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Sample records for altered cerebral blood

  1. Cerebral blood volume alterations during fractional pneumoencephalography

    International Nuclear Information System (INIS)

    Voigt, K.; Greitz, T.

    1976-01-01

    Simultaneous and continuous measurements of the cerebral blood volume (CBV), cerebrospinal fluid (CSF) and blood pressure were carried out in six patients during fractional pneumoencephalography in order to examine intracranial volumetric interactions. Three patients (Group A) showed normal encephalographic findings, and in three patients (Group B) communicating hydrocephalus with convexity block was found encephalographically. In all patients the injection of air was followed by an immediate increase of CSF pressure and blood pressure and a concomitant decrease of CBV. The initial CSF pressure was invariably re-established within 3 to 3.5 min. During this time interval the CBV of the patients of Group B decreased significantly and 30 percent more than that of Group A. Furthermore, after restoration of the original CSF pressure, CBV returned to its initial level in all patients of Group A, whereas it remained unchanged or showed a further decrease in the patients of Group B. Removal of an amount of CSF corresponding to half of the amount of injected air was followed by a significant reactive hyperemic response in two normal patients. The intracranial volumetric alterations during fractional pneumoencephalography are discussed in detail with respect to the underlying physiologic mechanisms and are suggested as a model for acute and low pressure hydrocephalus

  2. Altered Cerebral Blood Flow Covariance Network in Schizophrenia.

    Science.gov (United States)

    Liu, Feng; Zhuo, Chuanjun; Yu, Chunshui

    2016-01-01

    Many studies have shown abnormal cerebral blood flow (CBF) in schizophrenia; however, it remains unclear how topological properties of CBF network are altered in this disorder. Here, arterial spin labeling (ASL) MRI was employed to measure resting-state CBF in 96 schizophrenia patients and 91 healthy controls. CBF covariance network of each group was constructed by calculating across-subject CBF covariance between 90 brain regions. Graph theory was used to compare intergroup differences in global and nodal topological measures of the network. Both schizophrenia patients and healthy controls had small-world topology in CBF covariance networks, implying an optimal balance between functional segregation and integration. Compared with healthy controls, schizophrenia patients showed reduced small-worldness, normalized clustering coefficient and local efficiency of the network, suggesting a shift toward randomized network topology in schizophrenia. Furthermore, schizophrenia patients exhibited altered nodal centrality in the perceptual-, affective-, language-, and spatial-related regions, indicating functional disturbance of these systems in schizophrenia. This study demonstrated for the first time that schizophrenia patients have disrupted topological properties in CBF covariance network, which provides a new perspective (efficiency of blood flow distribution between brain regions) for understanding neural mechanisms of schizophrenia.

  3. Extensive alterations of blood metabolites in pediatric cerebral malaria.

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    Sanchit Gupta

    Full Text Available Cerebral malaria (CM presents as an encephalopathy and is due to infection with Plasmodium falciparum. Patients are comatose, often with fever, recurrent seizures and this condition is associated with a high mortality rate. The etiology of the coma and seizures are poorly understood. Circulating small molecules and lipids have bioactive functions and alterations in their concentrations have been implicated in seizure disorders and other forms of encephalopathy. We carried out a comprehensive analysis of blood metabolites during CM to explore a biochemical basis of this encephalopathy. A paired metabolomics analysis was performed on the plasma samples of Malawian children (n = 11 during CM and at convalescence thirty days later, to identify differentially abundant molecules associated with CM. We also report plasma molecules associated with CM mortality (n = 4 compared to survival (n = 19. Plasma metabolites were identified through ultra high performance liquid chromatography/tandem mass spectrometry and gas chromatography/mass spectrometry to maximize compound detection and accuracy and then compared to a library for identification. We detected a total of 432 small molecules in the plasma and 247 metabolites were significantly differentially abundant between CM and convalescence (p 1.2. These results highlight the broad changes in blood chemistry during CM. We have identified metabolites that may impact central nervous system physiology and disease outcomes and can be further explored for their mechanistic roles into the pathophysiology of CM.

