposure to an activated oxygen generating system of xanthine oxidase, hypoxanthine, and Fe that made about 3 times the activated-O{sub 2} on the brain surface as ischemia/reperfusion caused reversible pial arteriolar dilation. After exposure, pial arteriolar dilation was reduced to CO{sub 2} and hypotension but not to Isu. NE constrictor responses were also unaltered. H{sub 2}O{sub 2} or H{sub 2}O{sub 2} + Fe caused constriction followed by reversible dilation. After exposure, pial arteriolar dilation in response to CO{sub 2} and hypotension was not altered. However, addition of xanthine oxidase and hypoxanthine with H{sub 2}O{sub 2} and Fe totally eliminated pial arteriolar dilator responses to CO{sub 2} and hypotension but did not decrease dilation caused by Isu or constriction caused by NE. The authors conclude that activated oxygen could produce the altered prostanoid dependent pial arteriolar responses observed following ischemia in piglets.

  7. Cerebral blood flow and metabolism during sleep

    DEFF Research Database (Denmark)

    Madsen, Peter Lund; Vorstrup, S

    1991-01-01

    investigations seem to identify site-specific changes in regional CBF and CMR during REM sleep. CBF and CMR are reflections of cerebral synaptic activity and the magnitude of reduction in these variables associated with deep sleep indicates that overall cerebral synaptic activity is reduced to approximately one......-half the level associated with wakefulness, while cerebral synaptic activity levels during REM sleep are similar to wakefulness. However, even though the new understanding of CBF and CMR during sleep provides significant and important information of the brain's mode of working during sleep, it does not at its...

  8. Postural Stability is Altered by Blood Shift

    Science.gov (United States)

    Marais, M.; Denise, P.; Guincetre, J. Y.; Normand, H.

    2008-06-01

    Non-vestibular influences as shift in blood volume changed perception of body posture. Then, factors affecting blood shift may alter postural control. The purpose of our study was to investigate the effects of leg venous contention on postural stability. Twelve subjects were studied on a balance plate for 5 minutes with the eyes closed, in 3 conditions: with no leg venous contention or grade 1 and 3 support stockings. Standard deviation of x and y position was calculated before and after the closure of the eyes. Strong venous contention altered postural stability, after the eyes were closed, during the first 10 s of standing. As support stockings prevent blood shift induced by upright posture, this result is in line with the hypothesis that blood shifts influence the perception of body orientation and postural control among others factors as vision, vestibular inputs... This strong venous contention could induce an increase of fall.

  9. Changes in mean cerebral blood flow velocity during cognitive task-induced cerebral fatigue in high performance fighter pilots

    Institute of Scientific and Technical Information of China (English)

    Yongsheng Chen

    2008-01-01

    BACKGROUND: Several studies have demonstrated that sustained cognitive tasks can induce cognitive fatigue and that the mean cerebral blood flow velocity changes in some cerebral regions during cerebral fatigue. OBJECTIVE: To dynamically monitor the changes in mean cerebral blood flow velocity in different brain regions of high performance fighter pilots during mental arithmetic tasks and consecutive performance tasks. DESIGN, TIME AND SETTING: The present neurophysiological trial, based on controlled observation, was performed at the Laboratory of Neurophysiology, Institute of Aviation Medicine, Air Force of China between January 2003 and December 2005. PARTICIPANTS: Forty-five males, high performance fighter pilots, averaging (27.6 ± 2.5) years, were recruited for this study. METHODS: The mean cerebral blood flow velocity in the anterior cerebral artery, middle cerebral artery, and posterior cerebral artery of subjects was dynamically tested using transcranial Doppler during 5- hour mental arithmetic tasks and during 5- hour consecutive performance tasks. The neurobehavioral ability index was analyzed throughout each trial according to the number of correct responses, false responses, and lost responses. Simultaneously, cerebral cognitive fatigue-induced lethargy was assessed by the Stanford Sleepiness Scale. MAIN OUTCOME MEASURES: Changes in mean cerebral blood flow velocity in the anterior cerebral artery, middle cerebral artery, and posterior cerebral artery; neurobehavioral ability index of mental arithmetic and consecutive performance tasks; Stanford Sleepiness Scale scores. RESULTS: During mental arithmetic tasks, the mean cerebral blood flow velocity in the anterior cerebral artery increased during hour 2 and decreased after hour 4. There was no significant change in mean cerebral blood flow velocity in the middle cerebral artery and posterior cerebral artery. During hour 4, cerebral cognitive fatigue was observed and, simultaneously, Stanford Sleepiness

  10. Role of hydrogen sulfide in early blood-brain barrier disruption following transient focal cerebral ischemia.

    Directory of Open Access Journals (Sweden)

    Zheng Jiang

    Full Text Available We determined the role of endogenous hydrogen sulfide (H2S in cerebral vasodilation/hyperemia and early BBB disruption following ischemic stroke. A cranial window was prepared over the left frontal, parietal and temporal cortex in mice. Transient focal cerebral Ischemia was induced by directly ligating the middle cerebral artery (MCA for two hours. Regional vascular response and cerebral blood flow (CBF during ischemia and reperfusion were measured in real time. Early BBB disruption was assessed by Evans Blue (EB and sodium fluorescein (Na-F extravasation at 3 hours of reperfusion. Topical treatment with DL-propargylglycine (PAG, an inhibitor for cystathionine γ-lyase (CSE and aspartate (ASP, inhibitor for cysteine aminotransferase/3-mercaptopyruvate sulfurtransferase (CAT/3-MST, but not O-(Carboxymethylhydroxylamine hemihydrochloride (CHH, an inhibitor for cystathionine β-synthase (CBS, abolished postischemic cerebral vasodilation/hyperemia and prevented EB and Na-F extravasation. CSE knockout (CSE-/- reduced postischemic cerebral vasodilation/hyperemia but only inhibited Na-F extravasation. An upregulated CBS was found in cerebral cortex of CSE-/- mice. Topical treatment with CHH didn't further alter postischemic cerebral vasodilation/hyperemia, but prevented EB extravasation in CSE-/- mice. In addition, L-cysteine-induced hydrogen sulfide (H2S production similarly increased in ischemic side cerebral cortex of control and CSE-/- mice. Our findings suggest that endogenous production of H2S by CSE and CAT/3-MST during reperfusion may be involved in postischemic cerebral vasodilation/hyperemia and play an important role in early BBB disruption following transient focal cerebral ischemia.

  11. Comparison of Cerebral Oxygen Saturation and Cerebral Perfusion Computed Tomography in Cerebral Blood Flow in Patients with Brain Injury.

    Science.gov (United States)

    Trofimov, Alexey O; Kalentiev, George; Voennov, Oleg; Grigoryeva, Vera

    2016-01-01

    The purpose of this study was to determine the relationship between cerebral tissue oxygen saturation and cerebral blood volume in patients with traumatic brain injury. Perfusion computed tomography of the brain was performed in 25 patients with traumatic brain injury together with simultaneous SctO2 level measurement using cerebral near-infrared oxymetry. The mean age of the injured persons was 34.5±15.6 years (range 15-65); 14 men, 11 women. The Injury Severity Score (ISS) values were 44.4±9.7 (range 25-81). The Glasgow Coma Score (GCS) mean value before the study was 10.6±2.1 (range 5-13). SctO2 ranged from 51 to 89%, mean 62±8.2%. Cerebral blood volume (CBV) values were 2.1±0.67 ml/100 g (min 1.1; max 4.3 ml/100 g). Cerebral blood flow (CBF) was 31.99±13.6 ml/100 g×min. Mean transit time (MTT) values were 5.7±4.5 s (min 2.8; max 34.3 s). The time to peak (TTP) was 22.2±3.1 s. A statistically significant correlation was found between SctO2 level and cerebral blood volume (CBV) level (R=0.9; pperfusion.

  12. Regional cerebral blood flow during hypoxia-ischemia in immature rats

    Energy Technology Data Exchange (ETDEWEB)

    Vannucci, R.C.; Lyons, D.T.; Vasta, F.

    1988-02-01

    Immature rats subjected to a combination of unilateral common carotid artery ligation and hypoxia sustain brain damage confined largely to the ipsilateral cerebral hemisphere. To ascertain the extent and distribution of ischemic alterations in the brains of these small animals, we modified the Sakurada technique to measure regional cerebral blood flow using carbon-14 autoradiography. Seven-day-old rats underwent right common carotid artery ligation following which they were rendered hypoxic with 8% O2 at 37 degrees C. Before and during hypoxia, the rat pups received an injection of iodo(/sup 14/C)antipyrine for determination of regional cerebral blood flow. Blood flows to individual structures of the ipsilateral cerebral hemisphere were not influenced by arterial occlusion alone; flows to the contralateral hemisphere and to the brainstem and cerebellum actually increased by 25-50%. Hypoxia-ischemia was associated with decreases in regional cerebral blood flow of the ipsilateral hemisphere such that by 2 hours, flows to subcortical white matter, neocortex, striatum, and thalamus were 15, 17, 34, and 41% of control, respectively. The hierarchy of the blood flow reductions correlated closely with the distribution and extent of ischemic neuronal necrosis. However, unlike the pathologic pattern of this model, the degree of ischemia appeared homogeneous within each brain region. Blood flows to contralateral cerebral hemispheric structures were relatively unchanged from prehypoxic values, whereas flows to the brainstem and cerebellum nearly doubled and tripled, respectively. Thus, ischemia is the predominant factor that determines the topography of tissue injury to major regions of immature rat brain, whereas metabolic factors may influence the heterogeneous pattern of damage seen within individual structures.

  13. Altered sense of agency in children with spastic cerebral palsy

    DEFF Research Database (Denmark)

    Ritterband-Rosenbaum, Anina; Christensen, Mark S; Kliim-Due, Mette;

    2011-01-01

    ABSTRACT: Background Children diagnosed with spastic Cerebral Palsy (CP) often show perceptual and cognitive problems, which may contribute to their functional deficit. Here we investigated if altered ability to determine whether an observed movement is performed by themselves (sense of agency......) contributes to the motor deficit in children with CP. Methods Three groups; 1) CP children, 2) healthy peers, and 3) healthy adults produced straight drawing movements on a pen-tablet which was not visible for the subjects. The produced movement was presented as a virtual moving object on a computer screen...... the movements in 310 seconds, whereas healthy children and especially CP children were significantly slower (p...

  14. Cerebral blood flow and oxidative metabolism during human endotoxemia

    DEFF Research Database (Denmark)

    Møller, Kirsten; Strauss, Gitte Irene; Qvist, Jesper;

    2002-01-01

    The proinflammatory cytokine, tumor necrosis factor-alpha (TNF-alpha), has been suggested to mediate septic encephalopathy through an effect on cerebral blood flow (CBF) and metabolism. The effect of an intravenous bolus of endotoxin on global CBF, metabolism, and net flux of cytokines...... and catecholamines was investigated in eight healthy young volunteers. Cerebral blood flow was measured by the Kety-Schmidt technique at baseline (during normocapnia and voluntary hyperventilation for calculation of subject-specific cerebrovascular CO reactivity), and 90 minutes after an intravenous bolus...

  15. 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...... changes in CBF using a cerebral blood flow index (CFI). Changes over time for UT-NIRS CFI and (133)Xenon single photon emission computer tomography ((133)Xe-SPECT) CBF data were assessed in 10 healthy volunteers after an intravenous bolus of acetazolamide. UT-NIRS CFI was measured continuously and SPECT...

  16. 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...

  17. Capillary pericytes regulate cerebral blood flow in health and disease

    DEFF Research Database (Denmark)

    Hall, Catherine N; Reynell, Clare; Gesslein, Bodil;

    2014-01-01

    Increases in brain blood flow, evoked by neuronal activity, power neural computation and form the basis of BOLD (blood-oxygen-level-dependent) functional imaging. Whether blood flow is controlled solely by arteriole smooth muscle, or also by capillary pericytes, is controversial. We demonstrate...... blood flow, capillaries dilate before arterioles and are estimated to produce 84% of the blood flow increase. In pathology, ischaemia evokes capillary constriction by pericytes. We show that this is followed by pericyte death in rigor, which may irreversibly constrict capillaries and damage the blood......-brain barrier. Thus, pericytes are major regulators of cerebral blood flow and initiators of functional imaging signals. Prevention of pericyte constriction and death may reduce the long-lasting blood flow decrease that damages neurons after stroke....

  18. 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.

  19. Increased cerebral blood flow in preeclampsia with magnetic resonance imaging

    NARCIS (Netherlands)

    Zeeman, GG; Hatab, MR; Twickler, DM

    2004-01-01

    Objective: The purpose of this study was to compare third trimester and nonpregnant cerebral blood flow of women with preeclampsia to normotensive control subjects with the use of magnetic resonance imaging techniques. Study design: Nine normotensive pregnant women and 12 untreated women with preecl

  20. Longitudinal Cerebral Blood Flow Changes during Speech in Hereditary Ataxia

    Science.gov (United States)

    Sidtis, John J.; Strother, Stephen C.; Naoum, Ansam; Rottenberg, David A.; Gomez, Christopher

    2010-01-01

    The hereditary ataxias constitute a group of degenerative diseases that progress over years or decades. With principal pathology involving the cerebellum, dysarthria is an early feature of many of the ataxias. Positron emission tomography was used to study regional cerebral blood flow changes during speech production over a 21 month period in a…

  1. Ozone Therapy on Cerebral Blood Flow: A Preliminary Report

    Directory of Open Access Journals (Sweden)

    Bernardino Clavo

    2004-01-01

    Full Text Available Ozone therapy is currently being used in the treatment of ischemic disorders, but the underlying mechanisms that result in successful treatment are not well known. This study assesses the effect of ozone therapy on the blood flow in the middle cerebral and common carotid arteries. Seven subjects were recruited for the therapy that was performed by transfusing ozone-enriched autologous blood on 3 alternate days over 1 week. Blood flow quantification in the common carotid artery (n = 14 was performed using color Doppler. Systolic and diastolic velocities in the middle cerebral artery (n = 14 were estimated using transcranial Doppler. Ultrasound assessments were conducted at the following three time points: 1 basal (before ozone therapy, 2 after session #3 and 3 1 week after session #3. The common carotid blood flow had increased by 75% in relation to the baseline after session #3 (P < 0.001 and by 29% 1 week later (P = 0.039. In the middle cerebral artery, the systolic velocity had increased by 22% after session #3 (P = 0.001 and by 15% 1 week later (P = 0.035, whereas the diastolic velocity had increased by 33% after session #3 (P < 0.001 and by 18% 1 week later (P = 0.023. This preliminary Doppler study supports the clinical experience of achieving improvement by using ozone therapy in peripheral ischemic syndromes. Its potential use as a complementary treatment in cerebral low perfusion syndromes merits further clinical evaluation.

  2. Cerebral blood flow response to propranolol in streptozotocin diabetic rats

    DEFF Research Database (Denmark)

    Lass, Preben; Knudsen, G M

    1990-01-01

    The influence of propranolol on cerebral blood flow (CBF) was tested in streptozotocin diabetic rats and in control animals. Resting CBF values were 40% lower in the diabetic rats compared with controls. Intravenous injection of propranolol (2 mg kg-1) decreased CBF significantly in the control...

  3. 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...

  4. Assessment of maternal cerebral blood flow in patients with preeclampsia

    Directory of Open Access Journals (Sweden)

    Mandić Vesna

    2005-01-01

    Full Text Available Introduction Systemic vasoconstrktion 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 beginning of eclamptic attack and 3 the application of anticonvidsive therapy. Material and methods 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 p < 0.05. Results Significantly increased Pi, Ri and all velocities were established in the group of patients with severe preeclampsia compared with the other two groups. In the group with severe preeclamsia we registrated significantly increased values of all velocities (patients with signs of threatening eclampsia. After MgSO4 treatment in patients with severe preeclampsia significantly decreased values of Pi, Ri, S/D ratio and all velocities were registered. Discussion In the studied group of patients with severe preclampsia we found increased velocity values, Pi and Ri, especially in

  5. Regional cerebral blood flow abnormalities in patients with primary hyperparathyroidism

    Energy Technology Data Exchange (ETDEWEB)

    Cermik, Tevfik F. [Hospital of the University of Trakya, Department of Nuclear Medicine, Edirne (Turkey); Trakya Universitesi Hastanesi, Nukleer Tip Anabilim Dali, Gullapoglu Yerleskesi, Edirne (Turkey); Kaya, Meryem; Bedel, Deniz; Berkarda, Sakir; Yigitbasi, Oemer N. [Hospital of the University of Trakya, Department of Nuclear Medicine, Edirne (Turkey); Ugur-Altun, Betuel [Hospital of the University of Trakya, Department of Internal Medicine, Division of Endocrinology, Edirne (Turkey)

    2007-04-15

    We assessed the alterations in regional cerebral blood flow (rCBF) in patients with primary hyperparathyroidism (PHP) before parathyroidectomy by semiquantitative analysis of brain single photon emission computed tomography (SPECT) images. Included in this prospective study were 14 patients (mean age 47.6 {+-} 10.4 years; 3 male, 11 female) and 10 control subjects (mean age 36.0 {+-} 8.5 years, 6 male, 4 female) were SPECT imaging was performed using a dual-headed gamma camera 60-90 min after intravenous administration of 925 MBq Tc-99m HMPAO. The corticocerebellar rCBF ratios were calculated from 52 brain areas and reference lower values (RLVs) were calculated from the rCBF ratios of control subjects. The regional ratios that were below the corresponding RLV were considered abnormal (hypoperfused). Hypoperfusion was shown in 171 out of 728 regions (23%) and there was a significant correlation between serum calcium, PTH levels and the sum of hypoperfused regions in the patient group (R = 0.75 and P = 0.001, and R = 0.75, P = 0.001, respectively). Significantly reduced rCBF were found in the following cortical regions: bilateral cingulate cortex, superior and inferior frontal cortex, anterior temporal cortex, precentral gyrus, postcentral gyrus and parietal cortex, and right posterior temporal cortex. Our results indicate that alterations in rCBF in patients with PHP can be demonstrated with brain SPECT. The correlation between serum calcium, PTH levels and the sum of hypoperfused regions indicates that there may be a strong relationship between rCBF abnormalities and increased levels of serum calcium and PTH. In addition, the degree of rCBF abnormalities could be determined by brain SPECT in PHP patients with or without psychiatric symptoms. (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. Intraventricular hemorrhage in the preterm neonate: timing and cerebral blood flow changes

    Energy Technology Data Exchange (ETDEWEB)

    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.

    1984-03-01

    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.

  8. [The landmarks of the measurement of cerebral blood flow].

    Science.gov (United States)

    István, Nyáry

    2008-01-30

    History of the measurement of local cerebral blood flow may cover a period of one and a half centuries. Parallel forthcoming of both theoretical and technical development were the key elements of ensuing progress resulting in the present state, when by the aid of in vivo blood flow and metabolic maps, we can visualize locales of brain functioning and their interconnections. Two theoretical landmarks should be mentioned in this historic process. First, the work of Adolf Fick, as the starter of quantitative measurements in this field, and Seymour Kety's model of a single, homogenously perfused tissue element. The solution of this model, in the form of Kety's equation is still fundamental to present day blood flow mapping techniques. Among the numerous investigators over the past years, two Hungarian scientist can be named as major contributors. Kálmán Sántha made substantial studies with continuous registration of local cerebral blood flow by the aid of thermocouples, while Emil P6sztor invented the hydrogen clearance method for the measurement of local cerebral blood flow both in human and in animal studies.

  9. Alterations of blood brain barrier function in hyperammonemia: an overview.

    Science.gov (United States)

    Skowrońska, Marta; Albrecht, Jan

    2012-02-01

    Ammonia is a neurotoxin involved in the pathogenesis of neurological conditions associated with hyperammonemia, including hepatic encephalopathy, a condition associated with acute--(ALF) or chronic liver failure. This article reviews evidence that apart from directly affecting the metabolism and function of the central nervous system cells, ammonia influences the passage of different molecules across the blood brain barrier (BBB). A brief description is provided of the tight junctions, which couple adjacent cerebral capillary endothelial cells to each other to form the barrier. Ammonia modulates the transcellular passage of low-to medium-size molecules, by affecting their carriers located at the BBB. Ammonia induces interrelated aberrations of the transport of the large neutral amino acids and aromatic amino acids (AAA), whose influx is augmented by exchange with glutamine produced in the course of ammonia detoxification, and maybe also modulated by the extracellularly acting gamma-glutamyl moiety transferring enzyme, gamma-glutamyl-transpeptidase. Impaired AAA transport affects neurotransmission by altering intracerebral synthesis of catecholamines (serotonin and dopamine), and producing "false neurotransmitters" (octopamine and phenylethylamine). Ammonia also modulates BBB transport of the cationic amino acids: the nitric oxide precursor, arginine, and ornithine, which is an ammonia trap, and affects the transport of energy metabolites glucose and creatine. Moreover, ammonia acting either directly or in synergy with liver injury-derived inflammatory cytokines also evokes subtle increases of the transcellular passage of molecules of different size (BBB "leakage"), which appears to be responsible for the vasogenic component of cerebral edema associated with ALF.

  10. Influence of remote ischemic preconditioning on cerebral oxygen metabolism and cerebral blood flow indexes of patients with ischemic cerebrovascular disease

    Institute of Scientific and Technical Information of China (English)

    Hui Lu; Ning-Ning Cui; Bin-Cheng Wang

    2016-01-01

    Objective:To study the influence of remote ischemic preconditioning on cerebral oxygen metabolism and cerebral blood flow indexes of patients with ischemic cerebrovascular disease. Methods:A total of 58 patients with ischemic cerebrovascular disease in our hospital from April 2015 to January 2016 were selected as the study object, and 58 patients were randomly divided into two groups, 29 patients in control group were treated with routine treatment, 29 patients in observation group were treated with remote ischemic preconditioning on the basic treatment of control group, then the cerebral oxygen metabolism and cerebral blood flow indexes of two groups before the treatment and at first, third and sixth month after the treatment were respectively detected and compared.Results:The cerebral oxygen metabolism and cerebral blood flow indexes of two groups before the treatment all showed no significant differences (allP>0.05), while the cerebral oxygen metabolism and cerebral blood flow indexes of observation group at first, third and sixth month after the treatment were all significantly better than those before the treatment, and the results were all significantly better than those of control group at the same time too (allP>0.05).Conclusions: The influence of remote ischemic preconditioning on cerebral oxygen metabolism and cerebral blood flow indexes of patients with ischemic cerebrovascular disease are better, and its application value for the patients with ischemic cerebrovascular disease is higher.

  11. Regional cerebral blood flow in fibromyalgia

    Energy Technology Data Exchange (ETDEWEB)

    Kwiatek, R.; Barnden, L.; Rowe, C.; McKinnon, J.; Pile, K. [The Queen Elizabeth Hospital , Adelaide, SA (Australia)

    1998-06-01

    Full text: Little is known of the aetiology of fibromyalgia (FM), a condition diagnosed on the basis of widespread chronic pain and multiple tender points. We have used Tc-99m HMPAO SPECT to compare regional cerebral bloodflow (rCBF) in 17 women who fulfill American College of Rheumatology criteria for FM to 22 age, sex and education matched controls. Both Statistical Parametric Mapping (SPM95) and coregistered MRI guided ROI were used for analysis. SPM95 revealed statistically significant hypoperfusion in the pontine tegmentum (p=0.048) and a trend to hypoperfusion in the left putamen (p=0.07). MRI guided ROI placement by an operator blinded to clinical information and the coregistered SPECT images, confirmed significant hypoperfusion of the left thalamus (p<0.0001) and the pontine tegmentum (p=0.001) and revealed trends towards hypoperfusion in the caudate nuclei and right thalamus. These results are consistent with the hypothesis that FM is due to dysfunction of central pain pathways. Spinothalamic neurones are known to be involved in pain perception and there are synapse connections to the thalamus in the gigantocellular part of the medulla and pons

  12. 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

  13. Timing and topography of cerebral blood flow, aura, and headache during migraine attacks

    DEFF Research Database (Denmark)

    Olesen, J; Friberg, L; Olsen, T S

    1990-01-01

    and statistically significant spatial relations. The first observable event was a decrease of regional cerebral blood flow posteriorly in one cerebral hemisphere. Further development of this pathological process was accompanied by the aura symptoms. Thereafter headache occurred while regional cerebral blood flow...... remained decreased. During the headache phase, regional cerebral blood flow gradually changed from abnormally low to abnormally high without apparent change in headache. In some patients headache disappeared while regional cerebral blood flow remained increased. Although regional cerebral blood flow...... reduction and aura symptoms in the great majority of patients were unilateral, one-third had bilateral headache. Unilateral headache usually localized to the side on which regional cerebral blood flow was reduced and from which the aura symptoms originated (i.e., aura symptoms were perceived to occur...

  14. Effect of pregnancy on regional cerebral blood flow

    Energy Technology Data Exchange (ETDEWEB)

    Nagamachi, Shigeki; Hoshi, Hiroaki; Jinnouchi, Seishi; Ohnishi, Takashi; Futami, Shigemi; Watanabe, Katsushi; Ikeda, Tomoaki; Mori, Norimasa [Miyazaki Medical Coll., Kiyotake (Japan)

    1993-12-01

    Regional cerebral blood flow (r-CBF) of 10 pregnant women were quantified by {sup 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{sub co2} concentration increased significantly after artificial abortion. Although its mechanism is unknown, our preliminary work demonstrates that r-CBF increased by pregnancy. (author).

  15. Tomographic cerebral blood flow measurement during carotid surgery

    DEFF Research Database (Denmark)

    Rathenborg, Lisbet Knudsen; Vorstrup, Sidsel; Olsen, K S

    1994-01-01

    OBJECTIVES: The aim of the study was to depict regional cerebral blood flow (rCBF) during carotid cross clamping using 99mTechnetium-hexamethylpropylene amine oxime (TcHMPAO). This tracer rapidly passes the blood-brain barrier and is retained for hours in the brain tissue. Injecting TcHMPAO during...... RESULTS: We found a significant correlation between stump pressure and enhancement of side-to-side asymmetry in rCBF due to carotid cross clamping. Pronounced variations were seen in which regions were deprived of perfusion during clamping. CONCLUSION: TcHMPAO allows tomographic assessment of CBF during...

  16. The impact of early aerobic exercise on brain microvascular alterations induced by cerebral hypoperfusion.

    Science.gov (United States)

    Leardini-Tristão, Marina; Borges, Juliana Pereira; Freitas, Felipe; Rangel, Raquel; Daliry, Anissa; Tibiriçá, Eduardo; Estato, Vanessa

    2017-02-15

    The therapeutic potential of early exercise training following cerebral hypoperfusion was investigated on brain perfusion and inflammation in rats with permanent bilateral occlusion of the common carotid arteries (2VO). Wistar rats were subjected to 2VO or sham surgery and each group was then subdivided randomly into sedentary or exercise groups. Early exercise training was initiated after three days of 2VO or sham surgery and consisted of seven days of treadmill training (30min/day at ∼60% of maximal exercise test), composing four groups: 1) Sham sedentary (Sham-Sed), 2) Sham exercised (Sham-Ex), 3) 2VO sedentary (2VO-Sed) and 4) 2VO exercised (2VO-Ex). Microvascular cerebral blood flow (MCBF) and NADPH oxidase and eNOS gene expression were evaluated by laser speckle contrast imaging and RT-PCR, respectively, and brain functional capillary density and endothelial-leukocyte interactions were evaluated by fluorescence intravital video-microscopy. The 2VO-Sed group presented a decrease in MCBF (Sham-Sed: 230.9±12.2 vs. 2VO-Sed: 183.6±10.6 arbitrary perfusion units, Pexercise was able to prevent the cerebral microvascular inflammation by decreasing endothelial-leukocyte interactions (2VO-Ex: 0.9±0.3 vs. 2VO-Sed: 5±0.6cells/min/100μm, Pbrain NADPH oxidase gene expression (2VO-Ex: 1.7±0.1 arbitrary units, Pexercise may represent a means of preventing the microvascular alterations induced by chronic cerebral hypoperfusion.

  17. 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...

  18. 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.

  19. Autoregulation of cerebral blood flow in orthostatic hypotension

    Science.gov (United States)

    Novak, V.; Novak, P.; Spies, J. M.; Low, P. A.

    1998-01-01

    BACKGROUND AND PURPOSE: We sought to evaluate cerebral autoregulation in patients with orthostatic hypotension (OH). METHODS: We studied 21 patients (aged 52 to 78 years) with neurogenic OH during 80 degrees head-up tilt. Blood flow velocities (BFV) from the middle cerebral artery were continuously monitored with transcranial Doppler sonography, as were heart rate, blood pressure (BP), cardiac output, stroke volume, CO2, total peripheral resistance, and cerebrovascular resistance. RESULTS: All OH patients had lower BP (PTPR (P.75) but with a flat slope. An expansion of the "autoregulated" range was seen in some patients. The OH_AF group was characterized by a profound fall in BFV in response to a small reduction in BP (mean deltaBP .75). CONCLUSIONS: The most common patterns of cerebral response to OH are autoregulatory failure with a flat flow-pressure relationship or intact autoregulation with an expanded autoregulated range. The least common pattern is autoregulatory failure with a steep flow-pressure relationship. Patients with patterns 1 and 2 have an enhanced capacity to cope with OH, while those with pattern 3 have reduced capacity.

  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. [Measurement of cerebral blood flow using phase-contrast MRI].

    Science.gov (United States)

    Obata, T; Shishido, F; Koga, M; Ikehira, H; Kimura, F; Yoshida, K

    1997-07-01

    The development of phase-contrast magnetic resonance imaging(P-C MRI) provides a noninvasive method for measurement of volumetric blood flow(VFR). The VFR of the left and right internal carotid arteries and basilar artery were measured using P-C MRI, and total cerebral blood flow(tCBF) was calculated by summing up the VFR values in three vessels. We investigated the changes in these blood flows as influenced from age, head size, height, weight, body surface area and handedness. Moreover, regional CBF(rCBF) was measured by combining with the single photon emission computed tomography(SPECT) of 123I. The blood flows were 142 +/- 58 mL/ min(mean +/- SD) in the basilar artery, 229 +/- 86 mL/min in the left, 223 +/- 58 mL/min in the right internal carotid artery, and tCBF was 617 +/- 128 mL/min(Ref. Magn Resn Imaging 14:P. 1143, 1996). Significant increases were observed in head-size-related change of VFR in the basilar artery and height-related change of tCBF. The value of rCBF was easily acquired in combination with SPECT. Phase-contrast MRI is useful for a noninvasive and rapid analysis of cerebral VFR and has potential for clinical use.

  2. Cerebral oximetry and cerebral blood flow monitoring in 2 pediatric survivors with out-of-hospital cardiac arrest.

    Science.gov (United States)

    Abramo, Thomas; Aggarwal, Nitin; Kane, Ian; Crossman, Kristen; Meredith, Mark

    2014-04-01

    In pediatric out-of-hospital cardiac arrest (POHCA), cardiovascular monitoring tools have improved resuscitative endeavors and cardiovascular outcomes but with still poor neurologic outcomes. Regarding cardiac arrest in patients with congenital heart disease during surgery, the application of cerebral oximetry with blood volume index (BVI) during the resuscitation has shown significant results and prognostic significance. We present 2 POHCA patients who had cerebral oximetry with BVI monitoring during their arrest and postarrest phase in the emergency department and its potential prognostic aspect.Basic procedures include left and right cerebral oximetry with BVI monitoring at every 5-second interval during cardiac arrest, resuscitation, and postarrest in 2 POHCA patients in the pediatric emergency department.Regional cerebral tissue oxygen saturation (rSo2) with BVI readings in these 2 POHCA survivors demonstrated interesting cerebral physiology, blood flow, and potential prognostic outcome. In 1 patient, the reference range of cerebral rSo2 with positive blood flow during arrest and postarrest phases consistently occurred. This neurologic monitoring had its significance when the resuscitation effectiveness was used and end-tidal CO2 changes were lost. The other patient's cerebral rSo2 with simultaneous BVI readings and trending showed the effectiveness of the emergency medical services (EMS) resuscitation.Cerebral oximetry with cerebral blood flow index monitoring in these POHCA survivors demonstrates compelling periarrest and postarrest cerebral physiology information and prognostication. Cerebral oximetry with cerebral BVI monitoring during these arrest phases has potential as a neurologic monitor for the resuscitative intervention's effectiveness and its possible neurologic prognostic application in the pediatric OCHA patients.

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

    Energy Technology Data Exchange (ETDEWEB)

    Yoshikawa, Hideto; Fueki, Noboru; Suzuki, Hisaharu; Sakuragawa, Norio; Iio, Masaaki (National Central Hospital for Mental, Nervous and Muscular Disorders, Tokyo (Japan))

    1992-05-01

    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{sub 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{sub 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).

  4. Laser Doppler flowmetry to measure changes in cerebral blood flow.

    Science.gov (United States)

    Sutherland, Brad A; Rabie, Tamer; Buchan, Alastair M

    2014-01-01

    Laser Doppler flowmetry (LDF) is a method by which relative cerebral blood flow (CBF) of the cortex can be measured. Although the method is easy to employ, LDF only measures relative CBF, while absolute CBF cannot be quantified. LDF is useful for investigating CBF changes in a number of different applications including neurovascular and stroke research. This chapter will prepare the reader for rodent experiments using LDF with two preparations. The closed skull preparation can be used to monitor CBF with an intact skull, but in adult rats, thinning of the skull is required to obtain an accurate cortical CBF signal. The open skull preparation requires a craniotomy to expose the surface of the brain and the LDF probe is held close to the surface to measure cerebral perfusion.

  5. Regional cerebral blood flow change in a case of Alzheimer's disease with musical hallucinations.

    Science.gov (United States)

    Mori, Takaaki; Ikeda, Manabu; Fukuhara, Ryuji; Sugawara, Yoshifumi; Nakata, Shigeru; Matsumoto, Naomi; Nestor, Peter J; Tanabe, Hirotaka

    2006-06-01

    We examined alteration of regional cerebral blood flow (rCBF) in a case of Alzheimer's disease (AD) patient with musical hallucination. To detect regions related to musical hallucination, single-photon emission computed tomography (SPECT) imaging of the patient and nine sex, age, and cognitive function-matched AD patients without delusions and hallucinations were compared using statistical parametric mapping 99 (SPM99). In comparison with controls, the patient had increased rCBF in left temporal regions and left angular gyrus. This profile could be relevant to the neuroanatomical basis of musical hallucinations.

  6. [Intraoperative monitoring of cerebral blood-flow and condition of cerebral at open and endovascular interventions in carotid system].

    Science.gov (United States)

    Kuntsevich, G I; Tanashian, M M; Skrylev, S I; Krotenkova, M V; Shchipakin, V L; Koshcheev, A Iu; Lagoda, O V; Gemdzhian, E G; Medvedev, R B; Kulikova, S N

    2011-01-01

    The aim of our research is to study hemodynamic and embolic situation during the carotid endarterectomy (CEA), carotid angioplastic and stenting (CAS), and to reveal the prognostic significance of the data provided by intraoperative monitoring of the brain blood flow in exposing acute ischemic lesions in brain. Intraoperative monitoring of blood flow in artery ophthalmic vas carried out with 60% of patients, in the middle cerebral artery-with 40% during the main stages of CEA, and with 64 patients in the middle cerebral artery during CAS. The comparison of the data of intraoperative monitoring of blood flow in middle cerebral artery with the result of brain diffusion-weighted magnetic resonance imaging (DW-MRI) 24 hours after the operation shows, that solid microembolic signals and vasospasm are prognostic signals (sensibility and specifics make up 95%) in the development of acute ischemic cerebral lesions. The monitoring of blood flow in artery ophthalmic is of the greatest diagnostic value in estimation of the hemodynamic situation, but it is of the lowest practical value in detecting microembolic signals. According to the data of the intraoperative blood flow monitoring in middle cerebral artery in group CEA the development of acute ischemic cerebral lesions were predicted with 11,1% of patients and the cause of postoperative stroke, developed by 2,9% of the patients, was specified. According to the result of DW-MRI, acute ischemic cerebral lesions were diagnosed with 21% of patients, that is, 18% of ischemic cerebral lesions were asymptomatic. In group CAS ischemic cerebral lesions were prognosed with 30% of patients, actually they were later detected with 40,6% of cases by means of DW-MRI. According to the data of intraoperative of blood flow monitoring the cause of the development of postoperative stroke was specified in 6,2% of cause; in 34,4% of cause the acute ischemic cerebral lesions were asymptomatic.

  7. T2’-Imaging to Assess Cerebral Oxygen Extraction Fraction in Carotid Occlusive Disease: Influence of Cerebral Autoregulation and Cerebral Blood Volume

    Science.gov (United States)

    Deichmann, Ralf; Pfeilschifter, Waltraud; Hattingen, Elke; Singer, Oliver C.; Wagner, Marlies

    2016-01-01

    Purpose Quantitative T2'-mapping detects regional changes of the relation of oxygenated and deoxygenated hemoglobin (Hb) by using their different magnetic properties in gradient echo imaging and might therefore be a surrogate marker of increased oxygen extraction fraction (OEF) in cerebral hypoperfusion. Since elevations of cerebral blood volume (CBV) with consecutive accumulation of Hb might also increase the fraction of deoxygenated Hb and, through this, decrease the T2’-values in these patients we evaluated the relationship between T2’-values and CBV in patients with unilateral high-grade large-artery stenosis. Materials and Methods Data from 16 patients (13 male, 3 female; mean age 53 years) with unilateral symptomatic or asymptomatic high-grade internal carotid artery (ICA) or middle cerebral artery (MCA) stenosis/occlusion were analyzed. MRI included perfusion-weighted imaging and high-resolution T2’-mapping. Representative relative (r)CBV-values were analyzed in areas of decreased T2’ with different degrees of perfusion delay and compared to corresponding contralateral areas. Results No significant elevations in cerebral rCBV were detected within areas with significantly decreased T2’-values. In contrast, rCBV was significantly decreased (pperfusion delay and decreased T2’. Furthermore, no significant correlation between T2’- and rCBV-values was found. Conclusions rCBV is not significantly increased in areas of decreased T2’ and in areas of restricted perfusion in patients with unilateral high-grade stenosis. Therefore, T2’ should only be influenced by changes of oxygen metabolism, regarding our patient collective especially by an increase of the OEF. T2’-mapping is suitable to detect altered oxygen consumption in chronic cerebrovascular disease. PMID:27560515

  8. Carbon dioxide induced changes in cerebral blood flow and flow velocity: Role of cerebrovascular resistance and effective cerebral perfusion pressure

    NARCIS (Netherlands)

    F. Grüne (Frank); S. Kazmaier (Stephan); R.J. Stolker (Robert J.); G.H. Visser (Gerhard Henk); A. Weyland (Andreas)

    2015-01-01

    textabstractIn addition to cerebrovascular resistance (CVR) zero flow pressure (ZFP), effective cerebral perfusion pressure (CPPe) and the resistance area product (RAP) are supplemental determinants of cerebral blood flow (CBF). Until now, the interrelationship of PaCO2 -induced changes in CBF, CVR,

  9. 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

    2014-01-01

    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 ne

  10. Structural network alterations and neurological dysfunction in cerebral amyloid angiopathy

    NARCIS (Netherlands)

    Reijmer, Yael D.; Fotiadis, Panagiotis; Martinez-Ramirez, Sergi; Salat, David H.; Schultz, Aaron; Shoamanesh, Ashkan; Ayres, Alison M.; Vashkevich, Anastasia; Rosas, Diana; Schwab, Kristin; Leemans, Alexander; Biessels, Geert Jan; Rosand, Jonathan; Johnson, Keith A.; Viswanathan, Anand; Gurol, M. Edip; Greenberg, Steven M.

    2015-01-01

    Cerebral amyloid angiopathy is a common form of small-vessel disease and an important risk factor for cognitive impairment. The mechanisms linking small-vessel disease to cognitive impairment are not well understood. We hypothesized that in patients with cerebral amyloid angiopathy, multiple small s

  11. Narcolepsy: regional cerebral blood flow during sleep and wakefulness

    Energy Technology Data Exchange (ETDEWEB)

    Sakai, F.; Meyer, J.S.; Karacan, I.; Yamaguchi, F.; Yamamoto, M.

    1979-01-01

    Serial measurements of regional cerebral blood flow were made by the 135Xe inhalation method during the early stages of sleep and wakefulness in eight normal volunteers and 12 patients with narcolepsy. Electroencephalogram, electro-oculogram, and submental electromyogram were recorded simultaneously. In normals, mean hemispheric gray matter blood flow (Fg) during stages I and II sleep was significantly less than waking values. Maximum regional blood flow decreases during sleep occurred in the brainstem-cerebellar, right inferior temporal, and bilateral frontal regions. In patients with narcolepsy, mean hemispheric Fg while awake was 80.5 +- 13 ml per 100 gm brain per minute. During REM sleep, mean hemispheric Fg increased concurrently with large increases in brainstem-cerebellar region flow. During stages I and II sleep without REM, there were significant increases in mean hemispheric Fg and brainstem-cerebellar Fg, just the opposite of changes in normals. In narcolepsy, there appears to be a reversal of normal cerebral deactivation patterns, particularly involving the brainstem, during stages I and II sleep.

  12. Intraoperative multi-exposure speckle imaging of cerebral blood flow.

    Science.gov (United States)

    Richards, Lisa M; Kazmi, Sm Shams; Olin, Katherine E; Waldron, James S; Fox, Douglas J; Dunn, Andrew K

    2017-01-01

    Multiple studies have demonstrated that laser speckle contrast imaging (LSCI) has high potential to be a valuable cerebral blood flow monitoring technique during neurosurgery. However, the quantitative accuracy and sensitivity of LSCI is limited, and highly dependent on the exposure time. An extension to LSCI called multi-exposure speckle imaging (MESI) overcomes these limitations, and was evaluated intraoperatively in patients undergoing brain tumor resection. This clinical study ( n = 8) recorded multiple exposure times from the same cortical tissue area spanning 0.5-20 ms, and evaluated images individually as single-exposure LSCI and jointly using the MESI model. This study demonstrated that the MESI estimates provided the broadest flow sensitivity for sampling the flow magnitude in the human brain, closely followed by the shorter exposure times. Conservation of flow analysis on vascular bifurcations was used to validate physiological accuracy, with highly conserved flow estimates (blood flow changes after tissue cautery. Results from this study demonstrate that intraoperative MESI can be performed with high quantitative accuracy and sensitivity for cerebral blood flow monitoring.

  13. 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...

  14. 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.

  15. Trigeminal cardiac reflex and cerebral blood flow regulation

    Directory of Open Access Journals (Sweden)

    Dominga Lapi

    2016-10-01

    Full Text Available The stimulation of some facial regions is known to trigger the trigemino-cardiac reflex: the main stimulus is represented by the contact of the face with water. This phenomenon called diving reflex induces a set of reactions in the cardiovascular and respiratory systems occurring in all mammals, especially marine (whales, seals. During the immersion of the face in the water, the main responses are aimed at reducing the oxygen consumption of the organism. Accordingly reduction in heart rate, peripheral vasoconstriction, blood pooling in certain organs, especially the heart and brain, and an increase in blood pressure have been reported. Moreover, the speed and intensity of the reflex is inversely proportional to the temperature of the water: more cold the water, more reactions as described are strong. In the case of deep diving an additional effect, such as blood deviation, has been reported: the blood is requested within the lungs, to compensate for the increase in the external pressure, preventing them from collapsing.The trigeminal-cardiac reflex is not just confined to the diving reflex; recently it has been shown that a brief proprioceptive stimulation (10 min by jaw extension in rats produces interesting effects both at systemic and cerebral level, reducing the arterial blood pressure and vasodilating the pial arterioles. The arteriolar dilation is associated with rhythmic diameter changes characterized by an increase in the endothelial activity. Fascinating the stimulation of trigeminal nerve is able to activated the nitric oxide release by vascular endothelial. Therefore the aim of this review was to highlight the effects due to trigeminal cardiac reflex induced by a simple mandibular extension, because produced opposite effects compared to those elicited by the diving reflex as it induces hypotension and modulation of cerebral arteriolar tone.

  16. Trigeminal Cardiac Reflex and Cerebral Blood Flow Regulation

    Science.gov (United States)

    Lapi, Dominga; Scuri, Rossana; Colantuoni, Antonio

    2016-01-01

    The stimulation of some facial regions is known to trigger the trigemino-cardiac reflex: the main stimulus is represented by the contact of the face with water. This phenomenon called diving reflex induces a set of reactions in the cardiovascular and respiratory systems occurring in all mammals, especially marine (whales, seals). During the immersion of the face in the water, the main responses are aimed at reducing the oxygen consumption of the organism. Accordingly reduction in heart rate, peripheral vasoconstriction, blood pooling in certain organs, especially the heart, and brain and an increase in blood pressure have been reported. Moreover, the speed and intensity of the reflex is inversely proportional to the temperature of the water: more cold the water, more reactions as described are strong. In the case of deep diving an additional effect, such as blood deviation, has been reported: the blood is sequestered within the lungs, to compensate for the increase in the external pressure, preventing them from collapsing. The trigeminal-cardiac reflex is not just confined to the diving reflex; recently it has been shown that a brief proprioceptive stimulation (10 min) by jaw extension in rats produces interesting effects both at systemic and cerebral levels, reducing the arterial blood pressure, and vasodilating the pial arterioles. The arteriolar dilation is associated with rhythmic diameter changes characterized by an increase in the endothelial activity. Fascinating the stimulation of trigeminal nerve is able to activate the nitric oxide release by vascular endothelial cells. Therefore, the aim of this review was to highlight the effects due to trigeminal cardiac reflex induced by a simple mandibular extension. Opposite effects, such as hypotension, and modulation of cerebral arteriolar tone, were observed, when these responses were compared to those elicited by the diving reflex. PMID:27812317

  17. Cerebral blood flow assessment of preterm infants during respiratory therapy with the expiratory flow increase technique

    Directory of Open Access Journals (Sweden)

    Mariana Almada Bassani

    2016-06-01

    Full Text Available Abstract Objective: To assess the impact of respiratory therapy with the expiratory flow increase technique on cerebral hemodynamics of premature newborns. Methods: This is an intervention study, which included 40 preterm infants (≤34 weeks aged 8-15 days of life, clinically stable in ambient air or oxygen catheter use. Children with heart defects, diagnosis of brain lesion and/or those using vasoactive drugs were excluded. Ultrasonographic assessments with transcranial Doppler flowmetry were performed before, during and after the increase in expiratory flow session, which lasted 5min. Cerebral blood flow velocity and resistance and pulsatility indices in the pericallosal artery were assessed. Results: Respiratory physical therapy did not significantly alter flow velocity at the systolic peak (p=0.50, the end diastolic flow velocity (p=0.17, the mean flow velocity (p=0.07, the resistance index (p=0.41 and the pulsatility index (p=0.67 over time. Conclusions: The expiratory flow increase technique did not affect cerebral blood flow in clinically-stable preterm infants.

  18. 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...... studied both during a seizure and (in the same setting) in the interictal period; six patients were studied only in the interictal period, and one patient was studied only during a seizure. Studies during seizures all showed marked flow increases in areas presumed to participate in the seizure activity....... 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...

  19. Cerebral blood flow autoregulation in experimental liver failure

    DEFF Research Database (Denmark)

    Dethloff, T.J.; Larsen, F.S.; Knudsen, Gitte Moos

    2008-01-01

    Patients with acute liver failure (ALF) display impairment of cerebral blood flow (CBF) autoregulation, which may contribute to the development of fatal intracranial hypertension, but the pathophysiological mechanism remains unclear. In this study, we examined whether loss of liver mass causes...... impairment of CBF autoregulation. Four rat models were chosen, each representing different aspects of ALF: galactosamine (GlN) intoxication represented liver necrosis, 90% hepatectomy (PHx90) represented reduction in liver mass, portacaval anastomosis (PCA) represented shunting of blood....../toxins into the systemic circulation thus mimicking intrahepatic shunting in ALF, PCA+NH(3) provided information about the additional effects of hyperammonemia Rats were intubated and sedated with pentobarbital. We measured CBF with laser Doppler, intracranial pressure (ICP) was measured in the fossa posterior...

  20. Relationship between cardiac function and resting cerebral blood flow

    DEFF Research Database (Denmark)

    Henriksen, Otto M; Jensen, Lars T; Krabbe, Katja;

    2014-01-01

    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...

  1. 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.)

  2. Cerebral blood flow in small vessel disease: A systematic review and meta-analysis.

    Science.gov (United States)

    Shi, Yulu; Thrippleton, Michael J; Makin, Stephen D; Marshall, Ian; Geerlings, Mirjam I; de Craen, Anton Jm; van Buchem, Mark A; Wardlaw, Joanna M

    2016-10-01

    White matter hyperintensities are frequent on neuroimaging of older people and are a key feature of cerebral small vessel disease. They are commonly attributed to chronic hypoperfusion, although whether low cerebral blood flow is cause or effect is unclear. We systematically reviewed studies that assessed cerebral blood flow in small vessel disease patients, performed meta-analysis and sensitivity analysis of potential confounders. Thirty-eight studies (n = 4006) met the inclusion criteria, including four longitudinal and 34 cross-sectional studies. Most cerebral blood flow data were from grey matter. Twenty-four cross-sectional studies (n = 1161) were meta-analysed, showing that cerebral blood flow was lower in subjects with more white matter hyperintensity, globally and in most grey and white matter regions (e.g. mean global cerebral blood flow: standardised mean difference-0.71, 95% CI -1.12, -0.30). These cerebral blood flow differences were attenuated by excluding studies in dementia or that lacked age-matching. Four longitudinal studies (n = 1079) gave differing results, e.g., more baseline white matter hyperintensity predated falling cerebral blood flow (3.9 years, n = 575); cerebral blood flow was low in regions that developed white matter hyperintensity (1.5 years, n = 40). Cerebral blood flow is lower in subjects with more white matter hyperintensity cross-sectionally, but evidence for falling cerebral blood flow predating increasing white matter hyperintensity is conflicting. Future studies should be longitudinal, obtain more white matter data, use better age-correction and stratify by clinical diagnosis.

  3. Alterations in the Cerebral Microvascular Proteome Expression Profile After Transient Global Cerebral Ischemia in Rat

    DEFF Research Database (Denmark)

    Spray, Stine; Johansson, Sara E; Edwards, Alistair V G;

    2016-01-01

    This study aimed at obtaining an in-depth mapping of expressional changes of the cerebral microvasculature after transient global cerebral ischemia (GCI) and the impact on these GCI-induced expressional changes of post-GCI treatment with a mitogen-activated protein kinase kinase (MEK1/2) inhibitor...

  4. Can cerebral blood volume be measured reproducibly with an improved near infrared spectroscopy system?

    NARCIS (Netherlands)

    Ven, M.T.P. van de; Colier, W.N.J.M.; Sluijs, M.C. van der; Walraven, D.; Oeseburg, B.; Folgering, H.T.M.

    2001-01-01

    In some circumstances, cerebral blood volume (CBV) can be used as a measure for cerebral blood flow. A new near infrared spectroscope was used for determining the reproducibility of CBV measurements assessed by the O2-method. Twenty-seven healthy subjects were investigated. An intrasubject coefficie

  5. Prediction of Cerebral Hyperperfusion Syndrome with Velocity Blood Pressure Index

    Directory of Open Access Journals (Sweden)

    Zhi-Chao Lai

    2015-01-01

    Full Text Available Background: Cerebral hyperperfusion syndrome is an important complication of carotid endarterectomy (CEA. An >100% increase in middle cerebral artery velocity (MCAV after CEA is used to predict the cerebral hyperperfusion syndrome (CHS development, but the accuracy is limited. The increase in blood pressure (BP after surgery is a risk factor of CHS, but no study uses it to predict CHS. This study was to create a more precise parameter for prediction of CHS by combined the increase of MCAV and BP after CEA. Methods: Systolic MCAV measured by transcranial Doppler and systematic BP were recorded preoperatively; 30 min postoperatively. The new parameter velocity BP index (VBI was calculated from the postoperative increase ratios of MCAV and BP. The prediction powers of VBI and the increase ratio of MCAV (velocity ratio [VR] were compared for predicting CHS occurrence. Results: Totally, 6/185 cases suffered CHS. The best-fit cut-off point of 2.0 for VBI was identified, which had 83.3% sensitivity, 98.3% specificity, 62.5% positive predictive value and 99.4% negative predictive value for CHS development. This result is significantly better than VR (33.3%, 97.2%, 28.6% and 97.8%. The area under the curve (AUC of receiver operating characteristic: AUC VBI = 0.981, 95% confidence interval [CI] 0.949-0.995; AUC VR = 0.935, 95% CI 0.890-0.966, P = 0.02. Conclusions: The new parameter VBI can more accurately predict patients at risk of CHS after CEA. This observation needs to be validated by larger studies.

  6. The phosphodiesterase 3 inhibitor cilostazol dilates large cerebral arteries in humans without affecting regional cerebral blood flow

    DEFF Research Database (Denmark)

    Birk, Steffen; Kruuse, Christina Rostrup; Petersen, Kenneth A;

    2004-01-01

    in the middle cerebral arteries (VMCA) was measured with transcranial Doppler, and the superficial temporal and radial arteries diameters were measured with ultrasonography. During the 4-hour observation period, there was no effect on systolic blood pressure (P = 0.28), but diastolic blood pressure decreased...

  7. Regional cerebral blood flow autoregulation in patients with fulminant hepatic failure

    DEFF Research Database (Denmark)

    Larsen, Fin Stolze; Strauss, Gitte Irene; Møller, Kirsten;

    2000-01-01

    The absence of cerebral blood flow autoregulation in patients with fulminant hepatic failure (FHF) implies that changes in arterial pressure directly influence cerebral perfusion. It is assumed that dilatation of cerebral arterioles is responsible for the impaired autoregulation. Recently, frontal...... blood flow was reported to be lower compared with other brain regions, indicating greater arteriolar tone and perhaps preserved regional cerebral autoregulation. In patients with severe FHF (6 women, 1 man; median age, 46 years; range, 18 to 55 years), we tested the hypothesis that perfusion...... in the anterior cerebral artery would be less affected by an increase in mean arterial pressure compared with the brain area supplied by the middle cerebral artery. Relative changes in cerebral perfusion were determined by transcranial Doppler-measured mean flow velocity (V(mean)), and resistance was determined...

  8. Autoregulation of cerebral blood flow in experimental focal brain ischemia.

    Science.gov (United States)

    Dirnagl, U; Pulsinelli, W

    1990-05-01

    The relationship between systemic arterial pressure (SAP) and neocortical microcirculatory blood-flow (CBF) in areas of focal cerebral ischemia was studied in 15 spontaneously hypertensive rats (SHRs) anesthetized with halothane (0.5%). Ischemia was induced by ipsilateral middle cerebral artery/common carotid artery occlusion and CBF was monitored continuously in the ischemic territory using laser-Doppler flowmetry during manipulation of SAP with I-norepinephrine (hypertension) or nitroprusside (hypotension). In eight SHRs not subjected to focal ischemia, we demonstrated that 0.5% halothane and the surgical manipulations did not impair autoregulation. Autoregulation was partly preserved in ischemic brain tissue with a CBF of greater than 30% of preocclusion values. In areas where ischemic CBF was less than 30% of preocclusion values, autoregulation was completely lost. Changes in SAP had a greater influence on CBF in tissue areas where CBF ranged from 15 to 30% of baseline (9% change in CBF with each 10% change in SAP) than in areas where CBF was less than 15% of baseline (6% change in CBF with each 10% change in SAP). These findings demonstrate that the relationship between CBF and SAP in areas of focal ischemia is highly dependent on the severity of ischemia. Autoregulation is lost in a gradual manner until CBF falls below 30% of normal. In areas without autoregulation, the slope of the CBF/SAP relationship is inversely related to the degree of ischemia.

  9. Heterogeneity of muscarinic receptor subtypes in cerebral blood vessels

    Energy Technology Data Exchange (ETDEWEB)

    Garcia-Villalon, A.L.; Krause, D.N.; Ehlert, F.J.; Duckles, S.P. (Department of Pharmacology, College of Medicine, University of California, Irvine (USA))

    1991-07-01

    The identity and distribution of muscarinic cholinergic receptor subtypes and associated signal transduction mechanisms was characterized for the cerebral circulation using correlated functional and biochemical investigations. Subtypes were distinguished by the relative affinities of a panel of muscarinic antagonists, pirenzepine, AF-DX 116 (11-2-((2-(diethylaminomethyl)- 1-piperidinyl)acetyl)-5,11-dihydro-6H- pyrido(2,3-b)(1,4)benzodiazepine-6-one), hexahydrosiladifenidol, methoctramine, 4-diphenylacetoxy-N-methylpiperidine methobromide, dicyclomine, para-fluoro-hexahydrosiladifenidol and atropine. Muscarinic receptors characterized by inhibition of (3H)quinuclidinylbenzilate binding in membranes of bovine pial arteries were of the M2 subtype. In contrast pharmacological analysis of (3H)-quinuclidinylbenzilate binding in bovine intracerebral microvessels suggests the presence of an M4 subtype. Receptors mediating endothelium-dependent vasodilation in rabbit pial arteries were of the M3 subtype, whereas muscarinic receptors stimulating endothelium-independent phosphoinositide hydrolysis in bovine pial arteries were of the M1 subtype. These findings suggest that characteristics of muscarinic receptors in cerebral blood vessels vary depending on the type of vessel, cellular location and function mediated.

  10. Cerebral blood flow in sickle cell cerebrovascular disease

    Energy Technology Data Exchange (ETDEWEB)

    Huttenlocher, P.R.; Moohr, J.W.; Johns, L.; Brown, F.D.

    1984-05-01

    Cerebral blood flow (CBF) has been studied by the xenon-133 (/sup 133/Xe) inhalation method in 16 children with suspected sickle cell cerebrovascular disease. Abnormalities consisting of decreases in total, hemispheral, or regional CBF were found in 17 of 26 studies. Eleven studies performed immediately after stroke, transient ischemic attack, or depression of state of alertness showed abnormalities. In addition to confirming regional cerebrovascular insufficiency in children with stroke due to major cerebral artery occlusion, the method detected diffuse decrease in CBF in children with stupor, coma, and seizures who had normal angiographic findings. In contrast, six of seven studies obtained after exchange transfusion or during maintenance on hypertransfusion therapy showed normal findings. The difference between results in patients with acute neurologic disturbances and those receiving transfusion therapy was statistically significant (P less than .005). The data indicate that the /sup 133/Xe method reliably demonstrates cerebrovascular impairment in sickle cell disease. They also suggest that CBF changes in patients with sickle cell disease can be reversed by exchange transfusion and by hypertransfusion therapy. The /sup 133/Xe CBF method may be useful for following up children with sickle cell disease who are at high risk for recurrent stroke.

  11. 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...... of the disease. Lateral CBF asymmetry is also very frequent; speech disorders are highly characteristic of left-sided flow reduction, while visuospatial apraxia is dominating in the right-sided cases. In advanced and severe cases of AD, CBF and metabolism tend to be more uniformly reduced throughout the cortex......, sparing only the primary visual and sensory-motor cortices. PET and SPECT measurement of brain perfusion and metabolism has added a new dimension to the knowledge of dementia disorders, with a better differential diagnosis between AD and other forms of dementia. The correlation with neuropsychological...

  12. Cerebral blood volume in humans by NIRS and PET

    Science.gov (United States)

    Pott, Frank; Knudsen, Gitte M.; Rostrup, Egill; Ide, Kojiro; Secher, Niels H.; Paulson, Olaf B.

    1998-01-01

    Near infrared spectroscopy (NIRS) determined changes in the cerebral blood volume (CBV) were compared to those obtained by positron emission tomography (PET) in five healthy volunteers (2 females). Two NIRS optodes were placed on the left forehead and NIRS-CBV was derived from the sum of oxyhemoglobin and deoxyhemoglobin. CBV changes were induced by hyperventilation and inhalation of 6% CO2. After 2 min inhalation of labeled carbon monoxide, data were sampled during 8 min for both PET- and NIRS-CBV as well as for the arterial carbon dioxide tension (PaCO2). The region of interest for PET-CBV was `banana-shaped' with boundaries corresponding to the position of the NIRS optodes on the transmission scan and to a depth of approximately 2 cm. During hyperventilation, PaCO2 decreased from 5.2 (4.6 - 5.8) to 4.6 (4.2 - 4.9) kPa and equally PET-CBV (from 3.9 (2.5 - 5.2) to 3.6 (3.0 - 4.8) ml (DOT) 100 g-1) and NIRS-CBV were reduced (by -0.14 [-0.38 - 0.50] ml (DOT) 100 g-1). During hypercapnia PaCO2 increased to 6.0 (5.9 - 7.0) kPa accompanied by parallel changes in PET- (to 4.5 (3.9 - 4.9) ml (DOT) 100 g-1) and NIRS-CBV (by 0.04 [-0.02 - 0.30] ml (DOT) 100 g-1) and the two variables were correlated (r equals 0.78, p arterial carbon dioxide tension, the cerebral blood volumes determined by near infrared spectroscopy and by positron emission tomography change in parallel but the change in NIRS-CBV is small compared to that obtained by PET.

  13. MEK1/2 inhibition attenuates vascular ETA and ETB receptor alterations after cerebral ischaemia

    DEFF Research Database (Denmark)

    Henriksson, Marie; Stenman, Emelie; Vikman, Petter;

    2007-01-01

    Cerebral ischaemia is associated with elevated levels of endothelin B (ETB) receptors in the ipsilateral middle cerebral artery (MCA). This up-regulation of ET receptors occurs via de novo transcription involving mitogen-activated protein kinases (MAPK). The aim of this study was to examine the e......, neurological symptoms, and ET receptor alteration. The vascular effects of U0126 provide new perspective on possible mechanisms of actions of MAPK inhibition in cerebral ischaemia.......Cerebral ischaemia is associated with elevated levels of endothelin B (ETB) receptors in the ipsilateral middle cerebral artery (MCA). This up-regulation of ET receptors occurs via de novo transcription involving mitogen-activated protein kinases (MAPK). The aim of this study was to examine...... the effect of inhibition of the MAP kinase/ERK kinase (MEK)1/2 on ET receptor alteration, brain damage, and neurology in experimental cerebral ischaemia. Transient middle cerebral artery occlusion (MCAO) was induced in male Wistar rats by the intraluminal filament technique. The animals received 100 mg...

  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......, but increases during cycling exercise. The increase in CMRO(2) is unaffected by beta-adrenergic blockade even though CBF is reduced suggesting that cerebral oxygenation becomes critical and a limited cerebral mitochondrial oxygen tension may induce fatigue. Also, sympathetic activity may drive cerebral non...