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

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    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

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

    International Nuclear Information System (INIS)

    Lee, Won Hyoung; Chung, Yong An; Seo, Ye Young; Yoo, Ik Dong; Na, Sae Jung; Jung, Hyun Suk; Kim, Ki Jun

    2009-01-01

    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: 19∼52 years, average age: 29.3±9.9 years) and 14 normal volunteers (male: 8, female: 6, age range: 19∼53 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

  6. Altered phase interactions between spontaneous blood pressure and flow fluctuations in type 2 diabetes mellitus: Nonlinear assessment of cerebral autoregulation

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    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.

  7. Cerebral blood flow response to hypoglycemia is altered in patients with type 1 diabetes and impaired awareness of hypoglycemia.

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    Wiegers, Evita C; Becker, Kirsten M; Rooijackers, Hanne M; von Samson-Himmelstjerna, Federico C; Tack, Cees J; Heerschap, Arend; de Galan, Bastiaan E; van der Graaf, Marinette

    2017-06-01

    It is unclear whether cerebral blood flow responses to hypoglycemia are altered in people with type 1 diabetes and impaired awareness of hypoglycemia. The aim of this study was to investigate the effect of hypoglycemia on both global and regional cerebral blood flow in type 1 diabetes patients with impaired awareness of hypoglycemia, type 1 diabetes patients with normal awareness of hypoglycemia and healthy controls ( n = 7 per group). The subjects underwent a hyperinsulinemic euglycemic-hypoglycemic glucose clamp in a 3 T MR system. Global and regional changes in cerebral blood flow were determined by arterial spin labeling magnetic resonance imaging, at the end of both glycemic phases. Hypoglycemia generated typical symptoms in patients with type 1 diabetes and normal awareness of hypoglycemia and healthy controls, but not in patients with impaired awareness of hypoglycemia. Conversely, hypoglycemia increased global cerebral blood flow in patients with impaired awareness of hypoglycemia, which was not observed in the other two groups. Regionally, hypoglycemia caused a redistribution of cerebral blood flow towards the thalamus of both patients with normal awareness of hypoglycemia and healthy controls, consistent with activation of brain regions associated with the autonomic response to hypoglycemia. No such redistribution was found in the patients with impaired awareness of hypoglycemia. An increase in global cerebral blood flow may enhance nutrient supply to the brain, hence suppressing symptomatic awareness of hypoglycemia. Altogether these results suggest that changes in cerebral blood flow during hypoglycemia contribute to impaired awareness of hypoglycemia.

  8. 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...

  9. 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 hypere...

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

    International Nuclear Information System (INIS)

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

    2012-01-01

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

  11. 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...

  12. Electromagnetic fields, such as those from mobile phones, alter regional cerebral blood flow and sleep and waking EEG.

    Science.gov (United States)

    Huber, R; Treyer, V; Borbély, A A; Schuderer, J; Gottselig, J M; Landolt, H-P; Werth, E; Berthold, T; Kuster, N; Buck, A; Achermann, P

    2002-12-01

    Usage of mobile phones is rapidly increasing, but there is limited data on the possible effects of electromagnetic field (EMF) exposure on brain physiology. We investigated the effect of EMF vs. sham control exposure on waking regional cerebral blood flow (rCBF) and on waking and sleep electroencephalogram (EEG) in humans. In Experiment 1, positron emission tomography (PET) scans were taken after unilateral head exposure to 30-min pulse-modulated 900 MHz electromagnetic field (pm-EMF). In Experiment 2, night-time sleep was polysomnographically recorded after EMF exposure. Pulse-modulated EMF exposure increased relative rCBF in the dorsolateral prefrontal cortex ipsilateral to exposure. Also, pm-EMF exposure enhanced EEG power in the alpha frequency range prior to sleep onset and in the spindle frequency range during stage 2 sleep. Exposure to EMF without pulse modulation did not enhance power in the waking or sleep EEG. We previously observed EMF effects on the sleep EEG (A. A. Borbély, R. Huber, T. Graf, B. Fuchs, E. Gallmann and P. Achermann. Neurosci. Lett., 1999, 275: 207-210; R. Huber, T. Graf, K. A. Cote, L. Wittmann, E. Gallmann, D. Matter, J. Schuderer, N. Kuster, A. A. Borbély, and P. Achermann. Neuroreport, 2000, 11: 3321-3325), but the basis for these effects was unknown. The present results show for the first time that (1) pm-EMF alters waking rCBF and (2) pulse modulation of EMF is necessary to induce waking and sleep EEG changes. Pulse-modulated EMF exposure may provide a new, non-invasive method for modifying brain function for experimental, diagnostic and therapeutic purposes.