  15. Simple exercises that significantly increase cerebral blood flow and cerebral oxygenation

    CERN Document Server

    Gersten, Alexander; Raz, Amir; Fried, Robert

    2011-01-01

    We tested the hypothesis that simple exercises may significantly increase cerebral blood flow (CBF) and/or cerebral oxygenation. Eighteen subjects ranging in age from nineteen to thirty nine participated in a four-stage study during which measurements of end tidal CO_2 (EtCO2 - by capnometer) and local brain oxygenation (by near-infrared spectroscopy (NIRS) sensor) were taken. The four stages were 1) baseline, 2) breathing exercises, 3) solving an arithmetic problem, and 4) biofeedback. During the breathing exercises there was a significant increase in EtCO2 indicating a significant increase in global CBF. The increase in global CBF was estimated on the basis of a theoretical model. During the arithmetic and biofeedback tasks there was a significant increase in the local (Fp1) oxygenation, but it varied between the different participants. The results may lead to new clinical applications of CBF and brain oxygenation monitoring and behavioral control. We foresee future more detailed investigations in the contr...

  16. Correlations of cerebral blood flow with language function in aphasic patients following cerebral infarction

    Energy Technology Data Exchange (ETDEWEB)

    Yokoyama, Eriko; Nagata, Ken; Uemura, Kazuo [Research Inst. for Brain and Blood Vessels, Akita (Japan)

    1997-04-01

    To elucidate the participation of the brain regions in language function, cerebral blood flow (CBF) which were measured with positron emission tomography (PET) were compared with the language scores based on the standard language test for aphasics in 97 right-handed patients with aphasia due to cerebral infarction. PET studies were performed on 71.4{+-}107.3 days after onset. By the linear regression analysis, the aphasic scores were correlated with the regional CBF from 55 brain regions. CBF from the left frontal, left temporal, and left parietal lobes significantly correlated with language scores of auditory comprehension, speaking, reading, writing, calculation, and repetition. Highly significant correlation was obtained from the left posterior inferior frontal, superior temporal, supramarginal and angular gyri. CBF from the right inferior frontal, right superior temporal, right parahippocampal and right anterior cingulate gyri also correlated with the auditory comprehension, speaking and reading. Accordingly, in addition to the classical language areas which play an essential roles in language function, the extensive areas in the left hemisphere and some part of the right hemisphere may be related to the language processing and recovery from aphasia. (author)

  17. Structural network alterations and neurological dysfunction in cerebral amyloid angiopathy

    Science.gov (United States)

    Reijmer, Yael D.; Fotiadis, Panagiotis; Martinez-Ramirez, Sergi; Salat, David H.; Schultz, Aaron; Shoamanesh, Ashkan; Ayres, Alison M.; Vashkevich, Anastasia; Rosas, Diana; Schwab, Kristin; Leemans, Alexander; Biessels, Geert-Jan; Rosand, Jonathan; Johnson, Keith A.; Viswanathan, Anand; Gurol, M. Edip

    2015-01-01

    Cerebral amyloid angiopathy is a common form of small-vessel disease and an important risk factor for cognitive impairment. The mechanisms linking small-vessel disease to cognitive impairment are not well understood. We hypothesized that in patients with cerebral amyloid angiopathy, multiple small spatially distributed lesions affect cognition through disruption of brain connectivity. We therefore compared the structural brain network in patients with cerebral amyloid angiopathy to healthy control subjects and examined the relationship between markers of cerebral amyloid angiopathy-related brain injury, network efficiency, and potential clinical consequences. Structural brain networks were reconstructed from diffusion-weighted magnetic resonance imaging in 38 non-demented patients with probable cerebral amyloid angiopathy (69 ± 10 years) and 29 similar aged control participants. The efficiency of the brain network was characterized using graph theory and brain amyloid deposition was quantified by Pittsburgh compound B retention on positron emission tomography imaging. Global efficiency of the brain network was reduced in patients compared to controls (0.187 ± 0.018 and 0.201 ± 0.015, respectively, P < 0.001). Network disturbances were most pronounced in the occipital, parietal, and posterior temporal lobes. Among patients, lower global network efficiency was related to higher cortical amyloid load (r = −0.52; P = 0.004), and to magnetic resonance imaging markers of small-vessel disease including increased white matter hyperintensity volume (P < 0.001), lower total brain volume (P = 0.02), and number of microbleeds (trend P = 0.06). Lower global network efficiency was also related to worse performance on tests of processing speed (r = 0.58, P < 0.001), executive functioning (r = 0.54, P = 0.001), gait velocity (r = 0.41, P = 0.02), but not memory. Correlations with cognition were independent of age, sex, education level, and other magnetic resonance imaging

  18. Cerebral blood flow in Alzheimer’s disease

    Directory of Open Access Journals (Sweden)

    Roher AE

    2012-10-01

    Full Text Available Alex E Roher,1 Josef P Debbins,2 Michael Malek-Ahmadi,3 Kewei Chen,4 James G Pipe,2 Sharmeen Maze,2 Christine Belden,3 Chera L Maarouf,1 Pradeep Thiyyagura,4 Hua Mo,4 Jesse M Hunter,1 Tyler A Kokjohn,1,5 Douglas G Walker,6 Jane C Kruchowsky,6 Marek Belohlavek,7 Marwan N Sabbagh,3 Thomas G Beach81The Longtine Center for Neurodegenerative Biochemistry, Banner Sun Health Research Institute, Sun City, 2Keller Center for Imaging Innovation, Neuroimaging Research, Barrow Neurological Institute, Phoenix, 3Cleo Roberts Center for Clinical Research, Banner Sun Health Research Institute, Sun City, 4Computational Image Analysis Program, Banner Alzheimer’s Institute, Phoenix, 5Department of Microbiology, Midwestern University, Glendale, 6Laboratory of Neuroinflammation, Banner Sun Health Research Institute, Sun City, 7Division of Cardiovascular Diseases, Mayo Clinic, Scottsdale, 8Civin Laboratory for Neuropathology, Banner Sun Health Research Institute, Sun City, AZ, USABackground: Alzheimer’s disease (AD dementia is a consequence of heterogeneous and complex interactions of age-related neurodegeneration and vascular-associated pathologies. Evidence has accumulated that there is increased atherosclerosis/arteriosclerosis of the intracranial arteries in AD and that this may be additive or synergistic with respect to the generation of hypoxia/ischemia and cognitive dysfunction. The effectiveness of pharmacologic therapies and lifestyle modification in reducing cardiovascular disease has prompted a reconsideration of the roles that cardiovascular disease and cerebrovascular function play in the pathogenesis of dementia.Methods: Using two-dimensional phase-contrast magnetic resonance imaging, we quantified cerebral blood flow within the internal carotid, basilar, and middle cerebral arteries in a group of individuals with mild to moderate AD (n = 8 and compared the results with those from a group of age-matched nondemented control (NDC subjects (n = 9

  19. Adenosine mediates decreased cerebral metabolic rate and increased cerebral blood flow during acute moderate hypoxia in the near-term fetal sheep.

    Science.gov (United States)

    Blood, Arlin B; Hunter, Christian J; Power, Gordon G

    2003-12-15

    Exposure of the fetal sheep to moderate to severe hypoxic stress results in both increased cortical blood flow and decreased metabolic rate. Using intravenous infusion of 8-cyclopentyl-1,3-dipropylxanthine (DPCPX), a selective adenosine A1 receptor antagonist that is permeable to the blood brain barrier, we examine the role of adenosine A1 receptors in mediating cortical blood flow and metabolic responses to moderate hypoxia. The effects of DPCPX blockade are compared to controls as well as animals receiving intravenous 8-(p-sulfophenyl)-theophylline) (8-SPT), a non-selective adenosine receptor antagonist which has been found to be blood brain barrier impermeable. Laser Doppler flow probes, tissue PO2, and thermocouples were implanted in the cerebral cortices of near-term fetal sheep. Catheters were placed in the brachial artery and sagittal sinus vein for collection of samples for blood gas analysis. Three to seven days later responses to a 30-min period of fetal hypoxemia (arterial PO2 10-12 mmHg) were studied with administration of 8-SPT, DPCPX, or vehicle. Cerebral metabolic rate was determined by calculation of both brain heat production and oxygen consumption. In response to hypoxia, control experiments demonstrated a 42 +/- 7 % decrease in cortical heat production and a 35 +/- 10 % reduction in oxygen consumption. In contrast, DPCPX infusion during hypoxia resulted in no significant change in brain heat production or oxygen consumption, suggesting the adenosine A1 receptor is involved in lowering metabolic rate during hypoxia. The decrease in cerebral metabolic rate was not altered by 8-SPT infusion, suggesting that the response is not mediated by adenosine receptors located outside the blood brain barrier. In response to hypoxia, control experiments demonstrated a 35 +/- 7 % increase in cortical blood flow. DPCPX infusion did not change this increase in cortical blood flow, however 8-SPT infusion attenuated increases in flow, indicating that hypoxic

  20. Cerebral blood flow in migraine and cortical spreading depression

    Energy Technology Data Exchange (ETDEWEB)

    Lauritzen, M.

    1987-01-01

    In a series of migraine patients, carotid arteriography was carried out as part of the clinical evalution. Nine patients developed a migrainous attack with focal neurological symptoms and headache after the angiography and during the subsequent, ongoing regional cerebral blood flow rCBF study. rCBF was measured by bolus injection of Xenon/sup 133/ into the internal carotid artery and a gamma camera with 254 collimated scintillation detectors covering the lateral aspect of the hemisphere. This technique depicts rCBF mainly at the level of the superficial cortex, with no depth resolution. The resolution is 1 cm/sup 2/ providing detailed spatial information of the cortical blood flow. Other methods for measuring local blood flow in animal and man employ a radioactive, freely diffusible tracer, in combination with an autoradiographic technique for the assessment of the tissue concentration, the so-called autoradiographic methods. In the series of patients with spontaneous migraine, rCBF was estimated using an in-vivo application of the autoradiographic principle. Xenon/sup 133/ was administered by inhalation and the time course of the arterial concentration curve was assessed by a scintillation detector over the upper right lung, since the arterial curve has been found to follow the shape of the lung curve. The rCBF was studied accompanying cortical spreading depression in rat experiments to evaluate wheter this phenomenon could explain the blood flow changes in migraine. (/sup 14/C) iodoantipyrine was given as an intravenous bolus injection and the brain content of indicator was determined by tissue sample or autoradiography after 10 or 20 seconds of isotope circulation. The conditions of the autoradiographic methods are that the flow remains constant within the period of measuring, and that the region under study is homogenous with regard to flow and lambda. (EG).

  1. pCO(2) and pH regulation of cerebral blood flow.

    Science.gov (United States)

    Yoon, Seonghun; Zuccarello, Mario; Rapoport, Robert M

    2012-01-01

    CO(2) serves as one of the fundamental regulators of cerebral blood flow (CBF). It is widely considered that this regulation occurs through pCO(2)-driven changes in pH of the cerebral spinal fluid (CSF), with elevated and lowered pH causing direct relaxation and contraction of the smooth muscle, respectively. However, some findings also suggest that pCO(2) acts independently of and/or in conjunction with altered pH. This action may be due to a direct effect of CSF pCO(2) on the smooth muscle as well as on the endothelium, nerves, and astrocytes. Findings may also point to an action of arterial pCO(2) on the endothelium to regulate smooth muscle contractility. Thus, the effects of pH and pCO(2) 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 HCO(3) (-) concentrations, i.e., solutions routinely employed to differentiate the effects of pH from pCO(2). In sum, it appears that pCO(2), independently and in conjunction with pH, may regulate CBF.

  2. Regional cerebral blood flow and blood volume in patients with subcortical arteriosclerotic encephalopathy (SAE).

    Science.gov (United States)

    Gückel, Friedemann J; Brix, Gunnar; Hennerici, Michael; Lucht, Robert; Ueltzhöffer, Christine; Neff, Wolfgang

    2007-10-01

    The aim of the present study was a detailed analysis of the regional cerebral blood flow and blood volume in patients with subcortical arteriosclerotic encephalopathy (SAE) by means of functional magnetic resonance imaging (MRI). A group of 26 patients with SAE and a group of 16 age-matched healthy volunteers were examined. Using a well-established dynamic susceptibility contrast-enhanced MRI method, the regional cerebral blood flow (rCBF) and blood volume (rCBV) were quantified for each subject in 12 different regions in the brain parenchyma. As compared to healthy volunteers, patients with SAE showed significantly reduced rCBF and rCBV values in white matter regions and in the occipital cortex. Regions containing predominantly grey matter show almost normal rCBF and rCBV values. In conclusion, quantitative analysis of rCBF and rCBV values demonstrates clearly that SAE is a disease that is associated with a reduced microcirculation predominantly in white matter.

  3. Effects of Blood Pressure Fluctuations on Cerebral Perfusion after Ischemic Stroke%血压波动对脑梗死后脑灌注的影响

    Institute of Scientific and Technical Information of China (English)

    聂志余; 靳令经

    2011-01-01

    Cerebral infarction affects both cerebral autoregulation and cerebral perfusion. This review article summarizes the published evidence of cerebral autoregulation impairment and cerebral blood flow alteration after cerebral infarction, including cerebrovascular small vessel disease leading to an impairment of vasoreactivity, blood flow velocities and cerebral blood flow associated positively with systemic blood pressure, perfusion declined on the infarcted side and lower blood pressure resulting in hypoperfusion in distal area of the narrowing main cerebral artery. The question should be thought by physicians about what is the 'best blood pressure range' in patients with cerebral infarction and it will be benefit for optimal recovery.%本文主要从脑血管的自动调节与自动调节受损、脑小血管病变可导致脑血管反应性受损、脑梗死患者脑血流速度、脑血流量与血压的相关性,脑梗死侧大脑半球脑灌注降低、低血压对脑主要动脉狭窄者可导致狭窄远端脑组织局部低灌注等几个方面来讨论脑梗死后血压的变化对脑血流速度、脑血流量的影响.给临床医生提出一个思考问题,在脑梗死的急性期把血压控制在多少才是最合适的水平,对患者的功能恢复最有益.

  4. Carbon dioxide induced changes in cerebral blood flow and flow velocity: role of cerebrovascular resistance and effective cerebral perfusion pressure.

    Science.gov (United States)

    Grüne, Frank; Kazmaier, Stephan; Stolker, Robert J; Visser, Gerhard H; Weyland, Andreas

    2015-09-01

    In addition to cerebrovascular resistance (CVR) zero flow pressure (ZFP), effective cerebral perfusion pressure (CPPe) and the resistance area product (RAP) are supplemental determinants of cerebral blood flow (CBF). Until now, the interrelationship of PaCO2-induced changes in CBF, CVR, CPPe, ZFP, and RAP is not fully understood. In a controlled crossover trial, we investigated 10 anesthetized patients aiming at PaCO2 levels of 30, 37, 43, and 50 mm Hg. Cerebral blood flow was measured with a modified Kety-Schmidt-technique. Zero flow pressure and RAP was estimated by linear regression analysis of pressure-flow velocity relationships of the middle cerebral artery. Effective cerebral perfusion pressure was calculated as the difference between mean arterial pressure and ZFP, CVR as the ratio CPPe/CBF. Statistical analysis was performed by one-way RM-ANOVA. When comparing hypocapnia with hypercapnia, CBF showed a significant exponential reduction by 55% and mean VMCA by 41%. Effective cerebral perfusion pressure linearly decreased by 17% while ZFP increased from 14 to 29 mm Hg. Cerebrovascular resistance increased by 96% and RAP by 39%; despite these concordant changes in mean CVR and Doppler-derived RAP correlation between these variables was weak (r=0.43). In conclusion, under general anesthesia hypocapnia-induced reduction in CBF is caused by both an increase in CVR and a decrease in CPPe, as a consequence of an increase in ZFP.

  5. Anxiety and cerebral blood flow during behavioral challenge. Dissociation of central from peripheral and subjective measures

    Energy Technology Data Exchange (ETDEWEB)

    Zohar, J.; Insel, T.R.; Berman, K.F.; Foa, E.B.; Hill, J.L.; Weinberger, D.R.

    1989-06-01

    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/sub 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.

  6. 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...

  7. Metabolic control of resting hemispheric cerebral blood flow is oxidative, not glycolytic

    OpenAIRE

    Powers, William. J.; Videen, Tom O.; Markham, Joanne; Walter, Vonn; Perlmutter, Joel S.

    2011-01-01

    Although the close regional coupling of resting cerebral blood flow (CBF) with both cerebral metabolic rate of oxygen (CMRO2) and cerebral metabolic rate of glucose (CMRglc) within individuals is well documented, there are few data regarding the coupling between whole brain flow and metabolism among different subjects. To investigate the metabolic control of resting whole brain CBF, we performed multivariate analysis of hemispheric CMRO2, CMRglc, and other covariates as predictors of resting ...

  8. Dragon's blood dropping pills have protective effects on focal cerebral ischemia rats model.

    Science.gov (United States)

    Xin, Nian; Yang, Fang-Ju; Li, Yan; Li, Yu-Juan; Dai, Rong-Ji; Meng, Wei-Wei; Chen, Yan; Deng, Yu-Lin

    2013-12-15

    Dragon's blood is a bright red resin obtained from Dracaena cochinchinensis (Lour.) S.C.Chen (Yunnan, China). As a traditional Chinese medicinal herb, it has great traditional medicinal value and is used for wound healing and to stop bleeding. Its main biological activity comes from phenolic compounds. In this study, phenolic compounds were made into dropping pills and their protective effects were examined by establishing focal cerebral ischemia rats model used method of Middle Cerebral Artery Occlusion (MCAO), and by investigating indexes of neurological scores, infarct volume, cerebral index, cerebral water content and oxidation stress. Compared to model group, high, middle and low groups of Dragon's blood dropping pills could improve the neurological function significantly (pDragon's blood dropping pills had protective effects on focal cerebral ischemia rats.

  9. Regulation of cerebral blood flow in mammals during chronic hypoxia: a matter of balance.

    Science.gov (United States)

    Ainslie, Philip N; Ogoh, Shigehiko

    2010-02-01

    Respiratory-induced changes in the partial pressures of arterial carbon dioxide (PaCO2) and oxygen (PaO2) play a major role in cerebral blood flow (CBF) regulation. Elevations in PaCO2 (hypercapnia) lead to vasodilatation and increases in CBF, whereas reductions in PaCO2 (hypocapnia) lead to vasoconstriction and decreases in CBF. A fall in PaO2 (hypoxia) below a certain threshold (balance between the myriad of vasodilators and constrictors derived from the endothelium, neuronal innervations and perfusion pressure. This review examines the extent and mechanisms by which hypoxia regulates CBF. Particular focus will be given to the marked influence of hypoxia associated with exposure to high altitude and chronic lung disease. The associated implications of these hypoxia-induced integrative alterations for the regulation of CBF are discussed, and future avenues for research are proposed.

  10. Regional cerebral blood flow assessed by 133Xe inhalation and emission tomography

    DEFF Research Database (Denmark)

    Shirahata, N; Henriksen, L; Vorstrup, S

    1985-01-01

    Regional cerebral blood flow (rCBF) in the cerebral hemispheres and the cerebellum was measured by single photon emission computed tomography with inhalation of 133Xe in 39 normal volunteers at test. The goal of this study was to assess the normal flow pattern and its variations. Five parallel...

  11. 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

    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...

  12. 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

    . 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...

  13. Cerebral blood flow in small vessel disease : A systematic review and meta-analysis

    NARCIS (Netherlands)

    Shi, Yulu; Thrippleton, Michael J; Makin, Stephen D; Marshall, Ian; Geerlings, Mirjam I; de Craen, Anton Jm; van Buchem, Mark A; Wardlaw, Joanna M

    2016-01-01

    White matter hyperintensities are frequent on neuroimaging of older people and are a key feature of cerebral small vessel disease. They are commonly attributed to chronic hypoperfusion, although whether low cerebral blood flow is cause or effect is unclear. We systematically reviewed studies that as

  14. 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 signi

  15. Regional cerebral blood flow during mechanical hyperventilation in patients with fulminant hepatic failure

    DEFF Research Database (Denmark)

    Strauss, Gitte Irene; Høgh, Peter; Møller, Kirsten;

    1999-01-01

    Hyperventilation is frequently used to prevent or postpone the development of cerebral edema and intracranial hypertension in patients with fulminant hepatic failure (FHF). The influence of such therapy on regional cerebral blood flow (rCBF) remains, however, unknown. In this study the CBF...

  16. Flunitrazepam does not alter cerebral distribution of buprenorphine in the rat.

    Science.gov (United States)

    Megarbane, Bruno; Pirnay, Stéphane; Borron, Stephen W; Trout, Hervé; Monier, Claire; Risède, Patricia; Boschi, Gabrielle; Baud, Frédéric J

    2005-07-04

    Deaths have been reported among heroin addicts related to combined buprenorphine and flunitrazepam use. The aim of this study was to determine the existence of a drug-drug interaction during the distribution phase of buprenorphine. Arterial blood gases were measured after intravenous administration of buprenorphine alone (30 mg/kg), flunitrazepam alone (40 mg/kg) or both drugs in rats. Buprenorphine kinetics was studied in plasma and in striatum using cerebral microdialysis, both alone and after rat pretreatment with flunitrazepam. In contrast to buprenorphine or flunitrazepam alone, buprenorphine in combination with flunitrazepam induced a significant, rapid and sustained respiratory depression. Arterial PCO2 was increased at 1.5 min (6.7+/-0.2 versus 5.4+/-0.3 and 5.5+/-0.3 kPa, respectively, P=0.04) (mean+/-S.E.M.), and arterial pH decreased (7.37+/-0.02 versus 7.45+/-0.02 and 7.45+/-0.01, respectively, P=0.03). Plasma buprenorphine kinetics was well described by a three-compartment linear model, with a distribution half-life of 7.4+/-2.7 min and an elimination half-life of 463.9+/-152.3 min. However, neither plasma nor striatal buprenorphine kinetics were significantly altered by pre-administration of flunitrazepam. The adverse interaction between flunitrazepam and buprenorphine cannot be explained by a pharmacokinetic drug-drug interaction during the distribution phase of buprenorphine.

  17. Methylophiopogonanone A Protects against Cerebral Ischemia/Reperfusion Injury and Attenuates Blood-Brain Barrier Disruption In Vitro.

    Directory of Open Access Journals (Sweden)

    Mingbao Lin

    Full Text Available Methylophiopogonanone A (MO-A, an active homoisoflavonoid of the Chinese herb Ophiopogon japonicus which has been shown to have protective effects on cerebral ischemia/reperfusion (I/R injury, has been demonstrated to have anti-inflammatory and anti-oxidative properties. However, little is known about its role in cerebral I/R injury. Therefore, in this study, by using a middle cerebral artery occlusion (MCAO and reperfusion rat model, the effect of MO-A on cerebral I/R injury was examined. The results showed that MO-A treatment reduced infarct volume and brain edema, improved neurological deficit scores, reversed animal body weight decreases, and increased animal survival time in the stroke groups. Western blotting showed that MO-A suppressed MMP-9, but restored the expression of claudin-3 and claudin-5. Furthermore, transmission electron microscopy were monitored to determine the blood-brain barrier (BBB alterations in vitro. The results showed that MO-A markedly attenuated BBB damage in vitro. Additionally, MO-A inhibited ROS production in ECs and MMP-9 release in differentiated THP-1 cells in vitro, and suppressed ICAM-1 and VCAM-1 expression in ECs and leukocyte/EC adhesion. In conclusion, our data indicate that MO-A has therapeutic potential against cerebral I/R injury through its ability to attenuate BBB disruption by regulating the expression of MMP-9 and tight junction proteins.

  18. Correlation of Cerebral Blood Flow with Memory in Patients with Cerebral Infarction%脑梗死病人脑血流与记忆的相关研究

    Institute of Scientific and Technical Information of China (English)

    汪洪; 侯靖边; 梁燕; 刘枢晓; 王文富

    2001-01-01

    Objective:To investigate the relation of cerebral blood flow(CBF) and memory in patients with cerebral infarction. Methods:The cerebral blood flow of 30 patients with cerebral infarction and 20 healthy controls was measured. The WMS was used for memory function assessment. Results: CBF and memory performance in patients group were lower than those of controls. There was a statistically significant correlation between CBF and memory performances. Conclusion: The decreasing of CBF was an important causal factor to the memory dysfunction in cerebral infarction patients.

  19. Unveiling astrocytic control of cerebral blood flow with optogenetics.

    Science.gov (United States)

    Masamoto, Kazuto; Unekawa, Miyuki; Watanabe, Tatsushi; Toriumi, Haruki; Takuwa, Hiroyuki; Kawaguchi, Hiroshi; Kanno, Iwao; Matsui, Ko; Tanaka, Kenji F; Tomita, Yutaka; Suzuki, Norihiro

    2015-06-16

    Cortical neural activities lead to changes in the cerebral blood flow (CBF), which involves astrocytic control of cerebrovascular tone. However, the manner in which astrocytic activity specifically leads to vasodilation or vasoconstriction is difficult to determine. Here, cortical astrocytes genetically expressing a light-sensitive cation channel, channelrhodopsin-2 (ChR2), were transcranially activated with a blue laser while the spatiotemporal changes in CBF were noninvasively monitored with laser speckle flowgraphy in the anesthetised mouse cortex. A brief photostimulation induced a fast transient increase in CBF. The average response onset time was 0.7 ± 0.7 sec at the activation foci, and this CBF increase spread widely from the irradiation spot with an apparent propagation speed of 0.8-1.1 mm/sec. The broad increase in the CBF could be due to a propagation of diffusible vasoactive signals derived from the stimulated astrocytes. Pharmacological manipulation showed that topical administration of a K(+) channel inhibitor (BaCl2; 0.1-0.5 mM) significantly reduced the photostimulation-induced CBF responses, which indicates that the ChR2-evoked astrocytic activity involves K(+) signalling to the vascular smooth muscle cells. These findings demonstrate a unique model for exploring the role of the astrocytes in gliovascular coupling using non-invasive, time-controlled, cell-type specific perturbations.

  20. EXPRESSION OF IL-2 AND SIL-2R AND ALTERATION OF CELL IMMUNITY IN PATIENTS WITH HYPERTENSIVE CEREBRAL HEMORRHAGE

    Institute of Scientific and Technical Information of China (English)

    Zhang Yuelin; Qiu Shudong; Shi Wei; Dang Xiaojun

    2006-01-01

    Objective To study the expression of interleukin-2 (IL-2), soluble interleukin-2 receptor (sIL-2R),determine the alteration of erythrocytic immunity and T cell subgroup in the blood of outer circulation in patients with hypertensive cerebral hemorrhage so and to probe into the relationship between them, and to explore the clinical significance. Methods Enzyme linked immnunosorbent assay (ELISA) was used to determine the content of IL-2 and sIL-2R. The immunoadsorption was employed to examine the erythrocytic immune activity and its regulating function.Streptavidin-peroxidase(S-P) was used to determine the cell number of CD3 (cluster of differentiation3), CD4 and CD8. Results The content of IL-2 in the group with hypertensive cerebral hemorrhage was significantly lower than that in the control group (P<0.01), and the content of sIL-2R increased. Red blood cell C3b receptor (RBC. C3b R)and RBC immune adherence enhancing factor (RFEB) dropped greatly (P<0.01), while RBC immune complex rosette (RBC. ICR) and RBC immune adherence inhibiting factor (RFIR) increased greatly. The cell number of CD3 and CD4decreased (P<0.01) and there was no obvious change in CD8 (P<0.05). Conclusion The decrease of immune function was observed in patients with hypertensive cerebral hemorrhage. The determination of the content of IL-2, sIL-2R, erythrocytic immunity and the activity of T subgroup has an important clinical significance in the occurrence,development, treatment, and prognosis of hypertensive cerebral hemorrhage.

  1. Iodoamphetamine as a new tracer for local cerebral blood flow in the rat

    DEFF Research Database (Denmark)

    Rapin, J R; Le Poncin-Lafitte, M; Duterte, D

    1984-01-01

    practically no differences. Autoradiographic quantification of the local cerebral blood flow, calculated according to the microsphere model, produced identical results for both molecules. However, compared with the values reported for other tracers, our values constituted an underestimation of white matter...

  2. The effect of water immersion during exercise on cerebral blood flow.

    NARCIS (Netherlands)

    Pugh, C.J.; Sprung, V.S.; Ono, K.; Spence, A.L.; Thijssen, D.H.J.; Carter, H.H.; Green, D.J.

    2015-01-01

    INTRODUCTION: Regular exercise induces recurrent increases in cerebrovascular perfusion. In peripheral arteries, such episodic increases in perfusion are responsible for improvement in arterial function and health. We examined the hypothesis that exercise during immersion augments cerebral blood flo

  3. Effects of race and sex on cerebral hemodynamics, oxygen delivery and blood flow distribution in response to high altitude

    Science.gov (United States)

    Liu, Jie; Liu, Yang; Ren, Li-Hua; Li, Li; Wang, Zhen; Liu, Shan-Shan; Li, Su-Zhi; Cao, Tie-Sheng

    2016-08-01

    To assess racial, sexual, and regional differences in cerebral hemodynamic response to high altitude (HA, 3658 m). We performed cross-sectional comparisons on total cerebral blood flow (TCBF = sum of bilateral internal carotid and vertebral arterial blood flows = QICA + QVA), total cerebrovascular resistance (TCVR), total cerebral oxygen delivery (TCOD) and QVA/TCBF (%), among six groups of young healthy subjects: Tibetans (2-year staying) and Han (Han Chinese) at sea level, Han (2-day, 1-year and 5-year) and Tibetans at HA. Bilateral ICA and VA diameters and flow velocities were derived from duplex ultrasonography; and simultaneous measurements of arterial pressure, oxygen saturation, and hemoglobin concentration were conducted. Neither acute (2-day) nor chronic (>1 year) responses showed sex differences in Han, except that women showed lower TCOD compared with men. Tibetans and Han exhibited different chronic responses (percentage alteration relative to the sea-level counterpart value) in TCBF (‑17% vs. 0%), TCVR (22% vs. 12%), TCOD (0% vs. 10%) and QVA/TCBF (0% vs. 2.4%, absolute increase), with lower resting TCOD found in SL- and HA-Tibetans. Our findings indicate racial but not sex differences in cerebral hemodynamic adaptations to HA, with Tibetans (but not Han) demonstrating an altitude-related change of CBF distribution.

  4. 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...... to baseline ventilation, whereas CMR(glu) increased. CONCLUSION: In patients with acute bacterial meningitis, we found variable levels of CBF and cerebrovascular CO(2) reactivity, a low a-v DO(2), low cerebral metabolic rates of oxygen and glucose, and a cerebral lactate efflux. In these patients...

  5. Role of nitric oxide synthases in early blood-brain barrier disruption following transient focal cerebral ischemia.

    Directory of Open Access Journals (Sweden)

    Zheng Jiang

    Full Text Available The role of nitric oxide synthases (NOSs in early blood-brain barrier (BBB disruption was determined using a new mouse model of transient focal cerebral ischemia. Ischemia was induced by ligating the middle cerebral artery (MCA at its M2 segment and reperfusion was induced by releasing the ligation. The diameter alteration of the MCA, arterial anastomoses and collateral arteries were imaged and measured in real time. BBB disruption was assessed by Evans Blue (EB and sodium fluorescein (Na-F extravasation at 3 hours of reperfusion. The reperfusion produced an extensive vasodilation and a sustained hyperemia. Although expression of NOSs was not altered at 3 hours of reperfusion, L-NAME (a non-specific NOS inhibitor abolished reperfusion-induced vasodilation/hyperemia and significantly reduced EB and Na-F extravasation. L-NIO (an endothelial NOS (eNOS inhibitor significantly attenuated cerebral vasodilation but not BBB disruption, whereas L-NPA and 7-NI (neuronal NOS (nNOS inhibitors significantly reduced BBB disruption but not cerebral vasodilation. In contrast, aminoguanidine (AG (an inducible NOS (iNOS inhibitor had less effect on either cerebral vasodilation or BBB disruption. On the other hand, papaverine (PV not only increased the vasodilation/hyperemia but also significantly reduced BBB disruption. Combined treatment with L-NAME and PV preserved the vasodilation/hyperemia and significantly reduced BBB disruption. Our findings suggest that nNOS may play a major role in early BBB disruption following transient focal cerebral ischemia via a hyperemia-independent mechanism.

  6. A simple model of cerebral blood flow dependence on arterial blood pressure

    CERN Document Server

    Gersten, Alexander

    2011-01-01

    It is shown that the dependence of the cerebral blood flow (CBF) on mean arterial blood pressure (MABP) can be described with a simple model having the following assumptions. Below certain MABP (denoted as MABP1) there are no autoregulatory or feedback mechanisms influencing CBF. Between MABP1 and MABP2 (MABP at which breakthrough accurs) there is a linear (on MABP) dependent feedback with a sloap depending very much on the individual considered. The classical autoregulation model with a plateau in between MABP1 and MABP2 is a particular case of this model. The model describes well the experiments performed on dogs (Harper 1966), for which the individual feedback sloap parameter varied to great extent, indicating the importance of mesurments on individuals against averaged mesurments (or measurments on diffent individuals) which superficially support the classical autoregulation. New effect of decreased CBF, while increasing MABP, was observed.

  7. Soluble epoxide hydrolase gene deletion improves blood flow and reduces infarct size after cerebral ischemia in reproductively senescent female mice

    Directory of Open Access Journals (Sweden)

    Kristen L Zuloaga

    2015-01-01

    Full Text Available Soluble epoxide hydrolase (sEH, a key enzyme in the metabolism of vasodilatory epoxyeicosatrienoic acids (EETs, is sexually dimorphic, suppressed by estrogen, and contributes to underlying sex differences in cerebral blood flow and injury after cerebral ischemia. We tested the hypothesis that sEH inhibition or gene deletion in reproductively senescent (RS female mice would increase cerebral perfusion and decrease infarct size following stroke. RS (15-18 month old and young (3-4 month old female sEH knockout (sEHKO mice and wild type (WT mice were subjected to 45 min middle cerebral artery occlusion (MCAO with laser Doppler perfusion monitoring. WT mice were treated with vehicle or a sEH inhibitor t-AUCB at the time of reperfusion and every 24hrs thereafter for 3 days. Differences in regional cerebral blood flow were measured in vivo using optical microangiography. Infarct size was measured 3 days after reperfusion. Infarct size and cerebral perfusion 24h after MCAO were not altered by age. Both sEH gene deletion and sEH inhibition increased cortical perfusion 24h after MCAO. Neither sEH gene deletion nor sEH inhibition reduced infarct size in young mice. However, sEH gene deletion, but not sEH inhibition of the hydrolase domain of the enzyme, decreased infarct size in RS mice. Results of these studies show that sEH gene deletion and sEH inhibition enhance cortical perfusion following MCAO and sEH gene deletion reduces damage after ischemia in RS female mice; however this neuroprotection in absent is young mice.

  8. Involvement of calcitonin gene-related peptide in migraine: regional cerebral blood flow and blood flow velocity in migraine patients

    DEFF Research Database (Denmark)

    Lassen, L.H.; Jacobsen, V.B.; Haderslev, P.A.

    2008-01-01

    g/min) or placebo for 20 min was studied in 12 patients with migraine without aura outside attacks. Xenon-133 inhalation SPECT-determined regional cerebral blood flow (rCBF) and transcranial Doppler (TCD)-determined blood velocity (V-mean) in the middle cerebral artery (MCA), as well as the heart......Calcitonin gene-related peptide (CGRP)-containing nerves are closely associated with cranial blood vessels. CGRP is the most potent vasodilator known in isolated cerebral blood vessels. CGRP can induce migraine attacks, and two selective CGRP receptor antagonists are effective in the treatment...... of migraine attacks. It is therefore important to investigate its mechanism of action in patients with migraine. We here investigate the effects of intravenous human alpha-CGRP (h alpha CGRP) on intracranial hemodynamics. In a double-blind, cross-over study, the effect of intravenous infusion of haCGRP (2 mu...

  9. Whole blood angiopoietin-1 and -2 levels discriminate cerebral and severe (non-cerebral malaria from uncomplicated malaria

    Directory of Open Access Journals (Sweden)

    Tangpukdee Noppadon

    2009-12-01

    Full Text Available Abstract Background Severe and cerebral malaria are associated with endothelial activation. Angiopoietin-1 (ANG-1 and angiopoietin-2 (ANG-2 are major regulators of endothelial activation and integrity. The aim of this study was to investigate the clinical utility of whole blood angiopoietin (ANG levels as biomarkers of disease severity in Plasmodium falciparum malaria. Methods The utility of whole blood ANG levels was examined in Thai patients to distinguish cerebral (CM; n = 87 and severe (non-cerebral malaria (SM; n = 36 from uncomplicated malaria (UM; n = 70. Comparative statistics are reported using a non-parametric univariate analysis (Kruskal-Wallis test or Chi-squared test, as appropriate. Multivariate binary logistic regression was used to examine differences in whole blood protein levels between groups (UM, SM, CM, adjusting for differences due to ethnicity, age, parasitaemia and sex. Receiver operating characteristic curve analysis was used to assess the diagnostic accuracy of the ANGs in their ability to distinguish between UM, SM and CM. Cumulative organ injury scores were obtained for patients with severe disease based on the presence of acute renal failure, jaundice, severe anaemia, circulatory collapse or coma. Results ANG-1 and ANG-2 were readily detectable in whole blood. Compared to UM there were significant decreases in ANG-1 (p Conclusions These results suggest that whole blood ANG-1/2 levels are promising clinically informative biomarkers of disease severity in malarial syndromes.

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

    Energy Technology Data Exchange (ETDEWEB)

    Otsuka, Makoto; Ichiya, Yuici; Kuwabara, Yasuo (Kyushu Univ., Fukuoka (Japan). Faculty of Medicine) (and others)

    1989-11-01

    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).

  11. HIV and chronic methamphetamine dependence affect cerebral blood flow.

    Science.gov (United States)

    Ances, Beau M; Vaida, Florin; Cherner, Mariana; Yeh, Melinda J; Liang, Christine L; Gardner, Carly; Grant, Igor; Ellis, Ronald J; Buxton, Richard B

    2011-09-01

    Human immunodeficiency virus (HIV) and methamphetamine (METH) dependence are independently associated with neuronal dysfunction. The coupling between cerebral blood flow (CBF) and neuronal activity is the basis of many task-based functional neuroimaging techniques. We examined the interaction between HIV infection and a previous history of METH dependence on CBF within the lenticular nuclei (LN). Twenty-four HIV-/METH-, eight HIV-/METH+, 24 HIV+/METH-, and 15 HIV+/METH+ participants performed a finger tapping paradigm. A multiple regression analysis of covariance assessed associations and two-way interactions between CBF and HIV serostatus and/or previous history of METH dependence. HIV+ individuals had a trend towards a lower baseline CBF (-10%, p = 0.07) and greater CBF changes for the functional task (+32%, p = 0.01) than HIV- subjects. Individuals with a previous history of METH dependence had a lower baseline CBF (-16%, p = 0.007) and greater CBF changes for a functional task (+33%, p = 0.02). However, no interaction existed between HIV serostatus and previous history of METH dependence for either baseline CBF (p = 0.53) or CBF changes for a functional task (p = 0.10). In addition, CBF and volume in the LN were not correlated. A possible additive relationship could exist between HIV infection and a history of METH dependence on CBF with a previous history of METH dependence having a larger contribution. Abnormalities in CBF could serve as a surrogate measure for assessing the chronic effects of HIV and previous METH dependence on brain function.

  12. Cerebral blood oxygenation changes induced by visual stimulation in humans

    Science.gov (United States)

    Wenzel, Rudiger; Obrig, Hellmuth; Ruben, Jan; Villringer, Kersten; Thiel, Andreas; Bernarding, Johannes; Dirnagl, Ulrich; Villringer, Arno

    1996-10-01

    We examined local changes of cerebral oxygenation in response to visual stimuli by means of near infrared spectroscopy. A sharply outlined colored moving stimulus which is expected to evoke a broad activation of the striate and prestriate cortex was presented to sixteen healthy subjects. Six of these subjects were also exposed to a colored stationary and a gray stationary stimulus. In two subjects the colored moving stimulus was tested against the colored stationary with an optode position presumably over area V5/MT. As a control condition, subjects performed a simple finger opposition task. Since the calcarine fissure varies greatly with respect to bony landmarks, optodes were positioned individually according to 3D reconstructed magnetic resonance imaging (MRI). Concentration changes in oxyhemoglobin (oxy-Hb) and deoxyhemoglobin (deoxy-Hb) were continuously monitored with a temporal resolution of 1 s, using an NIRO 500. In response to the visual stimulus, the grand average across all sixteen subjects resulted in a significant increase in oxy-Hb of 0.33 +/- 0.09 arbitrary units mirrored by a significant decrease in deoxy-Hb of -0.18 +/- 0.02 arbitrary units, while the motor control condition elicited no significant changes in any parameters. When the near infrared spectroscopy probes were positioned over area V5/MT, the drop of deoxy-Hb associated with the moving stimulus was significantly more pronounced than with the stationary stimulus in both subjects examined. No significant differences between the visual stimuli were observed at the optode position close to the calcarine fissure. The oxygenation changes observed in this study are consistent with the pattern we have reported for motor activation. They are in line with physiological considerations and functional MRI studies relying on blood oxygenation level-dependent contrast.

  13. Laser Doppler flowmetry is valid for measurement of cerebral blood flow autoregulation lower limit in rats

    DEFF Research Database (Denmark)

    Tonnesen, Jan; Pryds, Anders; Larsen, Erik Hviid

    2005-01-01

    Laser Doppler flowmetry (LDF) is a recent technique that is increasingly being used to monitor relative changes in cerebral blood flow whereas the intra-arterial 133xenon injection technique is a well-established method for repeated absolute measurements of cerebral blood flow. The aim of this st...... CO2 challenge. Haemodilution influences the two methods differently causing relative overestimation of blood flow by the laser Doppler technique compared to the 133xenon method....... of this study was to validate LDF for assessment of cerebral autoregulation and CO2 reactivity with the 133xenon injection technique as the gold standard. Simultaneous measurements of cerebral blood flow (CBF) were collected by LDF (CBFLDF) and the 133xenon method (CBFXe) while (1) cerebral autoregulation...... was challenged by controlled systemic haemorrhage, or (2) cerebral blood flow was varied by manipulating the arterial partial pressure of CO2 (Pa,CO2). LDF slightly overestimated CBF under conditions of haemorrhagic shock and haemodilution caused by controlled haemorrhage (paired t test, P

  14. Urine Test Strips to Exclude Cerebral Spinal Fluid Blood

    Directory of Open Access Journals (Sweden)

    Marshall, Robin A

    2011-02-01

    Full Text Available Introduction: Determining the presence or absence of red blood cells (RBC or their breakdown products in cerebrospinal fluid (CSF is essential for the evaluation of subarachnoid hemorrhage (SAH in headache patients. Current methodology for finding blood in the CSF is either spectrophotometric detection of pigment, which is time consuming and labor intensive, or visual assesment of samples for color change (xanthochromia, which is inaccurate. Bayer Multistix® urine test strips are designed to test urine for RBC by detecting the presence of hemoglobin. The aim of this pilot study was to evaluate the perfomance of urine reagent test strips for ruling out the presence of RBC in CSF.Methods: We compared color changes on Multistix® urine test strips to the standard of spectrophotometric absorbtion at 415nm and initial RBC counts in 138 visually clear CSF samples.Results: We performed Pearson Chi-Square and likelihood ratios on the results and found a correlation between a negative result on the urine test strip and less than 5 RBC per high power field and a spectrophotometric absorbance of less than 0.02% at 415nm in a CSF sample.Conclusion: These results warrant further investigation in the form of a prospective clinical validation as it may alter the emergency department evaluation for SAH. [West J Emerg Med. 2011;12(1:63-66.

  15. Planning-free cerebral blood flow territory mapping in patients with intracranial arterial stenosis.

    Science.gov (United States)

    Arteaga, Daniel F; Strother, Megan K; Davis, L Taylor; Fusco, Matthew R; Faraco, Carlos C; Roach, Brent A; Scott, Allison O; Donahue, Manus J

    2016-07-07

    A noninvasive method for quantifying cerebral blood flow and simultaneously visualizing cerebral blood flow territories is vessel-encoded pseudocontinuous arterial spin labeling MRI. However, obstacles to acquiring such information include limited access to the methodology in clinical centers and limited work on how clinically acquired vessel-encoded pseudocontinuous arterial spin labeling data correlate with gold-standard methods. The purpose of this work is to develop and validate a semiautomated pipeline for the online quantification of cerebral blood flow maps and cerebral blood flow territories from planning-free vessel-encoded pseudocontinuous arterial spin labeling MRI with gold-standard digital subtraction angiography. Healthy controls (n = 10) and intracranial atherosclerotic disease patients (n = 34) underwent 3.0 T MRI imaging including vascular (MR angiography) and hemodynamic (cerebral blood flow-weighted arterial spin labeling) MRI. Patients additionally underwent catheter and/or CT angiography. Variations in cross-territorial filling were grouped according to diameters of circle of Willis vessels in controls. In patients, Cohen's k-statistics were computed to quantify agreement in perfusion patterns between vessel-encoded pseudocontinuous arterial spin labeling and angiography. Cross-territorial filling patterns were consistent with circle of Willis anatomy. The intraobserver Cohen's k-statistics for cerebral blood flow territory and digital subtraction angiography perfusion agreement were 0.730 (95% CI = 0.593-0.867; reader one) and 0.708 (95% CI = 0.561-0.855; reader two). These results support the feasibility of a semiautomated pipeline for evaluating major neurovascular cerebral blood flow territories in patients with intracranial atherosclerotic disease.

  16. Measurement of cerebral blood flow using phase contrast magnetic resonance imaging and duplex ultrasonography.

    Science.gov (United States)

    Khan, Muhammad Ayaz; Liu, Jie; Tarumi, Takashi; Lawley, Justin Stevan; Liu, Peiying; Zhu, David C; Lu, Hanzhang; Zhang, Rong

    2017-02-01

    Phase contrast magnetic resonance imaging (PC-MRI) and color-coded duplex ultrasonography (CDUS) are commonly used for measuring cerebral blood flow in the internal carotid (ICA) and vertebral arteries. However, agreement between the two methods has been controversial. Recent development of high spatial and temporal resolution blood vessel wall edge-detection and wall-tracking methods with CDUS increased the accuracy and reliability of blood vessel diameter, hence cerebral blood flow measurement. The aim of this study was to compare the improved CDUS method with 3 T PC-MRI for cerebral blood flow measurements. We found that cerebral blood flow velocity measured in the ICA was lower using PC-MRI than CDUS (left ICA: PC-MRI, 18.0 ± 4.2 vs. CDUS, 25.6 ± 8.6 cm/s; right ICA: PC-MRI, 18.5 ± 4.8 vs. CDUS, 26.6 ± 6.7 cm/s, both p blood flow velocity measured in the left vertebral artery with PC-MRI was also lower than CDUS, but no differences in vertebral artery diameter were observed between the methods. Dynamic changes and/or intrinsic physiological fluctuations may have caused these differences in vessel diameter and velocity measurements between the methods. However, estimation of volumetric cerebral blood flow was similar and correlated between the methods despite the presence of large individual differences. These findings support the use of CDUS for cerebral blood flow measurements in the ICA and vertebral artery.

  17. Impaired fasting blood glucose is associated to cognitive impairment and cerebral atrophy in middle-aged non-human primates

    Science.gov (United States)

    Djelti, Fathia; Dhenain, Marc; Terrien, Jérémy; Picq, Jean-Luc; Hardy, Isabelle; Champeval, Delphine; Perret, Martine; Schenker, Esther; Epelbaum, Jacques; Aujard, Fabienne

    2017-01-01

    Age-associated cognitive impairment is a major health and social issue because of increasing aged population. Cognitive decline is not homogeneous in humans and the determinants leading to differences between subjects are not fully understood. In middle-aged healthy humans, fasting blood glucose levels in the upper normal range are associated with memory impairment and cerebral atrophy. Due to a close evolutional similarity to Man, non-human primates may be useful to investigate the relationships between glucose homeostasis, cognitive deficits and structural brain alterations. In the grey mouse lemur, Microcebus murinus, spatial memory deficits have been associated with age and cerebral atrophy but the origin of these alterations have not been clearly identified. Herein, we showed that, on 28 female grey mouse lemurs (age range 2.4-6.1 years-old), age correlated with impaired fasting blood glucose (rs=0.37) but not with impaired glucose tolerance or insulin resistance. In middle-aged animals (4.1-6.1 years-old), fasting blood glucose was inversely and closely linked with spatial memory performance (rs=0.56) and hippocampus (rs=−0.62) or septum (rs=−0.55) volumes. These findings corroborate observations in humans and further support the grey mouse lemur as a natural model to unravel mechanisms which link impaired glucose homeostasis, brain atrophy and cognitive processes. PMID:28039490

  18. 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 L

    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...... ammonia concentration and cerebral metabolic rate of blood ammonia (CMRA). We addressed these questions in a paired study design by investigating patients with cirrhosis during and after recovery from an acute episode of HE type C. CMRO(2), CBF, and CMRA were measured by dynamic positron emission...

  19. Cerebral blood flow and oxygenation in infants after birth asphyxia. Clinically useful information?

    DEFF Research Database (Denmark)

    Greisen, Gorm

    2014-01-01

    The term 'luxury perfusion' was coined nearly 50 years ago after observation of bright-red blood in the cerebral veins of adults with various brain pathologies. The bright-red blood represents decreased oxygen extraction and hence the perfusion is 'luxurious' compared to oxygen needs. Gradual loss...

  20. Effect of head rotation on cerebral blood velocity in the prone position

    DEFF Research Database (Denmark)

    Højlund, Jakob; Sandmand, Marie; Sonne, Morten;

    2012-01-01

    for cerebral blood flow. We tested in healthy subjects the hypothesis that rotating the head in the prone position reduces cerebral blood flow. Methods. Mean arterial blood pressure (MAP), stroke volume (SV), and CO were determined, together with the middle cerebral artery mean blood velocity (MCA V......(mean)) and jugular vein diameters bilaterally in 22 healthy subjects in the prone position with the head centered, respectively, rotated sideways, with and without positive pressure breathing (10 cmH(2)O). Results. The prone position reduced SV (by 5.4 ± 1.5%; P ...(mean) was maintained. The head-rotated prone position with positive pressure breathing augmented MAP further (87 ± 2 mmHg) but not CO, narrowed both jugular vein diameters, and reduced MCA V(mean) (by 8.6 ± 3.2 %). Conclusion. During positive pressure breathing the prone position with sideways rotated head reduces MCA...

  1. 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.

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

    DEFF Research Database (Denmark)

    Seifert, Thomas; Secher, Niels H

    2011-01-01

    , but not by beta1-adrenergic blockade. Furthermore, endurance training appears to lower the cerebral non-oxidative carbohydrate uptake and preserve cerebral oxygenation during submaximal exercise. This is possibly related to an attenuated catecholamine response. Finally, exercise promotes brain health as evidenced......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...... as evidenced by pharmacological manipulation of adrenergic and cholinergic receptors. Cholinergic blockade by glycopyrrolate blocks the exercise-induced increase in the transcranial Doppler determined mean flow velocity (MCA Vmean). Conversely, alpha-adrenergic activation increases that expression of cerebral...

  3. Cerebral Blood Flow, Heart Rate, and Blood Pressure Patterns during the Tilt Test in Common Orthostatic Syndromes

    Directory of Open Access Journals (Sweden)

    Peter Novak

    2016-01-01

    Full Text Available Objective. The head-up tilt test is widely used for evaluation of orthostatic intolerance. Although orthostatic symptoms usually reflect cerebral hypoperfusion, the cerebral blood flow velocity (CBFv profile in orthostatic syndromes is not well described. This study evaluated CBFv and cardiovascular patterns associated with the tilt test in common orthostatic syndromes. Methods. This retrospective study analyzed the tilt test of patients with history of orthostatic intolerance. The following signals were recorded: ECG, blood pressure, CBFv using transcranial Doppler, respiratory signals, and end tidal CO2. Results. Data from 744 patients were analyzed. Characteristic pattern associated with a particular orthostatic syndrome can be grouped into abnormalities predominantly affecting blood pressure (orthostatic hypotension, orthostatic hypertension syndrome, vasomotor oscillations, and neurally mediated syncope—cardioinhibitory, vasodepressor, and mixed, cerebral blood flow (orthostatic hypoperfusion syndrome, primary cerebral autoregulatory failure, and heart rate (tachycardia syndromes: postural tachycardia syndrome, paroxysmal sinus tachycardia, and inappropriate sinus tachycardia. Psychogenic pseudosyncope is associated with stable CBFv. Conclusions. The tilt test is useful add-on in diagnosis of several orthostatic syndromes. However diagnostic criteria for several syndromes had to be modified to allow unambiguous pattern classification. CBFv monitoring in addition to blood pressure and heart rate may increase diagnostic yield of the tilt test.

  4. Cerebral Blood Flow, Heart Rate, and Blood Pressure Patterns during the Tilt Test in Common Orthostatic Syndromes

    Science.gov (United States)

    2016-01-01

    Objective. The head-up tilt test is widely used for evaluation of orthostatic intolerance. Although orthostatic symptoms usually reflect cerebral hypoperfusion, the cerebral blood flow velocity (CBFv) profile in orthostatic syndromes is not well described. This study evaluated CBFv and cardiovascular patterns associated with the tilt test in common orthostatic syndromes. Methods. This retrospective study analyzed the tilt test of patients with history of orthostatic intolerance. The following signals were recorded: ECG, blood pressure, CBFv using transcranial Doppler, respiratory signals, and end tidal CO2. Results. Data from 744 patients were analyzed. Characteristic pattern associated with a particular orthostatic syndrome can be grouped into abnormalities predominantly affecting blood pressure (orthostatic hypotension, orthostatic hypertension syndrome, vasomotor oscillations, and neurally mediated syncope—cardioinhibitory, vasodepressor, and mixed), cerebral blood flow (orthostatic hypoperfusion syndrome, primary cerebral autoregulatory failure), and heart rate (tachycardia syndromes: postural tachycardia syndrome, paroxysmal sinus tachycardia, and inappropriate sinus tachycardia). Psychogenic pseudosyncope is associated with stable CBFv. Conclusions. The tilt test is useful add-on in diagnosis of several orthostatic syndromes. However diagnostic criteria for several syndromes had to be modified to allow unambiguous pattern classification. CBFv monitoring in addition to blood pressure and heart rate may increase diagnostic yield of the tilt test. PMID:27525257

  5. Laser speckle contrast imaging to measure changes in cerebral blood flow.

    Science.gov (United States)

    Winship, Ian R

    2014-01-01

    Laser speckle contrast imaging (LSCI) is a powerful tool capable of acquiring detailed maps of blood flow in arteries and veins on the cortical surface. Based on the blurring of laser speckle patterns by the motion of blood cells, LSCI can be combined with a variety of optical imaging preparations to acquire high-spatiotemporal resolution images of blood flow, and track changes in blood flow over time, using relatively simple instrumentation. Here, we describe methods for LSCI of cerebral blood flow via a thin skull imaging preparation in mice or rats. This preparation allows precise semiquantitative mapping of changes in blood flow over time using straightforward surgical protocols and equipment.

  6. Time-dependent changes in cerebral blood flow after acetazolamide loading into patients with hemodynamic cerebral ischemia. Relationship to cerebral oxygen metabolism

    Energy Technology Data Exchange (ETDEWEB)

    Kobayashi, Masakazu [Iwate Medical Univ., Morioka (Japan). School of Medicine

    2001-10-01

    The aim of this study was to clarify the relationship between time-dependent changes in cerebral blood flow (CBF) after acetazolamide loading and cerebral oxygen metabolism (CMRO{sub 2}). The subjects consisted of 30 patients with severe stenosis or occlusion of either internal carotid, middle cerebral, or vertebro-basilar artery. Regional CBF was measured at the resting state and 6, 16 and 30 minutes after intravenous administration of 1 gram of acetazolamide using the positron emission tomography in combination with the [{sup 15}O] H{sub 2}O bolus-injection method. Prior to CBF study, regional cerebral oxygen extraction fraction (OEF) was measured using the [{sup 15}O] O{sub 2} inhalation method. Regional CMRO{sub 2} was calculated based on CBF and OEF. According to the time-dependent changes in CBF responses to acetazolamide loading, the CBF responses are classified into good response type, paradoxical response type, and poor response type. Good response type (CBF increase rate more than 20% 6 minutes after acetazolamide loading), paradoxical response type (decrease of CBF 6 minutes after acetazolamide loading) and poor response type (CBF increase rate less than 20% 6 minutes after acetazolamide loading) were identified in 39, 11 and 10 areas, respectively. Brain areas with good response type showed normal OEF and normal CMRO{sub 2}. Brain areas with paradoxical response type showed increased OEF and normal CMRO{sub 2}. Brain areas with poor response type showed normal OEF and decreased CMRO{sub 2}. In view of these findings, the writer concludes that sequential measurement of cerebral blood flow (CBF) after acetazolamide loading enables one to know the regional cerebral oxygen metabolic state in patients with hemodynamic ischemia, and CBF should be measured at an early stage after the administration of acetazolamide to accurately detect misery perfusion. (author)

  7. 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.

  8. Dependency of cerebral blood flow upon mean arterial pressure in patients with acute bacterial meningitis

    DEFF Research Database (Denmark)

    Møller, Kirsten; Larsen, Fin Stolze; Qvist, Jesper;

    2000-01-01

    OBJECTIVE: Patients with acute bacterial meningitis are often treated with sympathomimetics to maintain an adequate mean arterial pressure (MAP). We studied the influence of such therapy on cerebral blood flow (CBF). DESIGN: Prospective physiologic trial. SETTING: The Department of Infectious...... Diseases, Copenhagen University Hospital, Denmark. PATIENTS: Sixteen adult patients with acute bacterial meningitis. INTERVENTION: Infusion of norepinephrine to increase MAP. MEASUREMENTS: During a rise in MAP induced by norepinephrine infusion, we measured relative changes in CBF by transcranial Doppler...... bacterial meningitis, CBF autoregulation is impaired. With recovery from meningitis, the cerebral vasculature regains the ability to maintain cerebral perfusion at a constant level despite variations in MAP....

  9. Hyperventilation-induced reduction in cerebral blood flow: Assessment by positron emission tomography

    Energy Technology Data Exchange (ETDEWEB)

    Bednarczyk, E.M.; Rutherford, W.F.; Leisure, G.P.; Munger, M.A.; Panacek, E.A.; Miraldi, F.D.; Green, J.A. (Case Western Reserve Univ. School of Medicine, Cleveland, OH (USA))

    1990-05-01

    The use of positron emission tomography (PET) has been well documented as a relatively noninvasive method of measuring cerebral blood flow (CBF), both globally and regionally. The utility of readily detecting alterations in CBF is apparent, particularly when applied to the evaluation of therapeutic interventions thought to influence CBF. We report the effects of hypocapnia, an experimental condition of known cerebral vasoconstriction, in ten normal volunteers. Subjects had brain blood flow evaluated utilizing H215O as the positron emitter before and after approximately five minutes of hyperventilation. Baseline CBF was measured as a mean +/- SD of 61.2 +/- 16.3 mL/min/100 g of tissue. Mean baseline arterial blood gas values were PaO2 107.4 +/- 14 mm Hg, PaCO2 37.7 +/- 0.89 mm Hg, and pH 7.39 (calculated from mean (H+)). Post hyperventilation, global CBF was measured as 31.1 +/- 10.8 mL/min/100 g. Mean arterial blood gas values were PaO2 141.7 +/- 21 mm Hg, PaCO2 19.7 +/- 5 mm Hg, and pH 7.63 (calculated from mean (H+)). CBF decreased by a mean of 49.5 +/- 11 percent. Data analysis using the Student's t-test showed a significant change over baseline in PaCO2 (p less than 0.001) and CBF (p less than 0.001), in the hyperventilated state. Correlations were noted between the decrease in CBF and change in PaCO2 (r = 0.81) as well as between hyperventilation PaCO2 and the change in CBF (r = 0.97). We conclude that, as measured by PET, CBF decreases significantly during a state of artificial hyperventilation to a degree consistent with results seen using other methods. PET appears to be a valuable tool in the assessment of interventions that could influence CBF.

  10. 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

    Specific types of brain activity as sensory perception auditory, somato-sensory or visual -or the performance of movements are accompanied by increases of blood flow and oxygen consumption in the cortical areas involved with performing the respective tasks. The activation patterns observed...... 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...

  11. Nitric oxide does not act as a mediator coupling cerebral blood flow to neural activity following somatosensory stimuli in rats

    DEFF Research Database (Denmark)

    Wang, Qian; Kjaer, T; Jørgensen, M B;

    1993-01-01

    The possible role of nitric oxide (NO) on vibrissa-stimulated increase of regional cerebral cerebral blood flow (rCBF) and cerebral metabolic rate of glucose (rCMRglu) was investigated in conscious Wistar rats by using an inhibitor of NO synthase, NG-nitro-L-arginine (NOLAG) at a concentration of...

  12. Dual role of cerebral blood flow in regional brain temperature control in the healthy newborn infant.

    Science.gov (United States)

    Iwata, Sachiko; Tachtsidis, Ilias; Takashima, Sachio; Matsuishi, Toyojiro; Robertson, Nicola J; Iwata, Osuke

    2014-10-01

    Small shifts in brain temperature after hypoxia-ischaemia affect cell viability. The main determinants of brain temperature are cerebral metabolism, which contributes to local heat production, and brain perfusion, which removes heat. However, few studies have addressed the effect of cerebral metabolism and perfusion on regional brain temperature in human neonates because of the lack of non-invasive cot-side monitors. This study aimed (i) to determine non-invasive monitoring tools of cerebral metabolism and perfusion by combining near-infrared spectroscopy and echocardiography, and (ii) to investigate the dependence of brain temperature on cerebral metabolism and perfusion in unsedated newborn infants. Thirty-two healthy newborn infants were recruited. They were studied with cerebral near-infrared spectroscopy, echocardiography, and a zero-heat flux tissue thermometer. A surrogate of cerebral blood flow (CBF) was measured using superior vena cava flow adjusted for cerebral volume (rSVC flow). The tissue oxygenation index, fractional oxygen extraction (FOE), and the cerebral metabolic rate of oxygen relative to rSVC flow (CMRO₂ index) were also estimated. A greater rSVC flow was positively associated with higher brain temperatures, particularly for superficial structures. The CMRO₂ index and rSVC flow were positively coupled. However, brain temperature was independent of FOE and the CMRO₂ index. A cooler ambient temperature was associated with a greater temperature gradient between the scalp surface and the body core. Cerebral oxygen metabolism and perfusion were monitored in newborn infants without using tracers. In these healthy newborn infants, cerebral perfusion and ambient temperature were significant independent variables of brain temperature. CBF has primarily been associated with heat removal from the brain. However, our results suggest that CBF is likely to deliver heat specifically to the superficial brain. Further studies are required to assess the

  13. Increase of cerebral blood flow at high altitude

    DEFF Research Database (Denmark)

    Lassen, N A

    1992-01-01

    CBF increases with acute hypoxia despite the opposing vasoconstrictor effects of the drop in pCO2 caused by hyperventilation. Maintaining normocapnia by adding CO2 the hypoxic CBF responsiveness about doubles. As we have shown recently by this test, the hypoxic CBF response is not blunted but rat...... vasodilatation cannot explain the usual (mild) form of AMS. But it may well be involved in the pathogenesis of the rare but severe cerebral form of AMS, as prolonged increased capillary pressure in vasodilated areas could lead to vasogenic cerebral edema....