  13. Early alterations in cerebral hemodynamics, brain metabolism, and blood-brain barrier permeability in experimental intracerebral hemorrhage.

    Science.gov (United States)

    Lee, E J; Hung, Y C; Lee, M Y

    1999-12-01

    The authors sought to ascertain the nature of the hemodynamic and metabolic derangement underlying acute pathophysiological events that occur after intracerebral hemorrhage (ICH). Cerebral perfusion pressure (CPP), flow velocity (FV) of the middle cerebral artery, and the arteriovenous contents of oxygen and lactate were investigated in 24 dogs subjected to sham operations (Group A, four animals) or intracerebral injections of 3 ml (Group B, 11 animals) or 5 ml (Group C, nine animals) autologous arterial blood. Twelve additional dogs received intravenous injections of 2% Evans blue or trypan blue dye to evaluate blood-brain barrier (BBB) changes. Within 1 hour, animals with ICH exhibited a rise in FV associated with significant reductions (pglycolysis. Furthermore, the data suggest that a selective increase in permeability, rather than anatomical disruption, of the BBB is involved in the acute pathophysiological events that occur after ICH, which may provide a possible gateway for systemic arterial lactate entering the SSS.

  14. Altered coupling of regional cerebral blood flow and brain temperature in schizophrenia compared with bipolar disorder and healthy subjects

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    Ota, Miho; Sato, Noriko; Sakai, Koji; Okazaki, Mitsutoshi; Maikusa, Norihide; Hattori, Kotaro; Hori, Hiroaki; Teraishi, Toshiya; Shimoji, Keigo; Yamada, Kei; Kunugi, Hiroshi

    2014-01-01

    Previous studies have suggested that schizophrenia patients have dysfunctional thermoregulation. The aim of this study was to examine whether brain temperature (BT) in schizophrenia patients differs from that in patients with bipolar disorder and healthy subjects by using magnetic resonance imaging. We also evaluated the possible relationship between BT and cerebral blood flow (CBF). We analyzed the temperature of lateral ventricles as the mean BT using diffusion-weighted imaging (DWI) thermometry, and evaluated the relationships between the BT and the CBF using pseudo-continuous arterial spin labeling (pCASL) among 3 diagnostic groups, 22 male patients with schizophrenia, 19 male patients with bipolar disorder, and 23 healthy male subjects. There were significant positive correlations between BT in the lateral ventricles and CBF in both the patients with bipolar disorder and healthy subjects. By contrast, there were significant negative correlations in patients with schizophrenia. We could not detect the significant difference in the surrogates of BT among three diagnostic groups. We showed that patients with schizophrenia, but not those with bipolar disorder, have dysfunctional thermoregulation in the brain. Brain temperature is highly dependent on cerebral metabolism and CBF, and thus uncoupling of cerebral metabolism and CBF may occur in schizophrenics. PMID:25182665

  15. 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.