  14. Intensive blood pressure lowering increases cerebral blood flow in older subjects with hypertension.

    Science.gov (United States)

    Tryambake, Dinesh; He, Jiabao; Firbank, Michael J; O'Brien, John T; Blamire, Andrew M; Ford, Gary A

    2013-06-01

    Hypertension is associated with reduced cerebral blood flow (CBF). Intensive (blood pressure (BP) lowering in older people might give greater reduction in cardiovascular risk, but there are concerns that this might produce hypoperfusion which may precipitate falls and possibly stroke. We determined the effect of intensive compared with usual BP lowering on CBF in hypertensive older subjects. Individuals aged >70 years with a history of systolic hypertension on 1 or no BP lowering drugs were recruited from primary care (n=37; age, 75±4 years; systolic BP, >150 mm Hg) and randomized to receive intensive (target BP, treatment. Baseline BP (ambulatory or in clinic) and baseline gray matter CBF were not significantly different between the groups. After treatment, BP was reduced significantly in both groups but fell more in the intensive group (26/17 versus 15/5 mm Hg; Phypertension increases CBF, compared with BP lowering to usual target. These findings suggest hypertension in older people shifts the autoregulatory CBF curve rightward and downward and is reversible with BP lowering.

  15. 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.

  16. EMP-induced alterations of tight junction protein expression and disruption of the blood-brain barrier.

    Science.gov (United States)

    Ding, Gui-Rong; Qiu, Lian-Bo; Wang, Xiao-Wu; Li, Kang-Chu; Zhou, Yong-Chun; Zhou, Yan; Zhang, Jie; Zhou, Jia-Xing; Li, Yu-Rong; Guo, Guo-Zhen

    2010-07-15

    The blood-brain barrier (BBB) is critical to maintain cerebral homeostasis. In this study, we examined the effects of exposure to electromagnetic pulse (EMP) on the functional integrity of BBB and, on the localization and expression of tight junction (TJ) proteins (occludin and ZO-1) in rats. Animals were sham or whole-body exposed to EMP at 200 kV/m for 400 pulses. The permeability of BBB in rat cerebral cortex was examined by using Evans Blue (EB) and lanthanum nitrate as vascular tracers. The localization and expression of TJ proteins were assessed by western blot and immunofluorescence analysis, respectively. The data indicated that EMP exposure caused: (i) increased permeability of BBB, and (ii) altered localization as well as decreased levels of TJ protein ZO-1. These results suggested that the alteration of ZO-1 may play an important role in the disruption of tight junctions, which may lead to dysfunction of BBB after EMP exposure.

  17. Alterations in gene expression and steroidogenesis in the testes of transient cerebral ischemia in male rats

    Institute of Scientific and Technical Information of China (English)

    ZHAO Bing-hai; GUO Yan-qin; LI Hong-zhi; LIU Jie-ting; WU Dan; YUAN Xiao-huan; LI Rong-wen; GUAN Li-xin

    2012-01-01

    Background Serum testosterone levels have been found lower in acute ischemic stroke male patients.However,the exact mechanism remains unclear.In the present study,we measured serum testosterone levels,steroidogenesisrelated genes and Leydig cells number in experimental transient cerebral ischemia male rats to elucidate the mechanism.Methods The middle cerebral arteries of adult male Sprague-Dawley rats were sutured for 120 minutes and then sacrificed after 24 hours.Blood was collected for measurement of serum testosterone,follicular stimulating hormone and estradiol levels,and testes were collected for measurement of steroidogenesis-retated gene mRNA levels and number of Leydig cells.Results Serum testosterone levels in rats after cerebral ischemia were significantly lower (0.53±0.16) ng/ml,n=7,mean±SE) compared with control ((2.33±0.60) ng/ml,n=7),while serum estradiol and follicular stimulating hormone levels did not change.The mRNA levels for luteinizing hormone receptor (Lhcgr),scavenger receptor class B member 1 (Scarb1),steroidogenic acute regulatory protein (StAR),cholesterol side chain cleavage enzyme (Cyp11a1),3β-hydroxysteroid dehydrogenase 1 (HSD311),17α-hydroxylese/20-lyase (Cyp17a1) and membrane receptor c-kit (kit) were significantly downregulated by cerebral ischemia,while luteinizing hormone,Kit ligand (KitL),17β-hydrosteroid dehydrogenase 3 (HSD17β3) and 5α-reductase (Srd5a1) were not affected.We also observed that,relative to control,the Leydig cell number did not change.Conclusions These results indicate that transient cerebral ischemia in the brain results in lower expression levels of steroidogenesis-related genes and thus lower serum testosterone level.Transient cerebral ischemia did not lower the number of Leydig cells.

  18. Intraoperative blood pressure and cerebral perfusion: strategies to clarify hemodynamic goals.

    Science.gov (United States)

    Williams, Monica; Lee, Jennifer K

    2014-07-01

    Blood pressure can vary considerably during anesthesia. If blood pressure falls outside the limits of cerebrovascular autoregulation, children can become at risk of cerebral ischemic or hyperemic injury. However, the blood pressure limits of autoregulation are unclear in infants and children, and these limits can shift after brain injury. This article will review autoregulation, considerations for the hemodynamic management of children with brain injuries, and research on autoregulation monitoring techniques.

  19. Intraoperative blood pressure and cerebral perfusion: strategies to clarify hemodynamic goals

    OpenAIRE

    Williams, Monica; Lee, Jennifer K.

    2014-01-01

    Blood pressure can vary considerably during anesthesia. If blood pressure falls outside the limits of cerebrovascular autoregulation, children can become at risk of cerebral ischemic or hyperemic injury. However, the blood pressure limits of autoregulation are unclear in infants and children, and these limits can shift after brain injury. This article will review autoregulation, considerations for the hemodynamic management of children with brain injuries, and research on autoregulation monit...

  20. ERK1/2 inhibition attenuates cerebral blood flow reduction and abolishes ET(B) and 5-HT(1B) receptor upregulation after subarachnoid hemorrhage in rat

    DEFF Research Database (Denmark)

    Beg, Saema A S; Hansen-Schwartz, Jacob A; Vikman, Petter J

    2006-01-01

    -regulated kinase (ERK1/2). In the present study, we hypothesized that inhibition of ERK1/2 alters the ET(B) and 5-HT(1B) receptor upregulation and at the same time prevents the sustained cerebral blood flow (CBF) reduction associated with SAH. The ERK1/2 inhibitor SB386023-b was injected intracisternally...... in conjunction with and after the induced SAH in rats. At 2 days after the SAH, cerebral arteries were harvested for quantitative real-time polymerase chain reaction, immunohistochemistry and analysis of contractile responses to endothelin-1 (ET-1; ET(A) and ET(B) receptor agonist) and 5-carboxamidotryptamine (5...

  1. Pressure passive cerebral blood flow and breakdown of the blood-brain barrier in experimental fetal asphyxia

    DEFF Research Database (Denmark)

    Lou, H C; Lassen, N A; Tweed, W A

    1979-01-01

    Cerebral blood flow (CBF) was studied in non-exteriorized near-term sheep fetuses using the radioactive microsphere technique. By partially occluding the umbilical vessels for a period of 1--1 1/2 hours a progressive and severe asphyxia with a final arterial pH of 6.90 was achieved. Varying...

  2. Single photon emission CT perfusion imaging of cerebral blood flow of early syphilis patients

    Institute of Scientific and Technical Information of China (English)

    施辛; 吴锦昌; 刘增礼; 唐军; 苏玉华

    2003-01-01

    Objective To injvestigate the cerebral blood flow of patients with early syphilis. Methods 99Tcm-ECD as brain perfusion imaging agent was used in single photon emission computed tomography (SPECT) for 32 patients with early syphilis and 15 controls. Visual analyses were made on every BSPECT image. Results The 32 patients with early syphilis had general, patchy hypoperfusion of cerebral blood flow. Fourteen of the 32 patients had 48 episodes of marked patchy hypoperfusion of rCBF. The responsible areas of hypoperfusion in a patchy distribution involved the left frontal lobe (6 episodes), right frontal lobe (3), left parietal lobe (7), right parietal lobe (6), left temporal lobe (11), right temporal lobe (5), left occipital lobe (3), left basal ganglia (3), cerebellum (1), and nerve nuceus (1). No abnormality was found in the control group.Conclusions Cerebral blood flow abnormalities exist in patients with early syphilis. General patchy hypoperfusion on SPECT imaging is common.

  3. The relationship between cerebral blood flow and volume in humans

    DEFF Research Database (Denmark)

    Rostrup, Egill; Knudsen, Gitte M; Law, Ian;

    2005-01-01

    The purpose of this study was to establish the relationship between regional CBF and CBV at normal, resting cerebral metabolic rates. Eleven healthy volunteers were investigated with PET during baseline conditions, and during hyper- and hypocapnia. Values for rCBF and rCBV were obtained using (15...

  4. Cerebral blood flow autoregulation in patients with acute bacterial meningitis

    DEFF Research Database (Denmark)

    Møller, Kirsten

    2001-01-01

    Ph.d. afhandlingen omhandler sammenhængen mellem hjernens blodtilførsel (CBF) og middelarterietrykket (MAP) hos patienter med akut bakteriel meningitis. Hos raske er CBF uafhængig af MAP, hvilket kaldes CBF autoregulation. Svækket autoregulation antages at øge risikoen for cerebral hypoperfusion ...

  5. Case with stenosis of internal carotid artery detected as a region of decreased blood flow by Tc-99m HMPAO cerebral blood flow scintigraphy

    Energy Technology Data Exchange (ETDEWEB)

    Hayashida, K.; Nishimura, T.; Uehara, T.; Imakita, S.; Yokota, I.; Ogura, H.; Oka, H.; Hayashi, M.; Kikuchi, H.

    1987-04-01

    Tc-99m hexamethylpropyleneamine oxime (= HMPAO) is expected to be an excellent agent as blood flow tracer of brain because it passes through blood brain barrier and is retained in brain parenchyma for several hours. Tc-99m HMPAO scintigraphy was applied to a patient complaining of transient ischemic attack without neurological findings. Left hemispheric hypoperfusion was detected by Tc-99m HMPAO cerebral blood flow scintigraphy. Although it was normal in CT and MRI, it was proved to be a 99 % stenosis of left internal carotid artery by digital subtraction angiography. Tc-99m HMPAO cerebral blood flow scintigraphy is useful for detecting abnormality of cerebral blood flow.

  6. Temporal changes in cardiac function and cerebral blood flow during sequential postmenopausal hormone replacement

    DEFF Research Database (Denmark)

    Sørensen, M B; Fritz-Hansen, T; Jensen, H H;

    2001-01-01

    OBJECTIVE: The purpose was to assess the temporal changes in cardiac function and cerebral blood flow during postmenopausal administration of estrogen with and without progestogen. STUDY DESIGN: Sixteen postmenopausal volunteers were assessed during estradiol plus sequential norethindrone acetate...... and placebo in two 12-week periods. Temporal changes were measured by magnetic resonance flow mapping 8 times. RESULTS: Systemic vascular resistance was reduced during estradiol (-6.9%; P ... (maximum increase, 5.2%; P Cerebral blood flow was reduced after 9 weeks of hormone replacement therapy (-37 mL/min; P =.01) but increased to baseline after...

  7. [Influence of 2-ethyl-6-methyl-3-hydroxypyridine hemisuccinate on cerebral blood perfusion in rats under experimental pathology conditions].

    Science.gov (United States)

    Gan'shina, T S; Gorbunov, A A; Gnezdilova, A V; Kurdiumov, I N; Avdiunina, N I; Piatin, B M; Mirzoian, R S

    2011-01-01

    Experiments on rats showed that 2-ethyl-6-methyl-3-hydroxypyridine hemisuccinate increases cerebral blood flow in the system of carotid arteries both in intact animals and under conditions of global transient ischemia. In combination with tropoxin, 2-ethyl-6-methyl-3-hydroxypyridine hemisuccinate enhances the blood flow in the inner carotid artery of intact rats and the local blood flow under conditions of global transient ischemia. A combination of 2-ethyl-6-methyl-3-hydroxypyridine hemisuccinate and tropoxin increases baseline cerebral blood flow and decreases the constrictor reaction of cerebral blood vessels to 5HT(2B/2C) receptor agonist meta-chlorophenylpiperazine.

  8. BH4 treatment in BH4-responsive PKU patients : Preliminary data on blood prolactin concentrations suggest increased cerebral dopamine concentrations

    NARCIS (Netherlands)

    van Vliet, Danique; Anjema, Karen; Jahja, Rianne; de Groot, Martijn J; Liemburg, Geertje B; Heiner-Fokkema, Rebecca; van der Zee, Eddy A; Derks, Terry G J; Kema, Ido P; van Spronsen, Francjan J

    2015-01-01

    In phenylketonuria (PKU), cerebral neurotransmitter deficiencies have been suggested to contribute to brain dysfunction. Present treatment aims to reduce blood phenylalanine concentrations by a phenylalanine-restricted diet, while in some patients blood phenylalanine concentrations also respond to c

  9. A study on measurement of the regional cerebral blood flow using autoradiographic method in moyamoya disease

    Energy Technology Data Exchange (ETDEWEB)

    Sasaki, Tomohiro; Kiya, Katsuzo; Yuki, Kiyoshi; Kawamoto, Hitoshi; Mizoue, Tatsuya; Kiura, Yoshihiro; Uozumi, Tohru [Hiroshima Prefectural Hospital (Japan); Ikawa, Fusao

    1997-11-01

    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{sub 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)

  10. THE PECULIARITIES OF CEREBRAL BLOOD FLOW IN PATIENTS WITH CHRONIC HEPATITIS

    Directory of Open Access Journals (Sweden)

    V. E. Kulikov

    2015-12-01

    Full Text Available Aim. To study extra- and intracranial hemodynamics in patients with chronic hepatitis of different activity.Material and methods. Ultrasonography of the cerebral blood flow was performed in 576 patients with chronic hepatitis.Results. Contralateral hemyspherical asymmetry (more than 30 % of the maximum linear rate of blood flow in the medium cerebral arteries and decrease in resistance index (0,55±0,09 and pulsativity index (1,34±0,66 were found in 33,8 % of patients with chronic hepatitis of high activity. Collateral blood flow reduction through connecting arteries of Willis circle was revealed in 13,8 % of patients. The tortuosity of arteries and thickening of intima-media complex was found in patients with chronic hepatitis (mainly of high activity. It leads to decline of cerebral blood flow.Conclusion. Symptomatic and asymptomatic cerebral blood flow disturbances were observed in 23,2% and 38,8% of patients with active chronic hepatitis respectively.

  11. THE PECULIARITIES OF CEREBRAL BLOOD FLOW IN PATIENTS WITH CHRONIC HEPATITIS

    Directory of Open Access Journals (Sweden)

    V. E. Kulikov

    2007-01-01

    Full Text Available Aim. To study extra- and intracranial hemodynamics in patients with chronic hepatitis of different activity.Material and methods. Ultrasonography of the cerebral blood flow was performed in 576 patients with chronic hepatitis.Results. Contralateral hemyspherical asymmetry (more than 30 % of the maximum linear rate of blood flow in the medium cerebral arteries and decrease in resistance index (0,55±0,09 and pulsativity index (1,34±0,66 were found in 33,8 % of patients with chronic hepatitis of high activity. Collateral blood flow reduction through connecting arteries of Willis circle was revealed in 13,8 % of patients. The tortuosity of arteries and thickening of intima-media complex was found in patients with chronic hepatitis (mainly of high activity. It leads to decline of cerebral blood flow.Conclusion. Symptomatic and asymptomatic cerebral blood flow disturbances were observed in 23,2% and 38,8% of patients with active chronic hepatitis respectively.

  12. Aquaporin 4 expression and ultrastructure of the blood-brain barrier following cerebral contusion injury

    Institute of Scientific and Technical Information of China (English)

    Xinjun Li; Yangyun Han; Hong Xu; Zhongshu Sun; Zengjun Zhou; Xiaodong Long; Yumin Yang; Linbo Zou

    2013-01-01

    This study aimed to investigate aquaporin 4 expression and the ultrastructure of the blood-brain barrier at 2–72 hours following cerebral contusion injury, and correlate these changes to the formation of brain edema. Results revealed that at 2 hours after cerebral contusion and laceration injury, aquaporin 4 expression significantly increased, brain water content and blood-brain barrier permeability increased, and the number of pinocytotic vesicles in cerebral microvascular endothelial cells increased. In addition, the mitochondrial accumulation was observed. As contusion and laceration injury became aggravated, aquaporin 4 expression continued to increase, brain water content and blood-brain barrier permeability gradually increased, brain capillary endothelial cells and astrocytes swelled, and capillary basement membrane injury gradually increased. The above changes were most apparent at 12 hours after injury, after which they gradually attenuated. Aquaporin 4 expression positively correlated with brain water content and the blood-brain barrier index. Our experimental findings indicate that increasing aquaporin 4 expression and blood-brain barrier permeability after cerebral contusion and laceration injury in humans is involved in the formation of brain edema.

  13. Cerebral hemodynamics after short- and long-term reduction in blood pressure in mild and moderate hypertension.

    NARCIS (Netherlands)

    Zhang, R.; Witkowski, S.; Fu, Q.; Claassen, J.A.H.R.; Levine, B.D.

    2007-01-01

    This study tested the hypothesis that acute reduction in blood pressure (BP) at the initial stage of antihypertensive therapy compromises brain perfusion and dynamic cerebral autoregulation in patients with hypertension. Cerebral blood flow velocity and BP were measured in patients with mild and mod

  14. Noninvasive cerebral blood oxygenation monitoring: clinical test of multiwavelength optoacoustic system

    Science.gov (United States)

    Petrov, Y. Y.; Prough, D. S.; Petrova, I.; Patrikeev, I. A.; Cicenaite, I.; Esenaliev, R. O.

    2007-02-01

    Continuous monitoring of cerebral blood oxygenation is critically important for treatment of patients with life-threatening conditions like severe brain injury or during cardiac surgery. We designed and built a novel multiwavelength optoacoustic system for noninvasive, continuous, and accurate monitoring of cerebral blood oxygenation. We use an Optical Parametric Oscillator as a light source. We successfully tested the system in vitro as well as in vivo in large animals (sheep) through thick tissues overlying blood vessels which drain venous blood out of the brain (e.g., superior sagittal sinus or jugular vein). Here we present the results of clinical tests of the system for continuous noninvasive cerebral blood oxygenation monitoring in the internal jugular vein of healthy volunteers. We applied our custom-built optoacoustic probe (which incorporated a wide-band acoustic transducer and an optical fiber) to the neck area overlying the internal jugular vein. We performed measurements with volunteers at 18 wavelengths in the near-infrared spectral range. Despite a thick layer of overlying connective tissue and low energy used in the experiments, we recorded signals with high signal-to-noise ratios for all volunteers. We found that the temporal (independent of signal amplitude) parameters of recorded profiles for different levels of blood oxygenation correlated well with the spectrum of effective attenuation coefficients of blood.

  15. 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.)

  16. Effect of pregnancy on autoregulation of cerebral blood flow in anterior versus posterior cerebrum.

    Science.gov (United States)

    Cipolla, Marilyn J; Bishop, Nicole; Chan, Siu-Lung

    2012-09-01

    Severe preeclampsia and eclampsia are associated with brain edema that forms preferentially in the posterior cerebral cortex possibly because of decreased sympathetic innervation of posterior cerebral arteries and less effective autoregulation during acute hypertension. In the present study, we examined the effect of pregnancy on the effectiveness of cerebral blood flow autoregulation using laser Doppler flowmetry and edema formation by wet:dry weight in acute hypertension induced by phenylephrine infusion in the anterior and posterior cerebrum from nonpregnant (n=8) and late-pregnant (n=6) Sprague-Dawley rats. In addition, we compared the effect of pregnancy on sympathetic innervation by tyrosine hydroxylase staining of posterior and middle cerebral arteries (n=5-6 per group) and endothelial and neuronal NO synthase expression using quantitative PCR (n=3 per group). In nonpregnant animals, there was no difference in autoregulation between the anterior and posterior cerebrum. However, in late-pregnant animals, the threshold of cerebral blood flow autoregulation was shifted to lower pressures in the posterior cerebrum, which was associated with increased neuronal NO synthase expression in the posterior cerebral cortex versus anterior. Compared with the nonpregnant state, pregnancy increased the threshold of autoregulation in both brain regions that was related to decreased expression of endothelial NO synthase. Lastly, acute hypertension during pregnancy caused greater edema formation in both brain cortices that was not attributed to changes in sympathetic innervation. These findings suggest that, although pregnancy shifted the cerebral blood flow autoregulatory curve to higher pressures in both the anterior and posterior cortices, it did not protect from edema during acute hypertension.

  17. Evaluation of the Extension of the Cerebral Blood Flow and its Main Parameters

    CERN Document Server

    Gersten, A

    1999-01-01

    Among the major factors controlling the cerebral blood flow (CBF) - cerebral perfusion pressure, arterial partial pressure of oxygen (PaO2), cerebral metabolism, arterial partial pressure of carbon dioxide (PaCO2), and cardiac output, the effect of PaCO2 is peculiar in being independent of autoregulatory CBF mechanisms and it allows to explore the full range of the CBF. We have developed a simple physical model, and have derived a simple four parameter formula, relating the CBF to PaCO2. The parameters can be extracted in an easy way, directly from the experimental data. With this model five experimental data sets of human, rats, baboons and dogs were well fitted. The same type of parametrization was also used successfully for fitting experimental data of PaO2 of dogs. We have also looked on the dependence of the parameters on other factors and were able to evaluate their dependence on the mean arterial blood pressure.

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

    Energy Technology Data Exchange (ETDEWEB)

    Dahl, A.; Russell, D.; Nyberg-Hansen, R.; Rootwelt, K. (Rikshospitalet, Oslo (Norway))

    1990-04-01

    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.

  19. Voluntary respiratory control and cerebral blood flow velocity upon ice-water immersion

    DEFF Research Database (Denmark)

    Mantoni, Teit; Rasmussen, Jakob Højlund; Belhage, Bo;

    2008-01-01

    INTRODUCTION: In non-habituated subjects, cold-shock response to cold-water immersion causes rapid reduction in cerebral blood flow velocity (approximately 50%) due to hyperventilation, increasing risk of syncope, aspiration, and drowning. Adaptation to the response is possible, but requires...... several cold immersions. This study examines whether thorough instruction enables non-habituated persons to attenuate the ventilatory component of cold-shock response. METHODS: There were nine volunteers (four women) who were lowered into a 0 degrees C immersion tank for 60 s. Middle cerebral artery mean......: Even without prior cold-water experience, subjects were able to suppress reflex hyperventilation following ice-water immersion, maintaining the cerebral blood flow velocity at a level not associated with impaired consciousness. This study implies that those susceptible to accidental cold...

  20. Genetic KCa3.1-deficiency produces locomotor hyperactivity and alterations in cerebral monoamine levels.

    Directory of Open Access Journals (Sweden)

    Kate Lykke Lambertsen

    Full Text Available BACKGROUND: The calmodulin/calcium-activated K(+ channel KCa3.1 is expressed in red and white blood cells, epithelia and endothelia, and possibly central and peripheral neurons. However, our knowledge about its contribution to neurological functions and behavior is incomplete. Here, we investigated whether genetic deficiency or pharmacological activation of KCa3.1 change behavior and cerebral monoamine levels in mice. METHODOLOGY/PRINCIPAL FINDINGS: In the open field test, KCa3.1-deficiency increased horizontal activity, as KCa3.1(-/- mice travelled longer distances (≈145% of KCa3.1(+/+ and at higher speed (≈1.5-fold of KCa3.1(+/+. Working memory in the Y-maze was reduced by KCa3.1-deficiency. Motor coordination on the rotarod and neuromuscular functions were unchanged. In KCa3.1(-/- mice, HPLC analysis revealed that turn-over rates of serotonin were reduced in frontal cortex, striatum and brain stem, while noradrenalin turn-over rates were increased in the frontal cortex. Dopamine turn-over rates were unaltered. Plasma catecholamine and corticosterone levels were unaltered. Intraperitoneal injections of 10 mg/kg of the KCa3.1/KCa2-activator SKA-31 reduced rearing and turning behavior in KCa3.1(+/+ but not in KCa3.1(-/- mice, while 30 mg/kg SKA-31 caused strong sedation in 50% of the animals of either genotypes. KCa3.1(-/- mice were hyperactive (≈+60% in their home cage and SKA-31-administration reduced nocturnal physical activity in KCa3.1(+/+ but not in KCa3.1(-/- mice. CONCLUSIONS/SIGNIFICANCE: KCa3.1-deficiency causes locomotor hyperactivity and altered monoamine levels in selected brain regions, suggesting a so far unknown functional link of KCa3.1 channels to behavior and monoaminergic neurotransmission in mice. The tranquilizing effects of low-dose SKA-31 raise the possibility to use KCa3.1/KCa2 channels as novel pharmacological targets for the treatment of neuropsychiatric hyperactivity disorders.

  1. PHARMACOLOGICAL CORRECTION OF CEREBRAL BLOOD FLOW DISTURBANCES IN WOMEN WITH ARTERIAL HYPERTENSION IN POSTMENOPAUSE

    Directory of Open Access Journals (Sweden)

    V. V. Yakusevich

    2005-01-01

    Full Text Available Aim: to study cerebral blood flow and cholesterol metabolism in menopausal women with arterial hypertension (AH; to evaluate dynamics of cerebral blood flow parameters and plasma lipid concentrations in these patients during 6-month antihypertensive and hypolipidemic therapy.Material and methods: 24 women with AH of I and II grade were examined. They were in postmenopausal period of life during 7,1±0,5 years. At the beginning of the study all women were prescribed moexipril as monotherapy, daily dose 7,5 – 15 mg. Patients with initial dislipidemia were prescribed lipid reducing drug atorvastatin in 10mg daily dose additionally to the antihypertensive therapy. Therefore all the patients were divided into two groups: I – monoteraphy with moexipril (13 people, II – combined therapy with moexipril and atorvastatin (11 people. At the beginning of the study and after 6 months all the patients passed through ultrasonic Dopplerography of vessels of head and neck, rheoencephalography, their lipoproteidogrammes were studied.Results: During 6-month therapy all the patients showed proved decrease in systolic and diastolic blood pressure, also positive dynamics of neuropsychological status, improvement in cerebral blood flow according to the results of Dopplerography of vessels and rheoencephalography. Normalization of plasma lipid spectrum was noted. More significant positive changes in cerebral hemodynamic parameters and plasma lipid spectrum were observed in patients, who received combined therapy with antihypertensive and lipid reducing drugs.Conclusion: Deterioration of cerebral hemodynamics is typical for women with long-lasting AH. The most positive influence on cerebral perfusion was received due to combined therapy with moexipril and atorvastatin.

  2. Inconsistent detection of changes in cerebral blood volume by near infrared spectroscopy in standard clinical tests.

    Science.gov (United States)

    Canova, D; Roatta, S; Bosone, D; Micieli, G

    2011-06-01

    The attractive possibility of near infrared spectroscopy (NIRS) to noninvasively assess cerebral blood volume and oxygenation is challenged by the possible interference from extracranial tissues. However, to what extent this may affect cerebral NIRS monitoring during standard clinical tests is ignored. To address this issue, 29 healthy subjects underwent a randomized sequence of three maneuvers that differently affect intra- and extracranial circulation: Valsalva maneuver (VM), hyperventilation (HV), and head-up tilt (HUT). Putative intracranial ("i") and extracranial ("e") NIRS signals were collected from the forehead and from the cheek, respectively, and acquired together with cutaneous plethysmography at the forehead (PPG), cerebral blood velocity from the middle cerebral artery, and arterial blood pressure. Extracranial contribution to cerebral NIRS monitoring was investigated by comparing Beer-Lambert (BL) and spatially resolved spectroscopy (SRS) blood volume indicators [the total hemoglobin concentration (tHb) and the total hemoglobin index, (THI)] and by correlating their changes with changes in extracranial circulation. While THIe and tHbe generally provided concordant indications, tHbi and THIi exhibited opposite-sign changes in a high percentage of cases (VM: 46%; HV: 31%; HUT: 40%). Moreover, tHbi was correlated with THIi only during HV (P < 0.05), not during VM and HUT, while it correlated with PPG in all three maneuvers (P < 0.01). These results evidence that extracranial circulation may markedly affect BL parameters in a high percentage of cases, even during standard clinical tests. Surface plethysmography at the forehead is suggested as complementary monitoring helpful in the interpretation of cerebral NIRS parameters.

  3. Cognitive profiles and regional cerebral blood flow patterns in dementia of the Alzheimer type

    DEFF Research Database (Denmark)

    Waldemar, G; Bruhn, P; Schmidt, E

    1994-01-01

    Individual cognitive profiles and correlations between cognitive functions and regional cerebral blood flow (rCBF) were analyzed in 20 consecutive patients with a clinical diagnosis of probable Alzheimer's disease (AD). CBF was measured with high resolution single photon emission computed...

  4. The effect of S. pneumoniae bacteremia on cerebral blood flow autoregulation in rats

    DEFF Research Database (Denmark)

    Pedersen, Michael; Brandt, Christian T.; Knudsen, Gitte Moos

    2008-01-01

    In the present study, we studied the effect of bacteremia on cerebral blood flow (CBF) autoregulation in a rat model of pneumococcal bacteremia and meningitis. Anesthetized rats were divided into five groups (A to E) and inoculated with pneumococci intravenously and normal saline intracisternally...

  5. 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

    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....

  6. Cerebral blood flow and metabolism in adults with acute bacterial meningitis

    DEFF Research Database (Denmark)

    Møller, Kirsten

    2007-01-01

    The intense intrathecal inflammation observed in acute bacterial meningitis (ABM) is associated with pronounced changes in cerebral blood flow (CBF) and metabolism. In seven substudies, CBF and metabolism were measured in adults with ABM as well as healthy volunteers during various interventions...

  7. 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

    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...

  8. Regional cerebral blood flow distribution in newly diagnosed schizophrenia and schizophreniform disorder

    DEFF Research Database (Denmark)

    Rubin, P; Holm, S; Madsen, P L

    1994-01-01

    Regional cerebral blood flow distribution (rCBF) in 24 first admissions with schizophrenia or schizophreniform disorder and in 17 healthy volunteers was examined. Single photon emission computed tomography with a brain-retained tracer, technetium-99m-d,l-hexamethyl-propylene amine oxime, was used...

  9. Cerebral white matter blood flow and energy metabolism in multiple sclerosis

    NARCIS (Netherlands)

    Steen, Christel; D'haeseleer, Miguel; Hoogduin, Johannes M.; Fierens, Yves; Cambron, Melissa; Mostert, Jop P.; Heersema, Dorothea J.; Koch, Marcus W.; De Keyser, Jacques

    2013-01-01

    Background: Cerebral blood flow (CBF) is reduced in normal-appearing white matter (NAWM) of subjects with multiple sclerosis (MS), but the underlying mechanism is unknown. Objective: The objective of this article is to assess the relationship between reduced NAWM CBF and both axonal mitochondrial me

  10. The influence of transcutaneous electrical neurostimulation (TENS) on human cerebral blood flow velocities

    NARCIS (Netherlands)

    ter Laan, Mark; van Dijk, J. Marc C.; Elting, Jan-Willem J.; Fidler, Vaclav; Staal, Michiel J.

    2010-01-01

    It has been shown that transcutaneous electrical neurostimulation (TENS) reduces sympathetic tone. Spinal cord stimulation (SCS) has proven qualities to improve coronary, peripheral, and cerebral blood circulation. Therefore, we postulate that TENS and SCS affect the autonomic nervous system in anal

  11. Very low cerebral blood volume predicts parenchymal hematoma in acute ischemic stroke

    DEFF Research Database (Denmark)

    Hermitte, Laure; Cho, Tae-Hee; Ozenne, Brice;

    2013-01-01

    BACKGROUND AND PURPOSE: Parenchymal hematoma (PH) may worsen the outcome of patients with stroke. The aim of our study was to confirm the relationship between the volume of very low cerebral blood volume (CBV) and PH using a European multicenter database (I-KNOW). A secondary objective was to exp...

  12. Influence of caffeine and caffeine withdrawal on headache and cerebral blood flow velocities

    NARCIS (Netherlands)

    Couturier, EGM; Laman, DM; vanDuijn, MAJ; vanDuijn, H

    1997-01-01

    Caffeine consumption may cause headache, particularly migraine. Its withdrawal also produces headaches and may be related to weekend migraine attacks. Transcranial Doppler sonography (TCD) has shown changes in cerebral blood flow velocities (BFV) during and between attacks of migraine. In order to e

  13. Two methods for calculating regional cerebral blood flow from emission computed tomography of inert gas concentrations

    DEFF Research Database (Denmark)

    Kanno, I; Lassen, N A

    1979-01-01

    Two methods are described for calculation of regional cerebral blood flow from completed tomographic data of radioactive inert gas distribution in a slice of brain tissue. It is assumed that the tomographic picture gives the average inert gas concentration in each pixel over data collection periods...

  14. Regional cerebral blood flow changes associated with clitorally induced orgasm in healthy women

    NARCIS (Netherlands)

    Georgiadis, Janniko R.; Kortekaas, Rudie; Kuipers, Rutger; Nieuwenburg, Arie; Pruim, Jan; Reinders, A. A. T. Simone; Holstege, Gert

    2006-01-01

    There is a severe lack of knowledge regarding the brain regions involved in human sexual performance in general, and female orgasm in particular. We used [(15)O]-H(2)O positron emission tomography to measure regional cerebral blood flow (rCBF) in 12 healthy women during a nonsexual resting state, cl

  15. A pilot study of regional cerebral blood flow in children with school phobia

    Institute of Scientific and Technical Information of China (English)

    钱昀

    2006-01-01

    Objective To explore the characteristics of the regional cerebral blood flow (rCBF) in children with school phobia. Methods The single - photon emission commputed tomography were performed in 17 children with school phobia and 11 normal controls. The rCBF distribution in regions of interest (ROIs) was compared

  16. The effect of the benzodiazepine antagonist flumazenil on regional cerebral blood flow in human volunteers

    DEFF Research Database (Denmark)

    Wolf, J; Friberg, L; Jensen, J

    1990-01-01

    The influence of the benzodiazepine antagonist flumazenil on regional cerebral blood flow (rCBF) was investigated in ten healthy, alert volunteers. The design was a randomized, placebo-controlled, double-blind, cross-over study. rCBF was measured by 133-Xe inhalation and single photon emission...

  17. Effect of propofol post-treatment on blood-brain barrier integrity and cerebral edema after transient cerebral ischemia in rats.

    Science.gov (United States)

    Lee, Jae Hoon; Cui, Hui Song; Shin, Seo Kyung; Kim, Jeong Min; Kim, So Yeon; Lee, Jong Eun; Koo, Bon-Nyeo

    2013-11-01

    Although propofol has been reported to offer neuroprotection against cerebral ischemia injury, its impact on cerebral edema following ischemia is not clear. The objective of this investigation is to evaluate the effects of propofol post-treatment on blood-brain barrier (BBB) integrity and cerebral edema after transient cerebral ischemia and its mechanism of action, focusing on modulation of aquaporins (AQPs), matrix metalloproteinases (MMPs), and hypoxia inducible factor (HIF)-1α. Cerebral ischemia was induced in male Sprague-Dawley rats (n = 78) by occlusion of the right middle cerebral artery for 1 h. For post-treatment with propofol, 1 mg kg(-1) min(-1) of propofol was administered for 1 h from the start of reperfusion. Nineteen rats undergoing sham surgery were also included in the investigation. Edema and BBB integrity were assessed by quantification of cerebral water content and extravasation of Evans blue, respectively, following 24 h of reperfusion. In addition, the expression of AQP-1, AQP-4, MMP-2, and MMP-9 was determined 24 h after reperfusion and the expression of HIF-1α was determined 8 h after reperfusion. Propofol post-treatment significantly reduced cerebral edema (P cerebral edema after transient cerebral ischemia, in association with reduced expression of AQP-1, AQP-4, MMP-2, and MMP-9. The decreased expression of AQPs and MMPs after propofol post-treatment might result from suppression of HIF-1α expression.

  18. Cerebral blood flow autoregulation in hypertension and effects of antihypertensive drugs

    DEFF Research Database (Denmark)

    Barry, David; Lassen, N A

    1984-01-01

    If antihypertensive treatment, especially emergency blood pressure lowering, is always to be safe, more thought should be given to autoregulation of cerebral blood in the hypertensive patient. This topic is reviewed in the present article, in the hypertensive patient. This topic is reviewed...... in the present article, particular emphasis being placed on the resetting of the lower limit of autoregulation to higher pressure in hypertension and the effects of acute administration of anti-hypertensive drugs on CBF and CBF-autoregulation....

  19. 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

    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 restriction...... 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....... 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....... Contrary to the only previous study in humans, which reported an insignificant 3% reduction in CMRO2 during sleep, we found a deep-sleep-associated statistically highly significant 25% decrease in CMRO2, a magnitude of depression according with studies of glucose uptake and reaching levels otherwise...

  20. Nimodipine pretreatment improves cerebral blood flow and reduces brain edema in conscious rats subjected to focal cerebral ischemia.

    Science.gov (United States)

    Jacewicz, M; Brint, S; Tanabe, J; Wang, X J; Pulsinelli, W A

    1990-11-01

    The effect of nimodipine pretreatment on CBF and brain edema was studied in conscious rats subjected to 2.5 h of focal cortical ischemia. An infusion of nimodipine (2 micrograms/kg/min i.v.) or its vehicle, polyethylene glycol 400, was begun 2 h before the ischemic interval and was continued throughout the survival period. Under brief halothane anesthesia, the animals' right middle cerebral and common carotid arteries were permanently occluded, and 2.5 h later, they underwent a quantitative CBF study ([14C]iodoantipyrine autoradiography followed by Quantimet 970 image analysis). Nimodipine treatment improved blood flow to the middle cerebral artery territory without evidence of a "vascular steal" and reduced the volume of the ischemic core (cortex with CBF of less than 25 ml/100 g/min) and accompanying edema by approximately 50% when compared with controls (p = 0.006 and 0.0004, respectively). Mild hypotension induced by nimodipine did not aggravate the ischemic insult. The ischemic core volumes, however, were 50-75% smaller than the 24-h infarct volumes generated in a similar paradigm that demonstrated 20-30% infarct reduction with continuous nimodipine treatment. These results suggest that nimodipine pretreatment attenuates the severity of early focal cerebral ischemia, but that with persistent ischemia, cortex surrounding the ischemic core undergoes progressive infarction and the early benefit of nimodipine treatment is only partly preserved.

  1. Cerebral blood flow and cerebrovascular reserve capacity in patients with occlusion or severe stenosis of cerebral arterial trunk

    Energy Technology Data Exchange (ETDEWEB)

    Yoshinaga, Shinya; Tanaka, Akira; Nakayama, Yoshiya; Tomonaga, Masamichi [Fukuoka Univ., Chikushino (Japan). Chikushi Hospital

    1997-12-01

    The cerebral blood flow (CBF) and the cerebrovascular reserve capacity (CVRC) were sequentially measured using a xenon enhanced CT scan in patients with transient ischemic attack or minor stroke due to an occlusion or a severe stenosis of the cerebral arterial trunk. The patients consisted of twelve males and one female ranging from 37 to 71 years of age (53 years on average). The vascular lesion was located in the internal carotid artery (7 patients) and in the middle cerebral artery (6 patients). Eleven patients received antiplatelet drug therapy, while two other patients underwent STA-MCA anastomosis. The CBF measurements were initially done within one month after the attack and then from 6 to 24 months (12 months on average) after the first study. Only one of 13 patients demonstrated a reattack during the period of observation and the CVRC decreased to 0% from the 14% level observed prior to the reattack, although the CBF was preserved. In the other twelve patients without a reattack, the CVRC was found to improve to 29.4% from 9.9% with statistical significance, even though the CBF remained the same in the first study. This study suggests hemodynamic insult to be closely related to the decreased in the CVRC, while STA-MCA anastomosis does not for prevent hemodynamic reattack based on a decrease in the CVRC in the early stage. (author)

  2. Radiohalogenated thienylethylamine derivatives for evaluating local cerebral blood flow

    Science.gov (United States)

    Goodman, Mark M.; Knapp, Jr., Furn F.

    1990-01-01

    Radiopharmaceuticals useful in brain imaging comprising radiohalogenated thienylethylamine derivatives. The compounds are 5-halo-thiophene-2-isopropyl amines able to cross the blood-brain barrier and be retained for a sufficient length of time to allow the evaluation or regional blood flow by radioimaging of the brain.

  3. The phosphodiesterase 5 inhibitor sildenafil has no effect on cerebral blood flow or blood velocity, but nevertheless induces headache in healthy subjects

    DEFF Research Database (Denmark)

    Kruuse, Christina; Thomsen, Lars Lykke; Jacobsen, Torsten Bjørn

    2002-01-01

    , and regional cerebral blood flow in the perfusion area of the middle cerebral artery (rCBFmca) was measured using single photon emission computed tomography and xenon inhalation. Radial and temporal artery diameters were studied using high-frequency ultrasound. Blood pressure and heart rate were recorded......Cyclic nucleotides are important hemodynamic regulators in many tissues. Glyceryl trinitrate markedly dilates large cerebral arteries and increases cGMP. Here, the authors study the effect of sildenafil, a selective inhibitor of cGMP-hydrolyzing phosphodiesterase 5 on cerebral hemodynamics...

  4. Restricted Arm Swing Affects Gait Stability and Increased Walking Speed Alters Trunk Movements in Children with Cerebral Palsy

    Science.gov (United States)

    Delabastita, Tijs; Desloovere, Kaat; Meyns, Pieter

    2016-01-01

    Observational research suggests that in children with cerebral palsy, the altered arm swing is linked to instability during walking. Therefore, the current study investigates whether children with cerebral palsy use their arms more than typically developing children, to enhance gait stability. Evidence also suggests an influence of walking speed on gait stability. Moreover, previous research highlighted a link between walking speed and arm swing. Hence, the experiment aimed to explore differences between typically developing children and children with cerebral palsy taking into account the combined influence of restricting arm swing and increasing walking speed on gait stability. Spatiotemporal gait characteristics, trunk movement parameters and margins of stability were obtained using three dimensional gait analysis to assess gait stability of 26 children with cerebral palsy and 24 typically developing children. Four walking conditions were evaluated: (i) free arm swing and preferred walking speed; (ii) restricted arm swing and preferred walking speed; (iii) free arm swing and high walking speed; and (iv) restricted arm swing and high walking speed. Double support time and trunk acceleration variability increased more when arm swing was restricted in children with bilateral cerebral palsy compared to typically developing children and children with unilateral cerebral palsy. Trunk sway velocity increased more when walking speed was increased in children with unilateral cerebral palsy compared to children with bilateral cerebral palsy and typically developing children and in children with bilateral cerebral palsy compared to typically developing children. Trunk sway velocity increased more when both arm swing was restricted and walking speed was increased in children with bilateral cerebral palsy compared to typically developing children. It is proposed that facilitating arm swing during gait rehabilitation can improve gait stability and decrease trunk movements in

  5. Alterations of interneurons of the gerbil hippocampus after transient cerebral ischemia: effect of pitavastatin.

    Science.gov (United States)

    Himeda, Toshiki; Hayakawa, Natsumi; Tounai, Hiroko; Sakuma, Mio; Kato, Hiroyuki; Araki, Tsutomu

    2005-11-01

    We investigated the immunohistochemical alterations of parvalbumin (PV)-expressing interneurons in the hippocampus after transient cerebral ischemia in gerbils in comparison with neuronal nitric oxide synthase (nNOS)-expressing interneurons. We also examined the effect of 3-hydroxy-3-methylglutaryl-coenzyme A reductase inhibitor pitavastatin against the damage of neurons and interneurons in the hippocampus after cerebral ischemia. Severe neuronal damage was observed in the hippocampal CA1 pyramidal neurons 5 and 14 days after ischemia. The PV immunoreactivity was unchanged up to 2 days after ischemia. At 5 and 14 days after ischemia, in contrast, a conspicuous reduction of PV immunoreactivity was observed in interneurons of the hippocampal CA1 sector. Furthermore, a significant decrease of PV immunoreactivity was found in interneurons of the hippocampal CA3 sector. No damage of nNOS-immunopositive interneurons was detected in the gerbil hippocampus up to 1 day after ischemia. Thereafter, a decrease of nNOS immunoreactive interneurons was found in the hippocampal CA1 sector up to 14 days after ischemia. Pitavastatin significantly prevented the neuronal cell loss in the hippocampal CA1 sector 5 days after ischemia. Our immunohistochemical study also showed that pitavastatin prevented significant decrease of PV- and nNOS-positive interneurons in the hippocampus after ischemia. Double-labeled immunostainings showed that PV immunoreactivity was not found in nNOS-immunopositive interneurons of the brain. The present study demonstrates that cerebral ischemia can cause a loss of both PV- and nNOS-immunoreactive interneurons in the hippocampal CA1 sector. Our findings also show that the damage to nNOS-immunopositive interneurons may precede the neuronal cell loss in the hippocampal CA1 sector after ischemia and nNOS-positive interneurons may play some role in the pathogenesis of cerebral ischemic diseases. Furthermore, our present study indicates that pitavastatin can

  6. Instability of the middle cerebral artery blood flow in response to CO2.

    Directory of Open Access Journals (Sweden)

    Rosemary E Regan

    Full Text Available BACKGROUND: The middle cerebral artery supplies long end-artery branches to perfuse the deep white matter and shorter peripheral branches to perfuse cortical and subcortical tissues. A generalized vasodilatory stimulus such as carbon dioxide not only results in an increase in flow to these various tissue beds but also redistribution among them. We employed a fast step increase in carbon dioxide to detect the dynamics of the cerebral blood flow response. METHODOLOGY/PRINCIPAL FINDINGS: The study was approved by the Research Ethics Board of the University Health Network at the University of Toronto. We used transcranial ultrasound to measure the time course of middle cerebral artery blood flow velocity in 28 healthy adults. Normoxic, isoxic step increases in arterial carbon dioxide tension of 10 mmHg from both hypocapnic and normocapnic baselines were produced using a new prospective targeting system that enabled a more rapid step change than has been previously achievable. In most of the 28 subjects the responses at both carbon dioxide ranges were characterised by more complex responses than a single exponential rise. Most responses were characterised by a fast initial response which then declined rapidly to a nadir, followed by a slower secondary response, with some showing oscillations before stabilising. CONCLUSIONS/SIGNIFICANCE: A rapid step increase in carbon dioxide tension is capable of inducing instability in the cerebral blood flow control system. These dynamic aspects of the cerebral blood flow responses to rapid changes in carbon dioxide must be taken into account when using transcranial blood flow velocity in a single artery segment to measure cerebrovascular reactivity.

  7. Regional cerebral blood flow and vasoreactivity to acetazolamide in childhood moyamoya disease

    Energy Technology Data Exchange (ETDEWEB)

    Kuroda, Satoshi; Hohkin, Kiyohiro; Kamiyama, Hiroyasu; Abe, Hiroshi [Hokkaido Univ., Sapporo (Japan). School of Medicine; Mitsumori, Kenji

    1995-04-01

    Using the 133-xenon inhalation method and single photon emission CT (SPECT), we measured regional cerebral blood flow (rCBF) and its reactivity to acetazolamide in 15 children with moyamoya disease (spontaneous occlusion of circle of Willis). In most of them, the mean hemispheric cerebral blood flow (mCBF) was similar to that of age-matched healthy children. However, their rCBF distribution was abnormal with low perfusion in the frontal and temporal lobes, and disturbed reactivity to acetazolamide in the frontal, temporal, and parietal lobes. After surgical revascularization of the anterior circulation with STA-MCA anastomosis and encephalo-duro-myo-anterio-sysnangiosis (EDAMS) these abnormal hemodynamics improved dramatically in the anterior circulation, including the frontal lobe. Postoperative SPECT studies revealed that cerebral vasodilatory capacity also improved in the occipital lobe and the basal ganglia. These results suggest that surgical revascularization of the anterior circulation should be carried out in order to improve cerebral hemodynamics as much as possible, especially in the frontal lobe, and it could also improve cerebral perfusion reserve in the posterior circulation. (author).

  8. Effect of Korea red ginseng on cerebral blood flow and superoxide production

    Institute of Scientific and Technical Information of China (English)

    Cuk Seong KIM; Jin Bong PARK; Kwang-Jin KIM; Seok Jong CHANG; Sung-Woo RYOO; Byeong Hwa JEON

    2002-01-01

    AIM: To investigate the effects of Korea red ginseng (KRG) on the cerebral perfusion rate in the rats and the generation of superoxide anion in the endothelial cells. METHODS: The cerebral perfusion rate was measured using laser-doppler flowmetry before and after the administration of crude saponin (CS) and saponin-free fraction (SFF) of KRG in the anesthetized rats. The superoxide generation was measured by the method based on lucigeninenhanced chemiluminescence in the cultured endothelial cells. RESULTS: The relative cerebral perfusion rate (rCBF) was significantly increased by the intraperitoneal injection of CS (100 mg/kg) in the rats, but SFF had no effect on the rCBF. Chronic treatment with CS for 7 d significantly inhibited the decrease of forebrain cerebral blood flow induced by clamping both carotid arteries in the rats. Furthermore, CS (0.1 g/L) significantly suppressed NADPH-induced superoxide generation in the human umbilical vein endothelial cells (P<0.01).CONCLUSION: The present study demonstrated that crude saponin fraction of KRG enhanced cerebral blood flow in rats. Furthermore, crude saponin fraction of KRG abrogated the NADPH-driven superoxide generation in endothelial cells.

  9. Absolute cerebral blood flow and blood volume measured by magnetic resonance imaging bolus tracking: comparison with positron emission tomography values

    DEFF Research Database (Denmark)

    Østergaard, Leif; Smith, D F; Vestergaard-Poulsen, Peter;

    1998-01-01

    The authors determined cerebral blood flow (CBF) with magnetic resonance imaging (MRI) of contrast agent bolus passage and compared the results with those obtained by O-15 labeled water (H215O) and positron emission tomography (PET). Six pigs were examined by MRI and PET under normo......- and hypercapnic conditions. After dose normalization and introduction of an empirical constant phi Gd, absolute regional CBF was calculated from MRI. The spatial resolution and the signal-to-noise ratio of CBF measurements by MRI were better than by the H215O-PET protocol. Magnetic resonance imaging cerebral...... blood volume (CBV) estimates obtained using this normalization constant correlated well with values obtained by O-15 labeled carbonmonooxide (C15O) PET. However, PET CBV values were approximately 2.5 times larger than absolute MRI CBV values, supporting the hypothesized sensitivity of MRI to small...

  10. Platelets alter gene expression profile in human brain endothelial cells in an in vitro model of cerebral malaria.

    Directory of Open Access Journals (Sweden)

    Mathieu Barbier

    Full Text Available Platelet adhesion to the brain microvasculature has been associated with cerebral malaria (CM in humans, suggesting that platelets play a role in the pathogenesis of this syndrome. In vitro co-cultures have shown that platelets can act as a bridge between Plasmodium falciparum-infected red blood cells (pRBC and human brain microvascular endothelial cells (HBEC and potentiate HBEC apoptosis. Using cDNA microarray technology, we analyzed transcriptional changes of HBEC in response to platelets in the presence or the absence of tumor necrosis factor (TNF and pRBC, which have been reported to alter gene expression in endothelial cells. Using a rigorous statistical approach with multiple test corrections, we showed a significant effect of platelets on gene expression in HBEC. We also detected a strong effect of TNF, whereas there was no transcriptional change induced specifically by pRBC. Nevertheless, a global ANOVA and a two-way ANOVA suggested that pRBC acted in interaction with platelets and TNF to alter gene expression in HBEC. The expression of selected genes was validated by RT-qPCR. The analysis of gene functional annotation indicated that platelets induce the expression of genes involved in inflammation and apoptosis, such as genes involved in chemokine-, TREM1-, cytokine-, IL10-, TGFβ-, death-receptor-, and apoptosis-signaling. Overall, our results support the hypothesis that platelets play a pathogenic role in CM.

  11. Cerebral Blood Flow Dynamics and Head-of-Bed Changes in the Setting of Subarachnoid Hemorrhage

    Directory of Open Access Journals (Sweden)

    David K. Kung

    2013-01-01

    Full Text Available Head-of-bed (HOB elevation is usually restricted in patients with aneurysmal subarachnoid hemorrhage (SAH. The goal of this study is to correlate HOB changes ( and with cerebral blood flow using transcranial Doppler (TCD and thermal diffusion probe in SAH patients. Thirteen patients with SAH were prospectively enrolled in the study. Eight patients underwent placement of a thermal diffusion probe for regional CBF measurement. CBF values were measured with the patients in flat ( and upright sitting positions ( at days 3, 7, and 10. The average increase in blood flow velocity when changing HOB from to was 7.8% on day 3, 0.1% on day 7, and 13.1% on day 10. The middle cerebral artery had the least changes in velocity. The average regional CBF measurement was 22.7 ± 0.3 mL/100 g/min in the supine position and 23.6 ± 9.1 mg/100 g/min in the sitting position. The changes were not statistically significant. None of the patients developed clinical cerebral vasospasm. Changing HOB position in the setting of SAH did not significantly affect cerebral or regional blood flow. These data suggest that early mobilization should be considered given the detrimental effects of prolonged bed rest.

  12. Changes in cerebral blood oxygenation induced by active standing test in children with POTS and NMS.

    Science.gov (United States)

    Endo, Ayumi; Fujita, Yukihiko; Fuchigami, Tatsuo; Takahashi, Shori; Mugishima, Hideo; Skatani, Kaoru

    2014-01-01

    Orthostatic dysregulation (OD) has been classified into subtypes by heart rate and blood pressure; however, the hemodynamics of brains have not yet been revealed. Therefore, we investigated changes in cerebral blood flow and oxygenation during an active standing test to clarify the pathophysiology of two subtypes: postural tachycardia syndrome (POTS) and neurally mediated syncope (NMS). We studied 31 children (15 boys, 16 girls; mean age, 14.0 ± 1.7 years) who presented with OD at the Department of Pediatrics and Child Health, Nihon University School of Medicine between 2009 and 2011. OD was diagnosed using the Japanese clinical guidelines for juvenile orthostatic dysregulation. After a 10-min resting period in the supine position, patients were asked to quickly stand up and keep upright for 10 min. Cerebral blood flow and cerebral oxygenation were measured using transcranial Doppler sonography and near-infrared spectroscopy. POTS showed a significant decrease of oxy-Hb and resistance index (RI), suggesting transient ischemia with maintainable cerebral autoregulation. NMS showed a decrease of oxy-Hb and an increase of RI, suggesting ischemia and impairment of autoregulation.

  13. Impaired autoregulation of cerebral blood flow in the distressed newborn infant

    DEFF Research Database (Denmark)

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

    1979-01-01

    Cerebral blood flow was measured, using the 133Xe clearance technique, a few hours after birth in 19 infants with varying degrees of respiratory distress syndrome. Ten of these infants had had asphyxia at birth. The least affected infants with normotension (systolic blood pressure 60 to 65 mm Hg...... at birth and infants with RDS only. CBF varied considerably with spontaneous variations in blood pressure, suggesting that autoregulation was lacking. This finding may explain why distressed premature infants are prone to develop massive capillary bleeding in the germinal layer with penetration...

  14. Ultrasound tagged near infrared spectroscopy does not detect hyperventilation-induced reduction in cerebral blood flow

    DEFF Research Database (Denmark)

    Lund, Anton; Secher, Niels H; Hirasawa, Ai;

    2016-01-01

    INTRODUCTION: Continuous non-invasive monitoring of cerebral blood flow (CBF) may be important during anaesthesia and several options are available. We evaluated the CerOx monitor that employs ultrasound tagged near infrared spectroscopy to estimate changes in a CBF index (CFI). METHODS: Seven...... by transcranial Doppler. Blood flow in the internal and external carotid artery (ICAf and ECAf) was determined using duplex ultrasonography and forehead skin blood flow (SkBF) and oxygenation (SskinO2) by laser Doppler and white light spectroscopy. RESULTS: During hyperventilation MCAvmean and ICAf decreased...

  15. Intrathoracic Pressure Regulation Improves Cerebral Perfusion and Cerebral Blood Flow in a Porcine Model of Brain Injury.

    Science.gov (United States)

    Metzger, Anja; Rees, Jennifer; Kwon, Young; Matsuura, Timothy; McKnite, Scott; Lurie, Keith G

    2015-08-01

    Brain injury is a leading cause of death and disability in children and adults in their most productive years. Use of intrathoracic pressure regulation (IPR) to generate negative intrathoracic pressure during the expiratory phase of positive pressure ventilation improves mean arterial pressure and 24-h survival in porcine models of hemorrhagic shock and cardiac arrest and has been demonstrated to decrease intracranial pressure (ICP) and cerebral perfusion pressure (CPP) in these models. Application of IPR for 240 min in a porcine model of intracranial hypertension (ICH) will increase CPP when compared with controls. Twenty-three female pigs were subjected to focal brain injury by insertion of an epidural Foley catheter inflated with 3 mL of saline. Animals were randomized to treatment for 240 min with IPR set to a negative expiratory phase pressure of -12 cmH2O or no IPR therapy. Intracranial pressure, mean arterial pressure, CPP, and cerebral blood flow (CBF) were evaluated. Intrathoracic pressure regulation significantly improved mean CPP and CBF. Specifically, mean CPP after 90, 120, 180, and 240 min of IPR use was 43.7 ± 2.8 mmHg, 44.0 ± 2.7 mmHg, 44.5 ± 2.8 mmHg, and 43.1 ± 1.9 mmHg, respectively; a significant increase from ICH study baseline (39.5 ± 1.7 mmHg) compared with control animals in which mean CPP was 36.7 ± 1.4 mmHg (ICH study baseline) and then 35.9 ± 2.1 mmHg, 33.7 ± 2.8 mmHg, 33.9 ± 3.0 mmHg, and 36.0 ± 2.7 mmHg at 90, 120, 180, and 240 min, respectively (P blood flow, as measured by an invasive CBF probe, increased in the IPR group (34 ± 4 mL/100 g-min to 49 ± 7 mL/100 g-min at 90 min) but not in controls (27 ± 1 mL/100 g-min to 25 ± 5 mL/100 g-min at 90 min) (P = 0.01). Arterial pH remained unchanged during the entire period of IPR compared with baseline values and control values. In this anesthetized pig model of ICH, treatment with IPR significantly improved CPP and CBF. This therapy may be of clinical value by noninvasively

  16. 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

  17. 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

  18. Dramatic Increase in Cerebral Blood Flow following Soman Intoxication If Signs of Symptoms Can Be Seen

    Directory of Open Access Journals (Sweden)

    Ann Göransson Nyberg

    2015-01-01

    Full Text Available Organophosphate poisoning is associated with adverse effects on the central nervous system such as seizure/convulsive activity and long term changes in neuronal networks. This study report an investigation designed to assess the consequences of Soman, a highly toxic organophosphorus compound, exposure on regional blood flow in the rat brain and peripheral organs. We performed repeated blood flow measurements in the same animal, using the microspheres technique, to characterize changes in regional blood flow at different times after Soman intoxication. In addition, the cardiopulmonary effects of Soman were followed during the intoxication. Administration of Soman (1 LD50; 90 µg/kg, s.c. to anaesthetized rats produced a decrease in blood acetylcholinesterase activity in all animals tested. Although, only six out of ten rats showed signs of poisoning like a decrease in respiratory rate, the results show that only animals with significant signs of poisoning demonstrated an increase in cerebral blood flow. We conclude that it is of great importance to treat all data individually. An overall mean can easily be misinterpreted and conceal important effects. We also conclude that the increase in cerebral blood flow has an important role in the effect on respiration and that this effect is independent of the blood acetylcholinesterase activity.

  19. Cerebral blood flow during static exercise in humans

    DEFF Research Database (Denmark)

    Rogers, H B; Schroeder, T; Secher, N H

    1990-01-01

    voluntary contraction (MVC) and utilized alternate legs. CBF (measured by the 133Xe clearance technique) was expressed by a noncompartmental flow index (ISI). Heart rate and mean arterial pressure increased from resting values of 73 (55-80) beats/min and 88 (74-104) mmHg to 106 (86-138) beats/min and 124...... (102-146) mmHg, respectively (P less than 0.0005), during the contraction at 32% MVC. Arterial PCO2 and central venous pressure did not change. Corrected to the average resting PCO2, CBF during control was 55 (35-73) ml.100 g-1.min-1 and remained constant during contractions. Cerebral vascular...... resistance increased from 1.5 (1.0-2.2) to 2.4 (1.4-3.0) mmHg. 100 g.min.ml-1 (P less than 0.025) at 32% of MVC. There was no difference in CBF between the two hemispheres at rest or during exercise. In contrast to dynamic leg exercise, static leg exercise is not associated with an increase in global CBF...

  20. Comparison of near-infrared spectroscopy with CT cerebral blood flow measurements in newborn piglets

    Science.gov (United States)

    Brown, Derek W.; Picot, Paul A.; Springett, Roger; Delpy, David T.; Lee, Ting-Yim

    2001-05-01

    Severely premature infants are often at high risk of cerebral hemorrhage or ischemic injury due to their inability to properly regulate blood flow to the brain. If blood flow is too high, the infant is at risk of cerebral hemorrhage, while too little blood flow can result in ischemic injury. The purpose of this research is to design and develop a means of non-invasively measuring cerebral blood flow (CBF) with near infrared spectroscopy (NIRS). Such a device would greatly aid the diagnosis and monitoring of afflicted infants. Previous attempts to measure CBF with NIRS have achieved limited success. In this study we acquired high signal-to-noise NIR spectrum from 600 to 980 nm with a cooled CCD spectrometer. This spectrometer enables the differential path length factor (DPF) to be estimated with accuracy using a second derivative technique described by Matcher et al. The validity of our new approach is determined via direct comparison with a previously validated computed tomography (CT) method. Three newborn piglets were studied. CBF measurements were performed at various partial arterial CO2 tensions (PaCO2) using both the NIRS and CT methods. The results of the two methods correlate well with a relationship of CBFCT equals -4.30 + 1.05 CBFNIRS (r2 equals 0.96).

  1. Measurement of local cerebral blood flow with (/sup 14/C)iodoantipyrine in the mouse

    Energy Technology Data Exchange (ETDEWEB)

    Jay, T.M.; Lucignani, G.; Crane, A.M.; Jehle, J.; Sokoloff, L.

    1988-02-01

    Local cerebral blood flow was measured in the mouse by means of the (/sup 14/C)iodoantipyrine method. This method has been previously used in the monkey, dog, cat, and rat, but its application to small mammals such as the mouse requires special attention to potential sources of error. The small size of the mouse brain requires special attention to the rapid removal and freezing of the brain to minimize effects of postmortem diffusion of tracer in the tissue. Because of the relatively low diameter/length ratios of the catheters needed for arterial sampling in small animals, substantial errors can occur in the determination of the time course of the (/sup 14/C)iodoantipyrine concentration in the arterial blood unless corrections for lag time and dead space washout in the catheter are properly applied. Local cerebral blood flow was measured in seven awake mice with appropriate care to minimize these sources of error. The values were found to vary from 48 ml/100 g/min in the corpus callosum to 198 ml/100 g/min in the inferior colliculus. The results demonstrate that the (/sup 14/C)iodoantipyrine method can be used to measure local cerebral blood flow in the mouse and that the values in that species are, in general, somewhat higher than those in the rat.

  2. Cerebral blood flow modulation insufficiency in brain networks in multiple sclerosis: A hypercapnia MRI study.

    Science.gov (United States)

    Marshall, Olga; Chawla, Sanjeev; Lu, Hanzhang; Pape, Louise; Ge, Yulin

    2016-12-01

    Cerebrovascular reactivity measures vascular regulation of cerebral blood flow and is responsible for maintaining healthy neurovascular coupling. Multiple sclerosis exhibits progressive neurodegeneration and global cerebrovascular reactivity deficits. This study investigates varied degrees of cerebrovascular reactivity impairment in different brain networks, which may be an underlying cause for functional changes in the brain, affecting long-distance projection integrity and cognitive function; 28 multiple sclerosis and 28 control subjects underwent pseudocontinuous arterial spin labeling perfusion MRI to measure cerebral blood flow under normocapnia (room air) and hypercapnia (5% carbon dioxide gas mixture) breathing. Cerebrovascular reactivity, measured as normocapnic to hypercapnic cerebral blood flow percent increase normalized by end-tidal carbon dioxide change, was determined from seven functional networks (default mode, frontoparietal, somatomotor, visual, limbic, dorsal, and ventral attention networks). Group analysis showed significantly decreased cerebrovascular reactivity in patients compared to controls within the default mode, frontoparietal, somatomotor, and ventral attention networks after multiple comparison correction. Regression analysis showed a significant correlation of cerebrovascular reactivity with lesion load in the default mode and ventral attention networks and with gray matter atrophy in the default mode network. Functional networks in multiple sclerosis patients exhibit varied amounts of cerebrovascular reactivity deficits. Such blood flow regulation abnormalities may contribute to functional communication disruption in multiple sclerosis.

  3. Beneficial effect of epinephrine infusion on cerebral and myocardial blood flows during CPR.

    Science.gov (United States)

    Koehler, R C; Michael, J R; Guerci, A D; Chandra, N; Schleien, C L; Dean, J M; Rogers, M C; Weisfeldt, M L; Traystman, R J

    1985-08-01

    It is hypothesized that epinephrine improves the ability to resuscitate the heart through a mechanism thought to be related to the increase in aortic pressure. Our results with epinephrine infusion during CPR are consistent with this hypothesis. Epinephrine selectively increased vascular resistance in noncerebral, noncoronary vascular beds, as indicated by a decrease in microsphere-determined blood flow in these areas. This increased vascular resistance raised aortic pressure during the chest compression phase and the relaxation phase of CPR. Because intracranial and right atrial pressures were only slightly higher with epinephrine, cerebral and myocardial perfusion pressures and blood flows were significantly improved. This beneficial effect (compared to no administration of a vasopressor) was more pronounced as CPR progressed beyond ten minutes. Enhanced cerebral and myocardial perfusion occurred with epinephrine when either the conventional or simultaneous compression and ventilation (SCV) mode of CPR was employed in dogs. Similar selective perfusion was sustained for 50 minutes of SCV-CPR with epinephrine, even when the onset of CPR was delayed five minutes. Regional brain blood flow differed in the delayed-CPR group in that cerebellum, brain stem, and thalamic regions initially had higher blood flows. In an infant animal model of CPR using conventional CPR in piglets, epinephrine also was found to increase cerebral and myocardial blood flows. These results show that administration of epinephrine benefits different age groups of different species with different modes of CPR; that benefits occur even with delayed onset of CPR which is associated with additional anoxia and acidosis; and that epinephrine administration is particularly effective in sustaining cerebral and coronary perfusion during prolonged CPR.

  4. Effect of Vestibular Impairment on Cerebral Blood Flow Response to Dynamic Roll Tilt

    Science.gov (United States)

    Serrador, J. M.; Black, F. O.; Schlgel, Todd T.; Lipsitz, L. A.; Wood, S. J.

    2008-01-01

    Change to upright posture results in reductions in cerebral perfusion pressure due to hydrostatic pressure changes related to gravity. Since vestibular organs, specifically the otoliths, provide information on position relative to gravity, vestibular inputs may assist in adaptation to the upright posture. The goal of this study was to examine the effect of direct vestibular stimulation on cerebral blood flow (CBF). To examine the role of otolith inputs we screened 165 subjects for vestibular function and classified subjects as either normal or impaired based on ocular torsion. Ocular torsion, an indication of otolith function, was assessed during sinusoidal roll tilt of 20 degrees at 0.01 Hz (100 sec per cycle). Subjects with torsion one SD below the mean were classified as impaired while subjects one SD above the mean were considered normal. During one session subjects were placed in a chair that was sinusoidally rotated 25 degrees in the roll plane at five frequencies: 0.25 & 0.125 Hz for 80 sec, 0.0625 Hz for 160 sec and 0.03125 Hz and 0.015625 Hz for 320 sec. During testing, CBF (transcranial Doppler), blood pressure (Finapres), and end tidal CO2 (Puritan Bennet) were measured continuously. Ocular torsion was assessed from infrared images of the eyes. All rotations were done in the dark with subjects fixated on a red LED directly at the center of rotation. In the normal group, dynamic tilt resulted in significant changes in both blood pressure and cerebral blood flow velocity that was related to the frequency of stimulus. In contrast the impaired group did not show similar patterns. As expected normal subjects demonstrated significant ocular torsion that was related to stimulus frequency while impaired subjects had minimal changes. These data suggest that vestibular inputs have direct effects on cerebral blood flow regulation during dynamic tilt. Supported by NASA.

  5. Effects of GSM 900 MHz on middle cerebral artery blood flow assessed by transcranial Doppler sonography.

    Science.gov (United States)

    Ghosn, Rania; Thuróczy, György; Loos, Nathalie; Brenet-Dufour, Valérie; Liabeuf, Sophie; de Seze, René; Selmaoui, Brahim

    2012-12-01

    Mobile phone use has increased worldwide but its possible effects on the brain remain unclear. The aim of the present study was to investigate the effect of acute exposure to a radio frequency electromagnetic field (RF EMF) generated by a mobile phone operating in the Global System for Mobile Communication (GSM) 900 MHz on cerebral blood flow. Twenty-nine volunteers attended two experimental sessions: a sham exposure session and a real exposure session in a cross-over double-blind study in which a mobile phone was positioned on the left side of the head. In one session, the mobile phone was operated without RF radiation (sham phone) and in the other study it was operated with RF radiation (real phone) for 20 min. Thus, each subject served as its own control. Middle cerebral artery blood flow was monitored noninvasively by transcranial Doppler sonography to measure middle cerebral artery blood flow velocity. Pulsatility index and resistance index were also evaluated. A voluntary breath holding physiological test was carried out as a positive control for testing cerebral vasoreactivity. Hemodynamic variables were recorded and analyzed before, during and after mobile phone exposure. No significant changes were detected in studied variables in middle cerebral arteries during sham or real exposure. In the exposed side the cerebral blood flow velocity, the pulsatility index and the resistance index during sham and real exposure were respectively: [61.9 ± 1.3, 61.7 ± 1.3 cm/s (P = 0.89)]; [0.93 ± 0.03, 0.90 ± 0.02 (P = 0.84)] and [0.58 ± 0.01, 0.58 ± 0.01 (P = 0.96)] at baseline; and [60.6 ± 1.3, 62 ± 1.6 cm/s (P = 0.40)]; [0.91 ± 0.03, 0.87 ± 0.03 (P = 0.97)]; [0.57 ± 0.01, 0.56 ± 0.01 (P = 0.82)] after 20 min of exposure. Twenty minutes of RF exposure to a mobile phone does not seem to affect the cerebral circulation.

  6. Blood flow in the cerebral venous system: modeling and simulation.

    Science.gov (United States)

    Miraucourt, Olivia; Salmon, Stéphanie; Szopos, Marcela; Thiriet, Marc

    2017-04-01

    The development of a software platform incorporating all aspects, from medical imaging data, through three-dimensional reconstruction and suitable meshing, up to simulation of blood flow in patient-specific geometries, is a crucial challenge in biomedical engineering. In the present study, a fully three-dimensional blood flow simulation is carried out through a complete rigid macrovascular circuit, namely the intracranial venous network, instead of a reduced order simulation and partial vascular network. The biomechanical modeling step is carefully analyzed and leads to the description of the flow governed by the dimensionless Navier-Stokes equations for an incompressible viscous fluid. The equations are then numerically solved with a free finite element software using five meshes of a realistic geometry obtained from medical images to prove the feasibility of the pipeline. Some features of the intracranial venous circuit in the supine position such as asymmetric behavior in merging regions are discussed.

  7. Regional cerebral blood flow and glucose metabolism following transient forebrain ischemia.

    Science.gov (United States)

    Pulsinelli, W A; Levy, D E; Duffy, T E

    1982-05-01

    Progressive brain damage after transient cerebral ischemia may be related to changes in postischemic cerebral blood flow and metabolism. Regional cerebral blood flow (rCBF) and cerebral glucose utilization (rCGU) were measured in adult rats prior to, during (only rCBF), and serially after transient forebrain ischemia. Animals were subjected to 30 minutes of forebrain ischemia by occluding both common carotid arteries 24 hours after cauterizing the vertebral arteries. Regional CBF was measured by the indicator-fractionation technique using 4-iodo-[14C]-antipyrine. Regional CGU was measured by the 2-[14C]deoxyglucose method. The results were correlated with the distribution and progression of ischemic neuronal damage in animals subjected to an identical ischemic insult. Cerebral blood flow to forebrain after 30 minutes of moderate to severe ischemia (less than 10% control CBF) was characterized by 5 to 15 minutes of hyperemia; rCBF then fell below normal and remained low for as long as 24 hours. Post-ischemic glucose utilization in the forebrain, except in the hippocampus, was depressed below control values at 1 hour and either remained low (neocortex, striatum) or gradually rose to normal (white matter) by 48 hours. In the hippocampus, glucose utilization equaled the control value at 1 hour and fell below control between 24 and 48 hours. The appearance of moderate to severe morphological damage in striatum and hippocampus coincided with a late rise of rCBF above normal and with a fall of rCGU; the late depression of rCGU was usually preceded by a period during which metabolism was increased relative to adjacent tissue. Further refinement of these studies may help identify salvageable brain after ischemia and define ways to manipulate CBF and metabolism in the treatment of stroke.

  8. Rizatriptan does not change cerebral blood flow velocity during migraine attacks.

    Science.gov (United States)

    Gori, S; Morelli, N; Bellini, G; Bonanni, E; Manca, L; Orlandi, G; Iudice, A; Murri, L

    2005-04-30

    Rizatriptan represents a major advance in the treatment of migraine attack: inhibition of peripheral trigeminal nerve and constriction of intracranial extracerebral blood vessels have been proposed as its main antimigraine mechanisms of action. Although many studies may suggest that rizatriptan causes highly selective vasoconstriction within intracranial extracerebral vessels (i.e., meningeal arteries), no literature data are available to date on possible cerebral hemodynamic changes in humans after treatment with rizatriptan. The aim of this study was to evaluate the effect of rizatriptan on cerebral blood flow velocity performing transcranial Doppler during spontaneous attacks of migraine without aura. Fourteen patients suffering from migraine without aura were monitored to evaluate mean flow velocity changes on both middle cerebral arteries during migraine attack 30 min before and 120 min after oral administration of rizatriptan 10mg. Monitoring was repeated for 30 min during the pain-free period. All patients turned out to be drug responders and no significant mean flow velocity changes were observed between the pain-free period and pre-treatment phase; besides no significant difference in mean flow velocity value have been detected between the periods after the drug administration during the attack versus both pre-treatment period and pain-free phase. These findings indicate that the antimigraine action of rizatriptan is not associated with clear intracranial cerebral hemodynamic changes and may support its cerebrovascular safety.

  9. Transcranial Doppler blood flow measurement during cesarean section in two patients with cerebral vascular disease.

    Science.gov (United States)

    Smiley, R M; Ridley, D M; Hartmann, A; Ciliberto, C F; Baxi, L

    2002-07-01

    We present two cases of neurovascular disease in pregnancy in which transcranial Doppler was used to assess the status of the cerebral circulation during cesarean section under regional anesthesia. One woman had been found to have moyamoya disease, following a series of transient ischemic attacks during her first pregnancy, which ended in spontaneous abortion. On this occasion she was delivered by cesarean section under slowly-induced epidural anesthesia, using ephedrine to maintain the blood pressure, and transcranial Doppler revealed no change in signal in her left middle cerebral artery. Both mother and baby had an uneventful post natal course. The second case involved a primiparous woman with a large arteriovenous malformation that had been detected following generalized seizures, which were treated with valproic acid. Her cesarean section was conducted under spinal anesthesia, and her blood pressure maintained with ephedrine. Again transcranial Doppler revealed no change in signal in her middle cerebral artery during the procedure. We believe this is a potentially useful technique to monitor the cerebral circulation intraoperatively in the presence of cerebrovascular disease.

  10. Focal ischaemia caused by instability of cerebrovascular tone during attacks of hemiplegic migraine. A regional cerebral blood flow study

    DEFF Research Database (Denmark)

    Friberg, L; Olsen, T S; Roland, P E

    1987-01-01

    During the course of hemiplegic migraine in 3 patients, changes in regional cerebral blood flow (rCBF) were recorded by the intracarotid 133Xe method and a 254 multidetector camera covering one hemisphere. The rCBF measurements were performed in conjunction with cerebral angiography. During...

  11. Alterations in cell surface area and deformability of individual human red blood cells in stored blood

    CERN Document Server

    Park, HyunJoo; Lee, SangYun; Kim, Kyoohyun; Sohn, Yong-Hak; Jang, Seongsoo; Park, YongKeun

    2015-01-01

    The functionality and viability of stored human red blood cells (RBCs) is an important clinical issue in transfusion. To systematically investigate changes in stored whole blood, the hematological properties of individual RBCs were quantified in blood samples stored for various periods with and without a preservation solution called CPDA-1. With 3-D quantitative phase imaging techniques, the optical measurements of the 3-D refractive index (RI) distributions and membrane fluctuations were done at the individual cell level. From the optical measurements, the morphological (volume, surface area and sphericity), biochemical (hemoglobin content and concentration), and mechanical parameters (dynamic membrane fluctuation) were simultaneously quantified to investigate the functionalities and their progressive alterations in stored RBCs. Our results show that the stored RBCs without CPDA-1 had a dramatic morphological transformation from discocytes to spherocytes within 2 weeks which was accompanied with significant ...

  12. Dose reduction in dynamic perfusion CT of the brain: effects of the scan frequency on measurements of cerebral blood flow, cerebral blood volume, and mean transit time

    Energy Technology Data Exchange (ETDEWEB)

    Wiesmann, Martin [University of Munich, Department of Neuroradiology, Muenchen (Germany); Klinikum der Universitaet Muenchen - Grosshadern, Abteilung fuer Neuroradiologie, Muenchen (Germany); Berg, Scott; Stoeckelhuber, B.M. [University of Luebeck, Department of Radiology, Luebeck (Germany); Bohner, G.; Klingebiel, R. [University Medicine Berlin, Department of Neuroradiology, Charite, Berlin (Germany); Schoepf, V.; Yousry, I.; Linn, J. [University of Munich, Department of Neuroradiology, Muenchen (Germany); Missler, U. [Evangelisches Krankenhaus Duisburg-Nord, Department of Neuroradiology, Duisburg (Germany)

    2008-12-15

    The influence of the frequency of computed tomography (CT) image acquistion on the diagnostic quality of dynamic perfusion CT (PCT) studies of the brain was investigated. Eight patients with clinically suspected acute ischemia of one hemisphere underwent PCT, performed on average 3.4 h after the onset of symptoms. Sixty consecutive images per slice were obtained with individual CT images obtained at a temporal resolution of two images per second. Eight additional data sets were reconstructed with temporal resolutions ranging from one image per second to one image per 5 s. Cerebral blood flow (CBF), cerebral blood volume (CBV) and mean transit time (MTT) measurements were performed in identical regions of interest. Two neuroradiologists evaluated the PCT images visually to identify areas of abnormal perfusion. Perfusion images created up to a temporal resolution of one image per 3 s were rated to be diagnostically equal to the original data. Even at one image per 4 s, all areas of infarction were identified. Quantitative differences of CBF, CBV and MTT measurements were {<=}10% up to one image per 3 s. For PCT of the brain, temporal resolution can be reduced to one image per 3 s without significant compromise in image quality. This significantly reduces the radiation dose of the patient. (orig.)

  13. Proteomic Identification of Altered Cerebral Proteins in the Complex Regional Pain Syndrome Animal Model

    Directory of Open Access Journals (Sweden)

    Francis Sahngun Nahm

    2014-01-01

    Full Text Available Background. Complex regional pain syndrome (CRPS is a rare but debilitating pain disorder. Although the exact pathophysiology of CRPS is not fully understood, central and peripheral mechanisms might be involved in the development of this disorder. To reveal the central mechanism of CRPS, we conducted a proteomic analysis of rat cerebrum using the chronic postischemia pain (CPIP model, a novel experimental model of CRPS. Materials and Methods. After generating the CPIP animal model, we performed a proteomic analysis of the rat cerebrum using a multidimensional protein identification technology, and screened the proteins differentially expressed between the CPIP and control groups. Results. A total of 155 proteins were differentially expressed between the CPIP and control groups: 125 increased and 30 decreased; expressions of proteins related to cell signaling, synaptic plasticity, regulation of cell proliferation, and cytoskeletal formation were increased in the CPIP group. However, proenkephalin A, cereblon, and neuroserpin were decreased in CPIP group. Conclusion. Altered expression of cerebral proteins in the CPIP model indicates cerebral involvement in the pathogenesis of CRPS. Further study is required to elucidate the roles of these proteins in the development and maintenance of CRPS.

  14. BH4 treatment in BH4-responsive PKU patients: preliminary data on blood prolactin concentrations suggest increased cerebral dopamine concentrations.

    Science.gov (United States)

    van Vliet, Danique; Anjema, Karen; Jahja, Rianne; de Groot, Martijn J; Liemburg, Geertje B; Heiner-Fokkema, M Rebecca; van der Zee, Eddy A; Derks, Terry G J; Kema, Ido P; van Spronsen, Francjan J

    2015-01-01

    In phenylketonuria (PKU), cerebral neurotransmitter deficiencies have been suggested to contribute to brain dysfunction. Present treatment aims to reduce blood phenylalanine concentrations by a phenylalanine-restricted diet, while in some patients blood phenylalanine concentrations also respond to cofactor treatment with tetrahydrobiopterin (BH4). Recently, a repurposing approach of BH4 was suggested to increase cerebral neurotransmitter synthesis. To investigate whether BH4 may improve cerebral dopamine concentrations in PKU patients beyond its effect through lowering blood phenylalanine concentrations, we investigated blood prolactin concentrations-as a parameter of brain dopamine availability. We retrospectively compared blood prolactin in relation to blood phenylalanine concentrations of nine (male) BH4-responsive PKU patients, when being treated without and with BH4. Blood prolactin concentrations positively correlated to blood phenylalanine concentrations (p=0.002), being significantly lower with than without BH4 treatment (p=0.047). In addition, even in this small number of male patients, blood prolactin concentrations tended to be lower at increasing BH4 dose (p=0.054), while taking blood phenylalanine concentrations into account (p=0.002). In individual BH4-responsive patients, median blood prolactin concentrations were significantly lower while using BH4 than before using BH4 treatment (p=0.024), whereas median blood phenylalanine concentrations tended to be lower, but this did not reach statistical significance (p=0.107). Therefore, these data show that high blood phenylalanine in BH4-responsive PKU male patients seems to be associated with increased blood prolactin concentrations, suggesting reduced cerebral dopamine availability. Moreover, these data suggest that BH4 treatment in itself could decrease blood prolactin concentrations in a dose-responsive way, independent of blood phenylalanine concentrations. We conclude that these preliminary data

  15. Measurement of cerebral blood flow rate and its relationship with brain function using optical coherence tomography

    Science.gov (United States)

    Liu, Jian; Wang, Yi; Zhao, Yuqian; Dou, Shidan; Ma, Yushu; Ma, Zhenhe

    2016-03-01

    Activity of brain neurons will lead to changes in local blood flow rate (BFR). Thus, it is important to measure the local BFR of cerebral cortex on research of neuron activity in vivo, such as rehabilitation evaluation after stroke, etc. Currently, laser Doppler flowmetry is commonly used for blood flow measurement, however, relatively low resolution limits its application. Optical coherence tomography (OCT) is a powerful noninvasive 3D imaging modality with high temporal and spatial resolutions. Furthermore, OCT can provide flow distribution image by calculating Doppler frequency shift which makes it possible for blood flow rate measurement. In this paper, we applied OCT to measure the blood flow rate of the primary motor cortex in rats. The animal was immobilized and anesthetized with isoflurane, an incision was made along the sagittal suture, and bone was exposed. A skull window was opened on the primary motor cortex. Then, blood flow rate changes in the primary motor cortex were monitored by our homemade spectral domain OCT with a stimulation of the passive movement of the front legs. Finally, we established the relationship between blood flow rate and the test design. The aim is to demonstrate the potential of OCT in the evaluation of cerebral cortex function.

  16. Closed versus open endotracheal suctioning in preterm infants: effects on cerebral oxygenation and blood volume.

    Science.gov (United States)

    Mosca, F A; Colnaghi, M; Lattanzio, M; Bray, M; Pugliese, S; Fumagalli, M

    1997-01-01

    The aim of our study was to compare, using near-infrared spectroscopy (NIRS), the effects on cerebral intracellular oxygenation and cerebral blood volume (CBV) of closed endotracheal suctioning (CS), which permits continuous ventilation of the patient, with open endotracheal suctioning (OS), which requires disconnection from the ventilator. Eleven preterm infants were studied. Each patient underwent one CS, followed, after 60 min, by one OS, or vice versa, three times during the same day. Modifications in CBV and oxidized cytochrome oxidase (CytO2) were continuously detected by NIRS; arterial oxygen saturation (SaO2) heart rate (HR), transcutaneous carbon dioxide tension and mean arterial blood pressure were simultaneously recorded. Significant reductions in HR and SaO2 were observed following OS; the magnitude and duration of these negative effects of suctioning were significantly reduced with CS. In addition, the decrease in CBV was more pronounced than following CS. No changes in CytO2 concentration were seen.

  17. 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

    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......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...

  18. Regional cerebral blood flow in stroke by 133Xenon inhalation and emission tomography

    DEFF Research Database (Denmark)

    Lassen, N A; Henriksen, L; Paulson, O

    1981-01-01

    A rapidly rotating single-photon emission tomograph was used to study regional cerebral blood flow by 133Xenon inhalation. Using a rotation speed of 180 degrees/5 sec a tomographic picture of the average Xenon concentration in 3 slices is obtained. By taking a sequence of 4 one-minute tomograms...... normal subjects and 10 unselected patients with stroke. The CBF tomograms localized appropriate ischemic areas in all 10 patients. In one patient the conventional x-ray tomogram was negative, while the flow tomogram clearly showed a decreased flow in consonance with the clinical findings. Regional...... cerebral blood flow measured tomographically by 133Xenon inhalation circumvents the extra-cranial contamination and the superposition of intracranial tissues that hamper 133Xenon inhalation flow studies using stationary detectors....

  19. Assessment of cerebral blood flow autoregulation (CBF AR) with rheoencephalography (REG): studies in animals

    Science.gov (United States)

    Popovic, Djordje; Bodo, Michael; Pearce, Frederick; van Albert, Stephen; Garcia, Alison; Settle, Tim; Armonda, Rocco

    2013-04-01

    The ability of cerebral vasculature to regulate cerebral blood flow (CBF) in the face of changes in arterial blood pressure (SAP) or intracranial pressure (ICP) is an important guard against secondary ischemia in acute brain injuries, and official guidelines recommend that therapeutic decisions be guided by continuous monitoring of CBF autoregulation (AR). The common method for CBF AR monitoring, which rests on real-time derivation of the correlation coefficient (PRx) between slow oscillations in SAP and ICP is, however, rarely used in clinical practice because it requires invasive ICP measurements. This study investigated whether the correlation coefficient between SAP and the pulsatile component of the non-invasive transcranial bioimpedance signal (rheoencephalography, REG) could be used to assess the state and lower limit of CBF AR. The results from pigs and rhesus macaques affirm the utility of REG; however, additional animal and clinical studies are warranted to assess selectivity of automatic REG-based evaluation of CBF AR.

  20. The Cerebral Blood Flow Biomedical Informatics Research Network (CBFBIRN) Data Repository

    Science.gov (United States)

    Shin, David D.; Ozyurt, I. Burak; Brown, Gregory G.; Fennema-Notestine, Christine; Liu, Thomas T.

    2015-01-01

    Arterial spin labeling (ASL) MRI provides an accurate and reliable measure of cerebral blood flow (CBF). A rapidly growing number of CBF measures are being collected both in clinical and research settings around the world, resulting in a large volume of data across a wide spectrum of study populations and health conditions. Here, we describe a central CBF data repository with integrated processing workflows, referred to as the Cerebral Blood Flow Biomedical Informatics Research Network (CBFBIRN). The CBFBIRN provides an integrated framework for the analysis and comparison of CBF measures across studies and sites. In this work, we introduce the main capabilities of the CBFBIRN (data storage, processing and sharing), describe what types of data are available, explain how users can contribute to the data repository and access existing data from it, and discuss our long term plans for the CBFBIRN. PMID:26032887

  1. Cerebrolysin effects on neurological outcomes and cerebral blood flow in acute ischemic stroke

    OpenAIRE

    Amiri-Nikpour MR; Nazarbaghi S; Ahmadi-Salmasi B; Mokari. T.; Tahamtan U; Rezaei Y

    2014-01-01

    Mohammad Reza Amiri-Nikpour,1 Surena Nazarbaghi,1 Babak Ahmadi-Salmasi,1 Tayebeh Mokari,2 Urya Tahamtan,2 Yousef Rezaei3 1Department of Neurology, Imam Khomeini Hospital, 2School of Medicine, 3Seyyed-al-Shohada Heart Center, Urmia University of Medical Sciences, Urmia, Iran Background: Cerebrolysin, a brain-derived neuropeptide, has been shown to improve the neurological outcomes of stroke, but no study has demonstrated its effect on cerebral blood flow. This study aimed to determine the ce...

  2. Voluntary respiratory control and cerebral blood flow velocity upon ice-water immersion

    DEFF Research Database (Denmark)

    Mantoni, Teit; Rasmussen, Jakob Højlund; Belhage, Bo;

    2008-01-01

    In non-habituated subjects, cold-shock response to cold-water immersion causes rapid reduction in cerebral blood flow velocity (approximately 50%) due to hyperventilation, increasing risk of syncope, aspiration, and drowning. Adaptation to the response is possible, but requires several cold...... immersions. This study examines whether thorough instruction enables non-habituated persons to attenuate the ventilatory component of cold-shock response....

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

    OpenAIRE

    2016-01-01

    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...

  4. Possibility of enhanced risk of retinal neovascularization in repeated blood donors: blood donation and retinal alteration

    Directory of Open Access Journals (Sweden)

    Rastmanesh R

    2011-09-01

    Full Text Available Reza RastmaneshDepartment of Clinical Nutrition and Dietetics, Shahid Beheshti University of Medical Sciences, National Nutrition and Food Technology Research Institute, Tehran, IranAbstract: Repeated blood donors manifest clinical, subclinical, and biochemical signs of iron deficiency anemia, have significantly higher erythropoietin and vascular endothelial growth factor (VEGF concentrations, and decreased tissue oxygen saturation, oxygenated tissue hemoglobin, and regional cerebral oxygen saturation. Erythropoietin and VEGF are potent retinal angiogenic factors which may initiate and promote the retinal angiogenesis process independently or simultaneously. Increases in circulating levels of erythropoietin and VEGF are proportionate to the levels of hematocrit, hypoxemia, and tissue hypoxia. It is suggested that higher erythropoietin production following iron deficiency anemia-induced chronic hypoxemia/hypoxia may, hypothetically, enhance the risk of retinal angiogenesis and/or neovascularization, possibly by inducing hypoxia inducible factor-1 alpha, which consequently upregulates genes stimulating angiogenesis, resulting in formation of a new vasculature, possibly by modulation of signal transducer and activator of transcription 3 signaling in the retina. Implications of this hypothesis cover erythropoietin doping, chronic hypoxia, and hypoxemic situations, such as angiogenesis-related cardiac and pulmonary diseases.Keywords: repeated blood donation, erythropoietin, retinal neovascularization, vascular endothelial growth factor, hypoxia

  5. Mean arterial pressure change associated with cerebral blood flow in healthy older adults.

    Science.gov (United States)

    Deverdun, Jeremy; Akbaraly, Tasnime N; Charroud, Celine; Abdennour, Meriem; Brickman, Adam M; Chemouny, Stephane; Steffener, Jason; Portet, Florence; Bonafe, Alain; Stern, Yaakov; Ritchie, Karen; Molino, François; Le Bars, Emmanuelle; Menjot de Champfleur, Nicolas

    2016-10-01

    We investigate over a 12-year period the association between regional cerebral blood flow (CBF) and cardiovascular risk factors in a prospective cohort of healthy older adults (81.96 ± 3.82 year-old) from the Cognitive REServe and Clinical ENDOphenotype (CRESCENDO) study. Cardiovascular risk factors were measured over 12 years, and gray matter CBF was measured at the end of the study from high-resolution magnetic resonance imaging using arterial spin labeling. The association between cardiovascular risk factors, their long-term change, and CBF was assessed using multivariate linear regression models. Women were observed to have higher CBF than men (p < 0.05). Increased mean arterial pressure (MAP) over the 12-year period was correlated with a low cerebral blood flow (p < 0.05, R(2) = 0.21), whereas no association was detected between CBF and MAP at the time of imaging. High levels of glycemia tended to be associated with low cerebral blood flow values (p < 0.05). Age, alcohol consumption, smoking status, body mass index, history of cardiovascular disease, and hypertension were not associated with CBF. Our main result suggests that change in MAP is the most significant predictor of future CBF in older adults.

  6. Blood -brain barrier disruption was less under isoflurane than pentobarbital anesthesia via a PI3K/Akt pathway in early cerebral ischemia.

    Science.gov (United States)

    Chi, Oak Z; Mellender, Scott J; Kiss, Geza K; Liu, Xia; Weiss, Harvey R

    2017-02-24

    One of the important factors altering the degree of blood-brain barrier (BBB) disruption in cerebral ischemia is the anesthetic used. The phosphoinositide 3-kinase (PI3K)/Akt signaling pathway has been reported to be involved in modulating BBB permeability and in isoflurane induced neuroprotection. This study was performed to compare the degree of BBB disruption in focal cerebral ischemia under isoflurane vs pentobarbital anesthesia and to determine whether inhibition of PI3K/Akt would affect the disruption in the early stage of focal cerebral ischemia. Permanent middle cerebral artery (MCA) occlusion was performed in rats under 1.4% isoflurane or pentobarbital (50mg/kg i.p.) anesthesia with controlled ventilation. In half of each group LY294002, which is a PI3K/Akt inhibitor, was applied on the ischemic cortex immediately after MCA occlusion. After one hour of MCA occlusion, the transfer coefficient (Ki) of (14)C-α-aminoisobutyric acid ((14)C-AIB) was determined to quantify the degree of BBB disruption. MCA occlusion increased the Ki both in the isoflurane and pentobarbital anesthetized rats. However, the value of Ki was lower under isoflurane (11.5±6.0μL/g/min) than under pentobarbital (18.3±7.1μL/g/min) anesthesia. The Ki of the contralateral cortex of the pentobarbital group was higher (+74%) than that of the isoflurane group. Application of LY294002 on the ischemic cortex increased the Ki (+99%) only in the isoflurane group. The degree of BBB disruption by MCA occlusion was significantly lower under isoflurane than pentobarbital anesthesia in the early stage of cerebral ischemia. Our data demonstrated the importance of choice of anesthetics and suggest that PI3K/Akt signaling pathway plays a significant role in altering BBB disruption in cerebral ischemia during isoflurane but not during pentobarbital anesthesia.

  7. Alterations in Blood Coagulation and Viscosity Among Young Male Cigarette Smokers of Al-Jouf Region in Saudi Arabia.

    Science.gov (United States)

    Almarshad, Hassan A; Hassan, Fathelrahman M

    2016-05-01

    Hemorheology, a measure of rheological properties of blood, is often correlated with cerebral blood flow and cardiac output; an increased blood viscosity may increase the risk of thrombosis or thromboembolic events. Previous studies have reported a large variation in hemorheological properties of blood among smokers. This prompted us to conduct coagulation experiments to evaluate the effect of cigarette smoking on hematological parameters, like cell counts, and coagulation parameters among young males in Al-Jouf region, Saudi Arabia. The hematological and coagulation parameters were used to relate the changes in viscosity and coagulation to smoking. A total of 321 male participants (126 nonsmokers and 195 smokers) were enrolled into the study as randomized sample. Complete blood count was measured by hematology analyzer, and coagulation tests were performed by coagulation analyzer. Thettest analysis was performed to compare the relationships of variables between the 2 groups. The results confirmed that smoking alters some hematology parameters leading to significant deterioration in blood flow properties. Smoking also increased the hematocrit (HCT), whole blood viscosity (WBV), and plasma viscosity (PV) but decreased the international normalized ratio (INR). The decrease in INR was found to be associated with the increase in WBV, PV, and HCT. Further investigations are necessary to assess the reversibility of such changes in cessation of smoking or other elements of influence.

  8. Cerebral extraction of N-13 ammonia: its dependence on cerebral blood flow and capillary permeability, surface area product. [Dogs; monkeys

    Energy Technology Data Exchange (ETDEWEB)

    Phelps, M.E.; Huang, S.C.; Kuhl, D.E.; Hoffman, E.J.; Slin, C.

    1979-01-01

    /sup 13/N-labeled ammonia was used to investigate: (1) the cerebral extraction and clearance of ammonia; (2) the mechanicsm by which capillaries accommodate changes in cerebral blood flow (CBF); and (3) its use for the measure of CBF. This was investigated by measuring the single pass extraction of /sup 13/NH/sub 3/ in rhesus monkeys during P/sub a/CO/sub 2/ induced changes in CBF, and with dog studies using in vitro tissue counting techniques to examine /sup 13/NH/sub 3/ extraction in gray and white matter, mixed tissue, and cerebellum during variations in CBF produced by combinations of embolization, local brain compression, and changes in P/sub a/CO/sub 2/. The single pass extraction fraction of /sup 13/NH/sub 3/ varied from about 70 to 20% over a CBF range of 12 to 140cc/min/100gms. Capillary permeability-surface area product (PS) estimates from this data and the dog experiments show PS increasing with CBF. The magnitude and rate of increase in PS with CBF was highest in gray matter > mixed tissue > white matter. Tissue extraction of /sup 13/NH/sub 3/ vs CBF relationship was best described by a unidirectional transport model in which CBF increases by both recruitment of capillaries and by increases of blood velocity in open capillaries. Glutamine synthetase, which incorporates /sup 13/NH/sub 3/ into glutamine, appears to be anatomically located in astrocytes in general and specifically in the astrocytic pericapillary end-feet that are in direct contact with gray and white matter capillaries. The net /sup 13/NH/sub 3/ extraction subsequent to an i.v. injection increases nonlinearly with CBF. Doubling or halving basal CBF produced from 40 to 50% changes in the /sup 13/N tissue concentrations with further increases in CBF associated with progressively smaller changes in /sup 13/N concentrations. /sup 13/NH/sub 3/ appears to be a good tracer for the detection of cerebral ischemia with positron tomography but exhibits a poor response at high values of CBF.

  9. Changes in regional cerebral blood flow during the course of classic migraine attacks

    DEFF Research Database (Denmark)

    Lauritzen, M; Skyhøj Olsen, T; Lassen, N A

    1983-01-01

    and were examined by a series of rCBF studies, spaced by intervals of 5 to 10 minutes. A wave of reduced blood flow originating in the posterior part of the brain and progressing anteriorly was observed in eight of the nine patients. The oligemia advanced at a speed of 2 mm per minute over the hemisphere......Regional cerebral blood flow (rCBF) following carotid arteriography was studied in thirteen patients with classic migraine. Using the 133xenon intraarterial injection method, rCBF was measured in 254 areas in one hemisphere. Nine patients developed a characteristic attack following arteriography...

  10. Attempts to Improve Absolute Quantification of Cerebral Blood Flow in Dynamic Susceptibility Contrast Magnetic Resonance Imaging: A Simplified T1-Weighted Steady-State Cerebral Blood Volume Approach

    Energy Technology Data Exchange (ETDEWEB)

    Wirestam, R.; Knutsson, L.; Risberg, J.; Boerjesson, S.; Larsson, E.M.; Gustafson, L.; Passant, U.; Staahlberg, F. [Depts. of Medical Radiation Physics, Diagnostic Radiology, Psychiatry, and Psychogeriatrics, Lund Univ, Lund (Sweden)

    2007-07-15

    Background: Attempts to retrieve absolute values of cerebral blood flow (CBF) by dynamic susceptibility contrast magnetic resonance imaging (DSC-MRI) have typically resulted in overestimations. Purpose: To improve DSC-MRI CBF estimates by calibrating the DSC-MRI-based cerebral blood volume (CBV) with a corresponding T1-weighted (T1W) steady-state (ss) CBV estimate. Material and Methods: 17 volunteers were investigated by DSC-MRI and 133Xe SPECT. Steady-state CBV calculation, assuming no water exchange, was accomplished using signal values from blood and tissue, before and after contrast agent, obtained by T1W spin-echo imaging. Using steady-state and DSC-MRI CBV estimates, a calibration factor K = CBV(ss)/CBV(DSC) was obtained for each individual. Average whole-brain CBF(DSC) was calculated, and the corrected MRI-based CBF estimate was given by CBF(ss) = KxCBF(DSC). Results: Average whole-brain SPECT CBF was 40.1{+-}6.9 ml/min 100 g, while the corresponding uncorrected DSC-MRI-based value was 69.2{+-}13.8 ml/mi 100 g. After correction with the calibration factor, a CBF(ss) of 42.7{+-}14.0 ml/min 100 g was obtained. The linear fit to CBF(ss)-versus-CBF(SPECT) data was close to proportionality (R = 0.52). Conclusion: Calibration by steady-state CBV reduced the population average CBF to a reasonable level, and a modest linear correlation with the reference 133Xe SPECT technique was observed. Possible explanations for the limited accuracy are, for example, large-vessel partial-volume effects, low post-contrast signal enhancement in T1W images, and water-exchange effects.

  11. Matrix metalloproteinase-9 expression and blood brain barrier permeability in the rat brain after cerebral ischemia/reperfusion injury

    Institute of Scientific and Technical Information of China (English)

    Lifang Lei; Xiaohong Zi; Qiuyun Tu

    2008-01-01

    BACKGROUND: The integrity of the blood brain barrier (BBB) plays an important role in the patho-physiological process of cerebral ischemia/reperfusion injury. It has been recently observed that metalloproteinase-9 (MMP-9) is closely related to cerebral ischemia/reperfusion injuryOBJECTIVE: This study was designed to observe MMP-9 expression in the rat brain after cerebral ischemia/reperfusion injury and to investigate its correlation to BBB permeability.DESIGN, TIME AND SETTING: This study, a randomized controlled animal experiment, was performed at the Institute of Neurobiology, Central South University between September 2005 and March 2006.MATERIALS: Ninety healthy male SD rats, aged 3-4 months, weighing 200-280g, were used in the present study. Rabbit anti-rat MMP-9 polyclonal antibody (Boster, Wuhan, China) and Evans blue (Sigma, USA) were also used.METHODS: All rats were randomly divided into 9 groups with 10 rats in each group: normal control group, sham-operated group, and ischemia for 2 hours followed by reperfusion for 3,6,12 hours, 1,2,4 and 7 days groups. In the ischemia/reperfusion groups, rats were subjected to ischemia/reperfusion injury by suture occlusion of the right middle cerebral artery. In the sham-operated group, rats were merely subjected to vessel dissociation. In the normal control group, rats were not modeled.MAIN OUTCOME MEASURES: BBB permeability was assessed by determining the level of effusion of Evans blue. MMP-9 expression was detected by an immunohistochemical method.RESULTS: All 90 rats were included in the final analysis. BBB permeability alteration was closely correlated to ischemia/reperfusion time. BBB permeability began to increase at ischemia/reperfusion for 3 hours, then it gradually reached a peak level at ischemia/reperfusion for 1 day, and thereafter it gradually decreased. MMP-9 expression began to increase at ischemia/reperfusion for 3 hours, then gradually reached its peak level 2 days after perfusion, and thereafter

  12. The role of blood flow distribution in the regulation of cerebral oxygen availability in fetal growth restriction.

    Science.gov (United States)

    Luria, Oded; Bar, Jacob; Kovo, Michal; Malinger, Gustavo; Golan, Abraham; Barnea, Ofer

    2012-04-01

    Fetal growth restriction (FGR) elicits hemodynamic compensatory mechanisms in the fetal circulation. These mechanisms are complex and their effect on the cerebral oxygen availability is not fully understood. To quantify the contribution of each compensatory mechanism to the fetal cerebral oxygen availability, a mathematical model of the fetal circulation was developed. The model was based on cardiac-output distribution in the fetal circulation. The compensatory mechanisms of FGR were simulated and their effects on cerebral oxygen availability were analyzed. The mathematical analysis included the effects of cerebral vasodilation, placental resistance to blood flow, degree of blood shunting by the ductus venosus and the effect of maternal-originated placental insufficiency. The model indicated a unimodal dependency between placental blood flow and cerebral oxygen availability. Optimal cerebral oxygen availability was achieved when the placental blood flow was mildly reduced compared to the normal flow. This optimal ratio was found to increase as the hypoxic state of FGR worsens. The model indicated that cerebral oxygen availability is increasingly dependent on the cardiac output distribution as the fetus gains weight.

  13. Changes in the permeability of blood brain barrier and endothelial cell damage after cerebral ischemia

    Institute of Scientific and Technical Information of China (English)

    Ke Liu; Jiansheng Li

    2006-01-01

    OBJECTIVE: To investigate the effect of endothelial cells on the permeability of blood brain barrier (BBB) after brain injury and its effect mechanism.DATA SOURCES: We searched for the articles of permeability of BBB and endothelial cell injury after brain ischemia, which were published between January 1982 and December 2005, with the key words of "cerebral ischemia damage,blood brain barrier ( BBB),permeability,effect of endothelial cell (EC) and its variation mechanism"in English.STUDY SELECTION: The materials were primarily selected. The articles related to the changes in the permeability of BBB and the effect of endothelial cells as well as the change mechanism after cerebral ischemia damage were chosen. Repetitive studies or review articles were excluded.DATA EXTRACTION: Totally 55 related articles were collected, and 35 were excluded due to repetitive or review articles, finally 20 articles were involved.DATA SYNTHESIS: The content or viewpoints of involved literatures were analyzed. Cerebral ischemia had damage for endothelial cells, such as the inflow of a lot of Ca2+, the production of nitrogen monoxide and oxygen free radical, and aggravated destruction of BBB. After acceptors of inflammatory mediators on cerebrovascular endothelial cell membrane, such as histamine, bradykinin , 5-hydroxytryptamine and so on are activated, endothelial cells shrink and the permeability of BBB increases. Its mechanism involves in the inflow of extracellular Ca2+and the release of intracellular Ca2+ in the cells. Glycocalyx molecule on the surface of endothelial cell, having structural polytropy, is the determinative factor of the permeability of BBB. VEGF, intensively increasing the vasopermeability and mainly effecting on postcapillary vein and veinlet, is the strongest known blood vessel permeation reagent. Its chronic overexpression in the brain can lead the destruction of BBB.CONCLUSION: The injury of endothelial cell participants in the pathological mechanism of BBB

  14. Xueshuantong improves cerebral blood perfusion in elderly patients with lacunar infarction

    Institute of Scientific and Technical Information of China (English)

    Qifeng Gui; Yunmei Yang; Shihong Ying; Minming Zhang

    2013-01-01

    A total of 64 patients with acute lacunar infarction were enrolled within 24 hours of onset. The patients received conventional therapy (antiplatelet drugs and hypolipidemic drugs) alone or conventional therapy plus 450 mg Xueshuantong once a day. The main ingredient of the Xueshuantong lyophilized powder used for injection was Panax notoginseng saponins. Assessments were made at admission and at discharge using the National Institutes of Health Stroke Scale, the Activity of Daily Living and the Mini-Mental State Examination. Additionally, the relative cerebral blood flow, relative cerebral blood volume and relative mean transit time in the region of interest were calculated within 24 hours after the onset of lacunar infarction, using dynamic susceptibility contrast magnetic resonance perfusion imaging technology. Patients underwent a follow-up MRI scan after 4 weeks of treatment. There was an improvement in the Activity of Daily Living scores and a greater reduction in the scores on the National Institutes of Health Stroke Scale in the treatment group than in the control group. However, the Mini-Mental State Examination scores showed no significant differences after 4 weeks of treatment. Compared with the control group, the relative cerebral blood flow at discharge had increased and showed a greater improvement in the treatment group. Furthermore, there was a reduction in the relative mean transit time at discharge and the value was lower in the treatment group than in the control group. The experimental findings indicate that Xueshuantong treatment improves neurological deficits in elderly patients with lacunar infarction, and the mechanism may be related to increased cerebral perfusion.

  15. Challenges in understanding the impact of blood pressure management on cerebral oxygenation in the preterm brain

    Directory of Open Access Journals (Sweden)

    Aminath eAzhan

    2012-12-01

    Full Text Available Systemic hypotension in preterm infants has been related to increased mortality, cerebrovascular lesions and neurodevelopmental morbidity. Treatment of hypotension with inotropic medications aims at preservation of end organ perfusion and oxygen delivery, especially the brain. The common inotropic medications in preterm infants include dopamine, dobutamine, adrenalin, with adjunctive use of corticosteroids in cases of refractory hypotension. Whether maintenance of mean arterial blood pressure (MAP by use of inotropic medication is neuroprotective or not remains unclear. This review explores the different inotropic agents and their effects on perfusion and oxygenation in the preterm brain, in clinical studies as well as in animal models. Dopamine and adrenalin, because of their -adrenergic vasoconstrictor actions, have raised concerns of reduction in cerebral blood flow (CBF. Several studies in hypotensive preterm infants have shown that dopamine elevates CBF together with increased MAP, in keeping with limited cerebro-autoregulation. Adrenaline is also effective in raising cerebral perfusion together with MAP in preterm infants. Experimental studies in immature animals show no cerebro-vasoconstrictive effects of dopamine or adrenaline, but demonstrate the consistent findings of increased cerebral perfusion and oxygenation with the use of dopamine, dobutamine and adrenaline, alongside with raised MAP. Both clinical and animal studies report the transitory effects of adrenaline in increasing plasma lactate, and blood glucose, which might render its use as a 2nd line therapy. To investigate the cerebral effects of inotropic agents in long-term outcome in hypotensive preterm infants, carefully designed prospective research possibly including preterm infants with permissive hypotension is required. Preterm animal models would be useful in investigating the relationship between the physiological effects of inotropes and histopathology outcomes in

  16. The protective effect of HET0016 on brain edema and blood-brain barrier dysfunction after cerebral ischemia/reperfusion.

    Science.gov (United States)

    Liu, Yu; Wang, Di; Wang, Huan; Qu, Youyang; Xiao, Xingjun; Zhu, Yulan

    2014-01-28

    N-hydroxy-N-(4-butyl-2-methylphenyl) formamidine (HET0016) is a specific 20-hydroxyeicosatetraenoic acid (20-HETE) inhibitor which was first synthesized in 2001. It has been demonstrated that HET0016 reduces cerebral infarction volume in rat middle cerebral artery occlusion (MCAO) models. However, little is known about the role of HET0016 in the blood-brain barrier (BBB) dysfunction after cerebral ischemia/reperfusion (I/R) injury. The present study was designed to examine the effect of HET0016 in a MCAO and reperfusion rat model to determine whether it protects against brain edema and BBB disruption. Rats were subjected to 90 min MCAO, followed by 4, 24, 48, and 72 h reperfusion. Brain edema was measured according to the wet and dry weight method. BBB permeability based on the extravasation of Evans blue and sodium fluorescein was detected. BBB ultrastructure alterations were presented through transmission electron microscope. Superoxide production in ischemic tissue was also measured by dihydroethidium fluorescent probe. Western blot was used to analyze the expression of Claudin-5, ZO-1, MMP-9, and JNK pathway. At 24h after reperfusion, HET0016 reduced brain edema and BBB leakage. Ultrastructural damage of BBB and the increase of superoxide production were attenuated by HET0016 treatment. Western blot showed that HET0016 suppressed the activation of MMP-9 and JNK pathway but restored the expression of Claudin-5 and ZO-1. In conclusion, these results suggest that HET0016 protects BBB dysfunction after I/R by regulating the expression of MMP-9 and tight junction proteins. Furthermore, inhibition of oxidative stress and JNK pathway may be involved in this protecting effect.

  17. Morphological evaluation of the cerebral blood vessels in the late gestation fetal sheep following hypoxia in utero.

    Science.gov (United States)

    Baburamani, Ana A; Lo, Camden; Castillo-Melendez, Margie; Walker, David W

    2013-01-01

    Hypoxia can significantly contribute to the development of permanent brain injury in the term neonate; however the response of cerebral blood vessels is not well understood. This study aimed to quantitatively measure vascular density and morphology using laminin immunohistochemistry as a marker of blood vessels, and determine the effects of a single, severe bout of hypoxia (umbilical cord occlusion, UCO) late in gestation on the developing cerebrovasculature in fetal sheep. At 124-126 days gestation singleton fetal sheep underwent surgery for implantation of catheters and placement of an inflatable cuff around the umbilical cord. A 10 min UCO or sham UCO (n=5) occurred at 132 days gestation. Fetal brains were collected at 24 h (n=5) or 48 h (n=4) after UCO for vascular density and morphology analysis of laminin immunohistochemistry. 48 h following a single, brief bout of severe hypoxia late in gestation decreased vascular density was seen in the caudate nucleus and no changes in vascular morphology occurred. However closer analysis revealed a significant shift in the frequency of smaller (≤10 μm) to larger (≤100 μm) perimeter blood vessels in periventricular and subcortical white matter. Close examination of the frequency distribution of vascular perimeter highlights that alterations in vascular morphology persist in the near term fetal brain for up to 48 h following a brief (10 min) hypoxia in white but not gray matter. These findings suggest that the near term brain may still be vulnerable to white matter injury following in utero hypoxia.

  18. Proteasome alteration and delayed neuronal death in hippocampal CA1 and dentate gyrus regions following transient cerebral ischemia

    Institute of Scientific and Technical Information of China (English)

    Pengfei Ge; Tianfei Luo; Jizhou Zhang; Haifeng Wang; Wenchen Li; Yongxin Luan; Feng Ling; Yi'nan Luo

    2009-01-01

    BACKGROUND:Proteasome dysfunction has been reported to induce abnormal protein aggregation and cell death.OBJECTIVE:To investigate the effect of proteasome changes on delayed neuronal death in CA1 and dentate gyrus (DG) regions of the rat hippocampus following transient cerebral ischemia.DESIGN,TIME AND SETTING:A randomized,controlled animal experiment.The study was performed at the Department of Biochemistry and Molecular Biology,Norman Bethune Medical College of Jilin University,from September 2006 to May 2008.MATERIALS:Rabbit anti-19S S10B polyclonal antibody was purchased from Bioreagents,USA;propidium iodide and fluorescently-labeled goat anti-rabbit IgG were purchased from Jackson Immunoresearch,USA;hematoxylin and eosin staining solution was purchased from Sigma,USA;LSM 510 confocal microscope was purchased from Zeiss,Germany.METHODS:A total of 40 healthy Wistar rats,male,4 months old,were randomly divided into sham surgery group (n=8) and model group (n=32).Ischemic models were established in the model group by transient clamping of the bilateral carotid arteries and decreased blood pressure.After 20 minutes of global ischemia,the clamp was removed to allow blood flow for 30 minutes,4,24,and 72 hours,respectively,with 8 rats at each time point.The bilateral carotid arteries were not ligated in the sham surgery group.MAIN OUTCOME MEASURES:Neuronal death in the CA1 and DG regions was observed by hematoxylin-eosin staining.Proteasome expression in CA1 and DG region neurons was detected by immunohistochemistry.RESULTS:Hematoxylin-eosin staining showed neuronal death in the CA1 region alone at 72 hours of reperfusion following ischemia.In comparison to the sham surgery group,a significant decrease in proteasome expression was observed,by immunohistochemistry,in the CA1 and DG regions in the model group,following 30 minutes,4,24,and 72 hours of reperfusion (P<0.01).After 72 hours of reperfusion following ischemia,proteasome expression had almost completely

  19. Unilateral fetal-type circle of Willis anatomy causes right-left asymmetry in cerebral blood flow with pseudo-continuous arterial spin labeling: A limitation of arterial spin labeling-based cerebral blood flow measurements?

    Science.gov (United States)

    Barkeij Wolf, Jurriaan Jh; Foster-Dingley, Jessica C; Moonen, Justine Ef; van Osch, Matthias Jp; de Craen, Anton Jm; de Ruijter, Wouter; van der Mast, Roos C; van der Grond, Jeroen

    2016-09-01

    The accuracy of cerebral blood flow measurements using pseudo-continuous arterial spin labeling can be affected by vascular factors other than cerebral blood flow, such as flow velocity and arterial transit time. We aimed to elucidate the effects of common variations in vascular anatomy of the circle of Willis on pseudo-continuous arterial spin labeling signal. In addition, we investigated whether possible differences in pseudo-continuous arterial spin labeling signal could be mediated by differences in flow velocities. Two hundred and three elderly participants underwent magnetic resonance angiography of the circle of Willis and pseudo-continuous arterial spin labeling scans. Mean pseudo-continuous arterial spin labeling-cerebral blood flow signal was calculated for the gray matter of the main cerebral flow territories. Mean cerebellar gray matter pseudo-continuous arterial spin labeling-cerebral blood flow was significantly lower in subjects having a posterior fetal circle of Willis variant with an absent P1 segment. The posterior fetal circle of Willis variants also showed a significantly higher pseudo-continuous arterial spin labeling-cerebral blood flow signal in the ipsilateral flow territory of the posterior cerebral artery. Flow velocity in the basilar artery was significantly lower in these posterior fetal circle of Willis variants. This study indicates that pseudo-continuous arterial spin labeling measurements underestimate cerebral blood flow in the posterior flow territories and cerebellum of subjects with a highly prevalent variation in circle of Willis morphology. Additionally, our data suggest that this effect is mediated by concomitant differences in flow velocity between the supplying arteries.

  20. Altered lower leg muscle activation patterns in patients with cerebral palsy during cycling on an ergometer

    Directory of Open Access Journals (Sweden)

    Alves-Pinto A

    2016-06-01

    Full Text Available Ana Alves-Pinto,1,* Tobias Blumenstein,1,* Varvara Turova,1 Renée Lampe1,2 1Research Unit of the Buhl-Strohmaier Foundation for Cerebral Palsy and Paediatric Neuroorthopaedics, Orthopaedic Department, Klinikum rechts der Isar, 2Markus Würth Professorship, Technical University of Munich, Munich, Germany *These authors contributed equally to this work Objective: Cycling on a recumbent ergometer constitutes one of the most popular rehabilitation exercises in cerebral palsy (CP. However, no control is performed on how muscles are being used during training. Given that patients with CP present altered muscular activity patterns during cycling or walking, it is possible that an incorrect pattern of muscle activation is being promoted during rehabilitation cycling. This study investigated patterns of muscular activation during cycling on a recumbent ergometer in patients with CP and whether those patterns are determined by the degree of spasticity and of mobility.Methods: Electromyographic (EMG recordings of lower leg muscle activation during cycling on a recumbent ergometer were performed in 14 adult patients diagnosed with CP and five adult healthy participants. EMG recordings were done with an eight-channel EMG system built in the laboratory. The activity of the following muscles was recorded: Musculus rectus femoris, Musculus biceps femoris, Musculus tibialis anterior, and Musculus gastrocnemius. The degree of muscle spasticity and mobility was assessed using the Modified Ashworth Scale and the Gross Motor Function Classification System, respectively. Muscle activation patterns were described in terms of onset and duration of activation as well as duration of cocontractions.Results: Muscle activation in CP was characterized by earlier onsets, longer periods of activation, a higher occurrence of agonist–antagonist cocontractions, and a more variable cycling tempo in comparison to healthy participants. The degree of altered muscle activation

  1. Clinical studies of cerebral circulation using single photon emission computed tomography, 2; Evaluation of cerebral blood flow after acetazolamide loading on moyamoya disease

    Energy Technology Data Exchange (ETDEWEB)

    Uno, Toshiro [Gifu Univ. (Japan). Faculty of Medicine

    1993-09-01

    To evaluate cerebral blood flow (CBF) in patients with moyamoya disease, single photon emission computed tomography (SPECT) was performed using acetazolamide-activated {sup 133}Xe inhalation method. In the present investigation, 15 patients were subjected: 6 pediatric cases with the mean age of 10.8 years and 9 adult cases with the mean age of 44.6 years. The regional CBF (rCBF) was measured in the territory of anterior cerebral artery (ACA), middle cerebral artery (MCA), posterior cerebral artery (PCA), basal ganglia, and cerebellum. Cerebrovascular acetazolamide reactivity was evaluated from the rCBF measured before and after administration of acetazolamide. Namely, cerebrovascular acetazolamide reactivity was expressed as %CBF and calculated as follows: %CBF=100 x (CBF after acetazolamide administration-CBF at rest)/CBF at rest. rCBF in adult patients was decreased in the cerebral hemisphere, while that in childhood was significantly decreased in the territory of ACA. The %CBF after acetazolamide loading was decreased in the territory of ACA and MCA in both adult and childhood. When cerebral %CBF was compared to the cerebellar %CBF, the ratio of cerebral %CBF and cerebellar %CBF resulted in markedly lower in childhood than adult. rCBF and cerebrovascular acetazolamide reactivity were also measured before and after extracranial and intracranial (EC-IC) bypass surgery in three pediatric moyamoya patients. Although rCBF was increased immediately after EC-IC bypass surgery, the cerebrovascular acetazolamide reactivity remained blunted. These results meant that in the pediatric moyamoya patients cerebrovascular acetazolamide reactivity is more blunted than adult moyamoya patients. Also, the cerebral vessels in moyamoya disease were considered to be dilated to their limitation by the blood supplied through the EC-IC bypass and not to be expandable any more by acetazolamide. (author) 45 refs.

  2. Cerebral blood flow and autoregulation: current measurement techniques and prospects for noninvasive optical methods.

    Science.gov (United States)

    Fantini, Sergio; Sassaroli, Angelo; Tgavalekos, Kristen T; Kornbluth, Joshua

    2016-07-01

    Cerebral blood flow (CBF) and cerebral autoregulation (CA) are critically important to maintain proper brain perfusion and supply the brain with the necessary oxygen and energy substrates. Adequate brain perfusion is required to support normal brain function, to achieve successful aging, and to navigate acute and chronic medical conditions. We review the general principles of CBF measurements and the current techniques to measure CBF based on direct intravascular measurements, nuclear medicine, X-ray imaging, magnetic resonance imaging, ultrasound techniques, thermal diffusion, and optical methods. We also review techniques for arterial blood pressure measurements as well as theoretical and experimental methods for the assessment of CA, including recent approaches based on optical techniques. The assessment of cerebral perfusion in the clinical practice is also presented. The comprehensive description of principles, methods, and clinical requirements of CBF and CA measurements highlights the potentially important role that noninvasive optical methods can play in the assessment of neurovascular health. In fact, optical techniques have the ability to provide a noninvasive, quantitative, and continuous monitor of CBF and autoregulation.

  3. Prefrontal cerebral blood volume patterns while playing video games--a near-infrared spectroscopy study.

    Science.gov (United States)

    Nagamitsu, Shinichiro; Nagano, Miki; Yamashita, Yushiro; Takashima, Sachio; Matsuishi, Toyojiro

    2006-06-01

    Video game playing is an attractive form of entertainment among school-age children. Although this activity reportedly has many adverse effects on child development, these effects remain controversial. To investigate the effect of video game playing on regional cerebral blood volume, we measured cerebral hemoglobin concentrations using near-infrared spectroscopy in 12 normal volunteers consisting of six children and six adults. A Hitachi Optical Topography system was used to measure hemoglobin changes. For all subjects, the video game Donkey Kong was played on a Game Boy device. After spectroscopic probes were positioned on the scalp near the target brain regions, the participants were asked to play the game for nine periods of 15s each, with 15-s rest intervals between these task periods. Significant increases in bilateral prefrontal total-hemoglobin concentrations were observed in four of the adults during video game playing. On the other hand, significant decreases in bilateral prefrontal total-hemoglobin concentrations were seen in two of the children. A significant positive correlation between mean oxy-hemoglobin changes in the prefrontal region and those in the bilateral motor cortex area was seen in adults. Playing video games gave rise to dynamic changes in cerebral blood volume in both age groups, while the difference in the prefrontal oxygenation patterns suggested an age-dependent utilization of different neural circuits during video game tasks.

  4. Clinical application of /sup 99m/Tc-HM-PAO for cerebral blood flow imaging by SPECT. Comparison with cerebral blood flow study by PET

    Energy Technology Data Exchange (ETDEWEB)

    Inugami, Atsushi; Uemura, Kazuo; Shishido, Fumio; Tomura, Noriaki; Higano, Shuichi; Fujita, Hideaki; Kanno, Iwao

    1988-02-01

    Recently, a new tracer for cerebral blood flow (CBF) study; /sup 99m/Tc-labelled-hexamethyl-propyleneamine-oxime (/sup 99m/Tc-HM-PAO) was developed by Amersham international institute. In this paper, we reported the initial experience of tomographic CBF imaging with /sup 99m/Tc-HM-PAO in the comparison of CBF study using positron CT (PET) and 0 approx. 15 labelled CO/sub 2/. Thirty-nine patients with cerebro-vascular disease were examined mainly in the acute phase. All the subjects showed verious disturbances of CBF, which corresponded well to the PET study. However, the image-contrast with /sup 99m/Tc-HM-PAO were inferior to those of the PET study. /sup 99m/Tc-HM-PAO is considered to a good radiopharmaceutical which is readily applicable to eaven an emergency cases.