  16. Alterations of cerebral blood flow and cerebrovascular reserve in patients with chronic traumatic brain injury accompanying deteriorated intelligence

    International Nuclear Information System (INIS)

    Song, Ho Chun; Bom, Hee Seung

    2000-01-01

    The purpose of this study was to evaluate alterations of regional cerbral blood flow (CBF) and cerebrovascular reserve (CVR), and correlation between these alternations and cognitive dysfunctin in patients with chronic traumatic brain injury (TBI) and normal brain MRI findings. Thirty TBI patients and 19 healthy volunteers underwent rest/acetazolaminde brain SPECT using Tc-99m HMPAO. Korean-Wechsler Adult Intelligence scale test was also performed in the patient group. Statistical analysis was performed with statistical parametric mapping software (SPM '97). CBF was diminished in the left hemisphere including Wernicke's area in all patients with lower verbal scale scores. In addition, a reduction in CBF in the right frontal, temporal and parietal cortices was related with depressed scores in information, digital span, arithmetic and similarities. In patients with lower performance scale scores, CBF was mainly diminished in the right hemisphere including superior temporal and supramarginal gyri, premotor, primary somatomotor and a part of prefrontal cortices, left frontal lobe and supramarginal gyrus. CVR was diminished in sixty-four Brodmann's areas compared to control. A reduction in CVR was demonstrated bilaterally in the frontal and temporal lobes in patients with lower scores in both verbal and performance tests, and in addition, both inferior parietal and occipital lobes in information subset. Alterations of CBF and CVR were demonstrated in the symptomatic TBI patients with normal MRI finding. These alterations were correlated with the change of intelligence, of which the complex functions are subserved by multiple interconnected cortical structures.=20

  17. Alterations of cerebral blood flow and cerebrovascular reserve in patients with chronic traumatic brain injury accompanying deteriorated intelligence

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    Song, Ho Chun; Bom, Hee Seung [Chonnam National Univ. Hospital, Kwangju (Korea, Republic of)

    2000-06-01

    The purpose of this study was to evaluate alterations of regional cerbral blood flow (CBF) and cerebrovascular reserve (CVR), and correlation between these alternations and cognitive dysfunctin in patients with chronic traumatic brain injury (TBI) and normal brain MRI findings. Thirty TBI patients and 19 healthy volunteers underwent rest/acetazolaminde brain SPECT using Tc-99m HMPAO. Korean-Wechsler Adult Intelligence scale test was also performed in the patient group. Statistical analysis was performed with statistical parametric mapping software (SPM '97). CBF was diminished in the left hemisphere including Wernicke's area in all patients with lower verbal scale scores. In addition, a reduction in CBF in the right frontal, temporal and parietal cortices was related with depressed scores in information, digital span, arithmetic and similarities. In patients with lower performance scale scores, CBF was mainly diminished in the right hemisphere including superior temporal and supramarginal gyri, premotor, primary somatomotor and a part of prefrontal cortices, left frontal lobe and supramarginal gyrus. CVR was diminished in sixty-four Brodmann's areas compared to control. A reduction in CVR was demonstrated bilaterally in the frontal and temporal lobes in patients with lower scores in both verbal and performance tests, and in addition, both inferior parietal and occipital lobes in information subset. Alterations of CBF and CVR were demonstrated in the symptomatic TBI patients with normal MRI finding. These alterations were correlated with the change of intelligence, of which the complex functions are subserved by multiple interconnected cortical structures.

  18. 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....

  19. Distinct pattern of cerebral blood flow alterations specific to schizophrenics experiencing auditory verbal hallucinations with and without insight: a pilot study.

    Science.gov (United States)

    Jing, Rixing; Huang, Jiangjie; Jiang, Deguo; Lin, Xiaodong; Ma, Xiaolei; Tian, Hongjun; Li, Jie; Zhuo, Chuanjun