  5. Effect of pregnancy and nitric oxide on the myogenic vasodilation of posterior cerebral arteries and the lower limit of cerebral blood flow autoregulation.

    Science.gov (United States)

    Chapman, Abbie C; Cipolla, Marilyn J; Chan, Siu-Lung

    2013-09-01

    Hemorrhage during parturition can lower blood pressure beyond the lower limit of cerebral blood flow (CBF) autoregulation that can cause ischemic brain injury. However, the impact of pregnancy on the lower limit of CBF autoregulation is unknown. We measured myogenic vasodilation, a major contributor of CBF autoregulation, in isolated posterior cerebral arteries (PCAs) from nonpregnant and late-pregnant rats (n = 10/group) while the effect of pregnancy on the lower limit of CBF autoregulation was studied in the posterior cerebral cortex during controlled hemorrhage (n = 8). Pregnancy enhanced myogenic vasodilation in PCA and shifted the lower limit of CBF autoregulation to lower pressures. Inhibition of nitric oxide synthase (NOS) prevented the enhanced myogenic vasodilation during pregnancy but did not affect the lower limit of CBF autoregulation. The shift in the autoregulatory curve to lower pressures during pregnancy is likely protective of ischemic injury during hemorrhage and appears to be independent of NOS.

  6. Effect of Head Rotation on Cerebral Blood Velocity in the Prone Position

    Science.gov (United States)

    Højlund, Jakob; Sandmand, Marie; Sonne, Morten; Mantoni, Teit; Jørgensen, Henrik L.; Belhage, Bo; van Lieshout, Johannes J.; Pott, Frank C.

    2012-01-01

    Background. The prone position is applied to facilitate surgery of the back and to improve oxygenation in the respirator-treated patient. In particular, with positive pressure ventilation the prone position reduces venous return to the heart and in turn cardiac output (CO) with consequences for cerebral blood flow. We tested in healthy subjects the hypothesis that rotating the head in the prone position reduces cerebral blood flow. Methods. Mean arterial blood pressure (MAP), stroke volume (SV), and CO were determined, together with the middle cerebral artery mean blood velocity (MCA Vmean) and jugular vein diameters bilaterally in 22 healthy subjects in the prone position with the head centered, respectively, rotated sideways, with and without positive pressure breathing (10 cmH2O). Results. The prone position reduced SV (by 5.4 ± 1.5%; P < 0.05) and CO (by 2.3 ± 1.9 %), and slightly increased MAP (from 78 ± 3 to 80 ± 2 mmHg) as well as bilateral jugular vein diameters, leaving MCA Vmean unchanged. Positive pressure breathing in the prone position increased MAP (by 3.6 ± 0.8 mmHg) but further reduced SV and CO (by 9.3 ± 1.3 % and 7.2 ± 2.4 % below baseline) while MCA Vmean was maintained. The head-rotated prone position with positive pressure breathing augmented MAP further (87 ± 2 mmHg) but not CO, narrowed both jugular vein diameters, and reduced MCA Vmean (by 8.6 ± 3.2 %). Conclusion. During positive pressure breathing the prone position with sideways rotated head reduces MCA Vmean ~10% in spite of an elevated MAP. Prone positioning with rotated head affects both CBF and cerebrovenous drainage indicating that optimal brain perfusion requires head centering. PMID:22988456

  7. Regional cerebral blood flow and cognitive deficits in chronic lyme disease.

    Science.gov (United States)

    Fallon, Brian A; Keilp, John; Prohovnik, Isak; Heertum, Ronald Van; Mann, J John

    2003-01-01

    This study examined brain functioning in patients with Lyme encephalopathy. Eleven patients underwent neuropsychological tests and Xenon(133)-regional cerebral blood flow (rCBF) studies, using an external detector system. Each rCBF scan was age- and sex-matched to two archival, normal controls. While few differences were noted on gray-matter flow indices (ISI, fg), Lyme patients demonstrated significant flow reductions in white matter index (k(2)) (p=.004), particularly in the posterior temporal and parietal lobes bilaterally (p=.003). Flow reductions in white matter areas were significantly associated with deficits in memory (r=.66, p=.027) and visuospatial organization (r=.62, p=.041). Results suggest that Lyme encephalopathy may be a disease primarily affecting the cerebral white matter.

  8. Cerebral blood flow velocities are reduced during attacks of unilateral migraine without aura

    DEFF Research Database (Denmark)

    Thomsen, L L; Iversen, Helle Klingenberg; Olesen, J

    1995-01-01

    aura in 25 patients. Blood velocity in the middle cerebral artery was lower on the headache side (59 cm/s) than on the non-headache side (65 cm/s) during the migraine attack. No such difference was found outside of attack (65 cm/s both sides). The difference (headache side minus non-headache side......) was on average -6.1 cm/s during attack compared to -0.4 cm/s outside of attack (p = 0.01). Assuming that rCBF is unchanged during attacks of migraine without aura, our results suggest a 9% increase in middle cerebral artery lumen (cross-sectional area) on the affected side during unilateral attacks of migraine...... without aura. The findings, however, do not necessarily mean that arterial dilatation is the only or even the most significant cause of pain....

  9. Sleep apnea termination decreases cerebral blood volume: a near-infrared spectroscopy case study

    Science.gov (United States)

    Virtanen, Jaakko; Noponen, Tommi; Salmi, Tapani; Toppila, Jussi; Meriläinen, Pekka

    2009-07-01

    Medical near-infrared spectroscopy (NIRS) can be used to estimate cerebral haemodynamic changes non-invasively. Sleep apnea is a common sleep disorder where repetitive pauses in breathing decrease the quality of sleep and exposes the individual to various health problems. We have measured oxygenated and deoxygenated haemoglobin concentration changes during apneic events in sleep from the forehead of one subject using NIRS and used principal component analysis to extract extracerebral and cortical haemodynamic changes from NIRS signals. Comparison of NIRS signals with EEG, bioimpedance, and pulse oximetry data suggests that termination of apnea leads to decreases in cerebral blood volume and flow that may be related to neurological arousal via neurovascular coupling.

  10. Arterial pressure and cerebral blood flow variability: friend or foe? A review

    Directory of Open Access Journals (Sweden)

    Caroline Alice Rickards

    2014-04-01

    Full Text Available Variability in arterial pressure and cerebral blood flow has traditionally been interpreted as a marker of cardiovascular decompensation, and has been associated with negative clinical outcomes across varying time scales, from impending orthostatic syncope to an increased risk of stroke. Emerging evidence, however, suggests that increased hemodynamic variability may, in fact, be protective in the face of acute challenges to perfusion, including significant central hypovolemia and hypotension (including hemorrhage, and during cardiac bypass surgery. This review presents the dichotomous views on the role of hemodynamic variability on clinical outcome, including the physiological mechanisms underlying these patterns, and the potential impact of increased and decreased variability on cerebral perfusion and oxygenation. We suggest that reconciliation of these two apparently discrepant views may lie in the time scale of hemodynamic variability; short time scale variability appears to be cerebroprotective, while mid to longer term fluctuations are associated with primary and secondary end-organ dysfunction.

  11. 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.

  12. Blood-Brain Barrier Alterations Provide Evidence of Subacute Diaschisis in an Ischemic Stroke Rat Model

    Science.gov (United States)

    Garbuzova-Davis, Svitlana; Rodrigues, Maria C. O.; Hernandez-Ontiveros, Diana G.; Tajiri, Naoki; Frisina-Deyo, Aric; Boffeli, Sean M.; Abraham, Jerry V.; Pabon, Mibel; Wagner, Andrew; Ishikawa, Hiroto; Shinozuka, Kazutaka; Haller, Edward; Sanberg, Paul R.; Kaneko, Yuji; Borlongan, Cesario V.

    2013-01-01

    Background Comprehensive stroke studies reveal diaschisis, a loss of function due to pathological deficits in brain areas remote from initial ischemic lesion. However, blood-brain barrier (BBB) competence in subacute diaschisis is uncertain. The present study investigated subacute diaschisis in a focal ischemic stroke rat model. Specific focuses were BBB integrity and related pathogenic processes in contralateral brain areas. Methodology/Principal Findings In ipsilateral hemisphere 7 days after transient middle cerebral artery occlusion (tMCAO), significant BBB alterations characterized by large Evans Blue (EB) parenchymal extravasation, autophagosome accumulation, increased reactive astrocytes and activated microglia, demyelinization, and neuronal damage were detected in the striatum, motor and somatosensory cortices. Vascular damage identified by ultrastuctural and immunohistochemical analyses also occurred in the contralateral hemisphere. In contralateral striatum and motor cortex, major ultrastructural BBB changes included: swollen and vacuolated endothelial cells containing numerous autophagosomes, pericyte degeneration, and perivascular edema. Additionally, prominent EB extravasation, increased endothelial autophagosome formation, rampant astrogliosis, activated microglia, widespread neuronal pyknosis and decreased myelin were observed in contralateral striatum, and motor and somatosensory cortices. Conclusions/Significance These results demonstrate focal ischemic stroke-induced pathological disturbances in ipsilateral, as well as in contralateral brain areas, which were shown to be closely associated with BBB breakdown in remote brain microvessels and endothelial autophagosome accumulation. This microvascular damage in subacute phase likely revealed ischemic diaschisis and should be considered in development of treatment strategies for stroke. PMID:23675488

  13. Blood-brain barrier alterations provide evidence of subacute diaschisis in an ischemic stroke rat model.

    Directory of Open Access Journals (Sweden)

    Svitlana Garbuzova-Davis

    Full Text Available BACKGROUND: Comprehensive stroke studies reveal diaschisis, a loss of function due to pathological deficits in brain areas remote from initial ischemic lesion. However, blood-brain barrier (BBB competence in subacute diaschisis is uncertain. The present study investigated subacute diaschisis in a focal ischemic stroke rat model. Specific focuses were BBB integrity and related pathogenic processes in contralateral brain areas. METHODOLOGY/PRINCIPAL FINDINGS: In ipsilateral hemisphere 7 days after transient middle cerebral artery occlusion (tMCAO, significant BBB alterations characterized by large Evans Blue (EB parenchymal extravasation, autophagosome accumulation, increased reactive astrocytes and activated microglia, demyelinization, and neuronal damage were detected in the striatum, motor and somatosensory cortices. Vascular damage identified by ultrastuctural and immunohistochemical analyses also occurred in the contralateral hemisphere. In contralateral striatum and motor cortex, major ultrastructural BBB changes included: swollen and vacuolated endothelial cells containing numerous autophagosomes, pericyte degeneration, and perivascular edema. Additionally, prominent EB extravasation, increased endothelial autophagosome formation, rampant astrogliosis, activated microglia, widespread neuronal pyknosis and decreased myelin were observed in contralateral striatum, and motor and somatosensory cortices. CONCLUSIONS/SIGNIFICANCE: These results demonstrate focal ischemic stroke-induced pathological disturbances in ipsilateral, as well as in contralateral brain areas, which were shown to be closely associated with BBB breakdown in remote brain microvessels and endothelial autophagosome accumulation. This microvascular damage in subacute phase likely revealed ischemic diaschisis and should be considered in development of treatment strategies for stroke.

  14. Subanesthetic concentration of sevoflurane increases regional cerebral blood flow more, but regional cerebral blood volume less, than subanesthetic concentration of isoflurane in human volunteers.

    Science.gov (United States)

    Lorenz, I H; Kolbitsch, C; Hörmann, C; Schocke, M; Felber, S; Zschiegner, F; Hinteregger, M; Kremser, C; Pfeiffer, K P; Benzer, A

    2001-10-01

    Both sevoflurane and isoflurane are used in moderate concentrations in neuroanesthesia practice. The limiting factors for using higher concentrations of inhalational anesthetics in patients undergoing neurosurgery are the agents' effects on cerebral blood flow (CBF) and cerebral blood volume (CBV). In particular, an increase in CBV, which is a key determinant of intracranial pressure, may add to the neurosurgical patient's perioperative risk. To compare the effects of a subanesthetic concentration (0.4 minimum alveolar concentration) of sevoflurane or isoflurane on regional CBF (rCBF), regional CBV (rCBV) and regional mean transit time (rMTT), contrast-enhanced magnetic resonance imaging perfusion measurements were made in spontaneously breathing human volunteers. Absolute changes in rCBF, regional CBV, and rMTT during administration of either drug in regions of interest outlined bilaterally in white and grey matter were nonparametrically (Mann-Whitney test) analyzed. Sevoflurane increased rCBF in practically all regions (absolute change, 4.44 +/- 2.87 to 61.54 +/- 2.39 mL/100g per minute) more than isoflurane did (absolute change, 12.91 +/- 2.52 to 52.67 +/- 3.32 mL/100g per minute), which decreased frontal, parietal, and white matter rCBF (absolute change, -1.12 +/- 0.59 to -14.69 +/- 3.03 mL/100g per minute). Regional CBV was higher in most regions during isoflurane administration (absolute change, 0.75 +/- 0.03 to 4.92 +/- 0.16 mL/100g) than during sevoflurane administration (absolute change, 0.05 +/- 0.14 to 3.57 +/- 0.14 mL/100g). Regional mean transit time was decreased by sevoflurane (absolute change, -0.18 +/- 0.05 to -0.60 +/- 0.04 s) but increased by isoflurane (absolute change, 0.19 +/- 0.03 to 0.69 +/- 0.04 s). In summary, regional CBV was significantly lower during sevoflurane than during isoflurane administration, although sevoflurane increased rCBF more than isoflurane, which even decreased rCBF in some regions. For sevoflurane and, even more

  15. Gene expression signatures in the peripheral blood after radiosurgery of human cerebral arteriovenous malformations

    Energy Technology Data Exchange (ETDEWEB)

    Zabel-du Bois, Angelika [Dept. of Radiation Oncology, German Cancer Research Center, Heidelberg (Germany); Dept. of RadioOncology, Univ. of Heidelberg (Germany); Wagner-Ecker, Mechthild; Schwager, Christian; Wirkner, Ute; Huber, Peter E. [Dept. of Radiation Oncology, German Cancer Research Center, Heidelberg (Germany); Milker-Zabel, Stefanie; Debus, Juergen [Dept. of RadioOncology, Univ. of Heidelberg (Germany); Abdollahi, Amir [Dept. of Radiation Oncology, German Cancer Research Center, Heidelberg (Germany); Dept. of RadioOncology, Univ. of Heidelberg (Germany); Center of Cancer Systems Biology, Tufts Univ. School of Medicine, Boston, MA (United States)

    2010-02-15

    Purpose: To unravel biological mechanisms potentially resulting in the obliteration process after radiosurgery (RS) of human cerebral arteriovenous malformations (AVMs) by investigating molecular signatures on the transcriptomic level in peripheral blood of patients. Patients and Methods: Venous blood samples were obtained at definite points of time before and after RS. The samples were tested for radiation-induced changes regarding biological markers (mRNA) using cDNA and oligo-microarray technology. The corresponding expression profiles were correlated with clinical data and obliteration signs in radiologic imaging. Results: The proof of principle that RS outcome can be successfully correlated with transcriptomics of cellular blood components as disease parameter was demonstrated. The authors identified 76 differentially regulated genes (p < 0.001) after RS. Interestingly, in particular genes with known roles in antiangiogenic and procoagulative pathways were identified as potentially relevant. In particularly, the authors found a significant downregulation of neuropilin-2, protein C inhibitor and cyclin-dependent kinase 6. They also found that low pretreatment blood mRNA levels of TLR4 (toll-like receptor 4) and STAT3 (signal transducer and activator of transcription 3) correlated with fast obliteration of AVMs. Conclusion: The authors report on a novel technique for molecular biological analysis of blood from patients with cerebral AVM treated with RS. Differential regulation of genes in peripheral blood was successfully correlated with RS and time to obliteration of AVMs. The identified genes indicate a potential new methodology to monitor RS, which may result in an individualized therapy and optimized follow-up. (orig.)

  16. Excitatory amino acid changes in the brains of rhesus monkeys following selective cerebral deep hypothermia and blood flow occlusion

    Institute of Scientific and Technical Information of China (English)

    Jun Pu; Xiaoqun Niu; Jizong Zhao

    2013-01-01

    Selective cerebral deep hypothermia and blood flow occlusion can enhance brain tolerance to ischemia and hypoxia and reduce cardiopulmonary complications in monkeys. Excitotoxicity induced by the release of a large amount of excitatory amino acids after cerebral ischemia is the major mechanism underlying ischemic brain injury and nerve cell death. In the present study, we used selective cerebral deep hypothermia and blood flow occlusion to block the bilateral common carotid arteries and/or bilateral vertebral arteries in rhesus monkey, followed by reperfusion using Ringer's solution at 4°C. Microdialysis and transmission electron microscope results showed that selective cerebral deep hypothermia and blood flow occlusion inhibited the release of glutamic acid into the extracellular fluid in the brain frontal lobe and relieved pathological injury in terms of the ultrastructure of brain tissues after severe cerebral ischemia. These findings indicate that cerebral deep hypothermia and blood flow occlusion can inhibit cytotoxic effects and attenuate ischemic/ hypoxic brain injury through decreasing the release of excitatory amino acids, such as glutamic acid.

  17. Equal contribution of increased intracranial pressure and subarachnoid blood to cerebral blood flow reduction and receptor upregulation after subarachnoid hemorrhage. Laboratory investigation

    DEFF Research Database (Denmark)

    Ansar, Saema; Edvinsson, Lars

    2009-01-01

    OBJECT: Cerebral ischemia remains the key cause of disability and death in the late phase after subarachnoid hemorrhage (SAH), and its pathogenesis is still poorly understood. The purpose of this study was to examine whether the change in intracranial pressure or the extravasated blood causes...... the late cerebral ischemia and the upregulation of receptors or the cerebral vasoconstriction observed following SAH. METHODS: Rats were allocated to 1 of 3 experimental conditions: 1) cisternal injection of 250 microl blood (SAH Group), 2) cisternal injection of 250 microl NaCl (Saline Group), or 3......) the same procedure but without fluid injection (Sham Group). Two days after the procedure, the basilar and middle cerebral arteries were harvested, and contractile responses to endothelin (ET)-1 and 5-carboxamidotryptamine (5-CT) were investigated by means of myography. In addition, real-time polymerase...

  18. Regional cerebral blood flow imaging assessment of brain function reconstruction in elderly hemiplegia patients by body weight support treadmill training

    Institute of Scientific and Technical Information of China (English)

    Wenqing Wang; Yongping Liu; Diqing Wang; Yanshuang Li; Jinglai Hao; Hongwei Zhang; Sheng Bi; Changshui Weng

    2011-01-01

    The mechanism underlying body weight support treadmill training in elderly hemiplegic stroke patients is largely unknown. This study aimed to elucidate the changes of cortical blood flow in seven elderly patients with post-stroke hemiplegia before and after body weight support treadmill training by semi-quantitative analysis of regional cerebral blood flow assessed by single photon emission computed tomography. Body weight support treadmill training for 6 months was effective in improving cerebral blood flow and promoting the walking speed and balance recovery in elderly patients with post-stroke hemiplegia.

  19. Characteristic patterns of cerebral blood perfusion and cognitive impairment in patients with Parkinsons disease

    Energy Technology Data Exchange (ETDEWEB)

    Jeong, Y. J.; Park, M. J.; Cha, J. G.; Kim, S. H.; Kim, J. W.; Kang, D. Y. [Dong-A University College of medicine, Pusan (Korea, Republic of)

    2005-07-01

    Parkinsons disease (PD) is a neurodegenerative disorder that represents cognitive impairment as well as motor symptoms. Even in the early stages of PD, cognitive alterations can be demonstrated by careful neuropsychological test. The purposes of this study are to investigate the pattern of cognitive impairment and the regional cerebral blood flow (rCBF) using Tc-99m HMPAO SPECT in patients with PD. One hundred and twenty two patients with PD and 35 control subjects participated in this study. Patients with PD who had dementia clinically or K-MMSE score below 25 points or with severe motor dysfunction to interfere with the tests were also excluded. They were all matched for age (61{+-}10 vs 61{+-}8), education periods (8.8{+-}4.9 vs 8.8{+-}4.5), and K-MMSE score (27{+-}1.6 vs 27{+-}1.5). All subjects were evaluated using the Seoul Neuropsychological Screening Battery (SNSB) and Tc-99m HMPAO SPECT with SPM software to measure rCBF. Patients with PD performed worse in digit span backward, Rey Complex Figure Test, visual memory, semantic fluency, stroop test, and alternating hand movement test(p<0.05) compared with control group. On SNSB test, 100 patients (82.0%) showed some abnormalities. Eighty-six patients (70.5%) showed frontal dysfunction, 47 (38.5%) memory impairment, 33 (27.0%) language dysfunction, 25 (20.5%) attention deficit and 22 (18.3%) visuospatial dysfunction in the order of frequency. Eight patients with PD showed single memory domain MCI and 28 single non-memory domain MCI (20 frontal dysfunction). Multiple domain MCI was found in 64 patients with PD. SPM analysis of the SPECT image revealed multiple perfusion deficit in the both frontal, temporal, both limbic lobes, Lt. parietal and Lt. Putamen. It is concluded that abnormalities of cognitive function be detected very commonly in patients with PD. MCI in PD patients is most frequently involved in the item of frontal lobe function. SPECT image might be helpful to explain cognitive impairment in some

  20. Hemoglobin, hematocrit, and changes in cerebral blood flow : The Second Manifestations of ARTerial disease-Magnetic Resonance study

    NARCIS (Netherlands)

    van der Veen, Pieternella H.; Muller, Majon; Vincken, Koen L.; Westerink, Jan; Mali, Willem P. T. M.; van der Graaf, Yolanda; Geerlings, Mirjam I.; Doevendans, PAFM

    2015-01-01

    Hemoglobin and hematocrit are important determinants of blood viscosity and arterial oxygen content and may therefore influence cerebral blood flow (CBF). We examined cross-sectional and prospective associations of hemoglobin and hematocrit with CBF in 569 patients with manifest arterial disease (me

  1. [Tissular alterations and defence reactions in cymothoids parasited teleosteans (Crustacea - Isopoda - blood sucking) (author's transl)].

    Science.gov (United States)

    Romestand, B; Janicot, M; Trilles, J P

    1977-01-01

    Some tissual alterations of the parasitic microbiotope are shown in fishes harbouring Cymothoidae (blood-sucking Isopods). These alterations consist mainly in a hypertrophied epidermis and a deeply disturbed conjunctive tissue; moreover, it can be observed an important production of mucus on the tegument surface and a rush of blood cells (lymphocytes, eosenophilic granulated cells) and of cells of histiocytary origin (giant multinucleated cells).

  2. 20-Hydroxyeicosatetraenoic Acid Inhibition by HET0016 Offers Neuroprotection, Decreases Edema, and Increases Cortical Cerebral Blood Flow in a Pediatric Asphyxial Cardiac Arrest Model in Rats.

    Science.gov (United States)

    Shaik, Jafar Sadik B; Poloyac, Samuel M; Kochanek, Patrick M; Alexander, Henry; Tudorascu, Dana L; Clark, Robert Sb; Manole, Mioara D

    2015-11-01

    Vasoconstrictive and vasodilatory eicosanoids generated after cardiac arrest (CA) may contribute to cerebral vasomotor disturbances and neurodegeneration. We evaluated the balance of vasodilator/vasoconstrictor eicosanoids produced by cytochrome P450 (CYP) metabolism, and determined their role on cortical perfusion, functional outcome, and neurodegeneration after pediatric asphyxial CA. Cardiac arrest of 9 and 12 minutes was induced in 16- to 18-day-old rats. At 5 and 120 minutes after CA, we quantified the concentration of CYP eicosanoids in the cortex and subcortical areas. In separate rats, we inhibited 20-hydroxyeicosatetraenoic acid (20-HETE) synthesis after CA and assessed cortical cerebral blood flow (CBF), neurologic deficit score, neurodegeneration, and edema. After 9 minutes of CA, vasodilator eicosanoids markedly increased versus sham. Conversely, after 12 minutes of CA, vasoconstrictor eicosanoid 20-HETE increased versus sham, without compensatory increases in vasodilator eicosanoids. Inhibition of 20-HETE synthesis after 12 minutes of CA decreased cortical 20-HETE levels, increased CBF, reduced neurologic deficits at 3 hours, and reduced neurodegeneration and edema at 48 hours versus vehicle-treated rats. In conclusion, cerebral vasoconstrictor eicosanoids increased after a pediatric CA of 12 minutes. Inhibition of 20-HETE synthesis improved cortical perfusion and short-term neurologic outcome. These results suggest that alterations in CYP eicosanoids have a role in cerebral hypoperfusion and neurodegeneration after CA and may represent important therapeutic targets.

  3. The effect of nitrous oxide on cerebral blood flow velocity in children anaesthetised with sevoflurane.

    Science.gov (United States)

    Rowney, D A; Fairgrieve, R; Bissonnette, B

    2004-01-01

    To determine the effects of nitrous oxide on middle cerebral artery blood flow velocity (CBFV) during sevoflurane anaesthesia in children, CBFV was measured using transcranial Doppler sonography in 16 ASA I or II children. Anaesthesia consisted of 1.0 MAC sevoflurane in 30% oxygen with intermittent positive pressure ventilation maintaining FEco2 at 38 mmHg (5.0 kPa) and a caudal epidural block using 0.25% bupivacaine 1.0 ml.kg-1. The remainder of the inspired gas was varied in one of two sequences either air/nitrous oxide/air or nitrous oxide/air/nitrous oxide. The results showed that CBFV decreased when nitrous oxide was replaced by air (p = 0.03) and returned to its initial value when nitrous oxide was reintroduced. CBFV increased when air was replaced by nitrous oxide (p = 0.04) and returned to its initial value when air was reintroduced. Mean heart rate and blood pressure remained constant. We conclude that nitrous oxide increases cerebral blood flow velocity in healthy children anaesthetised with 1.0 MAC sevoflurane.

  4. Effect of coil embolization on blood flow through a saccular cerebral aneurysm

    Indian Academy of Sciences (India)

    Vishal Agrawal; Chandan Paul; M K Das; K Muralidhar

    2015-05-01

    Coil embolization is a mildly invasive endovascular method for treatment of a cerebral aneurysm. The presence of a coil reduces fluid loading of the blood vessel and delays further deformation of the walls. Its effectiveness depends on the coil porosity and permeability apart from the nature of flow pulsations and its geometry. In the present work, a three dimensional numerical study of pulsatile flow of blood through an artery with saccular cerebral aneurysm is reported. The flow is unsteady but is taken to be laminar and incompressible. The coil is treated as homogeneous and isotropic porous medium. A comparative study has been carried out on aneurysms with and without a coil insert considering blood as a non-Newtonian fluid. The simulation is carried out for Reynolds numbers $Re$ = 500 and 1500. Results show that the velocity magnitude within the coil embolized aneurysm becomes negligible after coil insertion. The wall shear stress within the aneurysm decreases to a great extent for both Reynolds numbers. Pressure levels remain relatively unchanged. Overall, reduced wall loading with a coil stabilizes the growth of the aneurysm and thus provides an advantage.

  5. Human cerebral blood volume measurements using dynamic contrast enhancement in comparison to dynamic susceptibility contrast MRI

    Energy Technology Data Exchange (ETDEWEB)

    Artzi, Moran [Tel Aviv Sourasky Medical Center, Functional Brain Center, The Wohl Institute for Advanced Imaging, Tel Aviv (Israel); Tel Aviv University, Sackler Faculty of Medicine, Tel Aviv (Israel); Liberman, Gilad; Vitinshtein, Faina; Aizenstein, Orna [Tel Aviv Sourasky Medical Center, Functional Brain Center, The Wohl Institute for Advanced Imaging, Tel Aviv (Israel); Nadav, Guy [Tel Aviv Sourasky Medical Center, Functional Brain Center, The Wohl Institute for Advanced Imaging, Tel Aviv (Israel); Tel Aviv University, Faculty of Engineering, Tel Aviv (Israel); Blumenthal, Deborah T.; Bokstein, Felix [Tel Aviv Sourasky Medical Center, Neuro-Oncology Service, Tel Aviv (Israel); Bashat, Dafna Ben [Tel Aviv Sourasky Medical Center, Functional Brain Center, The Wohl Institute for Advanced Imaging, Tel Aviv (Israel); Tel Aviv University, Sackler Faculty of Medicine and Sagol School of Neuroscience, Tel Aviv (Israel)

    2015-07-15

    Cerebral blood volume (CBV) is an important parameter for the assessment of brain tumors, usually obtained using dynamic susceptibility contrast (DSC) MRI. However, this method often suffers from low spatial resolution and high sensitivity to susceptibility artifacts and usually does not take into account the effect of tissue permeability. The plasma volume (v{sub p}) can also be extracted from dynamic contrast enhancement (DCE) MRI. The aim of this study was to investigate whether DCE can be used for the measurement of cerebral blood volume in place of DSC for the assessment of patients with brain tumors. Twenty-eight subjects (17 healthy subjects and 11 patients with glioblastoma) were scanned using DCE and DSC. v{sub p} and CBV values were measured and compared in different brain components in healthy subjects and in the tumor area in patients. Significant high correlations were detected between v{sub p} and CBV in healthy subjects in the different brain components; white matter, gray matter, and arteries, correlating with the known increased tissue vascularity, and within the tumor area in patients. This work proposes the use of DCE as an alternative method to DSC for the assessment of blood volume, given the advantages of its higher spatial resolution, its lower sensitivity to susceptibility artifacts, and its ability to provide additional information regarding tissue permeability. (orig.)

  6. Cerebral and blood correlates of reduced functional connectivity in mild cognitive impairment.

    Science.gov (United States)

    Gonzalez-Escamilla, Gabriel; Atienza, Mercedes; Garcia-Solis, David; Cantero, Jose L

    2016-01-01

    Growing evidence suggests that decreased functional connectivity in cortical networks precedes clinical stages of Alzheimer's disease (AD), although our knowledge about cerebral and biological correlates of this phenomenon is limited. To shed light on this issue, we have investigated whether resting-state oscillatory connectivity patterns in healthy older (HO) and amnestic mild cognitive impairment (aMCI) subjects are related to anatomical grey matter (GM) and functional (2-[18F]fluoro-2-deoxy-D-glucose (FDG)-PET) changes of neuroelectric sources of alpha rhythms, and/or to changes in plasma amyloid-beta (Aβ) and serum lipid levels, blood markers tied to AD pathogenesis and aging-related cognitive decline. We found that aMCI subjects showed decreased levels of cortical connectivity, reduced FDG-PET intake of the precuneus, and GM atrophy of the thalamus, together with higher levels of Aβ and apolipoprotein B (ApoB) compared to HO. Interestingly, levels of high-density lipoprotein (HDL) cholesterol were positively correlated with the strength of neural-phase coupling in aMCI subjects, and increased triglycerides accompanied bilateral GM loss in the precuneus of aMCI subjects. Together, these findings provide peripheral blood correlates of reduced resting-state cortical connectivity in aMCI, supported by anatomo-functional changes in cerebral sources of alpha rhythms. This framework constitutes an integrated approach to assess functional changes in cortical networks through neuroimaging and peripheral blood markers during early stages of neurodegeneration.

  7. Modeling the Role of the Glymphatic Pathway and Cerebral Blood Vessel Properties in Alzheimer's Disease Pathogenesis.

    Directory of Open Access Journals (Sweden)

    Christina Rose Kyrtsos

    Full Text Available Alzheimer's disease (AD is the most common cause of dementia in the elderly, affecting over 10% population over the age of 65 years. Clinically, AD is described by the symptom set of short term memory loss and cognitive decline, changes in mentation and behavior, and eventually long-term memory deficit as the disease progresses. On imaging studies, significant atrophy with subsequent increase in ventricular volume have been observed. Pathology on post-mortem brain specimens demonstrates the classic findings of increased beta amyloid (Aβ deposition and the presence of neurofibrillary tangles (NFTs within affected neurons. Neuroinflammation, dysregulation of blood-brain barrier transport and clearance, deposition of Aβ in cerebral blood vessels, vascular risk factors such as atherosclerosis and diabetes, and the presence of the apolipoprotein E4 allele have all been identified as playing possible roles in AD pathogenesis. Recent research has demonstrated the importance of the glymphatic system in the clearance of Aβ from the brain via the perivascular space surrounding cerebral blood vessels. Given the variety of hypotheses that have been proposed for AD pathogenesis, an interconnected, multilayer model offers a unique opportunity to combine these ideas into a single unifying model. Results of this model demonstrate the importance of vessel stiffness and heart rate in maintaining adequate clearance of Aβ from the brain.

  8. Modeling the Role of the Glymphatic Pathway and Cerebral Blood Vessel Properties in Alzheimer's Disease Pathogenesis.

    Science.gov (United States)

    Kyrtsos, Christina Rose; Baras, John S

    2015-01-01

    Alzheimer's disease (AD) is the most common cause of dementia in the elderly, affecting over 10% population over the age of 65 years. Clinically, AD is described by the symptom set of short term memory loss and cognitive decline, changes in mentation and behavior, and eventually long-term memory deficit as the disease progresses. On imaging studies, significant atrophy with subsequent increase in ventricular volume have been observed. Pathology on post-mortem brain specimens demonstrates the classic findings of increased beta amyloid (Aβ) deposition and the presence of neurofibrillary tangles (NFTs) within affected neurons. Neuroinflammation, dysregulation of blood-brain barrier transport and clearance, deposition of Aβ in cerebral blood vessels, vascular risk factors such as atherosclerosis and diabetes, and the presence of the apolipoprotein E4 allele have all been identified as playing possible roles in AD pathogenesis. Recent research has demonstrated the importance of the glymphatic system in the clearance of Aβ from the brain via the perivascular space surrounding cerebral blood vessels. Given the variety of hypotheses that have been proposed for AD pathogenesis, an interconnected, multilayer model offers a unique opportunity to combine these ideas into a single unifying model. Results of this model demonstrate the importance of vessel stiffness and heart rate in maintaining adequate clearance of Aβ from the brain.

  9. Transcranial Doppler-determined change in posterior cerebral artery blood flow velocity does not reflect vertebral artery blood flow during exercise.

    Science.gov (United States)

    Washio, Takuro; Sasaki, Hiroyuki; Ogoh, Shigehiko

    2017-02-10

    We examined whether a change in posterior cerebral artery flow velocity (PCAv) reflected the posterior cerebral blood flow, in healthy subjects, during both static and dynamic exercise. PCAv and vertebral artery (VA) blood flow, as an index of posterior blood flow, were continuously measured during an exercise trial, using transcranial Doppler (TCD) ultrasonography and Doppler ultrasound, respectively. Static handgrip exercise significantly increased both PCAv and VA blood flow. Increasing intensity of dynamic exercise further increased VA blood flow from moderate exercise, while PCAv decreased to almost resting level. During both static and dynamic exercise, the PCA cerebrovascular conductance (CVC) index significantly decreased from rest (static and high intensity dynamic exercise; -11.5 ± 12.2% and -18.0 ± 16.8%; mean ± SD, respectively), despite no change in the CVC of VA. These results indicate that vasoconstriction occurred at PCA but not VA during exercise-induced hypertension. This discrepancy in vascular response to exercise between PCA and VA may be due to different cerebral arterial characteristics. Therefore, to determine the effect of exercise on posterior cerebral circulation, at least, we need to consider carefully which cerebral artery to measure, regardless of exercise mode.

  10. Simulation of Local Blood Flow in Human Brain under Altered Gravity

    Science.gov (United States)

    Kim, Chang Sung; Kiris, Cetin; Kwak, Dochan

    2003-01-01

    In addition to the altered gravitational forces, specific shapes and connections of arteries in the brain vary in the human population (Cebral et al., 2000; Ferrandez et al., 2002). Considering the geometric variations, pulsatile unsteadiness, and moving walls, computational approach in analyzing altered blood circulation will offer an economical alternative to experiments. This paper presents a computational approach for modeling the local blood flow through the human brain under altered gravity. This computational approach has been verified through steady and unsteady experimental measurements and then applied to the unsteady blood flows through a carotid bifurcation model and an idealized Circle of Willis (COW) configuration under altered gravity conditions.

  11. 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...... with a 254-channel dynamic gamma camera. During stereognostic discrimination with hand, mouth, or foot, the rCBF increased focally in the corresponding contralateral sensory-motor region and increased focally in the premotor part of the frontal lobe. The increase in the sensory region was attributed...

  12. [The diagnosis, treatment and prevention of early stages of cerebral blood flow insufficiency].

    Science.gov (United States)

    Martynov, Iu S; Girich, T I; Kuntsevich, G I; Sokov, E L; Malkova, E V; Borisova, N F; Nozdriukhina, N V; Shuvakhina, N A

    1998-01-01

    Biomicroscopy of bulbar conjuctiva as well as oencephalography were quite informative for discovery of subclinical manifestations of disorders of cerebral circulation (DCC). That conclusion resulted from the observation of 133 patients with early forms of vascular pathology of brain. Besides, to find the early signs, it was also worth while to perform some biochemical studies (coagulogram, studies of both rheologic properties and lipids of blood). In order to establish discirculatory encephalopathy it was also expedient to use ultrasonic dopplerography and electroencephalography. Efficiency of some medical-prophylactic measures (normalization of the diet, weight, muscular activity, administration of antiatherosclerotic drugs) that prevented the progression of aorta's stenosis was also demonstrated.

  13. Evaluation of regional cerebral blood flow in a patient with musical hallucinations.

    Science.gov (United States)

    Shoyama, Masaru; Ukai, Satoshi; Kitabata, Yuji; Yamamoto, Masahiro; Okumura, Masatoshi; Kose, Asami; Tsuji, Tomikimi; Shinosaki, Kazuhiro

    2010-02-01

    A 52-year-old woman with musical hallucinations was examined using brain single photon emission computed tomography (SPECT) with 99mTc-ECD. Changes in regional cerebral blood flow (rCBF) after carbamazepine treatment were assessed using a three-dimensional stereotaxic ROI template. Following treatment, rCBF was decreased in the subcortical structures and increased in the global cortical regions. From our findings, we propose that rCBF values in subcortical structures represent abnormalities similar to those reported in previous reports or other psychiatric disorders, while those in cortical regions suggest background brain dysfunctions that result in generation of musical hallucinations.

  14. Differences in regional cerebral blood flow during musical and verbal hallucinations.

    Science.gov (United States)

    Izumi, Yukiyo; Terao, Takeshi; Ishino, Yoichi; Nakamura, Jun

    2002-11-30

    A 51-year-old male patient suffered from both musical and verbal hallucinations with insight. We performed three single photon emission computed tomographic scans with the patient in different conditions: baseline without hallucinations, musical hallucinations, and verbal hallucinations. Clearly, different patterns of regional cerebral blood flow (rCBF) were observed during musical and verbal hallucinations. The findings suggest that musical and verbal hallucinations are associated with different patterns of rCBF, possibly reflecting the different causes of the two types of hallucinations.

  15. Focal increase of blood flow in the cerebral cortex of man during vestibular stimulation

    DEFF Research Database (Denmark)

    Friberg, L; Olsen, T S; Roland, P E

    1985-01-01

    This study is an attempt to reveal projection areas for vestibular afferents to the human brain. Changes in regional cerebral blood flow (rCBF) were measured over 254 cortical regions during caloric vestibular stimulation with warm water (44 degrees C). rCBF was measured when the external auditory...... meatus was irrigated with water at body temperature as a control to vestibular stimulation. During vestibular stimulation there was only a single cortical area, located in the superior temporal region, which showed a consistent focal activation in the hemisphere contralateral to the stimulated side...

  16. Paralympic athletes with cerebral palsy display altered pacing strategies in distance-deceived shuttle running trials.

    Science.gov (United States)

    Runciman, P; Tucker, R; Ferreira, S; Albertus-Kajee, Y; Derman, W

    2016-10-01

    This study investigated performance and physiology to understand pacing strategies in elite Paralympic athletes with cerebral palsy (CP). Six Paralympic athletes with CP and 13 able-bodied (AB) athletes performed two trials of eight sets of 10 shuttles (total 1600m). One trial was distance-deceived (DEC, 1000 m + 600 m) one trial was nondeceived (N-DEC, 1600 m). Time (s), heart rate (HR, bpm), ratings of perceived exertion (RPE, units), and electromyography of five bilateral muscles (EMG) were recorded for each set of both trials. The CP group ran slower than the AB group, and pacing differences were seen in the CP DEC trial, presenting as a flat pacing profile over the trial (P < 0.05). HR was higher and RPE was lower in the CP group in both trials (P < 0.05). EMG showed small differences between groups, sides, and trials. The present study provides evidence for a possible pacing strategy underlying exercise performance and fatigue in CP. The results of this study show (1) underperformance of the CP group, and (2) altered pacing strategy utilization in the CP group. We proposed that even at high levels of performance, the residual effects of CP may negatively affect performance through selection of conservative pacing strategies during exercise.

  17. 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...... 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...... nonfatiguing exercise. During exhaustive exercise, however, euhydration delayed but did not prevent the decline in cerebral perfusion. In conclusion, during prolonged exercise in the heat, dehydration accelerates the decline in CBF without affecting CMRO2 and also restricts extracranial perfusion. Thus...

  18. Influence of cerebral blood vessel movements on the position of perivascular synapses

    Science.gov (United States)

    DeFelipe, Javier

    2017-01-01

    Synaptic activity is regulated and limited by blood flow, which is controlled by blood vessel dilation and contraction. Traditionally, the study of neurovascular coupling has mainly focused on energy consumption and oxygen delivery. However, the mechanical changes that blood vessel movements induce in the surrounding tissue have not been considered. We have modeled the mechanical changes that movements of blood vessels cause in neighboring synapses. Our simulations indicate that synaptic densities increase or decrease during vascular dilation and contraction, respectively, near the blood vessel walls. This phenomenon may alter the concentration of neurotransmitters and vasoactive substances in the immediate vicinity of the vessel wall and thus may have an influence on local blood flow. PMID:28199396

  19. 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

  20. 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).

  1. Color functional images of the cerebral blood flow. [/sup 133/Xe

    Energy Technology Data Exchange (ETDEWEB)

    Toyama, H.; Iio, M.; Iisaka, J.; Chiba, K.; Yamada, H.; Matsui, K.; Hoshi, Y.; Fuse, M.

    1976-11-01

    Functional gamma imaging, in color, was established for regional cerebral blood flow (rCBF) using /sup 133/Xe. During 10 min after intracarotid injection of /sup 133/Xe in saline, 60 picture frames of the /sup 133/Xe clearance curve for the entire hemisphere were obtained. After nine-point smoothing, the rCBF for each of the 4,096 picture elements was calculated by two methods: the half-time method and the height-over-area method. Both the /sup 133/Xe clearance half-times and the calculated CBF values were displayed, using 13 steps of color, as functional CBF images of the brain. Images of peak count and total count were also displayed on the same frame of the color television. Forty-six studies, performed on 37 patients with various cerebral disorders, were divided into two types: diffuse and focal. In the diffuse type, a decrease in CBF was noted in cases of normal-pressure hydrocephalus; successful ventriculoperitoneal shunt operations were followed by recovery of CBF. Occlusion of the middle cerebral artery showed up as a wedge-shaped area of decreased CBF, even when the conventional brain scan looked normal. Increased perfusion to a tumor was frequently associated with decreased CBF in the rest of the lateral hemisphere; such a decrease could be improved by surgical removal of the tumor.

  2. Metabolic control of resting hemispheric cerebral blood flow is oxidative, not glycolytic.

    Science.gov (United States)

    Powers, William J; Videen, Tom O; Markham, Joanne; Walter, Vonn; Perlmutter, Joel S

    2011-05-01

    Although the close regional coupling of resting cerebral blood flow (CBF) with both cerebral metabolic rate of oxygen (CMRO(2)) and cerebral metabolic rate of glucose (CMRglc) within individuals is well documented, there are few data regarding the coupling between whole brain flow and metabolism among different subjects. To investigate the metabolic control of resting whole brain CBF, we performed multivariate analysis of hemispheric CMRO(2), CMRglc, and other covariates as predictors of resting CBF among 23 normal humans. The univariate analysis showed that only CMRO(2) was a significant predictor of CBF. The final multivariate model contained two additional terms in addition to CMRO(2): arterial oxygen content and oxygen extraction fraction. Notably, arterial plasma glucose concentration and CMRglc were not included in the final model. Our data demonstrate that the metabolic factor controlling hemispheric CBF in the normal resting brain is CMRO(2) and that CMRglc does not make a contribution. Our findings provide evidence for compartmentalization of brain metabolism into a basal component in which CBF is coupled to oxygen metabolism and an activation component in which CBF is controlled by another mechanism.

  3. Regional differences in the cerebral blood flow velocity response to hypobaric hypoxia at high altitudes.

    Science.gov (United States)

    Feddersen, Berend; Neupane, Pritam; Thanbichler, Florian; Hadolt, Irmgard; Sattelmeyer, Vera; Pfefferkorn, Thomas; Waanders, Robb; Noachtar, Soheyl; Ausserer, Harald

    2015-11-01

    Symptoms of acute mountain sickness (AMS) may appear above 2,500 m altitude, if the time allowed for acclimatization is insufficient. As the mechanisms underlying brain adaptation to the hypobaric hypoxic environment are not fully understood, a prospective study was performed investigating neurophysiological changes by means of near infrared spectroscopy, electroencephalograpy (EEG), and transcranial doppler sonography at 100, 3,440 and 5,050 m above sea level in the Khumbu Himal, Nepal. Fourteen of the 26 mountaineers reaching 5,050 m altitude developed symptoms of AMS between 3,440 and 5,050 m altitude (Lake-Louise Score ⩾3). Their EEG frontal beta activity and occipital alpha activity increased between 100 and 3,440 m altitude, i.e., before symptoms appeared. Cerebral blood flow velocity (CBFV) in the anterior and middle cerebral arteries (MCAs) increased in all mountaineers between 100 and 3,440 m altitude. During further ascent to 5,050 altitude, mountaineers with AMS developed a further increase in CBFV in the MCA, whereas in all mountaineers CBFV decreased continuously with increasing altitude in the posterior cerebral arteries. These results indicate that hypobaric hypoxia causes different regional changes in CBFV despite similar electrophysiological changes.

  4. Effect of intracranial transplantation of CD34+ cells derived from human umbilical cord blood in rats with cerebral ischemia

    Institute of Scientific and Technical Information of China (English)

    LIU Hai-ying; ZHANG Qing-jun; LI Hong-jun; HAN Zhong-chao

    2006-01-01

    @@ As a source of transplantable stem cells, the CD34+ subpopulation in human umbilical cord blood (HUCB) has been used extensively to treat some hematopoietic system diseases. However,whether CD34+ cells hold the therapeutic potential to cerebral ischemia is unknown. The purpose of this study was to observe the recovery of neural function after transplantation of CD34+ cells derived from HUCB into ischemic cerebral tissue in rats.

  5. Coupling between arterial and venous cerebral blood flow during postural change.

    Science.gov (United States)

    Ogoh, Shigehiko; Washio, Takuro; Sasaki, Hiroyuki; Petersen, Lonnie G; Secher, Niels H; Sato, Kohei

    2016-12-01

    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 circulation, this study addressed both arterial and venous flow responses in the "anterior" and "posterior" parts of the brain when nine healthy subjects (5 men) were seated and flow was manipulated by hyperventilation and inhalation of 6% carbon dioxide (CO2). From a supine to a seated position, both internal carotid artery (ICA) and IJV blood flow decreased (P = 0.004 and P = 0.002), while vertebral artery (VA) flow did not change (P = 0.348) and VV flow increased (P = 0.024). In both supine and seated positions the ICA response to manipulation of end-tidal CO2 tension was reflected in IJV (r = 0.645 and r = 0.790, P blood flow (r = 0.771 and r = 0.828, P blood flow did not affect venous outflow, but the decrease in IJV blood flow was associated with the increase in VV blood flow (r = 0.479, P = 0.044). In addition, the increase in VV blood flow when seated was reflected in VA 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 blood flow when seated and that VV may influence VA blood flow.

  6. Collateral blood flow in different cerebrovascular hierarchy provides endogenous protection in cerebral ischemia.

    Science.gov (United States)

    Luo, Chuanming; Liang, Fengyin; Ren, Huixia; Yao, Xiaoli; Liu, Qiang; Li, Mingyue; Qin, Dajiang; Yuan, Ti-Fei; Pei, Zhong; Su, Huanxing

    2016-11-15

    Collateral blood flow as vascular adaptions to focal cerebral ischemia is well recognized. However, few studies directly investigate the dynamics of collateral vessel recruitment in vivo and little is known about the effect of collateral blood flow in different cerebrovascular hierarchy on the neuropathology after focal ischemic stroke. Here, we report that collateral blood flow is critically involved in blood vessel compensations following regional ischemia. We occluded a pial arteriole using femtosecond laser ablating under the intact thinned skull and documented the changes of collateral flow around the surface communication network and between the surface communication network and subsurface microcirculation network using in vivo two photon microscopy imaging. Occlusion of the pial arteriole apparently increased the diameter and collateral blood flow of its leptomeningeal anastomoses, which significantly reduced the cortical infarction size. This result suggests that the collateral flow via surface communicating network connected with leptomeningeal anastomoses could greatly impact on the extent of infarction. We then further occluded the target pial arteriole and all of its leptomeningeal anastomoses. Notably, this type of occlusion led to reversals of blood flow in the penetrating arterioles mainly proximal to the occluded pial arteriole in a direction from the subsurface microcirculation network to surface arterioles. Interesting, the cell death in the area of ischemic penumbra was accelerated when we performed occlusion to cease the reversed blood flow in those penetrating arterioles, suggesting that the collateral blood flow from subsurface microcirculation network exerts protective roles in delaying cell death in the ischemic penumbra. In conclusion, we provide the first experimental evidence that collateral blood vessels at different cerebrovascular hierarchy are endogenously compensatory mechanisms in brain ischemia. This article is protected by

  7. Presymptomatic cerebral blood flow changes in CHMP2B mutation carriers of familial frontotemporal dementia (FTD-3), measured with MRI

    DEFF Research Database (Denmark)

    Lunau, Line Andersen; Mouridsen, Kim; Rodell, Anders;

    2012-01-01

    OBJECTIVES: To assess functional changes measured by cerebral blood flow (CBF) in the presymptomatic stage of frontotemporal dementia linked to chromosome 3 (FTD-3) caused by a truncating mutation in CHMP2B. DESIGN: Case-control study. SETTING: A memory clinic and tertiary referrals centre...... changes in brain tissue perfusion were measured as CBF with two different MR techniques, gradient echo (GRE) and spin echo (SE), focusing on CBF in all cerebral vessels (GRE) and cerebral capillaries (SE), respectively. As planned, data analysis included co-registration of perfusion images to structural T...

  8. 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...

  9. Cerebrolysin effects on neurological outcomes and cerebral blood flow in acute ischemic stroke

    Directory of Open Access Journals (Sweden)

    Amiri-Nikpour MR

    2014-12-01

    Full Text Available Mohammad Reza Amiri-Nikpour,1 Surena Nazarbaghi,1 Babak Ahmadi-Salmasi,1 Tayebeh Mokari,2 Urya Tahamtan,2 Yousef Rezaei3 1Department of Neurology, Imam Khomeini Hospital, 2School of Medicine, 3Seyyed-al-Shohada Heart Center, Urmia University of Medical Sciences, Urmia, Iran Background: Cerebrolysin, a brain-derived neuropeptide, has been shown to improve the neurological outcomes of stroke, but no study has demonstrated its effect on cerebral blood flow. This study aimed to determine the cerebrolysin impact on the neurological outcomes and cerebral blood flow. Methods: In a randomized, double-blinded, placebo-controlled trial, 46 patients who had acute focal ischemic stroke were randomly assigned into two groups to receive intravenously either 30 mL of cerebrolysin diluted in normal saline daily for 10 days (n=23 or normal saline alone (n=23 adjunct to 100 mg of aspirin daily. All patients were examined using the National Institutes of Health Stroke Scale and transcranial Doppler to measure the mean flow velocity and pulsatility index (PI of their cerebral arteries at baseline as well as on days 30, 60, and 90. Results: The patients’ mean age was 60±9.7 years, and 51.2% of patients were male. The National Institutes of Health Stroke Scale was significantly lower in the cerebrolysin group compared with the placebo group on day 60 (median 10, interquartile range 9–11, P=0.008 and day 90 (median 11, interquartile range 10–13.5, P=0.001. The median of PI in the right middle cerebral artery was significantly lower in the cerebrolysin group compared with the placebo group on days 30, 60, and 90 (P<0.05. One patient in the cerebrolysin group and two patients in the placebo group died before day 30 (4.3% versus 8.7%. Conclusion: Cerebrolysin can be useful to improve the neurological outcomes and the PI of middle cerebral artery in patients with acute focal ischemic stroke. Keywords: ischemic stroke, cerebrolysin, neuroprotection, NIHSS, mean

  10. Association of Cerebral Amyloidosis, Blood Pressure, and Neuronal Injury with Late-life Onset Depression

    Directory of Open Access Journals (Sweden)

    Min Soo Byun

    2016-10-01

    Full Text Available Previous literature suggests that Alzheimer’s disease (AD process may contribute to late-life onset depression (LLOD. Therefore, we investigated the association of LLOD with cerebral amyloidosis and neuronal injury, the two key brain changes in AD, along with vascular risks. Twenty nine non-demented individuals who first experienced major depressive disorder (MDD after age of 60 years were included as LLOD subjects, and 27 non-demented elderly individuals without lifetime experience of MDD were included as normal controls (NC. Comorbid mild cognitive impairment (MCI was diagnosed in 48% of LLOD subjects and in 0% of NC. LLOD, irrespective of comorbid MCI diagnosis, was associated with prominent prefrontal cortical atrophy. Compared to NC, LLOD subjects with comorbid MCI (LLODMCI showed increased cerebral 11C-Pittsburg compound B (PiB retention and plasma beta-amyloid 1-40 and 1-42 peptides, as measures of cerebral amyloidosis; and, such relationship was not observed in overall LLOD or LLOD without MCI (LLODwoMCI. LLOD subjects, particularly the LLODwoMCI, had higher systolic blood pressure (SBP than NC. When analyzed in the same multiple logistic regression model that included prefrontal gray matter (GM density, cerebral amyloidosis and SBP as independent variables, only prefrontal GM density showed a significant independent association with LLOD regardless of MCI comorbidity status. Our findings suggest AD process might be related to LLOD via prefrontal neuronal injury in the MCI stage, whereas vascular processes—SBP elevation, in particular—are associated with LLOD via prefrontal neuronal injury even in cognitively intact or less impaired individuals.

  11. Association of Cerebral Amyloidosis, Blood Pressure, and Neuronal Injury with Late-Life Onset Depression

    Science.gov (United States)

    Byun, Min Soo; Choe, Young Min; Sohn, Bo Kyung; Yi, Dahyun; Han, Ji Young; Park, Jinsick; Choi, Hyo Jung; Baek, Hyewon; Lee, Jun Ho; Kim, Hyun Jung; Kim, Yu Kyeong; Yoon, Eun Jin; Sohn, Chul-Ho; Woo, Jong Inn; Lee, Dong Young

    2016-01-01

    Previous literature suggests that Alzheimer's disease (AD) process may contribute to late-life onset depression (LLOD). Therefore, we investigated the association of LLOD with cerebral amyloidosis and neuronal injury, the two key brain changes in AD, along with vascular risks. Twenty nine non-demented individuals who first experienced major depressive disorder (MDD) after age of 60 years were included as LLOD subjects, and 27 non-demented elderly individuals without lifetime experience of MDD were included as normal controls (NC). Comorbid mild cognitive impairment (MCI) was diagnosed in 48% of LLOD subjects and in 0% of NC. LLOD, irrespective of comorbid MCI diagnosis, was associated with prominent prefrontal cortical atrophy. Compared to NC, LLOD subjects with comorbid MCI (LLODMCI) showed increased cerebral 11C-Pittsburg compound B (PiB) retention and plasma beta-amyloid 1–40 and 1–42 peptides, as measures of cerebral amyloidosis; and, such relationship was not observed in overall LLOD or LLOD without MCI (LLODwoMCI). LLOD subjects, particularly the LLODwoMCI, had higher systolic blood pressure (SBP) than NC. When analyzed in the same multiple logistic regression model that included prefrontal gray matter (GM) density, cerebral amyloidosis, and SBP as independent variables, only prefrontal GM density showed a significant independent association with LLOD regardless of MCI comorbidity status. Our findings suggest AD process might be related to LLOD via prefrontal neuronal injury in the MCI stage, whereas vascular processes—SBP elevation, in particular—are associated with LLOD via prefrontal neuronal injury even in cognitively intact or less impaired individuals. PMID:27790137

  12. Genetic enhancement of microsomal epoxide hydrolase improves metabolic detoxification but impairs cerebral blood flow regulation.

    Science.gov (United States)

    Marowsky, Anne; Haenel, Karen; Bockamp, Ernesto; Heck, Rosario; Rutishauser, Sibylle; Mule, Nandkishor; Kindler, Diana; Rudin, Markus; Arand, Michael

    2016-12-01

    Microsomal epoxide hydrolase (mEH) is a detoxifying enzyme for xenobiotic compounds. Enzymatic activity of mEH can be greatly increased by a point mutation, leading to an E404D amino acid exchange in its catalytic triad. Surprisingly, this variant is not found in any vertebrate species, despite the obvious advantage of accelerated detoxification. We hypothesized that this evolutionary avoidance is due to the fact that the mEH plays a dualistic role in detoxification and control of endogenous vascular signaling molecules. To test this, we generated mEH E404D mice and assessed them for detoxification capacity and vascular dynamics. In liver microsomes from these mice, turnover of the xenobiotic compound phenanthrene-9,10-oxide was four times faster compared to WT liver microsomes, confirming accelerated detoxification. mEH E404D animals also showed faster metabolization of a specific class of endogenous eicosanoids, arachidonic acid-derived epoxyeicosatrienoic acids (EETs) to dihydroxyeicosatrienoic acids (DHETs). Significantly higher DHETs/EETs ratios were found in mEH E404D liver, urine, plasma, brain and cerebral endothelial cells compared to WT controls, suggesting a broad impact of the mEH mutant on endogenous EETs metabolism. Because EETs are strong vasodilators in cerebral vasculature, hemodynamics were assessed in mEH E404D and WT cerebral cortex and hippocampus using cerebral blood volume (CBV)-based functional magnetic resonance imaging (fMRI). Basal CBV0 levels were similar between mEH E404D and control mice in both brain areas. But vascular reactivity and vasodilation in response to the vasodilatory drug acetazolamide were reduced in mEH E404D forebrain compared to WT controls by factor 3 and 2.6, respectively. These results demonstrate a critical role for mEH E404D in vasodynamics and suggest that deregulation of endogenous signaling pathways is the undesirable gain of function associated with the E404D variant.

  13. Differences in functional brain connectivity alterations associated with cerebral amyloid deposition in amnestic mild cognitive impairment

    Directory of Open Access Journals (Sweden)

    Dahyun eYi

    2015-02-01

    Full Text Available Despite potential implications for the early detection of impending AD, very little is known about the differences of large scale brain networks between amnestic MCI (aMCI with high cerebral amyloid beta protein (Aβ deposition (i.e., aMCI+ and aMCI with no or very little Aβ deposition (i.e., aMCI-. We first aimed to extend the current literature on altering intrinsic functional connectivity (FC of the default mode network (DMN and salience network (SN from CN to AD dementia. Second, we further examined the differences of the DMN and the SN between aMCI-, aMCI+, and CN. Forty-three older adult (12 CN, 10 aMCI+, 10 aMCI-, and 11 AD dementia subjects were included. All participants received clinical and neuropsychological assessment, resting state functional MRI, structural MRI, and Pittsburgh compound-B-PET scans. FC data were preprocessed using Multivariate Exploratory Linear Optimized Decomposition into Independent Components of FSL. Group comparisons were carried out using the dual-regression approach. In addition, to verify presence of grey matter (GM volume changes with intrinsic functional network alterations, Voxel Based Morphometry was performed on the acquired T1-weighted data. As expected, AD dementia participants exhibited decreased FC in the DMN compared to CN (in precuneus and cingulate gyrus. The degree of alteration in the DMN in aMCI+ compared to CN was intermediate to that of AD. In contrast, aMCI- exhibited increased FC in the DMN compared to CN (in precuneus as well as aMCI+. In terms of the SN, aMCI- exhibited decreased FC compared to both CN and aMCI+ particularly in the inferior frontal gyrus. FC within the SN in aMCI+ and AD did not differ from CN. Compared to CN, aMCI- showed atrophy in bilateral superior temporal gyri whereas aMCI+ showed atrophy in right precuneus. The results indicate that despite of the similarity in cross-sectional cognitive features aMCI- has quite different functional brain connectivity compared to

  14. Left-right cortical asymmetries of regional cerebral blood flow during listening to words

    DEFF Research Database (Denmark)

    Nishizawa, Y; Olsen, T S; Larsen, B;

    1982-01-01

    1. Regional cerebral blood flow (rCBF) was measured during rest and during listening to simple words. The xenon-133 intracarotid technique was used and results were obtained from 254 regions of seven right hemispheres and seven left hemispheres. The measurements were performed just after carotid...... angiography, carried out to exclude space occupying lesions. In all subjects the angiogram was normal. All were right handed. 2. Mean hemispheric blood flow of both left and right hemispheres increased 10% from the resting measurement during the listening task. This increase was due in part to activation...... widespread and intense increase, averaging 29% as compared to 18% on the right side. This left-sided dominance during verbal stimulation should be compared to the right-sided dominance of rCBF during nonverbal sound discrimination reported by Roland et al. (25, 26), who used precisely the same technique...

  15. Increased cerebral blood flow in MELAS shown by Tc-99m HMPAO brain SPECT

    Energy Technology Data Exchange (ETDEWEB)

    Peng, N.J.; Tsay, D.G. [Department of Nuclear Medicine, Kaohsiung Veterans General Hospital, Kaohsiung (Taiwan); Liu, R.S. [Department of Nuclear Medicine, Taipei Veterans General Hospital, National Yang-Ming University, Taipei (Taiwan); Li, J.Y.; Kong, K.W. [Division of Neurology, Department of Internal Medicine, Kaohsiung Veterans General Hospital, Kaohsiung (Taiwan); Kwok, C.G.; Strauss, H.W. [Division of Nuclear Medicine, Department of Radiology, Stanford University Medical Center, CA (United States)

    2000-01-01

    We report cerebral SPECT studies on two siblings with the syndrome of mitochondrial myopathy, encephalopathy, lactic acidosis and stroke-like episodes (MELAS). Tc-99m HMPAO brain SPECT was performed 8, 19 and 30 days after a stroke-like episode in one case and 10 days after a stroke-like episode, 6 h after a partial seizure and as a follow-up study in the other. Increased blood flow was seen in both these patients with stroke-like episodes due to MELAS. The cause of the increased blood flow is uncertain, but it may be related to the decreased pH created by local increase in lactic acid. (orig.)

  16. Cerebral blood flow regulation, exercise and pregnancy: why should we care?

    Science.gov (United States)

    Bisson, Michèle; Marc, Isabelle; Brassard, Patrice

    2016-05-01

    Cerebral blood flow (CBF) regulation is an indicator of cerebrovascular health increasingly recognized as being influenced by physical activity. Although regular exercise is recommended during healthy pregnancy, the effects of exercise on CBF regulation during this critical period of important blood flow increase and redistribution remain incompletely understood. Moreover, only a few studies have evaluated the effects of human pregnancy on CBF regulation. The present work summarizes current knowledge on CBF regulation in humans at rest and during aerobic exercise in relation to healthy pregnancy. Important gaps in the literature are highlighted, emphasizing the need to conduct well-designed studies assessing cerebrovascular function before, during and after this crucial life period to evaluate the potential cerebrovascular risks and benefits of exercise during pregnancy.

  17. High blood pressure and cerebral white matter lesion progression in the general population.

    Science.gov (United States)

    Verhaaren, Benjamin F J; Vernooij, Meike W; de Boer, Renske; Hofman, Albert; Niessen, Wiro J; van der Lugt, Aad; Ikram, M Arfan

    2013-06-01

    High blood pressure is considered an important risk factor for cerebral white matter lesions (WMLs) in the aging population. In a longitudinal population-based study of 665 nondemented persons, we investigated the longitudinal relationship of systolic blood pressure, diastolic blood pressure, and pulse pressure with annual progression of WMLs. Means of blood pressure were calculated over a 5-year period before longitudinal MRI scanning. WML progression was subsequently measured on 2 scans 3.5 years apart. We performed analyses with linear regression models and evaluated adjustments for age, sex, cardiovascular risk factors, and baseline WML volume. In addition, we evaluated whether treatment of hypertension is related to less WML progression. Both systolic and diastolic blood pressures were significantly associated with annual WML progression (regression coefficient [95% confidence interval], 0.08 [0.03; 0.14] mL/y and 0.09 [0.03; 0.15] mL/y per SD increase in systolic and diastolic blood pressure, respectively). Pulse pressure was also significantly associated with WML progression, but not independent from hypertension. After adjustment for baseline WML volume, only systolic blood pressure remained significantly associated: 0.05 (0.00; 0.09) mL/y per SD increase. People with uncontrolled untreated hypertension had significantly more WML progression than people with uncontrolled treated hypertension (difference [95% confidence interval], 0.12 [0.00; 0.23] mL/y). The present study further establishes high blood pressure to precede WMLs and implies that hypertension treatment could reduce WML progression in the general population.

  18. EFFECT OF ELECTROACUPUNCTURE ON CEREBRAL BLOOD FLOW,VIP AND ET IN RATS WITH VASCULAR DEMENTIA

    Institute of Scientific and Technical Information of China (English)

    申国明; 徐颖; 何峰; 许冠荪

    2004-01-01

    Objective: To investigate the relationship between electroacupuncture (EA)-induced improvement of regional cerebral blood flow and the alternations of vasoactive intestinal peptide (VIP) and endothelin (ET) in rats with experimental vascular dementia (VD).Methods: 40 Wistar rats were evenly randomized into sham-operation, model, medication (Nimotone) and EA groups.Vascular dementia model was established by repeated cerebral ischemia-reperfusion which was induced by occlusion and reopen of the bilateral common carotid arteries.EA (2~200 Hz, 2~3 mA) was applied to "Baihui"(GV 20), "Dazhui"(GV 14) and "Zusanli"(ST 36) for 30 min, once daily and continuously for 15 days.The regional cerebral blood flow (rCBF) in parietal lobe and hippocampus was determined with method of hydrogen clearance; a step-down avoidance test was adopted to observe the rats' behavior change; and plasma VIP and ET contents were assayed by radioimmunoassay.Results: In comparison with sham-operation group, the correct rate of step-down avoidance test, rCBF in parietal lobe and hippocampus and plasma VIP level in VD model group lowered significantly (P<0.01) and plasma ET increased considerably (P<0.01).However, compared with model group, the correct rate of step-down avoidance test, rCBF values and plasma VIP in EA group raised obviously while plasma ET declined significantly.No significant differences were found between EA and medication groups in the 4 indexes.Conclusion: EA can raise rCBF in the parietal lobe and hippocampus, elevate plasma VIP level and reduce plasma ET in rats with VD.

  19. 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)

  20. The reproducibility of cerebral blood flow with N-isopropyl-p-({sup 123}I) iodoamphetamine by arterial blood sampling method

    Energy Technology Data Exchange (ETDEWEB)

    Sasaki, Kazufumi; Tamura, Kiyohiko [Akita Univ. (Japan). Hospital; Hirano, Hiroko; Oyama, Yoichi; Kobayashi, Mitsuru; Tomura, Noriaki; Watari, Jiro

    1997-12-01

    The reproducibility of cerebral blood flow (CBF) based on the microsphere model with N-isopropyl-p-({sup 123}I) iodoamphetamine (IMP), was evaluated 4.58% (=CV) and was within 9%. The former was calculated from the elementary experiments, the latter was calculated with the CBF of 11 cases. On the clinical conditions, where we selected some astrocytomas of grade III injected ACNU super selectively with Seldinger catheter, and quantified CBF both pre and post ACNU ia by the ROI of 16.2 mm{phi}. On the other hand we have been monitoring the Cross Calibration Factors (CCFs) since we started CBF quantification. The CCFs during 5 years were all within the upper and the lower control limits. At a worst case the average deviation of CCF was 1.17% by a month, which is equal to 7.0% by 6 months. Then SPECT and well counter should be calibrated at least once every 6 months. (author)

  1. Microstructure and Cerebral Blood Flow within White Matter of the Human Brain: A TBSS Analysis.

    Directory of Open Access Journals (Sweden)

    Stéphanie Giezendanner

    Full Text Available White matter (WM fibers connect different brain regions and are critical for proper brain function. However, little is known about the cerebral blood flow in WM and its relation to WM microstructure. Recent improvements in measuring cerebral blood flow (CBF by means of arterial spin labeling (ASL suggest that the signal in white matter may be detected. Its implications for physiology needs to be extensively explored. For this purpose, CBF and its relation to anisotropic diffusion was analyzed across subjects on a voxel-wise basis with tract-based spatial statistics (TBSS and also across white matter tracts within subjects.Diffusion tensor imaging and ASL were acquired in 43 healthy subjects (mean age = 26.3 years.CBF in WM was observed to correlate positively with fractional anisotropy across subjects in parts of the splenium of corpus callosum, the right posterior thalamic radiation (including the optic radiation, the forceps major, the right inferior fronto-occipital fasciculus, the right inferior longitudinal fasciculus and the right superior longitudinal fasciculus. Furthermore, radial diffusivity correlated negatively with CBF across subjects in similar regions. Moreover, CBF and FA correlated positively across white matter tracts within subjects.The currently observed findings on a macroscopic level might reflect the metabolic demand of white matter on a microscopic level involving myelination processes or axonal function. However, the exact underlying physiological mechanism of this relationship needs further evaluation.

  2. Effects of axillary blockade on regional cerebral blood flow during dynamic hand contractions

    DEFF Research Database (Denmark)

    Friedman, D B; Friberg, L; Payne, G;

    1992-01-01

    Regional cerebral blood flow (rCBF) was measured at orbitomeatal (OM) plane +5.0 and +9.0 cm in 10 subjects at rest and during dynamic hand contractions before and after axillary blockade. Handgrip strength was significantly reduced, and rating of perceived exertion increased after blockade. During...... hand contractions before blockade, contralateral hemispheric cerebral blood flow (CBF) at OM +9.0 increased from a resting value of 58 (49-75) to 63 (52-82) ml.100 g-1.min-1; contralateral motor sensory rCBF at OM +9 from 58 (50-77) to 71 (64-84); motor sensory rCBF at OM +5 from 67 (54-76) to 77 (64......-87) and 70 (62-84) contralaterally and ipsilaterally, respectively; and supplementary motor area (SM) rCBF from 64 (53-69) to 75 (67-88) ml.100 g-1.min-1. During dynamic hand contractions after axillary blockade, CBF did not increase at OM +5 or in the SM. Furthermore, contralateral motor sensory rCBF at OM...

  3. Metabolomic Analysis of Clinical Plasma from Cerebral Infarction Patients Presenting with Blood Stasis

    Directory of Open Access Journals (Sweden)

    Min Ho Cha

    2015-01-01

    Full Text Available Blood stasis (BS is characterized as a disorder of blood circulation. In traditional Korean medicine (TKM, it is viewed as a cause factor of diseases such as multiple sclerosis and stroke. This study investigated differences in the plasma metabolites profiles of subjects displaying BS or non-BS patterns. Thirty-one patients with cerebral infarction diagnosed with BS and an equal number of sex- and age-matched non-BS patients were enrolled. Metabolic profiling was performed using UPLC-MS. The ratio of subjects with a rough pulse and purple coloration of the tongue was higher in patients presenting with BS pattern. Through metabolomics analysis, 82 metabolites that differed significantly between the BS and non-BS pattern were identified, and the two groups were significantly separated using an orthogonal partial least square-discriminant analysis model (P<0.001. Of these 82 metabolites, acetyl carnitine, leucine, kynurenine, phosphocholine, hexanoyl carnitine, and decanoyl carnitine were present in significantly higher levels in patients with a BS pattern than those with a non-BS pattern. Our results also demonstrated that seven plasma metabolites, including acyl-carnitines and kynurenine, were associated with a BS pattern, suggesting that variant plasma metabolic profiles may serve as a biomarker for diagnosis of BS in patients with cerebral infarction.

  4. Cerebral blood flow and oxygen metabolism in dementia with Lewy bodies

    Energy Technology Data Exchange (ETDEWEB)

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

    2000-06-01

    Regional cerebral blood flow (rCBF), oxygen metabolism (rCMRO{sub 2}) and the oxygen extraction fraction (rOEF) were measured using the steady-state {sup 15}O technique and positron emission tomography (PET) in six patients with dementia with Lewy bodies (DLB), and compared with ten patients with Alzheimer disease (AD) and six normal controls. In the AD patients, rCBF and rCMRO{sub 2} were significantly decreased in the frontal, parietal, and temporal cortices compared with controls. In DLB patients, rCBF and rCMRO{sub 2} were decreased in the frontal, parietal, temporal, and occipital cortices compared with controls, and were decreased more diffusely than in AD patients. rCBF and rCMRO{sub 2} were significantly decreased in occipital cortex compared with AD patients. rOEF was significantly increased in the parieto-temporal cortex in AD patients compared with controls. In DLB patients, rOEF was significantly increased not only in the parieto-temporal cortex but also in the occipital and frontal cortices compared with controls, and was significantly increased in the occipital cortex compared with AD patients. The diffuse reduction of cerebral blood flow and oxygen metabolism including the occipital cortex may be related to visual hallucination and other visuospatial deficits frequently seen in DLB patients. The increase in rOEF may be mainly due to the reduction in the vascular bed associated with decreased activity in the vasodilatory cholinergic system. (author)

  5. Effects of diving and oxygen on autonomic nervous system and cerebral blood flow.

    Science.gov (United States)

    Winklewski, Pawel J; Kot, Jacek; Frydrychowski, Andrzej F; Nuckowska, Magdalena K; Tkachenko, Yurii

    2013-09-01

    Recreational scuba diving is a popular leisure activity with the number of divers reaching several millions worldwide. Scuba diving represents a huge challenge for integrative physiology. In mammalian evolution, physiological reflexes developed to deal with lack of oxygen, rather than with an excess, which makes adaptations to scuba diving more difficult to describe and understand than those associated with breath-hold diving. The underwater environment significantly limits the use of equipment to register the organism's functions, so, in most instances, scientific theories are built on experiments that model real diving to some extent, like hyperbaric exposures, dive reflexes or water immersion. The aim of this review is to summarise the current knowledge related to the influence exerted by physiological conditions specific to diving on the autonomic nervous system and cerebral blood flow. The main factors regulating cerebral blood flow during scuba diving are discussed as follows: 1) increased oxygen partial pressure; 2) immersion-related trigemino-cardiac reflexes and 3) exposure to cold, exercise and stress. Also discussed are the potential mechanisms associated with immersion pulmonary oedema.

  6. Correlation of middle latency auditory evoked potentials and cerebral blood flow changes

    Energy Technology Data Exchange (ETDEWEB)

    Sugimoto, Seiichiro; Sugimoto, Akiko; Ohi, Takekazu; Matsukura, Shigeru; Watanabe, Katushi [Miyazaki Medical Coll., Kiyotake (Japan); Hoshi, Hiroaki

    1997-12-01

    The purpose of this study is to find the correlation between middle latency auditory evoked potentials (MLAEP) and sound activated single photon emission computed tomography (SPECT) studies. This study was performed on six normal right-handed volunteers with a mean age of 35.2{+-}7.6 years, using the split-dose technique. First, a SPECT study was performed on subjects in blinded, awake and silent states. After bilateral ears were stimulated with a click sound, MLAEP and a second SPECT study were performed. Subtraction of the first SPECT from the second SPECT revealed a statistically significant increase of cerebral blood flow (CBF) in the bilateral superior temporal region. Bilateral Na amplitudes of MLAEP had a statistically significant and good correlation with the percentages of CBF changes in the bilateral superior temporal region. The superior temporal cerebral blood flow activation can be expressed by electrophysiological activation. Moreover, correlation during the left Na components and left frontal and occipital lobe are discussed. (author)

  7. Cerebral blood flow measurement using fMRI and PET: a cross-validation study.

    Science.gov (United States)

    Chen, Jean J; Wieckowska, Marguerite; Meyer, Ernst; Pike, G Bruce

    2008-01-01

    An important aspect of functional magnetic resonance imaging (fMRI) is the study of brain hemodynamics, and MR arterial spin labeling (ASL) perfusion imaging has gained wide acceptance as a robust and noninvasive technique. However, the cerebral blood flow (CBF) measurements obtained with ASL fMRI have not been fully validated, particularly during global CBF modulations. We present a comparison of cerebral blood flow changes (DeltaCBF) measured using a flow-sensitive alternating inversion recovery (FAIR) ASL perfusion method to those obtained using H(2) (15)O PET, which is the current gold standard for in vivo imaging of CBF. To study regional and global CBF changes, a group of 10 healthy volunteers were imaged under identical experimental conditions during presentation of 5 levels of visual stimulation and one level of hypercapnia. The CBF changes were compared using 3 types of region-of-interest (ROI) masks. FAIR measurements of CBF changes were found to be slightly lower than those measured with PET (average DeltaCBF of 21.5 +/- 8.2% for FAIR versus 28.2 +/- 12.8% for PET at maximum stimulation intensity). Nonetheless, there was a strong correlation between measurements of the two modalities. Finally, a t-test comparison of the slopes of the linear fits of PET versus ASL DeltaCBF for all 3 ROI types indicated no significant difference from unity (P > .05).

  8. Cerebral Blood Flow Measurement Using fMRI and PET: A Cross-Validation Study

    Directory of Open Access Journals (Sweden)

    Jean J. Chen

    2008-01-01

    Full Text Available An important aspect of functional magnetic resonance imaging (fMRI is the study of brain hemodynamics, and MR arterial spin labeling (ASL perfusion imaging has gained wide acceptance as a robust and noninvasive technique. However, the cerebral blood flow (CBF measurements obtained with ASL fMRI have not been fully validated, particularly during global CBF modulations. We present a comparison of cerebral blood flow changes (ΔCBF measured using a flow-sensitive alternating inversion recovery (FAIR ASL perfusion method to those obtained using H2O15 PET, which is the current gold standard for in vivo imaging of CBF. To study regional and global CBF changes, a group of 10 healthy volunteers were imaged under identical experimental conditions during presentation of 5 levels of visual stimulation and one level of hypercapnia. The CBF changes were compared using 3 types of region-of-interest (ROI masks. FAIR measurements of CBF changes were found to be slightly lower than those measured with PET (average ΔCBF of 21.5±8.2% for FAIR versus 28.2±12.8% for PET at maximum stimulation intensity. Nonetheless, there was a strong correlation between measurements of the two modalities. Finally, a t-test comparison of the slopes of the linear fits of PET versus ASL ΔCBF for all 3 ROI types indicated no significant difference from unity (P>.05.

  9. [Evoked potentials and regional cerebral blood flow changes in conversion disorder: a case report and review].

    Science.gov (United States)

    Gürses, Nadide; Temuçin, Cağri Mesut; Lay Ergün, Eser; Ertuğrul, Aygün; Ozer, Suzan; Demir, Başaran

    2008-01-01

    Conversion disorder is defined as the presence of functional impairment in motor, sensory or neurovegetative systems which cannot be explained by a general medical condition. Although the diagnostic systems emphasize the absence of an organic basis for the dysfunction in conversion disorder, there has been a growing interest in the specific functional brain correlates of conversion symptoms in recent years, particularly by examining neuroimaging and neurophysiological measures. In this case report, regional cerebral blood flow changes and evoked potentials of a patient with conversion symptoms are presented. Somatosensory evoked potentials (SEP) of this patient with conversion disorder who had signs of movement disorder revealed that the latency to N20, P 25 waves were in normal limits while the amplitudes of the P25 and N33 components were extremely high (giant SEP). Regional cerebral blood flow assessment revealed hypoperfusion in the left parietal and temporal lobes of the brain. Three months after the first assessment, the control scans showed that the left parietal hypoperfusion disappeared while the left temporal hypoperfusion was still present. The following SEP evaluations which were repeated twice in three months intervals after the initial recordings, showed the persistence of the abnormalities in somatosensorial measures. The neurophysiological and neuroimaging findings in conversion disorder were reviewed and the results of the evaluations of this case were discussed in this article.

  10. The Longitudinal Evolution of Cerebral Blood Flow Regulation after Acute Ischaemic Stroke

    Directory of Open Access Journals (Sweden)

    Angela S.M. Salinet

    2014-08-01

    Full Text Available Background: Acute stroke is known to impair cerebral blood flow (CBF regulation, but the longitudinal changes of these effects have been poorly reported. The main CBF regulatory mechanisms [cerebral autoregulation (CA and neurovascular coupling (NVC] were assessed over 3 months after acute ischaemic stroke. Methods: Recordings of CBF velocity (CBFv, blood pressure (BP, and end-tidal CO2 were performed during 5 min baseline and 1 min passive movement of the elbow. Stroke patients were assessed Results: Fifteen acute stroke subjects underwent all 4 sessions and were compared to 22 control subjects. Baseline recordings revealed a significantly lower CBFv in the affected hemisphere within 72 h after stroke compared to controls (p = 0.02 and a reduction in CA index most marked at 2 weeks (p = 0.009. CBFv rise in response to passive arm movement was decreased bilaterally after stroke, particularly in the affected hemisphere (p Conclusion: The major novel finding of this study was that both CA and NVC regulatory mechanisms deteriorated initially following stroke onset, but returned to control levels during the recovery period. These findings are relevant to guide the timing of interventions to manipulate BP and potentially for the impact of intensive rehabilitation strategies that may precipitate acute physiological perturbations but require further exploration in a larger population that better reflects the heterogeneity of stroke. Further, they will also enable the potential influence of stroke subtype to be investigated.

  11. Low Cerebral Oxygen Consumption and Blood Flow in Patients With Cirrhosis and an Acute Episode of Hepatic Encephalopathy

    DEFF Research Database (Denmark)

    Iversen, Peter; Bak, Lasse Kristoffer; Waagepetersen, Helle Sønderby

    2009-01-01

    BACKGROUND & AIMS: It is unclear whether patients with hepatic encephalopathy (HE) have disturbed brain oxygen metabolism and blood flow. METHODS: We measured cerebral oxygen metabolism rate (CMRO(2)) by using (15)O-oxygen positron emission tomography (PET), and cerebral blood flow (CBF) by using....../min in patients with HE, 0.47 +/- 0.02 in patients without HE, and 0.49 +/- 0.03 in healthy subjects. CMRO(2) and CBF were correlated, and both variables correlated negatively with arterial ammonia concentration. Analysis of regional values, using individual magnetic resonance co-registrations, showed...... that the reductions in CMRO(2) and CBF in patients with HE were essentially generalized throughout the brain. CONCLUSIONS: The observations imply that reduced cerebral oxygen consumption and blood flow in cirrhotic patients with an acute episode of overt HE are associated with HE and not cirrhosis as such...

  12. Effects of aging on cerebral blood flow, oxygen metabolism, and blood oxygenation level dependent responses to visual stimulation.

    Science.gov (United States)

    Ances, Beau M; Liang, Christine L; Leontiev, Oleg; Perthen, Joanna E; Fleisher, Adam S; Lansing, Amy E; Buxton, Richard B

    2009-04-01

    Calibrated functional magnetic resonance imaging (fMRI) provides a noninvasive technique to assess functional metabolic changes associated with normal aging. We simultaneously measured both the magnitude of the blood oxygenation level dependent (BOLD) and cerebral blood flow (CBF) responses in the visual cortex for separate conditions of mild hypercapnia (5% CO(2)) and a simple checkerboard stimulus in healthy younger (n = 10, mean: 28-years-old) and older (n = 10, mean: 53-years-old) adults. From these data we derived baseline CBF, the BOLD scaling parameter M, the fractional change in the cerebral metabolic rate of oxygen consumption (CMRO(2)) with activation, and the coupling ratio n of the fractional changes in CBF and CMRO(2). For the functional activation paradigm, the magnitude of the BOLD response was significantly lower for the older group (0.57 +/- 0.07%) compared to the younger group (0.95 +/- 0.14%), despite the finding that the fractional CBF and CMRO(2) changes were similar for both groups. The weaker BOLD response for the older group was due to a reduction in the parameter M, which was significantly lower for older (4.6 +/- 0.4%) than younger subjects (6.5 +/- 0.8%), most likely reflecting a reduction in baseline CBF for older (41.7 +/- 4.8 mL/100 mL/min) compared to younger (59.6 +/- 9.1 mL/100 mL/min) subjects. In addition to these primary responses, for both groups the BOLD response exhibited a post-stimulus undershoot with no significant difference in this magnitude. However, the post-undershoot period of the CBF response was significantly greater for older compared to younger subjects. We conclude that when comparing two populations, the BOLD response can provide misleading reflections of underlying physiological changes. A calibrated approach provides a more quantitative reflection of underlying metabolic changes than the BOLD response alone.

  13. Sympathetically-induced changes in microvascular cerebral blood flow and in the morphology of its low-frequency waves.

    Science.gov (United States)

    Deriu, F; Roatta, S; Grassi, C; Urciuoli, R; Micieli, G; Passatore, M

    1996-06-10

    The effect of bilateral cervical sympathetic nerve stimulation on microvascular cerebral blood flow, recorded at various depths in the parietal lobe and in ponto-mesencephalic areas, was investigated by laser-Doppler flowmetry in normotensive rabbits. These areas were chosen as representative of the vascular beds supplied by the carotid and vertebro-basilar systems, which exhibit different degrees of sympathetic innervation, the former being richer than the latter. Sympathetic stimulation at 30 imp/s affects cerebral blood flow in 77% of the parietal lobe and in 43% of the ponto-mesencephalic tested areas. In both cases the predominant effect was a reduction in blood flow (14.7 +/- 5.1% and 4.1 +/- 2.4%, respectively). The extent of the reduction in both areas was less if the stimulation frequency was decreased. Sometimes mean cerebral blood flow showed a small and transient increase, mainly in response to low-frequency stimulation. The morphology was analysed of low-frequency spontaneous oscillations in cerebral blood flow, attributed to vasomotion. Present in 41% of the tested areas (frequency 4-12 cycles/min, peak-to-peak amplitude 10-40% of mean value), these waves decreased in amplitude and increased in frequency during sympathetic stimulation, irrespective of changes in mean flow. The possibility has been proposed that the sympathetic action on low-frequency spontaneous oscillations may contribute to the protective influence that this system is known to exert on the blood-brain barrier in hypertension.

  14. Effect of combined VEGF165/ SDF-1 gene therapy on vascular remodeling and blood perfusion in cerebral ischemia.

    Science.gov (United States)

    Hu, Guo-Jie; Feng, Yu-Gong; Lu, Wen-Peng; Li, Huan-Ting; Xie, Hong-Wei; Li, Shi-Fang

    2016-12-16

    OBJECTIVE Therapeutic neovascularization is a promising strategy for treating patients after an ischemic stroke; however, single-factor therapy has limitations. Stromal cell-derived factor 1 (SDF-1) and vascular endothelial growth factor (VEGF) proteins synergistically promote angiogenesis. In this study, the authors assessed the effect of combined gene therapy with VEGF165 and SDF-1 in a rat model of cerebral infarction. METHODS An adenoviral vector expressing VEGF165 and SDF-1 connected via an internal ribosome entry site was constructed (Ad- VEGF165-SDF-1). A rat model of middle cerebral artery occlusion (MCAO) was established; either Ad- VEGF165-SDF-1 or control adenovirus Ad- LacZ was stereotactically microinjected into the lateral ventricle of 80 rats 24 hours after MCAO. Coexpression and distribution of VEGF165 and SDF-1 were examined by reverse-transcription polymerase chain reaction, Western blotting, and immunofluorescence. The neurological severity score of each rat was measured on Days 3, 7, 14, 21, and 28 after MCAO. Angiogenesis and vascular remodeling were evaluated via bromodeoxyuridine and CD34 immunofluorescence labeling. Relative cerebral infarction volumes were determined by T2-weighted MRI and triphenyltetrazolium chloride staining. Cerebral blood flow, relative cerebral blood volume, and relative mean transmit time were assessed using perfusion-weighted MRI. RESULTS The Ad- VEGF165-SDF-1 vector mediated coexpression of VEGF165 and SDF-1 in multiple sites around the ischemic core, including the cortex, corpus striatum, and hippocampal granular layer. Coexpression of VEGF165 and SDF-1 improved neural function, reduced cerebral infarction volume, increased microvascular density and promoted angiogenesis in the ischemic penumbra, and improved cerebral blood flow and perfusion. CONCLUSIONS Combined VEGF165 and SDF-1 gene therapy represents a potential strategy for improving vascular remodeling and recovery of neural function after cerebral

  15. The effects of sevoflurane and propofol anesthesia on cerebral oxygenation in gynecological laparoscopic surgery

    OpenAIRE

    Kim, Sung-Jin; Kwon, Jae Young; Cho, Ah-Reum; Kim, Hae Kyu; Kim, Tae Kyun

    2011-01-01

    Background Both the Trendelenburg position and pneumoperitoneum with carbon dioxide have been reported to increase intracranial pressure (ICP) and to alter cerebral blood flow or cerebral blood volume. Also anesthetic agents have variable effects on cerebral hemodynamics and ICP. The present study was conducted to determine whether regional cerebral oxygen saturation (rSO2) values differ between propofol and sevoflurane anesthesia during laparoscopic surgery in the Trendelenburg position. Met...

  16. Clinical Observation on Influence of Chinese Medicines for Promoting Blood Circulation to Remove Blood Stasis on FIB and DD in Plasma of Patients with Cerebral Thrombosis

    Institute of Scientific and Technical Information of China (English)

    梁晖; 陈甦; 陈少芳

    2002-01-01

    Objective: to study the influence of Chinese medicines for promoting blood circulation to remove blood stasis on fibrinogen (FIB) and D-dimer (DD) in plasma of patients with cerebral thrombosis. Method: 73 inpatients with acute cerebral thrombosis were randomly divided into a control group of 34 cases and a treatment group of 39 cases. The content of FIB and DD in plasma was detected before treatment and on the 7th and 14th days after treatment. Result: FIB content in plasma after treatment was lower than that before treatment in the control group (P<0.01) and more remarkable in the treatment group (P<0.001). There was an obvious difference in DD content before and after treatment in both groups. DD content on the 7th and 14th days after treatment in the treatment group was obviously higher than that in the control group (P<0.01 and P<0.05 respectively). Conclusion: Chinese medicines for promoting blood circulation to remove blood stasis can reduce the FIB content in plasma of patients with cerebral thrombosis, raise the DD content in plasma, cause the peak of DD content appear earlier and obviously improve hypercoagulability of blood in patients with cerebral thrombosis.

  17. Spatial distributions of red blood cells significantly alter local haemodynamics.

    Directory of Open Access Journals (Sweden)

    Joseph M Sherwood

    Full Text Available Although bulk changes in red blood cell concentration between vessels have been well characterised, local distributions are generally overlooked. Red blood cells aggregate, deform and migrate within vessels, forming heterogeneous distributions which have considerable effect on local haemodynamics. The present study reports data on the local distribution of human red blood cells in a sequentially bifurcating microchannel, representing the branching geometry of the microvasculature. Imaging methodologies with simple extrapolations are used to infer three dimensional, time-averaged velocity and haematocrit distributions under a range of flow conditions. Strong correlation between the bluntness of the velocity and haematocrit profiles in the parent branch of the geometry is observed and red blood cell aggregation has a notable effect on the observed trends. The two branches of the first bifurcation show similar characteristics in terms of the shapes of the profiles and the extent of plasma skimming, despite the difference in geometric configuration. In the second bifurcation, considerable asymmetry between the branches in the plasma skimming relationship is observed, and elucidated by considering individual haematocrit profiles. The results of the study highlight the importance of considering local haematocrit distributions in the analysis of blood flow and could lead to more accurate computational models of blood flow in microvascular networks. The experimental approaches developed in this work provide a foundation for further examining the characteristics of microhaemodynamics.

  18. Effect of histamine on regional cerebral blood flow of the parietal lobe in rats.

    Science.gov (United States)

    Yang, Peng-Bo; Chen, Xin-Lin; Zhao, Jian-Jun; Zhang, Jian-Shui; Zhang, Jun-Feng; Tian, Yu-Mei; Liu, Yong

    2010-09-01

    Histamine is a powerful modulator that regulates blood vessels and blood flow. The effect of histamine on the extracortical vessels has been well described, while much less is known about the effect of histamine on intracortical vessels. In this study, we investigated the effect of histamine on regional cerebral blood flow in rat parietal lobe with laser Doppler flowmetry. The pharmacological characteristics of distinct ways (intracerebroventricular injection, intraperitoneal injection, and cranial window infusion) in applying histamine to the brain were also obtained and compared. Histamine applied in three ways all produced a decrease of rCBF in parietal lobe in a concentration-dependent manner. Cranial window infusion was the most effective way and intraperitoneal injection of L-histidine was the most ineffective, although it is a simple and applied way. To determine which type of receptor takes part in the vessel contraction induced by histamine, H1 receptor antagonist, diphenhydramine, and H2 receptor antagonist, cimetidine, were applied, respectively, before histamine administration. When the injection of cimetidine was conducted in advance, histamine still resulted in a decrease of infusion amount; while the injection of diphenhydramine was conducted in advance, the infusion of blood amount wasn't changed. These findings indicated that histamine could result in a reduction of rCBF in the rat parietal lobe and this effect of histamine may attribute partly to its combination with H1 receptor.

  19. Effects of anesthesia on the cerebral capillary blood flow in young and old mice

    Science.gov (United States)

    Moeini, Mohammad; Tabatabaei, Maryam S.; Bélanger, Samuel; Avti, Pramod; Castonguay, Alexandre; Pouliot, Philippe; Lesage, Frédéric

    2015-03-01

    Despite recent findings on the possible role of age-related cerebral microvasculature changes in cognition decline, previous studies of capillary blood flow in aging (using animal models) are scarce and limited to anesthetized conditions. Since anesthesia can have different effects in young and old animals, it may introduce a confounding effect in aging studies. The present study aimed to eliminate the potential confound introduced by anesthesia by measuring capillary blood flow parameters in both awake conditions and under isoflurane anesthesia. We used 2-photon laser scanning fluorescence microscopy to measure capillary diameter, red blood cell velocity and flux, hematocrit and capillary volumetric flow in individual capillaries in the barrel cortex of 6- and 24-month old C57Bl/6 mice. It was observed that microvascular properties are significantly affected by anesthesia leading to different trends in capillary blood flow parameters with aging when measured under awake or anesthetized conditions. The findings in this study suggest taking extra care in interpreting aging studies from anesthetized animals.

  20. Effects of cigarette smoking on cerebral blood flow in normal adults

    Energy Technology Data Exchange (ETDEWEB)

    Shinohara, Takao [Tokyo Medical Coll. (Japan)

    1997-11-01

    To elucidate the pharmacological effects of cigarette smoking on cerebral function and blood flow in normal adults, cerebral blood flow (CBF) was measured by positron emission tomography (PET) in 10 right-handed male healthy volunteers with a smoking habit after 12-hour abstinence. By the oxygen-15 intravenous injection method, quantitative CBF was measured repeatedly 6 times; during normal breathing (baseline), 5% CO{sub 2} inhalation and cigarette smoking. Sham smoking was performed during baseline and CO{sub 2} inhalation. To eliminate the effects from PaCO{sub 2}, CBF was adjusted based on the vascular reactivity to CO{sub 2} and PaCO{sub 2} during smoking. Pulse rate, systemic blood pressure and arterial nicotine level were increased during smoking. In the overall comparison, there was no significant change in the mean CBF during smoking as compared with baseline. Out of 19 sessions, CBF increased significantly in 7 sessions, while CBF decreased in 7 sessions and was unchanged in 5 sessions. The arterial concentration of nicotine correlated inversely with CBF. When the baseline CBF was relatively low, CBF increased during smoking, while it decreased when the baseline value was high. In the 3-dimensional statistical analysis of normalized CBF, a significant increase was seen in the nucleus accumbens, which is assumed to be related to the drug habits or addiction in previous studies. In the first smoking after abstinence, CBF increased in the orbitofrontal gyri, and this can be linked to reward or relaxation. By contrast, a significant decrease was observed in the occipital lobes and paracentral areas. (author)

  1. 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 exercise. During exhaustive exercise, however, euhydration delayed but did not prevent the decline in cerebral perfusion. In conclusion, during prolonged exercise in the heat, 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 .

  2. Hyperbaric oxygen therapy for cerebral blood flow and electroencephalogram in patients with acute cerebral infarction Choice for therapeutic occasion

    Institute of Scientific and Technical Information of China (English)

    Lei Chen; Fei Li; Dexiang Gu

    2007-01-01

    BACKGROUND: Hyperbaric oxygen (HBO) therapy increases blood oxygen content, changes cerebral blood flow (CBF) and cerebral metabolism. Its therapeutic effects on cerebrovascular disease have been fully confirmed, but the occasion for HBO therapy is still unclear.OBJECTIVE: To observe the therapeutic effects of HBO therapy at different time on CBF and electroencephalogram (EEG) in patients with acute cerebral infarction (CI).DESIGN: Randomized controlled trial.SETTING: Department of Neurology, Shidong Hospital, Yangpu District of Shanghai.PARTICIPANTS: Ninety-six inpatients with acute CI, admitted to Department of Neurology, Shidong Hospital, Yangpu District of Shanghai from January 2001 to December 2006, were involved in this experiment. The involved participants met the diagnosis criteria of acute CI and confirmed by skull CT or MRI. They all were patients with moderate CI (16- 30 points) according to neurologic deficit score formulated by Chinese Medical Association. Informed consents of detected items and therapeutic regimen were obtained from all the involved participants. They were randomized into two groups with 48 in each:early-stage treatment group and advanced-stage treatment group. Among the 48 patients in the early-stage treatment group, 21 male and 27 female, aged 53 -68 years, 22 patients were found with basal ganglia infarction, 10 with brain lobe infarction, 16 with multiple infarction, 27 accompanied with hypertension and 2 accompanied with diabetes mellitus. Among the 48 patients in the advanced-stage treatment group, 23 male and 25 female, aged 52 - 71 years, 25 patients were found with basal ganglia infarction, 10 with brain lobe infarction, 12 with multiple infarction, 1 with brain stem infarction, 28 accompanied with hypertension and 1 accompanied with diabetes mellitus.METHODS: After admission, patients of two groups received routine drug treatment. ① Patients in the early-stage treatment group and advanced-stage treatment group began to

  3. Effects of resveratrol alone or in combination with piperine on cerebral blood flow parameters and cognitive performance in human subjects: a randomised, double-blind, placebo-controlled, cross-over investigation

    OpenAIRE

    Wightman, Emma; Reay, Jonathon; Haskell, Crystal; Williamson, Gary; Dew, Tristan; Kennedy, David

    2014-01-01

    Previous research has shown that resveratrol can increase cerebral blood flow (CBF) in the absence of improved cognitive performance in healthy, young human subjects during the performance of cognitively demanding tasks. This lack of cognitive effects may be due to low bioavailability and, in turn, reduced bioefficacy of resveratrol in vivo. Piperine can alter polyphenol pharmacokinetics, but previous studies have not investigated whether this affects the efficacy of the target compound. Ther...

  4. Changes of cerebral blood flow in rats with acute cerebral ischemia and the effect of nitric oxide donor S-nitroso-N-acetyl-penicillamine

    Institute of Scientific and Technical Information of China (English)

    Feng Gao; Zhiqiang Yi; Guijun Lin

    2006-01-01

    BACKGROUND: Previous studies show that nitric oxide donor can increase cerebral blood flow and improve the function of neurons in cerebral ischemia, but the change does not happen in all the models of cerebral ischemia. OBJECTIVE: To observe the effects of nitric oxide donor S-nitroso-N-acetyl-penicillamine (SNAP) on the cerebral blood flow, cyclic guanosine monophosphate (cGMP) content in cerebral cortex, infarct volume and blood pressure in acute ischemic rat brain.DESIGN: A randomized and control animal experiment. SETTING: Department of Neurosurgery, Aerospace Central Hospital, Peking University. MATERIALS: Twenty-eight male Wistar rats of SPF grade, weighing 250-300 g, aged 10-12 weeks were randomly divided into control group (n =14) and SNAP-treated group (n =14). SNAP (5 mg/bottle) was provided by Beijing Chemical Reagent Company. Laser Doppler Flowmeter (FLO C1; Omegawave Inc., Tokyo, Japan) and immunoassay kit (Amersham Pharmacia Biotech, UK) were applied.METHODS: ① Model establishment: In the control group, models of cerebral ischemia were induced by ligating right common, internal and external carotid arteries; In the SNAP-treated group, models of cerebral ischemia were induced by ligating right common and external carotid arteries, followed by occluding middle cerebral artery and ligating internal carotid artery. ② Administration: In the SNAP-treated group, SNAP (100 μg/kg) was intravenously infused within 2 minutes, whereas in the control group, phosphate buffered saline (PBS, 1 mL) was intravenously infused (0.5 mL per minute). Six rats were used to measure the volume of cerebral infarction, and the other 8 rats were used to determine other indexes in each group respectively. ③ Determination of indexes: Regional cerebral blood flow (rCBF) was continuously measured by laser-Doppler flowmetry in the ischemic penumbra and contralateral cortex under the continuous monitoring of blood pressure, cGMP concentrations in brain tissue were determined

  5. Detecting altered postural control after cerebral concussion in athletes with normal postural stability

    OpenAIRE

    Cavanaugh, J; Guskiewicz, K.; Giuliani, C.; Marshall, S.; Mercer, V; Stergiou, N.

    2005-01-01

    Objective: To determine if approximate entropy (ApEn), a regularity statistic from non-linear dynamics, could detect changes in postural control during quiet standing in athletes with normal postural stability after cerebral concussion.

  6. Cerebral misery perfusion diagnosed using hypercapnic blood-oxygenation-level-dependent contrast functional magnetic resonance imaging: a case report

    Directory of Open Access Journals (Sweden)

    D'Souza Olympio

    2010-02-01

    Full Text Available Abstract Introduction Cerebral misery perfusion represents a failure of cerebral autoregulation. It is an important differential diagnosis in post-stroke patients presenting with collapses in the presence of haemodynamically significant cerebrovascular stenosis. This is particularly the case when cortical or internal watershed infarcts are present. When this condition occurs, further investigation should be done immediately. Case presentation A 50-year-old Caucasian man presented with a stroke secondary to complete occlusion of his left internal carotid artery. He went on to suffer recurrent seizures. Neuroimaging demonstrated numerous new watershed-territory cerebral infarcts. No source of arterial thromboembolism was demonstrable. Hypercapnic blood-oxygenation-level-dependent-contrast functional magnetic resonance imaging was used to measure his cerebrovascular reserve capacity. The findings were suggestive of cerebral misery perfusion. Conclusions Blood-oxygenation-level-dependent-contrast functional magnetic resonance imaging allows the inference of cerebral misery perfusion. This procedure is cheaper and more readily available than positron emission tomography imaging, which is the current gold standard diagnostic test. The most evaluated treatment for cerebral misery perfusion is extracranial-intracranial bypass. Although previous trials of this have been unfavourable, the results of new studies involving extracranial-intracranial bypass in high-risk patients identified during cerebral perfusion imaging are awaited. Cerebral misery perfusion is an important and under-recognized condition in which emerging imaging and treatment modalities present the possibility of practical and evidence-based management in the near future. Physicians should thus be aware of this disorder and of recent developments in diagnostic tests that allow its detection.

  7. Loss of Toll-like receptor 7 alters cytokine production and protects against experimental cerebral malaria

    OpenAIRE

    Baccarella, Alyssa; Huang, Brian W; Fontana, Mary F.; Kim, Charles C

    2014-01-01

    Background Malaria, caused by Plasmodium sp. parasites, is a leading cause of global morbidity and mortality. Cerebral malaria, characterized by neurological symptoms, is a life-threatening complication of malaria affecting over 500,000 young children in Africa every year. Because of the prevalence and severity of cerebral malaria, a better understanding of the underlying molecular mechanisms of its pathology is desirable and could inform future development of therapeutics. This study sought ...

  8. Equal contribution of increased intracranial pressure and subarachnoid blood to cerebral blood flow reduction and receptor upregulation after subarachnoid hemorrhage. Laboratory investigation

    DEFF Research Database (Denmark)

    Ansar, Saema; Edvinsson, Lars

    2009-01-01

    OBJECT: Cerebral ischemia remains the key cause of disability and death in the late phase after subarachnoid hemorrhage (SAH), and its pathogenesis is still poorly understood. The purpose of this study was to examine whether the change in intracranial pressure or the extravasated blood causes the...

  9. Cardiorespiratory and blood gas alterations during laparoscopic surgery for intra-uterine artificial insemination in dogs.

    Science.gov (United States)

    Fukushima, Fabíola B; Malm, Christina; Andrade, Maria Elisa J; Oliveira, Humberto P; Melo, Eliane G; Caldeira, Fátima Maria C; Gheller, Valentim A; Palhares, Maristela S; Macedo, Sabrina P; Figueiredo, Mariana S; Silva, Marcos X

    2011-01-01

    Cardiorespiratory and blood gas alterations were evaluated in 6 healthy dogs that underwent a laparoscopic procedure using isoflurane anesthesia and carbon dioxide (CO(2)) pneumoperitoneum for 30 min. Heart rate, respiratory rate, body temperature, venous blood pH, partial pressure of CO(2) and oxygen, oxygen saturation, total carbon dioxide (TCO(2)) and bicarbonate were monitored. Significant alterations were hypercapnia, hypoventilation, and respiratory acidosis.

  10. Melatonin reduces traumatic brain injur y-induced oxidative stress in the cerebral cortex and blood of rats

    Institute of Scientific and Technical Information of China (English)

    Nilgnenol; Mustafa Nazrolu

    2014-01-01

    Free radicals induced by traumatic brain injury have deleterious effects on the function and antioxidant vitamin levels of several organ systems including the brain. Melatonin possesses antioxidant effect on the brain by maintaining antioxidant enzyme and vitamin levels. We in-vestigated the effects of melatonin on antioxidant ability in the cerebral cortex and blood of traumatic brain injury rats. Results showed that the cerebral cortex β-carotene, vitamin C, vita-min E, reduced glutathione, and erythrocyte reduced glutathione levels, and plasma vitamin C level were decreased by traumatic brain injury whereas they were increased following melatonin treatment. In conclusion, melatonin seems to have protective effects on traumatic brain inju-ry-induced cerebral cortex and blood toxicity by inhibiting free radical formation and supporting antioxidant vitamin redox system.

  11. Regional cerebral blood flow in acute stage ischemic cerebrovascular disease by xenon-133 inhalation and single photon emission computerized tomography

    Energy Technology Data Exchange (ETDEWEB)

    Kurokawa, Hiroyuki (Akita Univ. (Japan). School of Medicine)

    1989-03-01

    During the period from February 1984 through June 1985, single photon emission computerized tomography (SPECT) with xenon-133 inhalation method has been performed for the measurement of regional cerebral blood flow (rCBF) during the first 48 hours of onset of cerebral infarction (n=71) and transient ischemic attack (n=21). X-ray CT (CT) and carotid arteriography were concurrently performed in all the patients. In repeated studies performed for 15 normal volunteers, rCBF measurement by SPECT was found reproducible. Mean values of rCBF for the right and left cerebral hemispheres were 60.3{plus minus}6.52 and 61.8{plus minus}6.91 ml/100 g/min, respectively. For cerebral infarction, ischemic foci corresponding to clinical symptoms were detected more frequently on SPECT than on CT (93% vs 63%). In all of the evaluable 35 patients with cerebral infarction, rCBF within the first 8 hours of onset was decreased: 31.0 ml/100 g/min for the internal carotid artery (ICA) occlusion and 36.0 ml/100 g/min for the middle cerebral artery (MCA) occlusion. Crossed cerebellar diaschisis was observed in 50% (9/18) for ICA occlusion and 37% (14/38) for MCA occlusion. For transient ischemic attack, there was no significant difference in the detection of ischemic foci between SPECT and CT (38% vs 43%). In detecting small foci especially in the deep regions such as the basal ganglia, SPECT was inferior to CT. Mean rCBF for transient ischemic attack tended to be lower than the normal rCBF (50.7 ml/100 g/min for the right cerebral hemisphere and 50.6 ml/100 g/min for the left cerebral hemisphere). SPECT may aid in predicting prognosis and chosing treatment strategy, as well as in determining cerebral hemodynamics. (N.K.).

  12. CLINICAL OBSERVATION ABOUT THE EFFECT OF BLOOD-LETTING OF JING-POINTS ON CEREBRAL BLOOD FLOW IN STROKE PATIENTS AT THE EARLY STAGE AND EXPERIMENTAL STUDY ON ITS MECHANISMS IN THE RABBIT

    Institute of Scientific and Technical Information of China (English)

    WANG Xiuyun; REN Shusheng; GUO Yi; ZHOU Guoping; ZHOU Zhiliang; PAN Rongqing; XU Tangping; LI Qing; WANG Xin; REN Huanzhong

    2002-01-01

    In this paper,the authors sum their research resuits about the effect of blood-letting of Jing(Well)-point on cerebral blood flow both in stroke patients and in experimental cerebral ischemia,cerebral hematoma and hypertension rabbits.In 30cases of stroke (cerebral hemorrhage and cerebral infarction)patients,blood flow state of the anterior cerebral artery(ACA),middle cerebral artery(MCA)and the posterior cerebral artery (PCA), and the blood flow velocity of the bilateral vertebral artery (VA)and the basil artery(BA)are determined before and afterpricking blood of the Twelve Jing-points.In experimental cerebral ischernia (by occlusion of the common carotid ertery) rabbits ,cerebral hematoma model rabbits and intravenous injection of noradrenaline induced hypertension rabbits, rheoencephalogram(REC) is detected before and after blood letting of the twelve"Jing -points.In these 30stroke patients,ultrasound Doppler examination's results show that in 22 cases (73.33%) whose blood flow velocity decreases,after blood-letting of the 12 Jing-points, it ncreases significantly(P< 0.01); in the rest 8 cases (26.67%) whose blood flow velocity speeds up,after treatment,it decreases evidently(P<tly (P< 0.01), showing a good dual-directional regulative effect of blood -letting therapy.In experimental cerebral ischemia rabbits,cerebral hematoma rabbits and hypertension rabbits whose REG lowers in the amplitude apparently ( P < 0.01 ), after blood letting stimulation of the 12 Jing-points, it increases at different degrees.Three patterns of stimulation as blood letting stimulation, pain stimulation and Jing-point stimulation, also the 3factors of blood-letting,may contribute to their effect on improvement of the cerebral blood flow.Somatic affterent nerve,sympathetic nerve of the vasular wall,central cholinergic nerve(M receptors)and adrenergic nerve (α receptors) participate in the effect of blood letting on cerebral blood flow.

  13. 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.

  14. Cerebral blood flow during paroxysmal EEG activation induced by sleep in patients with complex partial seizures

    Energy Technology Data Exchange (ETDEWEB)

    Gozukirmizi, E.; Meyer, J.S.; Okabe, T.; Amano, T.; Mortel, K.; Karacan, I.

    1982-01-01

    Cerebral blood flow (CBF) measurements were combined with sleep polysomnography in nine patients with complex partial seizures. Two methods were used: the 133Xe method for measuring regional (rCBF) and the stable xenon CT method for local (LCBF). Compared to nonepileptic subjects, who show diffuse CBF decreases during stages I-II, non-REM sleep onset, patients with complex partial seizures show statistically significant increases in CBF which are maximal in regions where the EEG focus is localized and are predominantly seen in one temporal region but are also propagated to other cerebral areas. Both CBF methods gave comparable results, but greater statistical significance was achieved by stable xenon CT methodology. CBF increases are more diffuse than predicted by EEG paroxysmal activity recorded from scalp electrodes. An advantage of the 133Xe inhalation method was achievement of reliable data despite movement of the head. This was attributed to the use of a helmet which maintained the probes approximated to the scalp. Disadvantages were poor resolution (7 cm3) and two-dimensional information. The advantage of stable xenon CT method is excellent resolution (80 mm3) in three dimensions, but a disadvantage is that movement of the head in patients with seizure disorders may limit satisfactory measurements.

  15. Sickle Cell Anemia: Reference Values of Cerebral Blood Flow Determined by Continuous Arterial Spin Labeling MRI

    Science.gov (United States)

    Arkuszewski, M.; Krejza, J.; Chen, R.; Melhem, E.R.

    2013-01-01

    Sickle cell anemia (SCA) is a chronic illness associated with progressive deterioration in patients' quality of life. The major complications of SCA are cerebrovascular accidents (CVA) such as asymptomatic cerebral infarct or overt stroke. The risk of CVA may be related to chronic disturbances in cerebral blood flow (CBF), but the thresholds of “normal” steady-state CBF are not well established. The reference tolerance limits of CBF can be useful to estimate the risk of CVA in asymptomatic children with SCA, who are negative for hyperemia or evidence of arterial narrowing. Continuous arterial spin labeling (CASL) MR perfusion allows for non-invasive quantification of global and regional CBF. To establish such reference tolerance limits we performed CASL MR examinations on a 3-Tesla MR scanner in a carefully selected cohort of 42 children with SCA (mean age, 8.1±3.3 years; range limits, 2.3–14.4 years; 24 females), who were not on chronic transfusion therapy, had no history of overt stroke or transient ischemic attack, were free of signs and symptoms of focal vascular territory ischemic brain injury, did not have intracranial arterial narrowing on MR angiography and were at low risk for stroke as determined by transcranial Doppler ultrasonography. PMID:23859242

  16. Sickle cell anemia: reference values of cerebral blood flow determined by continuous arterial spin labeling MRI.

    Science.gov (United States)

    Arkuszewski, M; Krejza, J; Chen, R; Melhem, E R

    2013-04-01

    Sickle cell anemia (SCA) is a chronic illness associated with progressive deterioration in patients' quality of life. The major complications of SCA are cerebrovascular accidents (CVA) such as asymptomatic cerebral infarct or overt stroke. The risk of CVA may be related to chronic disturbances in cerebral blood flow (CBF), but the thresholds of "normal" steady-state CBF are not well established. The reference tolerance limits of CBF can be useful to estimate the risk of CVA in asymptomatic children with SCA, who are negative for hyperemia or evidence of arterial narrowing. Continuous arterial spin labeling (CASL) MR perfusion allows for non-invasive quantification of global and regional CBF. To establish such reference tolerance limits we performed CASL MR examinations on a 3-Tesla MR scanner in a carefully selected cohort of 42 children with SCA (mean age, 8.1±3.3 years; range limits, 2.3-14.4 years; 24 females), who were not on chronic transfusion therapy, had no history of overt stroke or transient ischemic attack, were free of signs and symptoms of focal vascular territory ischemic brain injury, did not have intracranial arterial narrowing on MR angiography and were at low risk for stroke as determined by transcranial Doppler ultrasonography.

  17. Regional cerebral blood flow abnormalities in late-life depression. Relation to refractoriness and chronification

    Energy Technology Data Exchange (ETDEWEB)

    Awata, Shuichi; Konno, Michiko; Sato, Mitsumoto [Tohoku Univ., Sendai (Japan). School of Medicine; Ito, Hiroshi; Ono, Shuichi; Kawashima, Ryuta; Fukuda, Hiroshi

    1998-02-01

    We examined patterns of regional cerebral blood flow (rCBF) abnormalities in 18 patients with major depressive disorder in late life using single photon emission computed tomography (SPECT) and {sup 99m}Tc-hexamethyl-propylenamine oxime ({sup 99m}Tc-HMPAO). Compared with 13 age-matched controls, relative rCBF was significantly decreased bilaterally in the anterior cingulate gyrus, the prefrontal cortex, the temporal cortex, the parietal cortex, the hippocampus and the caudate nucleus. However, it was not correlated with the severity of depression or global cognitive dysfunction. In 10 patients with a prolonged depressive episode or prolonged residual symptoms (the refractory subgroup), robust and extensive decreases in rCBF were found compared with controls and the rCBF decreased significantly in the anterior cingulate gyrus and the prefrontal cortex compared with that in the non-refractory subgroup. In the non-reflactory subgroup, rCBF decreased significantly in the caudate nucleus and tended to decrease in the anterior cingulate gyrus compared with controls. These findings indicate that dysfunction of the limbic system, the cerebral association cortex and the caudate nucleus may be implicated in late-life depression and that robust and extensive hypoperfusion, especially in the anterior cingulate and the prefrontal regions, may relate to refractoriness or chronification of depression. (author). 60 refs.

  18. Dimethyl fumarate attenuates cerebral edema formation by protecting the blood-brain barrier integrity.

    Science.gov (United States)

    Kunze, Reiner; Urrutia, Andrés; Hoffmann, Angelika; Liu, Hui; Helluy, Xavier; Pham, Mirko; Reischl, Stefan; Korff, Thomas; Marti, Hugo H

    2015-04-01

    Brain edema is a hallmark of various neuropathologies, but the underlying mechanisms are poorly understood. We aim to characterize how tissue hypoxia, together with oxidative stress and inflammation, leads to capillary dysfunction and breakdown of the blood-brain barrier (BBB). In a mouse stroke model we show that systemic treatment with dimethyl fumarate (DMF), an antioxidant drug clinically used for psoriasis and multiple sclerosis, significantly prevented edema formation in vivo. Indeed, DMF stabilized the BBB by preventing disruption of interendothelial tight junctions and gap formation, and decreased matrix metalloproteinase activity in brain tissue. In vitro, DMF directly sustained endothelial tight junctions, inhibited inflammatory cytokine expression, and attenuated leukocyte transmigration. We also demonstrate that these effects are mediated via activation of the redox sensitive transcription factor NF-E2 related factor 2 (Nrf2). DMF activated the Nrf2 pathway as shown by up-regulation of several Nrf2 target genes in the brain in vivo, as well as in cerebral endothelial cells and astrocytes in vitro, where DMF also increased protein abundance of nuclear Nrf2. Finally, Nrf2 knockdown in endothelial cells aggravated subcellular delocalization of tight junction proteins during ischemic conditions, and attenuated the protective effect exerted by DMF. Overall, our data suggest that DMF protects from cerebral edema formation during ischemic stroke by targeting interendothelial junctions in an Nrf2-dependent manner, and provide the basis for a completely new approach to treat brain edema.

  19. The Utility of Cerebral Blood Flow as a Biomarker of Preclinical Alzheimer’s Disease

    Science.gov (United States)

    Hays, Chelsea C.; Zlatar, Zvinka Z.; Wierenga, Christina E.

    2017-01-01

    There is accumulating evidence suggesting that changes in brain perfusion are present long before the clinical symptoms of Alzheimer’s disease (AD), perhaps even before amyloid-β accumulation or brain atrophy. This evidence, consistent with the vascular hypothesis of AD, implicates cerebral blood flow (CBF) in the pathogenesis of AD and suggests its utility as a biomarker of preclinical AD. The extended preclinical phase of AD holds particular significance for disease-modification, as treatment would likely be most effective in this early asymptomatic stage of disease. This highlights the importance of identifying reliable and accurate biomarkers of AD that can differentiate normal aging from preclinical AD prior to clinical symptom manifestation. Cerebral perfusion, as measured by arterial spin labeling magnetic resonance imaging (ASL-MRI), has been shown to distinguish between normal controls and adults with AD. In addition to demonstrating diagnostic utility, CBF has shown usefulness as a tool for identifying those who are at risk for AD and for predicting subtle cognitive decline and conversion to mild cognitive impairment (MCI) and AD. Taken together, this evidence not only implicates CBF as a useful biomarker for tracking disease severity and progression, but also suggests that ASL-measured CBF may be useful for identifying candidates for future AD treatment trials, especially in the preclinical, asymptomatic phases of the disease. PMID:26898552

  20. Alterations of red blood cell metabolome in overhydrated hereditary stomatocytosis.

    NARCIS (Netherlands)

    Darghouth, D.; Koehl, B.; Heilier, J.F.; Madalinski, G.; Bovee, P.H.; Bosman, G.J.C.G.M.; Delaunay, J.; Junot, C.; Romeo, P.H.

    2011-01-01

    Overhydrated hereditary stomatocytosis, clinically characterized by hemolytic anemia, is a rare disorder of the erythrocyte membrane permeability to monovalent cations, associated with mutations in the Rh-associated glycoprotein gene. We assessed the red blood cell metabolome of 4 patients with this

  1. 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

    venous noradrenaline, and falling arterial carbon dioxide tension (P aCO 2) (R(2) ≥ 0.41, P ≤ 0.01) whereas CCA flow and conductance were related to elevated blood temperature. In conclusion, dehydration accelerated the decline in CBF by decreasing P aCO 2 and enhancing vasoconstrictor activity. However......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...

  2. Experimental arrest of cerebral blood flow in human subjects: the red wing studies revisited.

    Science.gov (United States)

    Smith, Brian A; Clayton, Ellen Wright; Robertson, David

    2011-01-01

    Loss of consciousness in pilots during rapid ascent after bombing missions was a major problem in World War II, and experiments were undertaken to study the cause of this phenomenon. Postulating impaired cerebral blood flow as a likely mechanism, the investigators developed a neck device, the KRA Cuff, which when inflated could shut off blood supply to the brain. With cessation of blood flow for up to 100 seconds, the investigators observed a sequence of responses, including unconsciousness, followed by dilated pupils, tonic/clonic movements, loss of bladder and eventually bowel control, and appearance of pathological reflexes. This study, carried out in prisoners and patients with schizophrenia in 1941-42, largely disappeared from public discourse for a number of years. It has received occasional attention subsequently and been considered controversial. Recently discovered records, including extensive written and photographic data from the studies, shed new light on the methods and motives of the research team. We describe here this new information and its implications for the scientific and ethical assessment of the study.

  3. Heterogeneity of neocortical cerebral blood flow deficits in dementia of the Alzheimer type

    DEFF Research Database (Denmark)

    Waldemar, G; Bruhn, P; Kristensen, M

    1994-01-01

    Regional cerebral blood flow (rCBF) was measured with high resolution brain dedicated single photon emission computer tomography (SPECT) and [99mTc]-d,l-hexamethyl-propylene-amine-oxime (HMPAO) in 25 patients with probable Alzheimer's disease and in 25 control subjects, selected according...... to rigorous inclusion and exclusion criteria. The aim was to analyse the topography of rCBF deficits in individual patients. In the group of patients with Alzheimer's disease as a whole, global CBF was reduced, but a factorial analysis of variance did not show disproportionate reduction of rCBF in any brain...... combination of two, three, or four, of four major brain regions (a left and right frontal and a left and right posterior region). All patients with Alzheimer's disease and none of the control subjects had an abnormal rCBF pattern. Eleven of the 13 different patterns were seen in the patients. Frontal changes...

  4. [Dynamics of local cerebral blood flow after thermodestruction of the thalamus in the dog].

    Science.gov (United States)

    Kaasik, A A; Asser, T K

    1987-01-01

    The dynamics of changes in local cerebral blood flow (LCBF) after stereotaxic thermodestruction of the right thalamus was studied by the method of hydrogen clearance. The experiments were conducted on 22 mongrel dogs. On the 10-12th day after implantation of platinum electrodes the initial values of LCBF were determined symmetrically in the thalami and frontal cortex of dogs who were awake. The animals were anesthetized, the initial values of LCBF were again determined, and destruction of the right thalamus was performed. Reactive hyperemia developed close to the focus of thermodestruction and persisted 90 minutes. In the remaining sites the reactive hyperemia was less manifest and was seen 10-15 minutes.

  5. Regional cerebral blood flow and cognitive function in patients with obsessive-compulsive disorder

    Directory of Open Access Journals (Sweden)

    Huirong Guo

    2014-01-01

    Full Text Available Objective: To explore the relationship between regional cerebral blood flow (CBF and cognitive function in obsessive-compulsive disorder (OCD. Method: Single-photon emission computed tomography (SPECT was performed for 139 OCD patients and 139 controls, and the radioactivity rate (RAR was calculated. Cognitive function was assessed by the Wisconsin Card Sorting Test (WCST. Results: The RARs of the prefrontal, anterior temporal, and right occipital lobes were higher in patients than controls. For the WCST, correct and classification numbers were significantly lower, and errors and persistent errors were significantly higher in OCD patients. Right prefrontal lobe RAR was negatively correlated with correct numbers, right anterior temporal lobe RAR was positively correlated with errors, and the RARs of the right prefrontal lobe and left thalamus were positively correlated with persistent errors. Conclusion: OCD patients showed higher CBF in the prefrontal and anterior temporal lobes, suggesting that these areas may be related with cognitive impairment.

  6. Smoking normalizes cerebral blood flow and oxygen consumption after 12-hour abstention

    DEFF Research Database (Denmark)

    Seyedi Vafaee, Manouchehr; Gjedde, Albert; Imamirad, Nasrin

    2015-01-01

    measurements of cerebral blood flow (CBF) and metabolic rate of oxygen (CMRO2) in 12 smokers who had refrained from smoking overnight, and in a historical group of nonsmokers, testing the prediction that overnight abstinence results in widespread, coupled reductions of CBF and CMRO2. At the end......Acute nicotine administration stimulates [14C]deoxyglucose trapping in thalamus and other regions of rat brain, but acute effects of nicotine and smoking on energy metabolism have rarely been investigated in human brain by positron emission tomography (PET). We obtained quantitative PET...... of the abstention period, global grey-matter CBF and CMRO2 were both reduced by 17% relative to nonsmokers. At 15 minutes after renewed smoking, global CBF had increased insignificantly, while global CMRO2 had increased by 11%. Regional analysis showed that CMRO2 had increased in the left putamen and thalamus...