    2018-01-23

    Schizophrenia is associated with widespread and complex cerebral blood flow (CBF) disturbance. Auditory verbal hallucinations (AVH) and insight are the core symptoms of schizophrenia. However, to the best of our knowledge, very few studies have assessed the CBF characteristics of the AVH suffered by schizophrenic patients with and without insight. Based on our previous findings, Using a 3D pseudo-continuous ASL (pcASL) technique, we investigated the differences in AVH-related CBF alterations in schizophrenia patients with and without insight. We used statistical parametric mapping (SPM8) and statistical non-parametric mapping (SnPM13) to perform the fMRI analysis. We found that AVH-schizophrenia patients without insight showed an increased CBF in the left temporal pole and a decreased CBF in the right middle frontal gyrus when compared to AVH-schizophrenia patients with insight. Our novel findings suggest that AVH-schizophrenia patients without insight possess a more complex CBF disturbance. Simultaneously, our findings also incline to support the idea that the CBF aberrant in some specific brain regions may be the common neural basis of insight and AVH. Our findings support the mostly current hypotheses regarding AVH to some extent. Although our findings come from a small sample, it provide the evidence that indicate us to conduct a larger study to thoroughly explore the mechanisms of schizophrenia, especially the core symptoms of AVHs and insight.

  20. Cerebral blood flow alterations as assessed by 3D ASL in cognitive impairment in patients with subcortical vascular cognitive impairment: A marker for disease severity

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    Yawen Sun

    2016-08-01

    Full Text Available Abnormal reductions in cortical cerebral blood flow (CBF have been identified in subcortical vascular cognitive impairment (SVCI. However, little is known about the pattern of CBF reduction in relation with degree of cognitive impairment. CBF measured with 3D Arterial Spin Labeling (ASL perfusion MRI helps detect functional changes in subjects with SVCI. We aimed to compare CBF maps in subcortical ischemic vascular disease (SIVD subjects with and without cognitive impairment and to detect the relationship of the regions of CBF reduction in the brain with the degree of cognitive impairment according to the z-score. A total of 53 subjects with SVCI and 23 matched SIVD subjects without cognitive impairment (controls underwent a whole-brain 3D ASL MRI in the resting state. Regional CBF (rCBF was compared voxel wise by using an analysis of variance design in a statistical parametric mapping program, with patient age and sex as covariates. Correlations were calculated between the rCBF value in the whole brain and the z-score in the 53 subjects with SVCI. Compared with the control subjects, SVCI group demonstrated diffuse decreased CBF in the brain. Significant positive correlations were determined in the rCBF values in the left hippocampus, left superior temporal pole gyrus, right superior frontal orbital lobe, right medial frontal orbital lobe, right middle temporal lobe, left thalamus, and right insula with the z-scores in SVCI group. The noninvasively quantified resting CBF demonstrated altered CBF distributions in the SVCI brain. The deficit brain perfusions in the temporal and frontal lobe, hippocampus, thalamus, and insula was related to the degree of cognitive impairment. Its relationship to cognition indicates the clinical relevance of this functional marker. Thus, our results provide further evidence for the mechanism underlying the cognitive deficit in patients with SVCI.

  1. 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......) blood flow velocity, photoplethysmographic finger BP, and step frequency were measured continuously during three consecutive 5-min intervals of treadmill running at increasing running intensities. Data were analysed in the time and frequency domains. BP data for seven subjects and MCA velocity data....... 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...

  2. Subcortical aphasia and cerebral blood flow using SPECT

    International Nuclear Information System (INIS)

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

    1985-01-01

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

  3. [Importance of the study of cerebral blood flow and regional oxygen consumption in cerebral ischemia].

    Science.gov (United States)