  7. Effects of acetazolamide on cerebral blood flow and brain tissue oxygenation

    DEFF Research Database (Denmark)

    Lassen, N A; Friberg, L; Kastrup, J

    1987-01-01

    Oral administration of 1 g of acetazolamide to 8 normal subjects studied at sea level and in normoxia caused an acute increase in cerebral blood flow (CBF). During the subsequent prolonged oral treatment with 1 g of acetazolamide daily, CBF returned to normal within 2 days. The alveolar CO2 tension...... decreased gradually to 70% of the control value, indicating hyperventilation. At sea level hyperventilation will not increase brain oxygenation significantly in normal man, as the arterial oxygen content only increases minimally, while CBF is unchanged. At high altitude the beneficial effects...... of acetazolamide on the symptoms of acute mountain sickness may well be due to an improved oxygen supply to the brain, as hyperventilation will, at the low ambient PO2, cause a significant increase of the arterial oxygen content, while CBF presumably is unaffected by the drug. During hypoxia at high altitude...

  8. Cerebral blood flow and brain shrinkage seen on CT during ACTH therapy.

    Science.gov (United States)

    Futagi, Y; Abe, J; Kawahigashi, K

    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.

  9. Quantitative measurement of cerebral blood flow on patients with early syphilis

    Institute of Scientific and Technical Information of China (English)

    ZHONG Ji-Jun; WU Jin-Chang; YANG Yi; TANG Jun; LIU Zeng-Li; SHI Xin

    2005-01-01

    To study quantitative change of cerebral blood flow (CBF) on patients with early syphilis, we have established a method on absolute measurement of rCBF by using SPECT with Ethyl Cysteinate Dimmer (ECD) as imaging agent, and the method was applied to measure rCBF on patients with early syphilis. The rCBF values measured by this method are highly consistent with the values measured by other classical methods such as SPECT (123I-IMP) and PET (15O-H2O). The rCBF values for early syphilis patients and the normal control show some statistical differences.A routine quantitative absolute measurement of rCBF featured with simple procedures is therefore on the way of maturation.

  10. Estimation of intersubject variability of cerebral blood flow measurements using MRI and positron emission tomography

    DEFF Research Database (Denmark)

    Henriksen, Otto Mølby; Larsson, Henrik B W; Hansen, Adam E;

    2012-01-01

    PURPOSE: To investigate the within and between subject variability of quantitative cerebral blood flow (CBF) measurements in normal subjects using various MRI techniques and positron emission tomography (PET). MATERIALS AND METHODS: Repeated CBF measurements were performed in 17 healthy, young...... subjects using three different MRI techniques: arterial spin labeling (ASL), dynamic contrast enhanced T1 weighted perfusion MRI (DCE) and phase contrast mapping (PCM). All MRI measurements were performed within the same session. In 10 of the subjects repeated CBF measurements by (15) O labeled water PET......L/100 g/min, 16.2% and 4.8%, for DCE 43.0 mL/100 g/min, 20.0%, 15.1% and for PET 41.9 mL/100 g/min, 16.5% and 11.9%, respectively. Only for DCE and PCM a significant positive correlation between measurements was demonstrated. CONCLUSION: These findings confirm large between subject variability in CBF...

  11. Epileptic Seizure Detection and Prediction Based on Continuous Cerebral Blood Flow Monitoring – a Review

    Directory of Open Access Journals (Sweden)

    Senay Tewolde

    2015-01-01

    Full Text Available Epilepsy is the third most common neurological illness, affecting 1% of the world’s population. Despite advances in medicine, about 25 to 30% of the patients do not respond to or cannot tolerate the severe side effects of medical treatment, and surgery is not an option for the majority of patients with epilepsy. The objective of this article is to review the current state of research on seizure detection based on cerebral blood flow (CBF data acquired by thermal diffusion flowmetry (TDF, and CBF-based seizure prediction. A discussion is provided on the applications, advantages, and disadvantages of TDF in detecting and localizing seizure foci, as well as its role in seizure prediction. Also presented are an overview of the present challenges and possible future research directions (along with methodological guidelines of the CBF-based seizure detection and prediction methods.

  12. Modeling of cerebral oxygen transport based on in vivo microscopic imaging of microvascular network structure, blood flow and oxygenation

    Directory of Open Access Journals (Sweden)

    Louis Gagnon

    2016-08-01

    Full Text Available 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.

  13. Regional cerebral blood flow during rest and skilled hand movements by xenon-133 inhalation and emission computerized tomography

    DEFF Research Database (Denmark)

    Lauritzen, M; Henriksen, L; Lassen, N A

    1981-01-01

    Regional cerebral blood flow (CBF) was studied in 16 normal adult volunteers during rest and in 10 the study was repeated during skilled hand movements. A fast-rotating ("dynamic"), single-photon emission computerized tomograph (ECT) with four detector heads was used. Xenon-133 was inhaled over a 1...

  14. Autistic Traits, ADHD Symptoms, Neurological Soft Signs and Regional Cerebral Blood Flow in Adults with Autism Spectrum Disorders

    Science.gov (United States)

    Manouilenko, Irina; Pagani, Marco; Stone-Elander, Sharon; Odh, Richard; Brolin, Fredrik; Hatherly, Robert; Jacobsson, Hans; Larsson, Stig A.; Bejerot, Susanne

    2013-01-01

    The resting regional cerebral blood flow (rCBF) patterns related to co-occurring symptoms such as inattention, hyperactivity, neurological soft signs and motor problems have not yet been disclosed in autism spectrum disorders (ASD). In this study thirteen adults with ASD and ten matched neurotypical controls underwent PET. The scores of rating…

  15. Electrical modulation of the sympathetic nervous system in order to augment cerebral blood flow : a protocol for an experimental study

    NARCIS (Netherlands)

    Ter Laan, Mark; van Dijk, J. Marc C.; Staal, Michiel J.; Elting, Jan-Willem J.

    2011-01-01

    Introduction: Cerebral blood flow (CBF) is regulated by several mechanisms. Neurogenic control has been a matter of debate, even though several publications reported the effects of changes in sympathetic tone on CBF. Transcutaneous electrical nerve stimulation and spinal-cord stimulation have been s

  16. 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).

  17. Two-photon microscopy with double-circle trajectories for in vivo cerebral blood flow measurements

    Science.gov (United States)

    Landolt, Andrin; Obrist, Dominik; Wyss, Matthias; Barrett, Matthew; Langer, Dominik; Jolivet, Renaud; Soltysinski, Tomasz; Roesgen, Thomas; Weber, Bruno

    2013-05-01

    Scanning microscopes normally use trajectories which produce full-frame images of an object at a low frame rate. Time-resolved measurements are possible if scans along a single line are repeated at a high rate. In conjunction with fluorescence labeling techniques, in vivo recording of blood flow in single capillaries is possible. The present work investigates scanning with double-circle trajectories to measure blood flow simultaneously in several vessels of a capillary network. With the trajectory centered near a bifurcation, a double circle crosses each vessel twice, creating a sensing gate for passing dark red blood cells in fluorescently labeled plasma. From the stack of scans repeated at 1,300 Hz, the time-resolved velocity is retrieved using an image correlation approach. Single bifurcation events can be identified from a few fluorescently labeled red blood cells. The applicability of the method for in vivo measurements is illustrated on the basis of two-photon laser scanning microscopy of the cerebral capillary network of mice. Its performance is assessed with synthetic data generated from a two-phase model for the perfusion in a capillary network. The calculation of velocities is found to be sufficiently robust for a wide range of conditions. The achievable limits depend significantly on the experimental conditions and are estimated to be in the 1 μm/s (velocity) and 0.1 s (time resolution) ranges, respectively. Some manual fine-tuning is required for optimal performance in terms of accuracy and time resolution. Further work may lead to improved reliability with which bifurcation events are identified in the algorithm and to include red blood cell flux and hematocrit measurements. With the capability for time-resolved measurements in all vessels of a bifurcation, double-circle scanning trajectories allow a detailed study of the dynamics in vascular networks.

  18. Regional vulnerability of longitudinal cortical association connectivity: Associated with structural network topology alterations in preterm children with cerebral palsy.

    Science.gov (United States)

    Ceschin, Rafael; Lee, Vince K; Schmithorst, Vince; Panigrahy, Ashok

    2015-01-01

    alteration in eigenvector centrality, clustering coefficient (inter-regional) and participation co-efficient (inter-modular) alterations of frontal-striatal and fronto-limbic nodes suggesting re-organization of these pathways. Both along tract and structural topology network measurements correlated strongly with motor and visual clinical outcome scores. This study shows the value of combining along-tract analysis and structural network topology in depicting not only selective parietal occipital regional vulnerability but also reorganization of frontal-striatal and frontal-limbic pathways in preterm children with cerebral palsy. These finding also support the concept that widespread, but selective posterior-anterior neural network connectivity alterations in preterm children with cerebral palsy likely contribute to the pathogenesis of neurosensory and cognitive impairment in this group.

  19. 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

  20. Effect of Acupuncture Signal after Brachial Plexus Blockade on Cerebral Blood Perfusion and Brain Cell Function

    Institute of Scientific and Technical Information of China (English)

    任永功; 郭长春; 贾少微

    2003-01-01

    Objective: Using single photon emission computed tomography (SPECT) to observe the influence of the up-transmitting of acupuncture signal into the brain in health volunteers whose nerve trunk was blocked by anesthetics. Methods: Thirty-one healthy volunteers were divided into two groups, the control group of 20 cases, and the brachial plexus blockade (BPB) group of 11 cases, with supraclavicular BPB route adopted. With the control group 2 acupoints were randomly selected (Hegu and Quchi of both sides), while with the BPB group Hegu and Quchi of anesthetic arm side were selected. Siemens ECAM/ICON SPECT system was used to conduct brain imaging using double imaging assay before acupuncture and 99mTc-ECD imaging agent during acupuncture for cerebral perfusion. The data were quantitatively analyzed by blood functional changing rate (BFCR%) mathematics model. Results: Before acupuncture, the control and BPB groups showed insignificant change by SPECT, but after electro-acupuncture (EA), the control group displayed improved motor and sensory cortex excitability in basal nuclei, contra-lateral thalamus, parietal and frontal lobe; while BPB group was characterized with reduction of the blood perfusion and cell function of contra-lateral thalamus of anesthetized arm. The difference between the two groups was significant (P<0.01). Conclusion: (1) After BPB, the up-transmitting of the acupuncture signal via upper limb into the brain, and its strength was impaired or blocked; (2) After BPB, the effect of acupuncture on cerebral perfusion and brain cell function of contra-lateral thalamus was impaired or blocked.

  1. Alterations of Blood Brain Barrier Function in Hyperammonemia: An Overview

    OpenAIRE

    2011-01-01

    Ammonia is a neurotoxin involved in the pathogenesis of neurological conditions associated with hyperammonemia, including hepatic encephalopathy, a condition associated with acute—(ALF) or chronic liver failure. This article reviews evidence that apart from directly affecting the metabolism and function of the central nervous system cells, ammonia influences the passage of different molecules across the blood brain barrier (BBB). A brief description is provided of the tight junctions, which c...

  2. [Effects of solcoseryl on the cerebral blood flow, intracranial pressure, systemic blood pressure and EEG in acute intracranial hypertensive cats (author's transl)].

    Science.gov (United States)

    Kubota, S; Asakura, T; Kitamura, K

    1976-02-01

    The experiment was performed on 86 cases under intraperitoneal pentobarbital anesthesia. One balloon was placed in the extradural space of right frontal region, and the other balloon was placed in the left extradural space and the intracranial pressure was measured. A needle was stereotaxically inserted into the subcortical area in order to measure the cerebral blood flow. Systemic blood pressure was recorded by inserting a catheter into the femoral artery, and electrocorticogram was also recorded. An expanding intracranial lesion was made by inflating the extradural balloon with physiological saline. The animals were arbitrarily divided into two groups.: 1) light or moderate groups which intracranial pressure before the injection of drug was below 400 mmH2O. 2) severe groups above 400 mmH2O. After the maintenance of the pressure, Solcoseryl was infused intravenously. The investigation was focused to observe whether Solcoseryl reveales any potent effect on cerebral blood flow, intracranial pressure, systemic blood pressure and on electroencephalogram in acute intracranial hypertension. Results 1) Intravenous injection of Solcoseryl had the effect of lowering intracranial pressure in the light or moderate and severe groups. Particularly, dose of 80 mg/kg showed the marked effect, though with a rebound phenomenon in the light or moderate groups. Furthermore, the effect was more marked and lasting by drip infusion of Solcoseryl and also by intravenous injection of Solcoseryl after pretreatment with hydrocortisone, and at this time no rebound phenomenon was recognized. 2) Solcoseryl had the effect of increasing the cerebral blood flow accompained with the lowering of intracranial pressure. 3) Systemic blood pressure was transiently lowered by the injection of Solcoseryl 20 mg/kg or 80 mg/kg and recovered immediately. 4) Solcoseryl had no effect on electroencephalogram in the severe groups. Conclusion On the basis of these results, it is rational to conclude that

  3. Alteration of peripheral blood lymphocyte subsets in acute pancreatitis

    Institute of Scientific and Technical Information of China (English)

    Miroslawa Pietruczuk; Milena I Dabrowska; Urszula Wereszczynska-Siemiatkowska; Andrzej Dabrowski

    2006-01-01

    AIM: To evaluate peripheral blood lymphocyte subsets in patients with acute pancreatitis (AP).METHODS: Twenty patients with mild AP (M-AP) and 15 with severe AP (S-AP) were included in our study. Peripheral blood lymphocytes were examined at d 1-3, 5,10 and 30 by means of flow cytometry.RESULTS: A significant depletion of circulating lymphocytes was found in AP. In the early AP, the magnitude of depletion was similar for T- and B- lymphocytes. In the late course of S-AP, B-lymphocytes were much more depleted than T-lymphocytes. At d 10, strong shift in the CD7+/CD19+ ratio implicating predominance of Tover B-lymphocytes in S-AP was found. Among T-lymphocytes, the significant depletion of the CD4+ population was observed in M-AP and S-AP, while CD8+ cells were in the normal range. Lymphocytes were found to strongly express activation markers: CD69, CD25, CD28,CD38 and CD122. Serum interleukin-2 (IL-2), IL-4, IL-5,IL-10, interferon-γ (IFN-γ) and tumor necrosis factor-α(TNF-α) levels were significantly increased in both forms of AP. The magnitude of elevation of cytokines known to be produced by Th2 was much higher than cytokines produced by Th1 cells.CONCLUSION: AP in humans is characterized by significant reduction of peripheral blood T- and B-lymphocytes.

  4. 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.

  5. 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.

  6. Compromised cerebrovascular modulation in chronic anxiety: evidence from cerebral blood flow velocity measured by transcranial Doppler sonography

    Institute of Scientific and Technical Information of China (English)

    Hong-Liang Zhang; Zhen-Ni Guo; Ge Yang; Le Yang; Ke Han; Jiang Wu; Yingqi Xing; Yi Yang

    2012-01-01

    Objective Cerebral autoregulation (CA) is the mechanism by which constant cerebral blood flow is maintained despite changes in cerebral perfusion pressure.CA can be evaluated by dynamic monitoring of cerebral blood flow velocity (CBFV) with transcranial Doppler sonography (TCD).The present study aimed to explore CA in chronic anxiety.Methods Subjects with Hamilton anxiety scale scores ≥14 were enrolled and the dynamic changes of CBFV in response to an orthostatic challenge were investigated using TCD.Results In both the anxious and the healthy subjects,the mean CBFV was significantly lower in the upright position than when supine.However,the CBFV changes from supine to upright differed between the anxious and the healthy groups.Anxious subjects showed more pronounced decreases in CBFV with abrupt standing.Conclusion Our results indicate that cerebrovascular modulation is compromised in chronic anxiety; anxious subjects have some insufficiency in maintaining cerebral perfusion after postural change.Given the fact that anxiety and impaired CA are associated with cardiovascular disease,early ascertainment of compromised cerebrovascular modulation using TCD might suggest interventional therapies in the anxious population,and improve the primary prevention of cardiovascular disease.

  7. Selective α1-adrenergic blockade disturbs the regional distribution of cerebral blood flow during static handgrip exercise.

    Science.gov (United States)

    Fernandes, Igor A; Mattos, João D; Campos, Monique O; Machado, Alessandro C; Rocha, Marcos P; Rocha, Natalia G; Vianna, Lauro C; Nobrega, Antonio C L

    2016-06-01

    Handgrip-induced increases in blood flow through the contralateral artery that supplies the cortical representation of the arm have been hypothesized as a consequence of neurovascular coupling and a resultant metabolic attenuation of sympathetic cerebral vasoconstriction. In contrast, sympathetic restraint, in theory, inhibits changes in perfusion of the cerebral ipsilateral blood vessels. To confirm whether sympathetic nerve activity modulates cerebral blood flow distribution during static handgrip (SHG) exercise, beat-to-beat contra- and ipsilateral internal carotid artery blood flow (ICA; Doppler) and mean arterial pressure (MAP; Finometer) were simultaneously assessed in nine healthy men (27 ± 5 yr), both at rest and during a 2-min SHG bout (30% maximal voluntary contraction), under two experimental conditions: 1) control and 2) α1-adrenergic receptor blockade. End-tidal carbon dioxide (rebreathing system) was clamped throughout the study. SHG induced increases in MAP (+31.4 ± 10.7 mmHg, P blood flow (+80.9 ± 62.5 ml/min, P 0.05). The reduction in ipsilateral ICA vascular conductance (VC) was greater compared with contralateral ICA (contralateral: -0.8 ± 0.8 vs. ipsilateral: -2.6 ± 1.3 ml·min(-1)·mmHg(-1), P blood flow (contralateral: +58.4 ± 21.5 vs. ipsilateral: +54.3 ± 46.2 ml/min, P > 0.05) and decreases in VC (contralateral: -0.4 ± 0.7 vs. ipsilateral: -0.4 ± 1.0 ml·min(-1)·mmHg(-1), P > 0.05). These findings indicate a role of sympathetic nerve activity in the regulation of cerebral blood flow distribution during SHG.

  8. Patterns of fetal lamb regional cerebral blood flow during and after prolonged hypoxia.

    Science.gov (United States)

    Ashwal, S; Majcher, J S; Vain, N; Longo, L D

    1980-10-01

    In an effort to determine to what extent cerebral blood flow (CBF) varies in different parts of the brain during prolonged fetal hypoxia, we measured flow to 34 regions in 12 chronically catheterized fetal lambs 130 to 140 days gestation. Control values of PO2, PCO2 pH, heart rate, and blood pressure were obtained, and CBF was measured by use of radioactive labeled microspheres during a control period, during (15-, 30-, and 90-min) reduction of maternal inspired O2 concentration (fetal arterial PO2 was maintained at 12 to 15 torr), and 60 min after returning the ewe to room air. control blood flow to cortical, subcortical, and brainstem structures equaled 134, 186, and 254 ml x min-1 x 100 g-1, respectively. During hypoxia, CBF increased 92%, and 60 min after fetal oxygenation was restored, it remained 50% above control values. We noted a similar response in regional CBF to the cortex, subcortex, and brainstem during and after hypoxia. Blood flow to smaller areas within the three major regions were quite homogenous and had a similar pattern of response to hypoxia. We conclude that: (1) significant fetal regional CBF differences occurred in utero with brainstem and subcortical flows being substantially greater than flows to other regions of the brain; (2) during prolonged intrauterine hypoxia, total regional CBF increased 92%; (3) 1 hr after fetal oxygenation was restored, CBF still remained 50% above control values; and finally, (4) there was no significant preferential shunting of regional CBF during prolonged hypoxia in utero.

  9. Mitochondrial genes are altered in blood early in Alzheimer's disease.

    Science.gov (United States)

    Lunnon, Katie; Keohane, Aoife; Pidsley, Ruth; Newhouse, Stephen; Riddoch-Contreras, Joanna; Thubron, Elisabeth B; Devall, Matthew; Soininen, Hikka; Kłoszewska, Iwona; Mecocci, Patrizia; Tsolaki, Magda; Vellas, Bruno; Schalkwyk, Leonard; Dobson, Richard; Malik, Afshan N; Powell, John; Lovestone, Simon; Hodges, Angela

    2017-01-07

    Although mitochondrial dysfunction is a consistent feature of Alzheimer's disease in the brain and blood, the molecular mechanisms behind these phenomena are unknown. Here we have replicated our previous findings demonstrating reduced expression of nuclear-encoded oxidative phosphorylation (OXPHOS) subunits and subunits required for the translation of mitochondrial-encoded OXPHOS genes in blood from people with Alzheimer's disease and mild cognitive impairment. Interestingly this was accompanied by increased expression of some mitochondrial-encoded OXPHOS genes, namely those residing closest to the transcription start site of the polycistronic heavy chain mitochondrial transcript (MT-ND1, MT-ND2, MT-ATP6, MT-CO1, MT-CO2, MT-C03) and MT-ND6 transcribed from the light chain. Further we show that mitochondrial DNA copy number was unchanged suggesting no change in steady-state numbers of mitochondria. We suggest that an imbalance in nuclear and mitochondrial genome-encoded OXPHOS transcripts may drive a negative feedback loop reducing mitochondrial translation and compromising OXPHOS efficiency, which is likely to generate damaging reactive oxygen species.

  10. Changes in cerebral blood flow and psychometric indicators in veterans with early forms of chronic brain ischemia

    Directory of Open Access Journals (Sweden)

    Vasilenko Т.М.

    2015-09-01

    Full Text Available The goal is to study the cerebral blood flow and psychometric characteristics in veterans of Afghanistan with early forms of chronic brain ischemia. Material and Methods. The study included 74 veterans of the Afghan war aged from 45 to 55 years: group 1, 28 people with NPNKM; Group 2-28 patients with circulatory encephalopathy stage 1; group 3-18 healthy persons. Doppler examination of cerebral vessels was carried out on the unit «Smart-lite». Reactive and personal anxiety of patients was assessed using the scale of Spielberger, evaluation of the quality of life through the test SAN. Determining the level of neuroticism and psychoticism was conducted by the scale of neuroticism and psy-choticism. Results: The study of cerebral blood flow in the Afghan war veterans showed signs of insolvency of carotid and carotid-basilar anastomoses, hypoperfusion phenomenon with the depletion of autoregulation, violation of the outflow of venous blood at the level of the microvasculature, accompanied by cerebral arteries spasm. More than 40% of patients with early forms of chronic brain ischemia had high personal anxiety, low levels of well-being and activity, with maximum expression of dyscirculatory hypoxia. Conclusion. Readaptation of veterans of Afghanistan is accompanied by the changes in psychometric performance and the formation of the earliest forms of brain chronic ischemia associated with inadequate hemodynamics providing increased functional activity of the brain and the inefficiency of compensatory-adaptive reactions.

  11. Laser Doppler flowmeter study on regional cerebral blood flow in early stage after standard superficial temporal artery-middle cerebral artery bypass surgery for moyamoya disease

    Institute of Scientific and Technical Information of China (English)

    GESANG Dun-zhu; ZHANG Dong; ZHAO Ji-zong; WANG Shuo; ZHAO Yuan-li; WANG Rong; SUN Jian-jun; MENG Ze

    2009-01-01

    Background Standard superficial temporal artery-middle cerebral artery (STA-MCA) bypass surgery is an effective treatment for moyamoya disease, but recent evidence suggests that postoperative cerebral hyperperfusion can occur. In this study, the trendline of changes in regional cerebral blood flow (rCBF) after surgery were continually monitored near the site of anastomosis in order to investigate both the efficacy of the procedure for improving rCBF and the possible riskof hyperperfusion.Methods Standard STA-MCA bypass surgery was performed on 13 patients, rCBF was measured continually using laser Doppler flowmetry (LDF) until the 5th day after the operation with the LDF probe implanted adjacent to the area of the anastomosis. The trendline of rCBF changes postoperatively was recorded for the analysis performed using SPSS 13.0.Results The baseline LDF value of cortical rCBF was (84.68±14.39) perfusion unit (PU), which was linear relative to absolute perfusion volume before anastomosis and (88.90±11.26) PU immediately after anastomosis (P >0.05). The value changed significantly from before to after anastomosis (P 0.05).Conclusions STA-MCA anastomosis improves the cerebral blood supply significantly in the early stage after surgery,however, the risk of symptomatic hyperperfusion may exist, which may possibly occur on the 1st day and 5th day after surgery. A LDF is useful for postoperative monitoring for both the efficacy of bypass and possible risk of neurologic deterioration or bleeding from hyperperfusion.

  12. Sesamin attenuates behavioral, biochemical and histological alterations induced by reversible middle cerebral artery occlusion in the rats.

    Science.gov (United States)

    Khan, Mohd Moshahid; Ishrat, Tauheed; Ahmad, Ajmal; Hoda, Md Nasrul; Khan, M Badruzzaman; Khuwaja, Gulrana; Srivastava, Pallavi; Raza, Syed Shadab; Islam, Fakhrul; Ahmad, Saif

    2010-01-05

    Restoration of blood flow to an ischemic brain region is associated with generation of reactive oxygen species (ROS) with consequent reperfusion injury. ROS cause lipid peroxidation, protein oxidation, and DNA damage, all of which are deleterious to cells. So diminishing the production of free radicals and scavenging them may be a successful therapeutic strategy for the protection of brain tissue in cerebral stroke. The present study investigated the neuroprotective effect of sesamin (Sn) to reduce brain injury after middle cerebral artery occlusion (MCAO). The middle cerebral artery (MCA) of adult male Wistar rat was occluded for 2h and reperfused for 22h. Sesamin is the most abundant lignan in sesame seed oil is a potent antioxidant. Sesamin (30 mg/kg) was given orally twice, 30 min before the onset of ischemia and 12h after reperfusion. The initial investigations revealed that sesamin reduced the neurological deficits in terms of behavior and reduced the level of thiobarbituric acid reactive species (TBARS), and protein carbonyl (PC) in the different areas of the brain when compared with the MCAO group. A significantly depleted level of glutathione and its dependent enzymes (glutathione peroxidase [GPx] and glutathione reductase [GR]) in MCAO group were protected significantly in MCAO group treated with sesamin. The present study suggests that sesamin may be able to attenuate the ischemic cell death and plays a crucial role as a neuroprotectant in regulating levels of reactive oxygen species in the rat brain. Thus, sesamin may be a potential compound in stroke therapy.

  13. Regional cerebral blood flow in various pediatric neurological patients using /sup 123/I-IMP SPECT

    Energy Technology Data Exchange (ETDEWEB)

    Konishi, Tohru; Naganuma, Yoshihiro; Hongou, Kazuhisa; Murakami, Miyako; Yamatani, Miwa; Okada, Toshio

    1988-03-01

    The recent development of a new radiopharmaceutical /sup 123/I-isopropyl-iodoamphetamine (IMP), which is taken up by the brain from the blood flow, has offered a possibility of constructing scintigraphy maps of regional cerebral blood flow (rCBF) using single photon emission CT. We used this mehtod in various pediatric neurological diseases. Six patients with cerebro-vascular disorders (moya-moya disease 2, infarction 3 and HHE syndrome 1), 6 patients with infectious diseases of CNS (acute encephalitis 4, septic meningitis 1 and SSPE 1) and a miscellaneous group of six patients were studied. The rCBF abnormalities in cerebro-vascular diseases were more extensive and frequent than x-ray CT abnormalities. Repeated studies of IMP-SPECT revealed usefulness for the understanding of changeable hemodynamic pathophysiology and for the judgment of theraptic effectiveness and prognosis. The rCBF decrease in infectious diseases tended to be more diffuse and slight than that in cerebro-vascular diseases. In almost all patients, the area of rCBF decrease coincided with the area of EEG slowing evaluated by EEG topographic analysis. Brain imaging using /sup 123/I-IMP SPECT may reveal functional abnormalities as well as organic lesions. /sup 123/I-IMP SPECT has introduced a new era for the useful application of nuclear medicine to the investigation of pediatric neurological diseases.

  14. Effects of histamine and related compounds on regional cerebral blood flow in rats.

    Science.gov (United States)

    Suzuki, G; Chen, Z; Sugimoto, Y; Fujii, Y; Kamei, C

    1999-11-01

    The effects of histamine and related compounds on regional cerebral blood flow (rCBF) in the hippocampus of conscious rats were studied. Intracerebroventricular injection of histamine caused a dose-dependent increase in rCBF in the hippocampus, and similar findings were observed with not only the H1 agonist, 2-thiazolylethylamine, but also the H2 agonist, dimaprit. Intraperitoneal injection of L-histidine also resulted in an increase in rCBF in the hippocampus, in parallel with elevation of histamine content in the brain. The increase in rCBF in the hippocampus induced by L-histidine was antagonized by both H1 and H2 antagonists (diphenhydramine, pyrilamine and zolantidine). In addition, when both antagonists were injected simultaneously, an additive effect was observed in antagonism of the L-histidine-induced increase in rCBF. L-Histidine caused no marked changes in blood pressure even at a dose of 1,500 mg/kg, which showed an increase in rCBF in the hippocampus. These results indicate that histamine elicited an increase in rCBF via both H1 and H2 receptors.

  15. Cardiorespiratory fitness mediates the effects of aging on cerebral blood flow

    Directory of Open Access Journals (Sweden)

    Benjamin eZimmerman

    2014-04-01

    Full Text Available The brain’s vasculature is likely to be subjected to the same age-related physiological and anatomical changes affecting the rest of the cardiovascular system. Since aerobic fitness is known to alleviate both cognitive and volumetric losses in the brain, it is important to investigate some of the possible mechanisms underlying these beneficial changes. Here we investigated the role that estimated cardiorespiratory fitness (eCRF plays in determining the relationship between aging and cerebral blood flow (CBF in a group of older adults (ages 55-85. Using arterial spin labeling to quantify CBF, we found that blood flow in the gray matter was positively correlated with eCRF and negatively correlated with age. Subsequent analyses revealed that eCRF fully mediated the effects of age on CBF in the gray matter, but not in the white matter. Additionally, regional measures of CBF were related to regional measures of brain volume. These findings provide evidence that age-related effects on cerebrovascular health and perfusion in older adults are largely influenced by their eCRF levels.

  16. Altered cerebral hemodynamics in early Alzheimer disease: a pilot study using transcranial Doppler.

    NARCIS (Netherlands)

    Claassen, J.A.H.R.; Diaz-Arrastia, R.; Martin-Cook, K.; Levine, B.D.; Zhang, R.

    2009-01-01

    Cerebrovascular disease may contribute to the development and progression of Alzheimer's disease (AD). This study investigated whether impairments in cerebral hemodynamics can be detected in early-stage AD. Nine patients with mild AD and eight cognitively normal controls matched for age underwent br

  17. Heat stress exacerbates the reduction in middle cerebral artery blood velocity during prolonged self-paced exercise.

    Science.gov (United States)

    Périard, J D; Racinais, S

    2015-06-01

    This study examined the influence of hyperthermia on middle cerebral artery mean blood velocity (MCA Vmean). Eleven cyclists undertook a 750 kJ self-paced time trial in HOT (35 °C) and COOL (20 °C) conditions. Exercise time was longer in HOT (56 min) compared with COOL (49 min; P heat appears to have exacerbated the reduction in MCA Vmean, in part via increases in peripheral blood flow and a decrease in arterial blood pressure.

  18. Diurnal variation in baseline human regional cerebral blood flow demonstrated by PET

    Energy Technology Data Exchange (ETDEWEB)

    Diehl, D.J.; Mintun, M.A.; Moore, R.Y. [Univ. of Pittsburgh, PA (United States)] [and others

    1994-05-01

    We have previously described the diurnal variation in regional cerebral blood flow (rCBF) response to bright light in human subjects as demonstrated by the positron emission tomography (PET) activation method. In this abstract, we report the differences in rCBF (an indicator of differences in regional neuronal activity) between the evening and midday dim light baseline scans which served as the control states in the above bright light activation study. Five right-handed, healthy volunteers underwent both an evening (8pm) and a midday (12N) O-15 water PET scanning session. Each scanning session was preceded by one hour of dim light adaptation (50 lux) and consisted of six rCBF scans at three different light intensities in an AABBCC sequence (A=50 lux, B=2500 lux, C=7000lux). Significant differences in rCBF between the evening and midday 50 lux states were identified using the statistical parametric mapping method developed by Friston et al (p<.001). The evening scans demonstrated areas of greater relative blood flow in the pineal gland, the lateral temporal cortex bilaterally, the right lateral prefrontal cortex, the superior aspect of the anterior cingulate, and the left thalamus. The midday scans showed areas of greater relative blood flow in the visual cortex, the left lateral prefrontal cortex. the inferior aspect of the anterior cingulate, the left parietal cortex and the cerebellum. Our results demonstrate an extensive diurnal variation in baseline human rCBF. This indicates that time of day may be an important variable in conducting and interpreting functional brain imaging studies. Furthermore, these results suggest possible neuroanatomical substrates through which the circadian system may regulate the various physiologic and behavioral processes that manifest circadian rhythms.

  19. Effects of dopamine infusion on cerebral blood flow, brain cell membrane function and energy metabolism in experimental Escherichia coli meningitis in the newborn piglet.

    OpenAIRE

    Park, Won Soon; Chang, Yun Sil; Shim, Jae Won; Kim, Mi Jung; Ko, Sun Young; Kim, Sung Shin; Hwang, Jong Hee; Choi, Chang Won; Lee, Munhyang

    2003-01-01

    In the present study, we tested whether maintenance of adequate cerebral perfusion pressure (CPP) by pharmacologically preventing systemic hypotension with dopamine infusion would prevent cerebral ischemia and attenuate energy depletion and neuronal injury even though intracranial pressure remains elevated in a newborn piglet meningitis model. Cerebral blood flow, measured at the end of the experiment using fluorescent microspheres, was significantly increased by dopamine infusion. The decrea...

  20. Autoradiographic imaging of cerebral ischaemia using a combination of blood flow and hypoxic markers in an animal model

    Energy Technology Data Exchange (ETDEWEB)

    Lythgoe, M.F. [Royal College of Surgeons Unit of Biophysics, Institute of Child Health, London (United Kingdom)]|[Department of Radiology, Great Ormond Street Hospital for Children NHS Trust, London (United Kingdom); Williams, S.R. [Royal College of Surgeons Unit of Biophysics, Institute of Child Health, London (United Kingdom); Wiebe, L.I. [University of Alberta, Edmonton, AB (Canada); McEwan, A.J.B. [University of Alberta, Edmonton, AB (Canada); Gordon, I. [Department of Radiology, Great Ormond Street Hospital for Children NHS Trust, London (United Kingdom)

    1997-01-01

    Current routine clinical techniques, including angiography and perfusional single-photon emission tomography, can be used to indicate problems in cerebral vascular supply and areas of cerebral hypoperfusion following a stroke, but cannot distinguish between ischaemic core and penumbra. In order to image specifically the penumbra, a method or indicator should be able to define areas with reduced blood flow, and a degree of metabolic compromise. In this context, the tissue could be regarded as hypoxic rather than ischaemic, and we have therefore chosen to investigate the potential of radio-labelled hypoxic markers in the study of ischaemia. In order to combine a hypoxic marker with a blood flow marker we used technetium-99m hexamethylpropylene amine oxime ({sup 99m}Tc-HMPAO) and iodine-125 iodoazomycin arabinoside ({sup 125}I-IAZA), during cerebral ischaemia in the rat middle cerebral artery occlusion model. {sup 99m}Tc-HMPAO and {sup 125}I-IAZA were injected simultaneously 2 h following occlusion of the middle cerebral artery, and 5 h before decapitation. Paired autoradiograms were produced and compared. Three distinct patterns emerged from the autoradiograms: slightly decreased perfusion with no uptake of the hypoxic marker indicating an area of misery perfusion; moderately decreased perfusion with concomitant uptake of iodoazomycin arabinoside, a region of hypoxia; and severely decreased perfusion with no retention of the hypoxic tracer. In conclusion, we present a new use for an imaging agent in the investigation of cerebral hypoxia. This agent, IAZA together with HMPAO, provides a means of separating the penumbra into regions of misery perfusion and hypoxia. The potential impact of this may be important in the clinical investigation of stroke. (orig.). With 3 figs.

  1. 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...

  2. [Alterations in cerebral perfusion in patients with systemic sclerosis and cognitive impairment].

    Science.gov (United States)

    Moreno-Gutiérrez, Juan; Coria-Moctezuma, Luis Alonso; del Pilar Cruz-Domínguez, María; Vera-Lastra, Olga Lidia

    2015-01-01

    Introducción: la esclerosis sistémica (ES) es una enfermedad autoinmune, sistémica, caracterizada por fibrosis, alteraciones inmunológicas y vasculares. La hipoperfusión cerebral puede ser causada por isquemia. Los trastornos cognitivos son causa importante de morbilidad. El objetivo de este estudio fue determinar la frecuencia de alteraciones en la perfusión cerebral (PC) en pacientes con ES y deterioro cognitivo (DC). Métodos: se estudiaron 88 pacientes con ES. A todos se les aplicó el Test de Montreal (TM) para evaluar el DC. A 15 pacientes con DC que cumplieron con los criterios (sin hipertensión arterial sistémica, diabetes mellitus, evento vascular cerebral, vasculitis, hipotiroidismo, depresión, sin ingesta de fármacos que interfieran con la evaluación cognitiva), se les midió la PC mediante Gamagrama Cerebral Perfusorio (GCP).Resultados: de los 88 pacientes con ES, 58 tuvieron DC con el TM. La PC se encontró disminuida en 12/15. La disminución de la PC se observó en los siguientes lóbulos (frontal en 9/15; temporal en 7/15, y parietal en 3/15. La concordancia entre el TM y GC fue 60 % para el lóbulo frontal, 46 % para el lóbulo temporal y 13 % parietal.Conclusiones: el DC es frecuente en la ES, la disminución de la PC fue más común en el lóbulo frontal, predominado en los pacientes de mayor edad y tiempo de evolución de la ES.

  3. Advanced glycation end products, oxidative stress and metalloproteinases are altered in the cerebral microvasculature during aging.

    Science.gov (United States)

    Safciuc, Florentina; Constantin, Alina; Manea, Adrian; Nicolae, Manuela; Popov, Doina; Raicu, Monica; Alexandru, Dorin; Constantinescu, Elena

    2007-11-01

    Biological aging is associated with an increased incidence of cerebrovascular disease. Recent findings indicate that oxidative stress promoting age-related changes of cerebral circulation are involved in neurodegenerative disorders such as Alzheimer's disease (AD) and Parkinson's disease. The aim of this study was to evaluate the contribution of cerebral microvessels to the oxidative stress during brain aging, by: (i) assessment of precursors for advanced glycation end products (AGE) formation, (ii) activities of antioxidant enzymes, namely superoxide dismutase (SOD), glutathione peroxidase (GPx) and glutathione disulfide reductase (GR), and (iii) the activities of metalloproteinases (MMPs), MMP-2 and MMP-9, involved in synaptogenesis and memory consolidation. The experiments were performed on two groups of male Wistar rats: 15 young (3-6 months old) and 15 aged (18-24 months old) animals. The cerebral microvessels were isolated by mechanical homogenization, the concentration of protein carbonyls and the activity of antioxidant enzymes were evaluated by spectrophotometry, and gelatin SDS-PAGE zymography was employed to evaluate MMP-2 and MMP-9 activities. The results showed that, by comparison with young rats, aged brain microvessels contain: (i) approximately 106 % increase of protein carbonyls production; (ii) approximately 68% higher GPx activity, unmodified activities of SOD and GR; (iii) approximately 30% diminishment in MMP-2 activity, and the specific occurrence of MMP-9 enzyme. The data suggest that the age-related changes of microvessels could increase the propensity for cerebral diseases and might represent, at least in part, a prerequisite for the deterioration of mental and physical status in the elderly.

  4. 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).

  5. In vivo cross-sectional characterization of cerebral alterations induced by intracerebroventricular administration of streptozotocin.

    Science.gov (United States)

    Kraska, Audrey; Santin, Mathieu D; Dorieux, Olène; Joseph-Mathurin, Nelly; Bourrin, Emmanuel; Petit, Fanny; Jan, Caroline; Chaigneau, Marion; Hantraye, Philippe; Lestage, Pierre; Dhenain, Marc

    2012-01-01

    Cerebral aging is often associated with the occurrence of neurodegenerative diseases leading to dementia. Animal models are critical to elucidate mechanisms associated to dementia and to evaluate neuroprotective drugs. Rats that received intracerebroventricular injection of streptozotocin (icv-STZ) have been reported as a model of dementia. In these animals, this drug induces oxidative stress and brain glucose metabolism impairments associated to insulin signal transduction failure. These mechanisms are reported to be involved in the pathogenesis of Alzheimer's disease and other dementia. Icv-STZ rats also display memory impairments. However, little is known about the precise location of the lesions induced by STZ administration. In this context, the present study characterized the cerebral lesions induced by two-doses of icv-STZ by using high-field magnetic resonance imaging to easily and longitudinally detect cerebral abnormalities and by using immunohistochemistry to evaluate neuronal loss and neuroinflammation (astrocytosis and microgliosis). We showed that, at high doses, icv-STZ induces severe and acute neurodegenerative lesions in the septum and corpus callosum. The lesions are associated with an inflammation process. They are less severe and more progressive at low doses. The relevance of high and low doses of icv-STZ to mimic dementia and evaluate new drugs is discussed in the final part of this article.

  6. 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.

  7. Continuous measurement of cerebral cortical blood flow by laser-Doppler flowmetry in a rat stroke model

    Energy Technology Data Exchange (ETDEWEB)

    Dirnagl, U.; Kaplan, B.; Jacewicz, M.; Pulsinelli, W. (Cornell Univ. Medical College, New York, NY (USA))

    1989-10-01

    Laser-Doppler flowmetry (LDF), a new method allowing instantaneous, continuous, and noninvasive measurements of microcirculatory blood flow in a small tissue sample, was evaluated for its accuracy in monitoring regional cerebral blood flow (rCBF) in the cortical microcirculation after focal cerebral ischemia. Wistar and spontaneously hypertensive rats (SHR, n = 19) were subjected to permanent occlusion of the middle cerebral and common carotid arteries. Absolute rCBF in a tissue sample of the ischemic hemisphere was measured autoradiographically with ({sup 14}C)iodoantipyrine as a tracer and compared to rCBF measured by LDF. Additionally, the percent change in rCBF between baseline and ischemic values was compared for both methods. Absolute rCBF values recorded with LDF correlated poorly (r = 0.54) with ({sup 14}C)iodoantipyrine measurements. In contrast LDF readings expressed as a percentage of ischemic vs. preocclusion readings (relative LDF readings) correlated very well (r = 0.91) with the percent change in (14C)iodoantipyrine measurements. We conclude that LDF does not provide accurate measurements of absolute rCBF values but this method allows accurate measurements of changes in rCBF due to induction of focal cerebral ischemia.

  8. Continuous measurement of cerebral cortical blood flow by laser-Doppler flowmetry in a rat stroke model.

    Science.gov (United States)

    Dirnagl, U; Kaplan, B; Jacewicz, M; Pulsinelli, W

    1989-10-01

    Laser-Doppler flowmetry (LDF), a new method allowing instantaneous, continuous, and noninvasive measurements of microcirculatory blood flow in a small tissue sample, was evaluated for its accuracy in monitoring regional cerebral blood flow (rCBF) in the cortical microcirculation after focal cerebral ischemia. Wistar and spontaneously hypertensive rats (SHR, n = 19) were subjected to permanent occlusion of the middle cerebral and common carotid arteries. Absolute rCBF in a tissue sample of the ischemic hemisphere was measured autoradiographically with [14C]iodoantipyrine as a tracer and compared to rCBF measured by LDF. Additionally, the percent change in rCBF between baseline and ischemic values was compared for both methods. Absolute rCBF values recorded with LDF correlated poorly (r = 0.54) with [14C]iodoantipyrine measurements. In contrast LDF readings expressed as a percentage of ischemic vs. preocclusion readings (relative LDF readings) correlated very well (r = 0.91) with the percent change in [14C]iodoantipyrine measurements. We conclude that LDF does not provide accurate measurements of absolute rCBF values but this method allows accurate measurements of changes in rCBF due to induction of focal cerebral ischemia.

  9. Study of cerebral blood flow by magnetic resonance 0. 5 T. Estudio de la perfusion cerebral con RM de 0,5 T

    Energy Technology Data Exchange (ETDEWEB)

    Torrijo, C.; Marti-Bonmati, L.; Palop, C.; Caballero, E.; Poyatos, C.; Sopena, R. (Hospital Doctor Peset. Servicio de Diagnostico por la Imagen. Valencia (Spain))

    1993-01-01

    To asses the cerebral blood flow by magnetic resonance, 1.5 T superconductor imagers have been used, taking slices of the brain for dynamic study following rapid iv administration of gadolinium (Gd-DTPA). Our aim was to attempt to reproduce these data with a 0.5 T superconductor imager. Thirty-two dynamic studies of the head were carried out. The first 10 were used to modify the methodology until a standard technique was achieved, which was employed for the remaining 22:T2*-weighted gradient-echo sequence (TR=50msec, TE=23 msec, angle=10*, thickness=10mm, matrix=128x64, FOV=250 mm), taking 15 slices in 75 seconds following a 20 ml iv bolus of Gd-DTPA. When the signal intensity was measured at the level of the cerebral cortex, a reduction was detected in association with the passage of Gd-DTPA through the cerebral microcirculation, with a mean signal loss of 5.96%[+-]2.25. This signal loss is significant (p<0.01) when compared with that reported in studies in which no contrast agent was used (2.54%[+-]0.6). The maximum signal loss appeared at times varying between 10 and 40 seconds after administration of the contrast medium. It is concluded that passage (perfusion) through the cerebral microcirculation can be observed at 0.5 T, although the attenuation values obtained are lower than those reported by other authors in their series. The time at which the signal loss appears after iv contrast administration is unpredictable, fact which further limits the utility of this methodology. (Author)

  10. Electrocardiographic and Blood Pressure Alterations During Electroconvulsive Therapy in Young Adults

    OpenAIRE

    Rumi Demetrio Ortega; Solimene Maria Cecília; Takada Júlio Yoshio; Grupi César José; Giorgi Dante Marcelo; Rigonatti Sérgio Paulo; Luz Protásio Lemos da; Ramires José Antonio Franchini

    2002-01-01

    OBJECTIVE - To study cardiovascular alterations in young patients with no apparent organic disease who underwent electroconvulsive therapy. METHODS - The study comprised 47 healthy patients (22 males and 25 females) with a mean age of 30.3 years, who underwent electroconvulsive therapy. Ambulatory blood pressure monitoring and continuous electrocardiographic monitoring (Holter monitor) were performed during 24 hours. Blood pressure and heart rate were assessed 4 hours prior to electric shock ...

  11. Poor agreement between transcranial Doppler and near-infrared spectroscopy-based estimates of cerebral blood flow changes in sepsis

    DEFF Research Database (Denmark)

    Toksvang, Linea N; Plovsing, Ronni R; Petersen, Marie W;

    2014-01-01

    BACKGROUND: Continuous monitoring of cerebral blood flow (CBF) may be valuable in critically ill patients with sepsis. In this study, we compared spatially resolved near-infrared spectroscopy (NIRS) to transcranial Doppler ultrasound (TCD)-derived estimates of noradrenaline-associated changes...... in CBF in such patients. METHODS: Mean arterial blood pressure (MAP) was elevated by increasing the noradrenaline infusion rate in eight mechanically ventilated, critically ill patients diagnosed with severe sepsis or septic shock. The associated changes in CBF were assessed by simultaneous ipsilateral......-derived estimates with a relative bias of 14% and limits of agreement of -18% to 45% change in CBF. CONCLUSION: Our findings stress that TCD and NIRS cannot be used interchangeably for monitoring changes in cerebral haemodynamics in critically ill patients with sepsis receiving vasopressor treatment...

  12. The postural reduction in middle cerebral artery blood velocity is not explained by PaCO2

    DEFF Research Database (Denmark)

    Immink, R V; Secher, N H; Roos, C M

    2006-01-01

    In the normocapnic range, middle cerebral artery mean velocity (MCA Vmean) changes approximately 3.5% per mmHg carbon-dioxide tension in arterial blood (PaCO2) and a decrease in PaCO2 will reduce the cerebral blood flow by vasoconstriction (the CO2 reactivity of the brain). When standing up MCA...... Vmean and the end-tidal carbon-dioxide tension (PETCO2) decrease, suggesting that PaCO2 contributes to the reduction in MCA Vmean. In a fixed body position, PETCO2 tracks changes in the PaCO2 but when assuming the upright position, cardiac output (Q) decreases and its distribution over the lung changes...

  13. The effect of isovolemic hemodilution with oxycyte, a perfluorocarbon emulsion, on cerebral blood flow in rats.

    Directory of Open Access Journals (Sweden)

    Zhong-jin Yang

    Full Text Available BACKGROUND: Cerebral blood flow (CBF is auto-regulated to meet the brain's metabolic requirements. Oxycyte is a perfluorocarbon emulsion that acts as a highly effective oxygen carrier compared to blood. The aim of this study is to determine the effects of Oxycyte on regional CBF (rCBF, by evaluating the effects of stepwise isovolemic hemodilution with Oxycyte on CBF. METHODOLOGY: Male rats were intubated and ventilated with 100% O(2 under isoflurane anesthesia. The regional (striatum CBF (rCBF was measured with a laser doppler flowmeter (LDF. Stepwise isovolemic hemodilution was performed by withdrawing 4ml of blood and substituting the same volume of 5% albumin or 2 ml Oxycyte plus 2 ml albumin at 20-minute intervals until the hematocrit (Hct values reached 5%. PRINCIPAL FINDINGS: In the albumin-treated group, rCBF progressively increased to approximately twice its baseline level (208+/-30% when Hct levels were less than 10%. In the Oxycyte-treated group on the other hand, rCBF increased by significantly smaller increments, and this group's mean rCBF was only slightly higher than baseline (118+/-18% when Hct levels were less than 10%. Similarly, in the albumin-treated group, rCBF started to increase when hemodilution with albumin caused the CaO(2 to decrease below 17.5 ml/dl. Thereafter, the increase in rCBF was accompanied by a nearly proportional decrease in the CaO(2 level. In the Oxycyte-treated group, the increase in rCBF was significantly smaller than in the albumin-treated group when the CaO(2 level dropped below 10 ml/dl (142+/-20% vs. 186+/-26%, and rCBF returned to almost baseline levels (106+/-15 when the CaO(2 level was below 7 ml/dl. CONCLUSIONS/SIGNIFICANCE: Hemodilution with Oxycyte was accompanied with higher CaO(2 and PO(2 than control group treated with albumin alone. This effect may be partially responsible for maintaining relatively constant CBF and not allowing the elevated blood flow that was observed with albumin.

  14. Regional cerebral blood flow in normal pressure hydrocephalus: diagnostic and prognostic aspects

    Energy Technology Data Exchange (ETDEWEB)

    Larsson, A. (Dept. of Neurology, Sahlgren Hospital, Goeteborg (Sweden)); Bergh, A.C. (Dept. of Clinical Physiology, Sahlgren Hospital, Goeteborg (Sweden)); Bilting, M. (Dept. of Neurosurgery, Sahlgren Hospital, Goeteborg (Sweden)); Aerlig, AA. (Dept. of Radiation Physics, Sahlgren Hospital, Goeteborg (Sweden)); Jacobsson, L. (Dept. of Radiation Physics, Sahlgren Hospital, Goeteborg (Sweden)); Stephensen, H. (Dept. of Neurosurgery, Sahlgren Hospital, Goeteborg (Sweden)); Wikkelsoe, C. (Dept. of Neurology, Sahlgren Hospital, Goeteborg (Sweden))

    1994-02-01

    Relative regional cerebral blood flow (rrCBF) was measured by SPET using [sup 99m]Tc-HMPAO as flow tracer, in 23 patients with normal pressure hydrocephalus (NPH). 1000 MBq [sup 99m]Tc-HMPAO was given intravenously and the rrCBF calculated as regional/cerebellar count level ratios. The patients were examined before and 3-12 months after ventriculoperitoneal shunt surgery. rrCBF was also determined in ten healthy aged matched volunteers who served as controls. The NPH patients had decreased rrCBF in the hippocampal regions and in the frontal and parietal white matter as compared to the controls. The frontal/parietal rrCBF ratio correlated with both psychiatric disability and the preoperative degree of incontinence. Decreased flow in frontal white matter, frontoparietal and hippocampal grey matter and a low frontalparietal grey matter flow ratio preoperatively correlated with improvement in both Mini Mental State score and psychiatric disability after shunt surgery. After shunt surgery the rrCBF increased in the mesencephalon, frontal grey and white matter, parietal white matter and hippocampus. The flow increase in hippocampal regions and frontal white matter correlated with improvement in psychiatric symptomatology. The results of this study regarding the frontal and hippocampal rrCBF patterns, and the clinical correlation, support the hypothesis that CBF changes in these regions are of patohphysiological and prognostic importance in NPH. (orig./MG)

  15. Flavor-Enhanced Modulation of Cerebral Blood Flow during Gum Chewing.

    Directory of Open Access Journals (Sweden)

    Yoko Hasegawa

    Full Text Available Flavor perception, the integration of taste and odor, is a critical factor in eating behavior. It remains unclear how such sensory signals influence the human brain systems that execute the eating behavior.WE TESTED CEREBRAL BLOOD FLOW (CBF IN THE FRONTAL LOBES BILATERALLY WHILE SUBJECTS CHEWED THREE TYPES OF GUM WITH DIFFERENT COMBINATIONS OF TASTE AND ODOR: no taste/no odor gum (C-gum, sweet taste/no odor gum (T-gum, and sweet taste/lemon odor gum (TO-gum. Simultaneous recordings of transcranial Doppler ultrasound (TCD and near infrared spectrometer (NIRS were used to measure CBF during gum chewing in 25 healthy volunteers. Bilateral masseter muscle activity was also monitored.We found that subjects could discriminate the type of gum without prior information. Subjects rated the TO-gum as the most flavorful gum and the C-gum as the least flavorful. Analysis of masseter muscle activity indicated that masticatory motor output during gum chewing was not affected by taste and odor. The TCD/NIRS measurements revealed significantly higher hemodynamic signals when subjects chewed the TO-gum compared to when they chewed the C-gum and T-gum.These data suggest that taste and odor can influence brain activation during chewing in sensory, cognitive, and motivational processes rather than in motor control.

  16. Relationships between Cerebral Blood Flow and IQ in Typically Developing Children and Adolescents.

    Science.gov (United States)

    Kilroy, Emily; Liu, Collin Y; Yan, Lirong; Kim, Yoon Chun; Dapretto, Mirella; Mendez, Mario F; Wang, Danny J J

    2011-01-01

    The objective of this study was to explore the relationships between IQ and cerebral blood flow (CBF) measured by arterial spin labeling (ASL) in children and adolescents. ASL was used to collect perfusion MRI data on 39 healthy participants aged 7 to 17. The Wechsler Abbreviated Intelligence Scale was administered to determine IQ scores. Multivariate regression was applied to reveal correlations between CBF and IQ scores, accounting for age, sex and global mean CBF. Voxel Based Morphometry (VBM) analysis, which measures regional cortical volume, was performed as a control. Regression analyses were further performed on CBF data with adjustment of regional gray matter density (GMD). A positive correlation between CBF and IQ scores was primarily seen in the subgenual/anterior cingulate, right orbitofrontal, superior temporal and right inferior parietal regions. An inverse relationship between CBF and IQ was mainly observed in bilateral posterior temporal regions. After adjusting for regional GMD, the correlations between CBF and IQ in the subgenual/anterior cingulate cortex, right orbitofrontal, superior temporal regions and left insula remained significant. These findings support the Parieto-Frontal Integration Theory of intelligence, especially the role of the subgenual/anterior cingulate cortex in the neural networks associated with intelligence. The present study also demonstrates the unique value of CBF in assessing brain-behavior relationships, in addition to structural morphometric measures.

  17. Dynamic cerebral autoregulation to induced blood pressure changes in human experimental and clinical sepsis

    DEFF Research Database (Denmark)

    Berg, Ronan M G; Plovsing, Ronni R; Bailey, Damian M

    2016-01-01

    (Pvolunteers at baseline; Pvolunteers after LPS). The corresponding RoR values increased from 0·46 (0·31-0·49) s(-1) at baseline to 0·58 (0·36-0·74) s(-1) after LPS (Pvolunteers, whereas they were similar to values observed in patients [0·43 (0·36-0·52) s...... shock. In this study, we hypothesized that this pattern of response would be identical during induced changes in blood pressure. Dynamic cerebral autoregulation was assessed in nine healthy volunteers and six septic patients. The healthy volunteers underwent a 4-h intravenous infusion of LPS (total dose......R). This was performed before and after LPS infusion in healthy volunteers, and within 72 h following clinical diagnosis of sepsis in patients. In healthy volunteers, thigh-cuff deflation caused a MAP reduction of 16 (13-20) % at baseline and 18 (16-20) % after LPS, while the MAP reduction was 12 (11-13) % in patients...

  18. Reduced serotonin synthesis and regional cerebral blood flow after anxiolytic treatment of social anxiety disorder.

    Science.gov (United States)

    Frick, Andreas; Åhs, Fredrik; Appel, Lieuwe; Jonasson, My; Wahlstedt, Kurt; Bani, Massimo; Merlo Pich, Emilio; Bettica, Paolo; Långström, Bengt; Lubberink, Mark; Fredrikson, Mats; Furmark, Tomas

    2016-11-01

    Social anxiety disorder (SAD) is associated with increased fear-related neural activity in the amygdala and we recently found enhanced serotonin synthesis rate in the same region. Anxiolytic agents like selective serotonin re-uptake inhibitors (SSRIs) and neurokinin-1 receptor (NK1R) antagonists reduce amygdala activity and may attenuate serotonin formation according to animal studies. Here, we examined the effects of SSRI pharmacotherapy, NK1R antagonism, and placebo on serotonin synthesis rate in relation to neural activity, measured as regional cerebral blood flow (rCBF), and symptom improvement in SAD. Eighteen SAD patients were randomized to receive daily double-blind treatment for six weeks either with the SSRI citalopram (n=6; 40mg), the NK1R antagonist GR205171 (n=6; 5mg; 4 weeks following 2 weeks of placebo), or placebo (n=6). Serotonin synthesis rate at rest and rCBF during stressful public speaking were assessed, before and after treatment, using positron emission tomography with the tracers [(11)C]5-hydroxytryptophan and [(15)O]water respectively. The Liebowitz Social Anxiety Scale (LSAS-SR) indexed symptom severity. All groups exhibited attenuated amygdala serotonin synthesis rate after treatment, which was associated with reduced amygdala rCBF during public speaking and accompanied by symptom improvement. These results are consistent with the notion that serotonin in the amygdala exerts an anxiogenic influence and, conversely, that anxiolysis is achieved through decreased serotonin formation in the amygdala.

  19. 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.

  20. Protective effects of taurine in traumatic brain injury via mitochondria and cerebral blood flow.

    Science.gov (United States)

    Wang, Qin; Fan, Weijia; Cai, Ying; Wu, Qiaoli; Mo, Lidong; Huang, Zhenwu; Huang, Huiling

    2016-09-01

    In mammalian tissues, taurine is an important natural component and the most abundant free amino acid in the heart, retina, skeletal muscle, brain, and leukocytes. This study is to examine the taurine's protective effects on neuronal ultrastructure, the function of the mitochondrial respiratory chain complex, and on cerebral blood flow (CBF). The model of traumatic brain injury (TBI) was made for SD rats by a fluid percussion device, with taurine (200 mg/kg) administered by tail intravenous injection once daily for 7 days after TBI. It was found that CBF was improved for both left and right brain at 30 min and 7 days post-injury by taurine. Reaction time was prolonged relative to the TBI-only group. Neuronal damage was prevented by 7 days taurine. Mitochondrial electron transport chain complexes I and II showed greater activity with the taurine group. The improvement by taurine of CBF may alleviate edema and elevation in intracranial pressure. Importantly taurine improved the hypercoagulable state.

  1. Regional cerebral blood flow during the auditory oddball task measured by positron emission tomography

    Energy Technology Data Exchange (ETDEWEB)

    Mochida, Masahiko [Kyorin Univ., Mitaka, Tokyo (Japan). Graduate School of Medicine

    1997-03-01

    Regional cerebral blood flow (rCBF) was measured by employing PET in nine healthy right-handed male subjects, while they simultaneously performed the auditory oddball task using tone bursts. Results showed that the rCBF value was highest in the transverse gyrus of Heschl in both right and left hemispheres. When comparing the rCBF values between right and left hemispheres, four areas had higher rCBF values in the left hemisphere and eight areas had higher rCBF values in the right hemisphere. Of these, the anterior and posterior parts of the superior temporal gyrus, especially, showed significant differences. The hemispheric differences in the rCBF values of the auditory areas can be attributed to the performance of the oddball task which requires higher processing of non verbal auditory input. The P300 amplitude which reflects the amount of the allocated information processing resources correlated positively with rCBF in the following areas: left piriform cortex, the transverse gyrus of Heschl in both left and right hemispheres. Mean-while, P300 amplitude correlated negatively with rCBF in the nucleus accumbens septi in both right and left hemispheres. The N100 amplitude evoked by frequent stimulus did not correlate with rCBF in almost all ROIs. (K.H.)

  2. The evaluation of regional cerebral blood flow in the chronic alcohol abuse patients

    Energy Technology Data Exchange (ETDEWEB)

    Chung, Y. A.; Kim, D. J.; Oh, J. H.; Kim, C. H.; Kim, S. H.; Sohn, H. S.; Chung, S. K. [The Catholic University of Korea, Seoul (Korea, Republic of)

    2005-07-01

    The use of alcohol is increasingly prevalent in our country and remains associated with innumerable social and economic problems. In addition, brain abnormalities have been proved by means of neuroimaging techniques not only in the first days of withdrawal, but also months after the last use of the substance in the patients. The purpose of the present study was to investigate patterns of the regional cerebral blood flow (rCBF) in alcoholic dementia. Six patients (all men; 44-67 years, mean age = 57.5 years) who fulfilled DSM-IV criteria for alcoholic dementia were enrolled in the study. RCBF measurements of resting state using Tc-99m ethyl cysteinate dimmer (ECD) SPECT were performed. The SPECT image was obtained 40 minutes after intravenous injection of 1110 MBq of Tc-99m ECD using a dual-head gamma camera (ECAM plus; Siemens, Erlangen, Germany). The normalized SPECT data from the alcoholic dementia group were compared with those from 12 healthy subjects. Alcoholic dementia patients showed significant decrement of rCBF in the left thalamus, superior frontal gyrus of left frontal lobe, left insula, postcentral gyrus of left parietal lobe, parahippocapal gyrus of left limbic lobe, right caudate, and cingulate gyrus of right limbic lobe than age-matched healthy subjects. Despite the small number of patients examined, the study supports the belief that patients with alcohol induced cognitive dysfunction have the neuro pathophysiology as those with classical alcoholic dementia.

  3. Effects of peritumoural oedema on cerebral blood flow and cerebrovascular reactivity in patients with alert consciousness

    Energy Technology Data Exchange (ETDEWEB)

    Chang, Chia-Cheng [Department of Neurosurgery, Yokohama Minami Kyosai Hospital, Yokohama (Japan); Department of Neurosurgery, Yokohama City University School of Medicine, 3-9 Fukuura, Kanazawa-ku, Yokohama, Japan 236-0004; Kuwana, Nobumasa; Ito, Susumu [Department of Neurosurgery, Yokohama Minami Kyosai Hospital, Yokohama (Japan); Ikegami, Tadashi [Department of Radiology, Yokohama Minami Kyosai Hospital, Yokohama (Japan); Yamamoto, Isao [Department of Neurosurgery, Yokohama City University School of Medicine, Yokohama (Japan)

    1999-11-01

    The effects of peritumoural oedema on cerebral blood flow (CBF) and cerebrovascular reactivity (CVR) were studied in 18 patients with alert consciousness. Hemispheric mean CBF was measured by performing first-pass radionuclide angiography using technetium-99m hexamethylpropylene amine oxime. CVR was measured as the percentage change from the baseline mean CBF value after acetazolamide administration. Patients were classified into three groups according to the severity of peritumoural oedema. The mean CBF of both hemispheres in each group was not significantly different from that of age-matched controls. CVR was preserved in patients with mild peritumoural oedema (n=6), but was significantly (P<0.01) reduced in patients with moderate (n=7) and severe peritumoural oedema (n=5). No significant correlation was found between the degree of midline shift and the mean CVR of both hemispheres (P=0.09). Surgical removal of the tumour significantly (P<0.05) improved the impaired CVR, although the mean CBF did not change. Administration of glucocorticoid improved the impaired CVR, without a change in the mean CBF, in a patient with a metastatic brain tumour. We conclude that CVR is impaired by the development of peritumoural oedema prior to changes in mean CBF. (orig.)

  4. Exercise intensity modulates the change in cerebral blood flow following aerobic exercise in chronic stroke.

    Science.gov (United States)

    Robertson, Andrew D; Crane, David E; Rajab, A Saeed; Swardfager, Walter; Marzolini, Susan; Shirzadi, Zahra; Middleton, Laura E; MacIntosh, Bradley J

    2015-08-01

    The mechanisms supporting functional improvement by aerobic exercise following stroke remain incompletely understood. This study investigated how cycling intensity and aerobic fitness influence cerebral blood flow (CBF) following a single exercise session. Thirteen community-living stroke survivors performed 20 min of semi-recumbent cycling at low and moderate intensities (40-50 and 60-70 % of heart rate reserve, respectively) as determined from an exercise stress test. CBF was quantified by arterial spin labeling MRI at baseline, as well as 30 and 50 min post-exercise. An intensity-dependent effect was observed in the right post-central and supramarginal gyri up to 50 min after exercise (uncorrected p Aerobic fitness was directly related to posterior cingulate and thalamic CBF, and inversely related to precuneal CBF at rest (R (2) ≥ 0.75); however, no relationship between fitness and the post-exercise change in CBF was observed. Divergent changes in regional CBF were observed in the right parietal cortex following low- and moderate-intensity exercise, which suggests that intensity of prescribed exercise may be useful in optimizing rehabilitation.

  5. Quantitative measurements of cerebral blood flow in volume imaging PET scanners

    Energy Technology Data Exchange (ETDEWEB)

    Smith, R.J.; Shao, L.; Freifelder, R.; Karp, J.S.; Ragland, J.D. [Univ. of Pennsylvania, Philadelphia, PA (United States)

    1995-08-01

    Quantitative measurements of Cerebral Blood Flow (CBF) are performed in a volume imaging PET Scanner by means of moderate activity infusions. In equilibrium infusions, activations are measured by scanning over 10 minutes with 16 minute activations. Typical measured whole brain CBF values are 37{+-}8 ml/min/100g, close to the value of 42 ml/min/100g reported by other groups using this method. For ramped infusions, scanning over 4 minutes with 5 minute activations results in whole brain CBFs of 49 {+-} 9 ml/min/100g, close to the Kety and Schmidt value of 50 ml/min/100g. Both equilibrium and ramped infusion methods have been used to study face and word memory in human subjects. Both methods were able to detect significant activations in regions implicated in human memory. The authors conclude that precise quantitation of regional CBF is achieved using both methods, and that ramped infusions also provide accurate measures of CBF. In addition a simplified protocol for ramped infusion studies has been developed. In this method the whole brain tissue time activity curve generated from dynamic scanning is replaced by an appropriately scaled camera coincidence countrate curve. The resulting whole brain CBF values are only 7% different from the dynamic scan and fit results. Regional CBFs (rCBF) may then be generated from the summed image (4.25 minutes) using a count density vs flow lookup table.

  6. Laser speckle contrast reveals cerebral blood flow dynamics evoked by optogenetically controlled neuronal activity

    Science.gov (United States)

    Li, Nan; Thakor, Nitish V.; Pelled, Galit

    2013-03-01

    As a critical basis of functional brain imaging, neurovascular coupling describes the link between neuronal and hemodynamic changes. The majority of in vivo neurovascular coupling studies was performed by inducing sensory stimulation via afferent inputs. Unfortunately such an approach results in recruiting of multiple types of cells, which confounds the explanation of neuronal roles in stimulus evoked hemodynamic changes. Recently optogenetics has emerged to provide immediate control of neurons by exciting or inhibiting genetically engineered neurons expressing light sensitive proteins. However, there is a need for optical methods capable of imaging the concurrent hemodynamic changes. We utilize laser speckle contrast imaging (LSCI) to obtain high resolution display of cerebral blood flow (CBF) in the vicinity of the targeted neural population. LSCI is a minimally invasive method for imaging CBF in microvessels through thinned skull, and produces images with high spatiotemporal resolution, wide field of view. In the integrated system light sources with different wavelengths and band-passing/blocking filters were used to allow simultaneous optical manipulation of neuronal activities and optical imaging of corresponding CBF. Experimental studies were carried out in a rodent model expressing channalrhodopsin (ChR2) in excitatory neurons in the somatosensory cortex (S1). The results demonstrated significant increases of CBF in response to ChR2 stimulation (exciting neuronal firing) comparable to the CBF response to contralateral forepaw stimulation. The approach promises to be an exciting minimally invasive method to study neurovascular coupling. The complete system provides a novel approach for broad neuroscience applications.

  7. 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.

  8. Micromachined lab-on-a-tube sensors for simultaneous brain temperature and cerebral blood flow measurements.

    Science.gov (United States)

    Li, Chunyan; Wu, Pei-Ming; Hartings, Jed A; Wu, Zhizhen; Cheyuo, Cletus; Wang, Ping; LeDoux, David; Shutter, Lori A; Ramaswamy, Bharat Ram; Ahn, Chong H; Narayan, Raj K

    2012-08-01

    This work describes the development of a micromachined lab-on-a-tube device for simultaneous measurement of brain temperature and regional cerebral blood flow. The device consists of two micromachined gold resistance temperature detectors with a 4-wire configuration. One is used as a temperature sensor and the other as a flow sensor. The temperature sensor operates with AC excitation current of 500 μA and updates its outputs at a rate of 5 Hz. The flow sensor employs a periodic heating and cooling technique under constant-temperature mode and updates its outputs at a rate of 0.1 Hz. The temperature sensor is also used to compensate for temperature changes during the heating period of the flow sensor to improve the accuracy of flow measurements. To prevent thermal and electronic crosstalk between the sensors, the temperature sensor is located outside the "thermal influence" region of the flow sensor and the sensors are separated into two different layers with a thin-film Copper shield. We evaluated the sensors for accuracy, crosstalk and long-term drift in human blood-stained cerebrospinal fluid. These in vitro experiments showed that simultaneous temperature and flow measurements with a single lab-on-a-tube device are accurate and reliable over the course of 5 days. It has a resolution of 0.013 °C and 0.18 ml/100 g/min; and achieves an accuracy of 0.1 °C and 5 ml/100 g/min for temperature and flow sensors respectively. The prototype device and techniques developed here establish a foundation for a multi-sensor lab-on-a-tube, enabling versatile multimodality monitoring applications.

  9. Changes in Regional Cerebral Blood Flow with Cognitive Behavioral Therapy in the Treatment of Panic Disorder

    Energy Technology Data Exchange (ETDEWEB)

    Won, K. S.; Jun, S. K.; Kim, J. B.; Jang, E. J. [College of Medicine, Univ. of Kyemyoung, Taegu (Korea, Republic of)

    2003-07-01

    This study attempted to prospectively investigate changes in regional cerebral blood flow (rCBF) on SPECT and clinical response to cognitive behavioral therapy (CBT) in patients with panic disorder with (PDA) and without (PD) agoraphobia. Using 99mTc-ECD brain SPECT, we assessed brain perfusion in 5 out patients at rest before and after CBT. The subjects received 12 weekly sessions of CBT. Subjects were assessed by Agoraphobic Cognitions Questionnaire, Body Sensations Questionnaire, Beck Anxiety Inventory, Anxiety Sensitivity Index, Beck Depression Inventory-II, Panic Disorder Severity Scale (PDSS) and clinical global improvement (CGI) scale measurement were used as outcome measures. Patients were considered responders to CBT if they are much or very much improved on CGI scale and have a PDSS score at least 30% below their baseline. The scans were statistically analyzed by using statistical parametric mapping (SPM99). The baseline scans were compared to the post-CBT scans by using the statistics option multi subject, different conditions. Of 5 subjects 4 were male, 3 diagnosed PDA, and 4 on anti-anxiety medication. All of the subjects were classified as CBT responders. Their mean pretreatment and posttreatment PDSS were 17.4 (SD=8.2) and 4.2 (SD=3.1), respectively. The results of SPM analysis showed a significant decrease in blood flow after CBT in the thalamus bilaterally and right middle frontal gyrus (Brodmann's area 6). All results were thresholded at an uncorrected p<0.001 (for voxel height) and a corrected p<0.04 (for spatial extent). These preliminary data suggest that SPM analysis of 99mTc-ECD brain SPECT can reveal the change of rCBF in patient with panic disorder before and after CBT and the CBT effect may be associated with limbic and thalamic networks. However this study was a short trial with small number of subjects. Further studies with larger patient cohorts are needed.

  10. Umbilical cord blood biomarkers of neurologic injury and the risk of cerebral palsy or infant death.

    Science.gov (United States)

    Costantine, Maged M; Weiner, Steven J; Rouse, Dwight J; Hirtz, Deborah G; Varner, Michael W; Spong, Catherine Y; Mercer, Brian M; Iams, Jay D; Wapner, Ronald J; Sorokin, Yoram; Thorp, John M; Ramin, Susan M; O'Sullivan, Mary J; Peaceman, Alan M; Simhan, Hyagriv N

    2011-12-01

    To evaluate the association between cerebral palsy (CP) or infant death and putative cord blood biomarkers of neurologic injury, we performed a nested case-control secondary analysis of a multicenter randomized trial of magnesium sulfate (MgSO(4)) versus placebo to prevent CP or death among offspring of women with anticipated delivery from 24 to 31 weeks' gestation. Cases were infants who died by 1 year (n=25) or developed CP (n=16), and were matched 1:2 to a control group (n=82) that survived without developing CP. Umbilical cord sera concentrations of S100B, neuron-specific enolase (NSE) and the total soluble form of the receptor for advanced glycation end-products (sRAGE) were measured by ELISA in duplicates. Maternal characteristics were similar between the 2 groups. Cases were born at a lower gestational age (GA) and had lower birth weight compared with controls. There were no differences in concentrations of the three biomarkers and the composite outcome of CP or infant death. However, S100B was higher (median 847.3 vs. 495.7 pg/ml; P=0.03) in infants who had CP and total sRAGE was lower (median 1259.3 vs. 1813.1 pg/ml; P=0.02) in those who died compared with the control group. When corrected for delivery GA and treatment group, both differences lost statistical significance. In conclusion, cord blood S100B level may be associated with CP, but this association was not significant after controlling for GA and MgSO(4) treatment.

  11. Hippocampal and Cerebral Blood Flow After Exercise Cessation in Master Athletes

    Directory of Open Access Journals (Sweden)

    Alfonso J. Alfini

    2016-08-01

    Full Text Available While endurance exercise training improves cerebrovascular health and has neurotrophic effects within the hippocampus, the effects of stopping this exercise on the brain remain unclear. Our aim was to measure the effects of 10 days of detraining on resting cerebral blood flow (rCBF in gray matter and the hippocampus in healthy and physically fit older adults. We hypothesized that rCBF would decrease in the hippocampus after a 10-day cessation of exercise training. Twelve master athletes, defined as older adults (age ≥ 50 years with long-term endurance training histories (≥ 15 years, were recruited from local running clubs. After screening, eligible participants were asked to cease all training and vigorous physical activity for 10 consecutive days. Before and immediately after the exercise cessation period, rCBF was measured with perfusion-weighted MRI. A voxel-wise analysis was used in gray matter, and the hippocampus was selected a priori as a structurally defined region of interest, to detect rCBF changes over time. Resting CBF significantly decreased in eight gray matter brain regions. These regions included: (L inferior temporal gyrus, fusiform gyrus, inferior parietal lobule, (R cerebellar tonsil, lingual gyrus, precuneus, and bilateral cerebellum (FWE p < 0.05. Additionally, rCBF within the left and right hippocampus significantly decreased after 10 days of no exercise training. These findings suggest that the cerebrovascular system, including the regulation of resting hippocampal blood flow, is responsive to short-term decreases in exercise training among master athletes. Cessation of exercise training among physically fit individuals may provide a novel method to assess the effects of acute exercise and exercise training on brain function in older adults.

  12. Age-related differences in cerebral blood flow underlie the BOLD FMRI signal in childhood

    Directory of Open Access Journals (Sweden)

    Pamela eMoses

    2014-04-01

    Full Text Available Functional magnetic resonance imaging (FMRI has become a premiere technique for studying the development and neural mediation of a wide range of typical and atypical behaviors in children. While the mechanism of the blood oxygen level-dependent (BOLD FMRI signal has been a focus of investigation in the mature brain, it has been largely unexamined in the developing brain. One critical component of the BOLD signal that has been noted to change with age is cerebral blood flow (CBF. Reports of CBF in children based on clinical radioactive tracing methods have found elevated CBF in childhood relative to adulthood, which could affect the BOLD response. This study used noninvasive arterial spin labeling (ASL MRI to study resting state and activity-driven CBF in conjunction with the functional BOLD response in healthy children 8 and 12 years of age and in adults. Participants performed a finger tapping task to generate robust activation measured in the motor cortex. Quantification of resting state CBF demonstrated higher CBF in 8 year olds and in 12 year olds relative to adults. The absolute increase in CBF between baseline rest and peak response during the motor task was also higher in children compared to adults. In contrast, the relative increase of CBF above baseline, expressed as percent of CBF change, was comparable across groups. The percent of BOLD signal change was also stable across age groups. This set of findings suggest that along with elevated CBF in childhood, other component processes of the BOLD response are also in an elevated state such that together they yield a net BOLD effect that resembles adults. These findings are consistent with our previous examination hemodynamics in primary sensory cortex. Although the magnitude of the BOLD response appears consistent between childhood and adulthood, the underlying physiology and cerebrovascular dynamics that give rise to the BOLD effect differ between immature and mature brains neural

  13. Differential increases in blood flow velocity in the middle cerebral artery after tourniquet deflation during sevoflurane, isoflurane or propofol anaesthesia.

    Science.gov (United States)

    Kadoi, Y; Kawauchi, C H; Ide, M; Saito, S; Mizutani, A

    2009-07-01

    The purpose of this study was to examine the comparative effects of sevoflurane, isoflurane or propofol on cerebral blood flow velocity after tourniquet deflation during orthopaedic surgery. Thirty patients undergoing elective orthopaedic surgery were randomly divided into sevoflurane, isoflurane and propofol groups. Anaesthesia was maintained with sevoflurane, isoflurane or propofol infusion in 33% oxygen and 67% nitrous oxide, in whatever concentrations were necessary to keep bispectral index values between 45 and 50. Ventilatory rate or tidal volume was adjusted to target PaCO2 of 35 mmHg. A 2.0 MHz transcranial Doppler probe was attached to the patient's head at the temporal window and mean blood flow velocity in the middle cerebral artery was continuously measured. The extremity was exsanguinated with an Esmarch bandage and the pneumatic tourniquet was inflated to a pressure of 450 mmHg. Arterial blood pressure, heart rate, velocity in the middle cerebral artery and arterial blood gas analysis were measured every minute for 10 minutes after release of the tourniquet in all three groups. Velocity in the middle cerebral artery in the three groups increased for five minutes after tourniquet deflation. Because of the different cerebrovascular effects of the three agents, the degree of increase in flow velocity in the isoflurane group was greater than in the other two groups, the change in flow velocity in the propofol group being the lowest (at three minutes after deflation 40 +/- 7%, 32 +/- 6% and 28 +/- 10% in the isoflurane, sevoflurane and propofol groups respectively, P < 0.05).

  14. On the treatment of cerebral arteriosclerosis from treating turbid blood%脑动脉硬化症从血浊论治探微

    Institute of Scientific and Technical Information of China (English)

    韩萍; 周永红; 唐明; 郭瑞友

    2016-01-01

    The thesis explores the mechanism of the treatment of cerebral arteriosclerosis from treating turbid blood by exploring the correlation between the turbid blood and cerebral arteriosclerosis, it elaborates that turbid blood is the pathological pivot of cerebral arteriosclerosis, therefore, purifying turbid blood is a vital measure in preventing and treating cerebral arteriosclerosis.%从血浊与脑动脉硬化症发病的相关性入手,深入探讨脑动脉硬化症从血浊论治的机理,论述血浊是脑动脉硬化症发病的病理枢纽,而清化血浊法为防治脑动脉硬化症的重要措施。

  15. Effect of mild cognitive impairment and APOE genotype on resting cerebral blood flow and its association with cognition.

    Science.gov (United States)

    Wierenga, Christina E; Dev, Sheena I; Shin, David D; Clark, Lindsay R; Bangen, Katherine J; Jak, Amy J; Rissman, Robert A; Liu, Thomas T; Salmon, David P; Bondi, Mark W

    2012-08-01

    Using whole-brain pulsed arterial spin labeling magnetic resonance imaging, resting cerebral blood flow (CBF) was measured in 20 mild cognitive impairment (MCI; 11 ɛ3 and 9 ɛ4) and 40 demographically matched cognitively normal (CN; 27 ɛ3 and 13 ɛ4) participants. An interaction of apolipoprotein (APOE) genotype (ɛ3 and ɛ4) and cognitive status (CN and MCI) on quantified gray-matter CBF corrected for partial volume effects was found in the left parahippocampal and fusiform gyri (PHG/FG), right middle frontal gyrus, and left medial frontal gyrus. In the PHG/FG, CBF was elevated for CN ɛ4 carriers but decreased for MCI ɛ4 carriers. The opposite pattern was seen in frontal regions: CBF was decreased for CN ɛ4 carriers but increased for MCI ɛ4 carriers. Cerebral blood flow in the PHG/FG was positively correlated with verbal memory for CN ɛ4 adults (r=0.67, P=0.01). Cerebral blood flow in the left medial frontal gyrus was positively correlated with verbal memory for MCI ɛ4 adults (r=0.70, P=0.05). Findings support dynamic pathophysiologic processes in the brain associated with Alzheimer's disease risk and indicate that cognitive status and APOE genotype have interactive effects on CBF. Correlations between CBF and verbal memory suggest a differential neurovascular compensatory response in posterior and anterior cortices with cognitive decline in ɛ4 adults.

  16. 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.)

  17. Distributed Cerebral Blood Flow estimation using a spatiotemporal hemodynamic response model and a Kalman-like Filter approach

    KAUST Repository

    Belkhatir, Zehor

    2015-11-23

    This paper discusses the estimation of distributed Cerebral Blood Flow (CBF) using spatiotemporal traveling wave model. We consider a damped wave partial differential equation that describes a physiological relationship between the blood mass density and the CBF. The spatiotemporal model is reduced to a finite dimensional system using a cubic b-spline continuous Galerkin method. A Kalman Filter with Unknown Inputs without Direct Feedthrough (KF-UI-WDF) is applied on the obtained reduced differential model to estimate the source term which is the CBF scaled by a factor. Numerical results showing the performances of the adopted estimator are provided.

  18. Changes in cerebral blood flow after acetazolamide: an experimental study comparing near-infrared spectroscopy and SPECT

    DEFF Research Database (Denmark)

    Schytz, H W; Wienecke, Troels; Jensen, Lars Thorbjørn;

    2009-01-01

    BACKGROUND AND PURPOSE: It is important to find a reliable and bedside method, which can estimate the cerebral blood flow (CBF) of patients in clinical settings. Estimation of CBF by calculating a blood flow index (BFI) using continuous wave near-infrared spectroscopy (CW-NIRS) and indocyanine...... green (ICG) as an i.v. tracer has been proposed to be a feasible and promising method. To validate if the BFI method can detect relative changes in CBF we compared data with the established method (133)Xenon single photon emission computer tomography ((133)Xe-SPECT). METHODS: Ten healthy subjects were...

  19. Electroacupuncture acutely improves cerebral blood flow and attenuates moderate ischemic injury via an endothelial mechanism in mice.

    Directory of Open Access Journals (Sweden)

    Ji Hyun Kim

    Full Text Available Electroacupuncture (EA is a novel therapy based on traditional acupuncture combined with modern eletrotherapy that is currently being investigated as a treatment for acute ischemic stroke. Here, we studied whether acute EA stimulation improves tissue and functional outcome following experimentally induced cerebral ischemia in mice. We hypothesized that endothelial nitric oxide synthase (eNOS-mediated perfusion augmentation was related to the beneficial effects of EA by interventions in acute ischemic injury. EA stimulation at Baihui (GV20 and Dazhui (GV14 increased cerebral perfusion in the cerebral cortex, which was suppressed in eNOS KO, but there was no mean arterial blood pressure (MABP response. The increased perfusion elicited by EA were completely abolished by a muscarinic acetylcholine receptor (mAChR blocker (atropine, but not a β-adrenergic receptor blocker (propranolol, an α-adrenergic receptor blocker (phentolamine, or a nicotinic acetylcholine receptor (nAChR blocker (mecamylamine. In addition, EA increased acetylcholine (ACh release and mAChR M3 expression in the cerebral cortex. Acute EA stimulation after occlusion significantly reduced infarct volume by 34.5% when compared to a control group of mice at 24 h after 60 min-middle cerebral artery occlusion (MCAO (moderate ischemic injury, but not 90-min MCAO (severe ischemic injury. Furthermore, the impact of EA on moderate ischemic injury was totally abolished in eNOS KO. Consistent with a smaller infarct size, acute EA stimulation led to prominent improvement of neurological function and vestibule-motor function. Our results suggest that acute EA stimulation after moderate focal cerebral ischemia, but not severe ischemia improves tissue and functional recovery and ACh/eNOS-mediated perfusion augmentation might be related to these beneficial effects of EA by interventions in acute ischemic injury.

  20. Intensive Blood-Pressure Lowering in Patients with Acute Cerebral Hemorrhage.

    Science.gov (United States)

    Qureshi, Adnan I; Palesch, Yuko Y; Barsan, William G; Hanley, Daniel F; Hsu, Chung Y; Martin, Renee L; Moy, Claudia S; Silbergleit, Robert; Steiner, Thorsten; Suarez, Jose I; Toyoda, Kazunori; Wang, Yongjun; Yamamoto, Haruko; Yoon, Byung-Woo

    2016-09-15

    within 7 days after randomization was significantly higher in the intensive-treatment group than in the standard-treatment group (9.0% vs. 4.0%, P=0.002). Conclusions The treatment of participants with intracerebral hemorrhage to achieve a target systolic blood pressure of 110 to 139 mm Hg did not result in a lower rate of death or disability than standard reduction to a target of 140 to 179 mm Hg. (Funded by the National Institute of Neurological Disorders and Stroke and the National Cerebral and Cardiovascular Center; ATACH-2 ClinicalTrials.gov number, NCT01176565 .).

  1. Blood supply of the posterior cerebral artery by the carotid system on angiograms

    NARCIS (Netherlands)

    Jongen, JCF; Franke, CL; Soeterboek, AAJGM; Versteege, CWM; Ramos, LMP; van Gijn, J

    2002-01-01

    Background and Purpose Occipital lobe infarcts are traditionally attributed to vertebrobasilar disease. However, anatomical studies indicate that in some people the supply of the posterior cerebral artery is via the carotid system. We investigated how often such a developmental variant in the cerebr

  2. The preliminary study of Ultraviolet-Irradiated and Oxygenated Blood Transfusion Therapy(UOBT) for Experimental Cerebral Infarction of Animal Brain Model

    Institute of Scientific and Technical Information of China (English)

    Su Xiu-Chu; Feng You-Qi; Zhou gang; Wu jun-yi

    2000-01-01

    In this presented study, we have developed a photochemical model of cerebral in farction in rabbit with stable and reproducible infarct size and extent. This model is similar to the pathological changes in human cerebral infarction. Using this model, therapeutic effects and mechanisms of UOBT on brain ischemic injury were invetigated in rabbits following the photochemical infarcnon The results showed that UOBT could significantly reduce the mtarcted size, and improve the cerebral blood flow compared with the control animals treated with non-u-radiated ad non-oxygenated blood transfusion. These data suggest that the UOBT may have a therapeutic potential for clinical rehabilitation effect in stroke treatment

  3. Assessment of blood flow velocity and pulsatility in cerebral perforating arteries with 7-T quantitative flow MRI.

    Science.gov (United States)

    Bouvy, W H; Geurts, L J; Kuijf, H J; Luijten, P R; Kappelle, L J; Biessels, G J; Zwanenburg, J J M

    2016-09-01

    Thus far, blood flow velocity measurements with MRI have only been feasible in large cerebral blood vessels. High-field-strength MRI may now permit velocity measurements in much smaller arteries. The aim of this proof of principle study was to measure the blood flow velocity and pulsatility of cerebral perforating arteries with 7-T MRI. A two-dimensional (2D), single-slice quantitative flow (Qflow) sequence was used to measure blood flow velocities during the cardiac cycle in perforating arteries in the basal ganglia (BG) and semioval centre (CSO), from which a mean normalised pulsatility index (PI) per region was calculated (n = 6 human subjects, aged 23-29 years). The precision of the measurements was determined by repeated imaging and performance of a Bland-Altman analysis, and confounding effects of partial volume and noise on the measurements were simulated. The median number of arteries included was 14 in CSO and 19 in BG. In CSO, the average velocity per volunteer was in the range 0.5-1.0 cm/s and PI was 0.24-0.39. In BG, the average velocity was in the range 3.9-5.1 cm/s and PI was 0.51-0.62. Between repeated scans, the precision of the average, maximum and minimum velocity per vessel decreased with the size of the arteries, and was relatively low in CSO and BG compared with the M1 segment of the middle cerebral artery. The precision of PI per region was comparable with that of M1. The simulations proved that velocities can be measured in vessels with a diameter of more than 80 µm, but are underestimated as a result of partial volume effects, whilst pulsatility is overestimated. Blood flow velocity and pulsatility in cerebral perforating arteries have been measured directly in vivo for the first time, with moderate to good precision. This may be an interesting metric for the study of haemodynamic changes in aging and cerebral small vessel disease. © 2015 The Authors NMR in Biomedicine Published by John Wiley & Sons Ltd.

  4. Suitable image parameters and analytical method for quantitatively measuring cerebral blood flow volume with phase-contrast magnetic resonance imaging.

    Directory of Open Access Journals (Sweden)

    Handa H

    1999-02-01

    Full Text Available The aim of this study was to determine suitable image parameters and an analytical method for phase-contrast magnetic resonance imaging (PC-MRI as a means of measuring cerebral blood flow volume. This was done by constructing an experimental model and applying the results to a clinical application. The experimental model was constructed from the aorta of a bull and circulating isotonic saline. The image parameters of PC-MRI (repetition time, flip angle, matrix, velocity rate encoding, and the use of square pixels were studied with percent flow volume (the ratio of actual flow volume to measured flow volume. The most suitable image parameters for accurate blood flow measurement were as follows: repetition time, 50 msec; flip angle, 20 degrees; and a 512 x 256 matrix without square pixels. Furthermore, velocity rate encoding should be set ranging from the maximum flow velocity in the vessel to five times this value. The correction in measuring blood flow was done with the intensity of the region of interest established in the background. With these parameters for PC-MRI, percent flow volume was greater than 90%. Using the image parameters for PC-MRI and the analytical method described above, we evaluated cerebral blood flow volume in 12 patients with occlusive disease of the major cervical arteries. The results were compared with conventional xenon computed tomography. The values found with both methods showed good correlation. Thus, we concluded that PC-MRI was a noninvasive method for evaluating cerebral blood flow in patients with occlusive disease of the major cervical arteries.

  5. Effects of striatal nitric oxide production on regional cerebral blood flow and seizure development in rats exposed to extreme hyperoxia.

    Science.gov (United States)

    Gasier, Heath G; Demchenko, Ivan T; Allen, Barry W; Piantadosi, Claude A

    2015-12-01

    The endogenous vasodilator and signaling molecule nitric oxide has been implicated in cerebral hyperemia, sympathoexcitation, and seizures induced by hyperbaric oxygen (HBO2) at or above 3 atmospheres absolute (ATA). It is unknown whether these events in the onset of central nervous system oxygen toxicity originate within specific brain structures and whether blood flow is diverted to the brain from peripheral organs with high basal flow, such as the kidney. To explore these questions, total and regional cerebral blood flow (CBF) were measured in brain structures of the central autonomic network in anesthetized rats in HBO2 at 6 ATA. Electroencephalogram (EEG) recordings, cardiovascular hemodynamics, and renal blood flow (RBF) were also monitored. As expected, mean arterial blood pressure and total and regional CBF increased preceding EEG spikes while RBF was unaltered. Of the brain structures examined, the earliest rise in CBF occurred in the striatum, suggesting increased neuronal activation. Continuous unilateral or bilateral striatal infusion of the nitric oxide synthase inhibitor N(ω)-nitro-L-arginine methyl ester attenuated CBF responses in that structure, but global EEG discharges persisted and did not differ from controls. Our novel findings indicate that: 1) cerebral hyperemia in extreme HBO2 in rats does not occur at the expense of renal perfusion, highlighting the remarkable autoregulatory capability of the kidney, and 2) in spite of a sentinel increase in striatal blood flow, additional brain structure(s) likely govern the pathogenesis of HBO2-induced seizures because EEG discharge latency was unchanged by local blockade of striatal nitric oxide production and concomitant hyperemia.

  6. Effect of the Principle of Activating Blood Circulation to Break Stasis on GMP-140 and D2 Dimer in Patients with Acute Cerebral Infarction

    Institute of Scientific and Technical Information of China (English)

    WANG Ning

    2005-01-01

    Objective:To explore the clinical efficacy of the principle of activating blood circulation to break stasis (ABCBS) and its influence on platelet membranous protein particle (GMP-140) and D2 dimer (Ddimer) before and after treatment. Methods: Eighty-eight patients with blood stasis syndrome (BSS) of acute cerebral infarction (ACI) were randomly divided into two groups, both of which were treated with conventional treatment, i.e. with western medicine (WM), with Salvia injection added through intravenously dripping.One of the two groups was used as the control and the other group as the treated group who had ABCBS herbs orally taken in addition. The duration of treatment course for both groups was 3 weeks. Results: There were changes in both groups over clinical symptoms, nerve function deficit scoring and GMP-140, D-dimer, but the treated group showed significantly better than that of the control group, (P<0.05). Conclusion: ABCBS principle could serve as an important auxiliary treating method for BSS of ACI, as it can effectively alter the blood of ACI patients which was viscous, condense, coagulant and aggregating.

  7. A novel method of combining blood oxygenation and blood flow sensitive magnetic resonance imaging techniques to measure the cerebral blood flow and oxygen metabolism responses to an unknown neural stimulus.

    Directory of Open Access Journals (Sweden)

    Aaron B Simon

    Full Text Available Simultaneous implementation of magnetic resonance imaging methods for Arterial Spin Labeling (ASL and Blood Oxygenation Level Dependent (BOLD imaging makes it possible to quantitatively measure the changes in cerebral blood flow (CBF and cerebral oxygen metabolism (CMRO(2 that occur in response to neural stimuli. To date, however, the range of neural stimuli amenable to quantitative analysis is limited to those that may be presented in a simple block or event related design such that measurements may be repeated and averaged to improve precision. Here we examined the feasibility of using the relationship between cerebral blood flow and the BOLD signal to improve dynamic estimates of blood flow fluctuations as well as to estimate metabolic-hemodynamic coupling under conditions where a stimulus pattern is unknown. We found that by combining the information contained in simultaneously acquired BOLD and ASL signals through a method we term BOLD Constrained Perfusion (BCP estimation, we could significantly improve the precision of our estimates of the hemodynamic response to a visual stimulus and, under the conditions of a calibrated BOLD experiment, accurately determine the ratio of the oxygen metabolic response to the hemodynamic response. Importantly we were able to accomplish this without utilizing a priori knowledge of the temporal nature of the neural stimulus, suggesting that BOLD Constrained Perfusion estimation may make it feasible to quantitatively study the cerebral metabolic and hemodynamic responses to more natural stimuli that cannot be easily repeated or averaged.

  8. A novel method of combining blood oxygenation and blood flow sensitive magnetic resonance imaging techniques to measure the cerebral blood flow and oxygen metabolism responses to an unknown neural stimulus.

    Science.gov (United States)

    Simon, Aaron B; Griffeth, Valerie E M; Wong, Eric C; Buxton, Richard B

    2013-01-01

    Simultaneous implementation of magnetic resonance imaging methods for Arterial Spin Labeling (ASL) and Blood Oxygenation Level Dependent (BOLD) imaging makes it possible to quantitatively measure the changes in cerebral blood flow (CBF) and cerebral oxygen metabolism (CMRO(2)) that occur in response to neural stimuli. To date, however, the range of neural stimuli amenable to quantitative analysis is limited to those that may be presented in a simple block or event related design such that measurements may be repeated and averaged to improve precision. Here we examined the feasibility of using the relationship between cerebral blood flow and the BOLD signal to improve dynamic estimates of blood flow fluctuations as well as to estimate metabolic-hemodynamic coupling under conditions where a stimulus pattern is unknown. We found that by combining the information contained in simultaneously acquired BOLD and ASL signals through a method we term BOLD Constrained Perfusion (BCP) estimation, we could significantly improve the precision of our estimates of the hemodynamic response to a visual stimulus and, under the conditions of a calibrated BOLD experiment, accurately determine the ratio of the oxygen metabolic response to the hemodynamic response. Importantly we were able to accomplish this without utilizing a priori knowledge of the temporal nature of the neural stimulus, suggesting that BOLD Constrained Perfusion estimation may make it feasible to quantitatively study the cerebral metabolic and hemodynamic responses to more natural stimuli that cannot be easily repeated or averaged.

  9. Anormalidades de fluxo sangüíneo cerebral em indivíduos dependentes de cocaína Cerebral blood flow abnormalities in cocaine dependent subjects

    Directory of Open Access Journals (Sweden)

    Sergio Nicastri

    2000-06-01

    Full Text Available INTRODUÇÃO: Nos últimos anos, tem havido relatos de anormalidades do fluxo sanguíneo cerebral em indivíduos com o abuso de cocaína, detectadas por meio de tomografia computadorizada por emissão de fóton único (SPECT. Esse padrão anormal de perfusão cerebral tem sido associado a prejuízos cognitivos mas não a alterações observáveis por meio de exames de neuroimagem estrutural. Um problema envolvendo a maioria dos trabalhos publicados sobre esse tema é a inclusão de um grande número de usuários de heroína nas amostras estudadas. Essa outra droga também parece afetar o padrão de perfusão cerebral, particularmente durante estados de abstinência. MÉTODOS: Quatorze pacientes dependentes de cocaína (nenhum com uso de opióides e 14 voluntários normais (grupo controle foram submetidos a exames de SPECT com dímero de etil-cisteína marcado com tecnécio-99m. A análise dos exames de SPECT foi realizada por meio de análise visual qualitativa das imagens obtidas (procedimento padrão na prática clínica, realizada por um radiologista não informado sobre o diagnóstico dos indivíduos avaliados. RESULTADOS: A análise visual revelou um padrão sugestivo de irregularidades do fluxo sangüíneo cerebral em nove pacientes, mas em apenas dois controles (p = 0,018; teste exato de Fisher bicaudal. CONCLUSÕES: Anormalidades de circulação cerebral podem ter relação com prejuízos cognitivos relatados em populações de dependentes de cocaína. Embora déficits de perfusão cerebral associados ao uso de cocaína possam ser irreversíveis, têm surgido relatos na literatura de tratamentos para essas anormalidades de fluxo sangüíneo. Alterações de fluxo sangüíneo cerebral associadas à dependência de cocaína ocorrem mesmo na ausência de abuso ou dependência de opióides.INTRODUCTION: In the last years, there have been reports of abnormalities in brain blood flow of cocaine abusers, detected by single photon computed

  10. 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;

    2016-01-01

    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...

  11. Nicotine effects on regional cerebral blood flow in awake, resting tobacco smokers.

    Science.gov (United States)

    Domino, E F; Minoshima, S; Guthrie, S; Ohl, L; Ni, L; Koeppe, R A; Zubieta, J K

    2000-12-01

    The hypothesis for this research was that regional cerebral blood flow (rCBF) would increase following nasal nicotine administration to overnight abstinent tobacco smokers in relationship to the known brain distribution of nicotinic cholinergic receptors (nAChRs). Nine male and nine female healthy adult smokers were studied. They abstained overnight from tobacco products for 10 or more hours prior to study the next morning. Nicotine nasal spray was given in doses of 1-2.5 mg total with half in each nostril while the subject was awake and resting in a supine position. Oleoresin of pepper solution in a similar volume was used as an active placebo to control for the irritating effects of nicotine. Both substances were given single blind to the subjects. Positron emission tomography (PET) with H(2)(15)O was used to measure rCBF. The data from each subject volunteer were normalized to global activity to better assess regional brain changes. Both nasal nicotine and pepper spray produced similar increases in CBF in somesthetic area II, consistent with the irritant effects of both substances. The mean rCBF effects of nasal pepper were subtracted from those of nasal nicotine to determine the actions of nicotine alone. The latter produced increases in rCBF in the thalamus, pons, Brodman area 17 of the visual cortex, and cerebellum. Some brain areas that contain a large number of nAChRs, such as the thalamus, showed an increase in CBF. Other areas that have few nAChRs, such as the cerebellum, also showed an increase in relative CBF. The hippocampal/parahippocampal areas showed greater regional decreases (left) and lesser increases (right) in CBF that correlated with the increase in plasma arterial nicotine concentrations. The results obtained indicate complex primary and secondary effects of nicotine in which only some regional brain CBF changes correlate with the known distribution of nAChR. No gender differences were noted.

  12. Doppler ultrasound evaluation of cerebral blood flow pattern in neonates with congenital heart disease

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Tae Hoon [Yongdong Severance Hospital, Seoul (Korea, Republic of); Kim, Mi Young; Kim, Yang Min; Lee, Soo Hyun; Kim, Soo Jin; Kim, Woong Han [Sejong General Hospital, Seoul (Korea, Republic of)

    2003-03-15

    To evaluate intracerebral resistive index (RI) values in neonates with congenital heart disease and to investigate their changes after the corrective surgery of the congenital heart disease. Sixty nine neonates with congenital heart disease who underwent brain ultrasonography were included. Resistive index values were obtained at the genu portion of the anterior cerebral arteries through the anterior fontanelles. The patients were divided into 4 groups according to the presence of associated patent ductus arteriosus (PDA) and intracranial RI values. We evaluated the types of congenital heart disease that could influence RI values. Resistive index values were statistically higher in patients with PDA than in patients without PDA (p<0.05). RI values were higher in cases of large PDA with left-to-right shunt, but within the normal range in cases of small or nearly closing PDA or large PDA with bidirectional blood flow or with right-to-left shunt. For those patients without PDA, RI values were higher when patients had pulmonary atresia with multiple collateral vessels into the lung or when truncus arteriosus was present. RI values were also high in patients with hypoplastic left heart syndrome. RI values were normalized after the ligation of PDA, but patients with hypoplastic left heart syndrome showed persistently high RI values even after the Norwood's operation with Blalock-Taussig shunt. RI values are influenced by various congenital heart diseases except PDA. Therefore, the presences of the congenital heart disease and its hemodynamic changes should be taken into consideration in the evaluation of the intracranial RI values using Doppler ultrasonography.

  13. Interactive effects of vascular risk burden and advanced age on cerebral blood flow

    Directory of Open Access Journals (Sweden)

    Katherine eBangen

    2014-07-01

    Full Text Available Vascular risk factors and cerebral blood flow (CBF reduction have been linked to increased risk of cognitive impairment and Alzheimer’s disease (AD; however the possible moderating effects of age and vascular risk burden on CBF in late life remain understudied. We examined the relationships among elevated vascular risk burden, age, CBF, and cognition. Seventy-one non-demented older adults completed an arterial spin labeling MR scan, neuropsychological assessment, and medical history interview. Relationships among vascular risk burden, age, and CBF were examined in a priori regions of interest (ROIs previously implicated in aging and AD. Interaction effects indicated that, among older adults with elevated vascular risk burden (i.e., multiple vascular risk factors, advancing age was significantly associated with reduced cortical CBF whereas there was no such relationship for those with low vascular risk burden (i.e., no or one vascular risk factor. This pattern was observed in cortical ROIs including medial temporal (hippocampus, parahippocampal gyrus, uncus, inferior parietal (supramarginal gyrus, inferior parietal lobule, angular gyrus, and frontal (anterior cingulate, middle frontal gyrus, medial frontal gyrus cortices. Furthermore, among those with elevated vascular risk, reduced CBF was associated with poorer cognitive performance. Such findings suggest that older adults with elevated vascular risk burden may be particularly vulnerable to cognitive change as a function of CBF reductions. Findings support the use of CBF as a potential biomarker in preclinical AD and suggest that vascular risk burden and regionally-specific CBF changes may contribute to differential age-related cognitive declines.

  14. SINGLE PHOTON EMISSION COMPUTED TOMOGRAPHY STUDY OF REGIONAL CEREBRAL BLOOD FLOW IN PATIENTS WITH HEMISPATIAL NEGLECT

    Institute of Scientific and Technical Information of China (English)

    尹雅芙; 任艳; 李亚明

    2003-01-01

    Objective.To explore the correlations between the occurrence and severity of neglect and the region,range or extent of the decrease in regional cerebral blood flow(rCBF). Methods. Nineteen dextromanual patients who were diagnosed as unilateral stroke clinically and hemispatial neglect by a neglect test battery received single photon emission computed tomography(SPECT) scans. Results. On images,the damages of patients with neglect were seen most frequently in the frontal cortex,and then in turn in the parietal cortex,occipital cortex,temporal cortex,basal ganglia and thalamus. Most patients with neglect had two or more regions damaged. The most significant region was temporal-parietal-occipi-tal(TPO)junction. The correlation coefficient between rCBF and the severity of neglect was -0.34(t=-1.5,P>0.05),and that between the decrease percentage of rCBF and the severity of neglect was 0.34(t=1.47,P>0.05). The correlation coefficients between the range,number of foci,the flow deficit size and the severity of neglect were 0.71(t=4.13,P<0.01),0.70(t=4.07,P<0.01)and 0.64(t=3.40, P<0.01),respectively. Conclusions. The severity of neglect correlates with rCBF and the decrease percentage of rCBF insignificantly,but correlates positively with the range,number of foci and the flow deficit size significantly. Hemispatial neglect is caused by the damage of multiple sites and combined damage results in more severe neglect.

  15. Autoregulation of cerebral blood flow to changes in arterial pressure in mild Alzheimer's disease.

    Science.gov (United States)

    Zazulia, Allyson R; Videen, Tom O; Morris, John C; Powers, William J

    2010-11-01

    Studies in transgenic mice overexpressing amyloid precursor protein (APP) demonstrate impaired autoregulation of cerebral blood flow (CBF) to changes in arterial pressure and suggest that cerebrovascular dysfunction may be critically important in the development of pathological Alzheimer's disease (AD). Given the relevance of such a finding for guiding hypertension treatment in the elderly, we assessed autoregulation in individuals with AD. Twenty persons aged 75±6 years with very mild or mild symptomatic AD (Clinical Dementia Rating 0.5 or 1.0) underwent (15)O-positron emission tomography (PET) CBF measurements before and after mean arterial pressure (MAP) was lowered from 107±13 to 92±9 mm Hg with intravenous nicardipine; (11)C-PIB-PET imaging and magnetic resonance imaging (MRI) were also obtained. There were no significant differences in mean CBF before and after MAP reduction in the bilateral hemispheres (-0.9±5.2 mL per 100 g per minute, P=0.4, 95% confidence interval (CI)=-3.4 to 1.5), cortical borderzones (-1.9±5.0 mL per 100 g per minute, P=0.10, 95% CI=-4.3 to 0.4), regions of T2W-MRI-defined leukoaraiosis (-0.3±4.4 mL per 100 g per minute, P=0.85, 95% CI=-3.3 to 3.9), or regions of peak (11)C-PIB uptake (-2.5±7.7 mL per 100 g per minute, P=0.30, 95% CI=-7.7 to 2.7). The absence of significant change in CBF with a 10 to 15 mm Hg reduction in MAP within the normal autoregulatory range demonstrates that there is neither a generalized nor local defect of autoregulation in AD.

  16. Regional cerebral blood flow changes associated with transcranial magnetic stimulation in refractory depressed patients

    Energy Technology Data Exchange (ETDEWEB)

    Kim, C. H.; Chung, Y. A.; Chae, J. H.; Oh, J. H.; Kim, S. H.; Sohn, H. S.; Chung, S. K. [The Catholic University of Korea, Seoul (Korea, Republic of)

    2005-07-01

    Imaging studies by repetitive transcranial magnetic stimulation (rTMS) demonstrates biological activities of the brain. The aim of this study was to investigate the patterns of regional cerebral blood flow (rCBF) after a series of therapeutic rTMS sessions. Nine patients with refractory depression who had not been responsive to appropriate pharmacotherapy over 1 year were randomly assigned to daily 1 Hz right-sided rTMS or 20 Hz left-sided rTMS sessions for over 3 weeks. Baseline and 3-week post-rTMS treatment SPECT images were obtained 40 minutes after intravenous injection of approximately 740925 MBq of Tc-99m ECD using a multi-detector scanner (ECAM plus; Siemens, Erlangen, Germany) equipped with a low-energy, fan-beam collimator. All patients showed a good clinical outcome. Statistically significant common increase in rCBF patterns was found in the fusiform gyrus of left temporal lobe, left hippocampus, left superior parietal lobule, superior frontal gyrus of right frontal lobe, right lateral globus pallidus and cingulated gyrus of both limbic lobes. And in the fusiform gyrus of left occipital lobe and middle frontal gyrus of right frontal lobe decreased uptake was seen compared to controls. Low-frequency rTMS on the right prefrontal cortex and high-frequency rTMS on the left prefrontal cortex for 3 weeks as an add-on regimen have increased activity in specific brain regions in patients with treatment refractory depression. Therapeutic TMS seems to influence distinct cortical regions, as well as different pathways, affecting rCBF in a homogeneous manner that is probably region dependent and illness related.

  17. Cerebral blood flow and metabolism for Broca's aphasia using positron emission tomography

    Energy Technology Data Exchange (ETDEWEB)

    Kato, Toshiaki

    1987-12-01

    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/sub 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/sub 2/ in BA patients with those in control patients may show the symptomatic thresholds to be 20 - 27 ml100 gmin for rCBF and 2.0 ml100 gmin for rCMRO/sub 2/. (Namekawa, K.).

  18. Multivariate evaluation of brain function by measuring regional cerebral blood flow and event-related potentials

    Energy Technology Data Exchange (ETDEWEB)

    Koga, Yoshihiko; Mochida, Masahiko; Shutara, Yoshikazu; Nakagawa, Kazumi [Kyorin Univ., Mitaka, Tokyo (Japan). School of Medicine; Nagata, Ken

    1998-07-01

    To measure the effect of events on human cognitive function, effects of odors by measurement regional cerebral blood flow (rCBF) and P300 were evaluated during the auditory odd-ball exercise. PET showed the increase in rCBF on the right hemisphere of the brain by coffee aroma. rCBF was measured by PET in 9 of right-handed healthy adults men, and P300 was by event-related potential (ERP) in each sex of 20 right-handed healthy adults. ERP showed the difference of the P300 amplitude between men and women, and showed the tendency, by odors except the lavender oil, that women had higher in the P300 amplitude than men. These results suggest the presence of effects on the cognitive function through emotional actions. Next, the relationship between rCBF and ERP were evaluated. The subjects were 9 of the right-handed healthy adults (average: 25.6{+-}3.4 years old). rCBF by PET and P300 amplitude by ERP were simultaneously recorded during the auditory odd-ball exercise using the tone-burst method (2 kHz of the low frequency aimed stimuli and 1 kHz of the high frequency non-aimed stimuli). The rCBF value was the highest at the transverse gyrus of Heschl and the lowest at the piriform cortex among 24 regions of interest (ROI) from both sides. The difference of P300 peak latent time among ROI was almost the same. The brain waves from Cz and Pz were similar and the average amplitude was highest at Pz. We found the high correlation in the right piriform cortex (Fz), and right (Fz, Cz) and left (Cz, Pz) transverse gyrus of Heschl between the P300 amplitude and rCBF. (K.H.)

  19. Cerebral blood flow and cerebrovascular reserve capacity: estimation by dynamic magnetic resonance imaging.

    Science.gov (United States)

    Schreiber, W G; Gückel, F; Stritzke, P; Schmiedek, P; Schwartz, A; Brix, G

    1998-10-01

    We have developed a new method for estimation of regional CBF (rCBF) and cerebrovascular reserve capacity on a pixel-by-pixel basis by means of dynamic magnetic resonance imaging (MRI). Thirteen healthy volunteers, 8 patients with occlusion and/or high grade stenosis of the internal carotid artery (ICA), and 2 patients with acute stroke underwent dynamic susceptibility-weighted contrast enhanced MRI. Using principles of indicator dilution theory and deconvolution analysis, maps of rCBF, regional cerebral blood volume, and of the mean transit time (MTT) were calculated. In patients with ICA occlusion/stenosis, cerebrovascular reserve capacity was assessed by the rCBF increase after acetazolamide stimulation. Mean gray and white matter rCBF values in normals were 67.1 and 23.7 mL x 100 g(-1) x min(-1), respectively. Before acetazolamide stimulation, six of eight patients with ICA occlusions showed decreased rCBF values; and in seven patients increased MTT values were observed in tissue ipsilateral to the occlusion. After acetazolamide stimulation, decreased cerebrovascular reserve capacity was observed in five of eight patients with ICA occlusion. In acute stroke, rCBF in the central core of ischemia was less than 8 mL x 100 g(-1) x min(-1). In peri-infarct tissue, rCBF and MTT were higher than in unaffected tissue but rCBF was normal. Dynamic MRI provides important clinical information on the hemodynamic state of brain tissue in patients with occlusive cerebrovascular disease or acute stroke.

  20. Comparison of cerebral blood flow measurement with [15O]-water positron emission tomography and arterial spin labeling magnetic resonance imaging: A systematic review.

    Science.gov (United States)

    Fan, Audrey P; Jahanian, Hesamoddin; Holdsworth, Samantha J; Zaharchuk, Greg

    2016-05-01

    Noninvasive imaging of cerebral blood flow provides critical information to understand normal brain physiology as well as to identify and manage patients with neurological disorders. To date, the reference standard for cerebral blood flow measurements is considered to be positron emission tomography using injection of the [(15)O]-water radiotracer. Although [(15)O]-water has been used to study brain perfusion under normal and pathological conditions, it is not widely used in clinical settings due to the need for an on-site cyclotron, the invasive nature of arterial blood sampling, and experimental complexity. As an alternative, arterial spin labeling is a promising magnetic resonance imaging technique that magnetically labels arterial blood as it flows into the brain to map cerebral blood flow. As arterial spin labeling becomes more widely adopted in research and clinical settings, efforts have sought to standardize the method and validate its cerebral blood flow values against positron emission tomography-based cerebral blood flow measurements. The purpose of this work is to critically review studies that performed both [(15)O]-water positron emission tomography and arterial spin labeling to measure brain perfusion, with the aim of better understanding the accuracy and reproducibility of arterial spin labeling relative to the positron emission tomography reference standard.

  1. Blood flow and oxygenation changes due to low-frequency repetitive transcranial magnetic stimulation of the cerebral cortex

    Science.gov (United States)

    Mesquita, Rickson C.; Faseyitan, Olufunsho K.; Turkeltaub, Peter E.; Buckley, Erin M.; Thomas, Amy; Kim, Meeri N.; Durduran, Turgut; Greenberg, Joel H.; Detre, John A.; Yodh, Arjun G.; Hamilton, Roy H.

    2013-06-01

    Transcranial magnetic stimulation (TMS) modulates processing in the human brain and is therefore of interest as a treatment modality for neurologic conditions. During TMS administration, an electric current passing through a coil on the scalp creates a rapidly varying magnetic field that induces currents in the cerebral cortex. The effects of low-frequency (1 Hz), repetitive TMS (rTMS) on motor cortex cerebral blood flow (CBF) and tissue oxygenation in seven healthy adults, during/after 20 min stimulation, is reported. Noninvasive optical methods are employed: diffuse correlation spectroscopy (DCS) for blood flow and diffuse optical spectroscopy (DOS) for hemoglobin concentrations. A significant increase in median CBF (33%) on the side ipsilateral to stimulation was observed during rTMS and persisted after discontinuation. The measured hemodynamic parameter variations enabled computation of relative changes in cerebral metabolic rate of oxygen consumption during rTMS, which increased significantly (28%) in the stimulated hemisphere. By contrast, hemodynamic changes from baseline were not observed contralateral to rTMS administration (all parameters, p>0.29). In total, these findings provide new information about hemodynamic/metabolic responses to low-frequency rTMS and, importantly, demonstrate the feasibility of DCS/DOS for noninvasive monitoring of TMS-induced physiologic effects.

  2. Crossed cerebellar diaschisis after stroke identified noninvasively with cerebral blood flow-weighted arterial spin labeling MRI

    Science.gov (United States)

    Strother, Megan K.; Buckingham, Cari; Faraco, Carlos C.; Arteaga, Daniel; Lu, Pengcheng; Xu, Yaomin; Donahue, Manus J.

    2015-01-01

    Background and Purpose Crossed cerebellar diaschisis (CCD) is most commonly investigated using hemodynamic PET and SPECT imaging. However, noninvasive MRI offers advantages of improved spatial resolution, allowing hemodynamic changes to be compared directly with structural findings and without concerns related to ionizing radiation exposure. The aim of this study was to evaluate relationships between CCD identified from cerebral blood flow (CBF)-weighted arterial spin labeling (ASL) MRI with cerebrovascular reactivity (CVR)-weighted blood oxygenation level dependent (BOLD) MRI, Wallerian degeneration, clinical motor impairment, and corticospinal tract involvement. Methods Subjects (n=74) enrolled in an ongoing observational stroke trial underwent CBF-weighted ASL and hypercapnic CVR-weighted BOLD MRI. Hemispheric asymmetry indices for basal cerebellar CBF, cerebellar CVR, and cerebral peduncular area were compared between subjects with unilateral supratentorial infarcts (n=18) and control subjects without infarcts (n=16). CCD required (1) supratentorial infarct and (2) asymmetric cerebellar CBF (>95% confidence interval relative to controls). Results In CCD subjects (n=9), CVR (p=0.04) and cerebral peduncular area (p < 0.01) were significantly asymmetric compared to controls. Compared to infarct subjects not meeting CCD criteria (n=9), CCD subjects had no difference in corticospinal tract location for infarct (p=1.0) or motor impairment (p=0.08). Conclusions CCD correlated with cerebellar CVR asymmetry and Wallerian degeneration. These findings suggest that noninvasive MRI may be a useful alternative to PET or SPECT to study structural correlates and clinical consequences of CCD following supratentorial stroke. PMID:26724658

  3. Cerebral blood flow and carbon dioxide reactivity in children with bacterial meningitis

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    Ashwal, S.; Stringer, W.; Tomasi, L.; Schneider, S.; Thompson, J.; Perkin, R. (Loma Linda Univ. School of Medicine, CA (USA))

    1990-10-01

    We examined total and regional cerebral blood flow (CBF) by stable xenon computed tomography in 20 seriously ill children with acute bacterial meningitis to determine whether CBF was reduced and to examine the changes in CBF during hyperventilation. In 13 children, total CBF was normal (62 +/- 20 ml/min/100 gm) but marked local variability of flow was seen. In five other children, total CBF was significantly reduced (26 +/- 10 ml/min/100 gm; p less than 0.05), with flow reduced more in white matter (8 +/- 5 ml/min/100 gm) than in gray matter (30 +/- 15 ml/min/100 gm). Autoregulation of CBF appeared to be present in these 18 children within a range of mean arterial blood pressure from 56 to 102 mm Hg. In the remaining two infants, brain dead within the first 24 hours, total flow was uniformly absent, averaging 3 +/- 3 ml/min/100 gm. In seven children, CBF was determined at two carbon dioxide tension (PCO2) levels: 40 (+/- 3) mm Hg and 29 (+/- 3) mm Hg. In six children, total CBF decreased 33%, from 52 (+/- 25) to 35 (+/- 15) ml/min/100 gm; the mean percentage of change in CBF per millimeter of mercury of PCO2 was 3.0%. Regional variability of perfusion to changes in PCO2 was marked in all six children. The percentage of change in CBF per millimeter of mercury of PCO2 was similar in frontal gray matter (3.1%) but higher in white matter (4.5%). In the seventh patient a paradoxical response was observed; total and regional CBF increased 25% after hyperventilation. Our findings demonstrate that (1) CBF in children with bacterial meningitis may be substantially decreased globally, with even more variability noted regionally, (2) autoregulation of CBF is preserved, (3) CBF/CO2 responsitivity varies among patients and in different regions of the brain in the same patient, and (4) hyperventilation can reduce CBF below ischemic thresholds.

  4. Cerebral metabolic and structural alterations in hereditary spastic paraplegia with thin corpus callosum assessed by MRS and DTI

    Energy Technology Data Exchange (ETDEWEB)

    Dreha-Kulaczewski, Steffi [Georg August University, Department of Pediatrics and Pediatric Neurology, Faculty of Medicine, Goettingen (Germany); Georg August University, MR Research in Neurology and Psychiatry, Goettingen (Germany); Dechent, Peter; Helms, Gunther [Georg August University, MR Research in Neurology and Psychiatry, Goettingen (Germany); Frahm, Jens [Biomedizinische NMR Forschungs GmbH, Max-Planck-Institut fuer Biophysikalische Chemie, Goettingen (Germany); Gaertner, Jutta; Brockmann, Knut [Georg August University, Department of Pediatrics and Pediatric Neurology, Faculty of Medicine, Goettingen (Germany)

    2006-12-15

    Hereditary spastic paraplegia with thin corpus callosum (HSP-TCC) is a complicated form of autosomal-recessive hereditary spastic paraplegia. Characteristic clinical features comprise progressive spastic gait, cognitive impairment, and ataxia. Diagnostic MRI findings include thinning of the corpus callosum and non-progressive white matter (WM) alterations. To study the extent of axonal involvement, we performed localized proton magnetic resonance spectroscopy (MRS) of the cerebral WM and cortical grey matter (GM) in a patient with HSP-TCC at 20 and 25 years of age. The second investigation included diffusion tensor imaging (DTI). While MRS of the GM was normal, affected WM was characterized by major metabolic alterations such as reduced concentrations of N-acetylaspartate and N-acetylaspartyl-glutamate, creatine and phosphocreatine, and choline-containing compounds as well as elevated levels of myo-inositol. These abnormalities showed progression over a period of 5 years. DTI revealed increased mean diffusivity as well as reduced fractional anisotropy in periventricular WM. The metabolic and structural findings are consistent with progressive neuroaxonal loss in the WM accompanied by astrocytic proliferation - histopathological changes known to occur in HSP-TCC. Our results are in agreement with the hypothesis that the primary pathological process in HSP-TCC affects the axon, possibly due to impaired axonal trafficking. (orig.)

  5. 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.)

  6. Regional cerebral blood flow and the effects of nicardipine, a new cerebral vasodilator, in patients with neuropsychiatric symptoms. A study of /sup 133/Xe inhalation method

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    Toyoda, Katsuhiro; Motomura, Naoyasu; Murata, Koen; Sakai, Toshiaki (Osaka Medical Coll., Takatsuki (Japan)); Yoshioka, Michio; Tsutsumi, Shigetoshi

    1984-02-01

    Regional cerebral blood flow (rCBF) was determined by /sup 133/Xe inhalation method in 22 neuropsychiatric patients with an average age of 65.8 years -- 14 patients having cerebrovascular disturbance (Group 1) and 8 patients having endogenous or organic psychosis or neurological lesions (Group 2). Furthermore, nicardipine was orally administered to the patients and its effects on rCBF and on neuropsychiatric symptoms were examined. Regarding the mean and abnormal decrease of rCBF in the bilateral hemispheres and the frequency of ischemic foci, there was no significant difference between the groups. However, regional ischemic focus was more frequently observed in Group 1 than in Group 2. Long-term serial administration of nicardipine increased the rCBF and improved psychiatric symptoms in some of the patients in Group 1.

  7. Structural alterations of the retinal microcirculation in the "prehypertensive" high- normal blood pressure state.

    Science.gov (United States)

    Grassi, Guido; Buzzi, Silvia; Dell'Oro, Raffaella; Mineo, Claudia; Dimitriadis, Kyriakos; Seravalle, Gino; Lonati, Laura; Cuspidi, Cesare

    2013-01-01

    The high-normal blood pressure (also known as prehypertension) is a clinical condition characterized by an increased cardiovascular risk as well as by the presence of target organ damage. This include an increased left ventricular mass, an endothelial dysfunction and an early renal functional and structural damage. Whether this is the case also for alterations of retinal vessels network, which are frequently detectable in established hypertension, is still largey undefined. The present paper, after discussing the main characteristics of the high-normal blood pressure state, will review the different approaches used throughout the years for assessing retinal microcirculatory network. Data collected by our group in subjects with high normal blood pressure will be also discussed, showing that arterial venular ratio values are reduced in this individuals with high-normal blood pressure and more so in established hypertension. These data indicate that retinal microvascular alterations 1) are of early appearance in the clinical course of hypertension and 2) are of frequent detection in the high-normal blood pressure state. The possible hemodynamic and non-hemodynamic mechanisms resposible for these structural alteations of the retinal microcirculation will be also discussed.

  8. Altered heart rate and blood pressure variability in mice lacking the Mas protooncogene

    Directory of Open Access Journals (Sweden)

    T. Walther

    2000-01-01

    Full Text Available Heart rate variability is a relevant predictor of cardiovascular risk in humans. A significant genetic influence on heart rate