    Clanet, M

    1987-06-18

    Studies of experimentally-induced ischaemia have shown that the intensity of neuronal suffering is related to the fall in perfusion rate. Below a certain level, called functional threshold, cerebral function is reversibly altered, whereas at a lower level (tissue necrosis threshold) the damage inflicted on neurons is irreversible. Between these two threshold lies a "penumbra zone". This concept of thresholds must be mitigated by 2 parameters: duration of ischaemia and selective vulnerability of the various structures affected. Variations in blood flow rate only indirectly affect the state of tissues. Techniques developed from positron emission tomography make it possible to evaluate the metabolic activity of brain tissue in vivo: oxygen consumption (CMRO2), oxygen extraction (EO2) and glucose consumption (CMRG) which are thus correlated to cerebral blood flow and cerebral blood volume, sometimes also to tissue pH. Normal relations between blood flow rate and metabolism may be altered. Misery perfusion reflects a fall in cerebral blood flow with an increase in EO2 and often a decrease in CMRO2, whereas luxury perfusion reflects an increase in cerebral blood flow rate with reduction of CMRO2, EO2 and CMRG. The type of alteration encountered in human ischaemia varies according to the nature of the accident: studies of transient accidents emphasize the different haemodynamic aspects of occlusion of the wider arteries. The metabolic and haemodynamic profiles of established ischaemic accidents vary according to their type and to the time of the study, reflecting the complexity of the physiopathological mechanisms involved; they are frequently associated with metabolic repercussions at a distance from the ischaemic focus, which supports the concept of diaschisis. Arteriopathic dementia probably does not result from chronic ischaemia of the cerebral parenchyma.

  4. 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

    blood flow distribution was depicted by single photon emission computed tomography at rest and during activation with the Wisconsin Card Sorting Test. A significant relative activation deficit in the left inferior-prefrontal region was revealed during the Wisconsin Card Sorting Test in the patient group......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....... Furthermore, the patients had impaired striatal suppression on the left side during the cognitive task. The test performance was significantly impaired in the patients. The inability to reduce striatal activity may be due to a lack of corticostriatal feedback during prefrontal activation....

  5. Regional cerebral blood flow in childhood headache

    International Nuclear Information System (INIS)

    Roach, E.S.; Stump, D.A.

    1989-01-01

    Regional cerebral blood flow (rCBF) was measured in 16 cranial regions in 23 children and adolescents with frequent headaches using the non-invasive Xenon-133 inhalation technique. Blood flow response to 5% carbon dioxide (CO2) was also determined in 21 patients, while response to 50% oxygen was measured in the two patients with hemoglobinopathy. Included were 10 patients with a clinical diagnosis of migraine, 4 with musculoskeletal headaches, and 3 with features of both types. Also studied were 2 patients with primary thrombocythemia, 2 patients with hemoglobinopathy and headaches, 1 patient with polycythemia, and 1 with headaches following trauma. With two exceptions, rCBF determinations were done during an asymptomatic period. Baseline rCBF values tended to be higher in these young patients than in young adults done in our laboratory. Localized reduction in the expected blood flow surge after CO2 inhalation, most often noted posteriorly, was seen in 8 of the 13 vascular headaches, but in none of the musculoskeletal headache group. Both patients with primary thrombocythemia had normal baseline flow values and altered responsiveness to CO2 similar to that seen in migraineurs; thus, the frequently reported headache and transient neurologic signs with primary thrombocythemia are probably not due to microvascular obstruction as previously suggested. These data support the concept of pediatric migraine as a disorder of vasomotor function and also add to our knowledge of normal rCBF values in younger patients. Demonstration of altered vasomotor reactivity to CO2 could prove helpful in children whose headache is atypical

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

    International Nuclear Information System (INIS)

    Clanet, M.

    1987-01-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

    Clanet, M.

    1987-06-18

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

  8. Effects of viscosity on cerebral blood flow after cardiac arrest

    NARCIS (Netherlands)

    Bisschops, L.L.A.; Pop, G.A.M.; Teerenstra, S.; Struijk, P.C.; Hoeven, J.G. van der; Hoedemaekers, C.W.E.

    2014-01-01

    OBJECTIVES: To determine blood viscosity in adult comatose patients treated with mild therapeutic hypothermia after cardiac arrest and to assess the relation between blood viscosity, cerebral blood flow, and cerebral oxygen extraction. DESIGN: Observational study. SETTING: Tertiary care university

  9. Postradiation regional cerebral blood flow in primates

    International Nuclear Information System (INIS)

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

    1986-01-01

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

  10. Cerebral blood flow changes in cluster headache

    International Nuclear Information System (INIS)

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

    1976-01-01

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

  11. Regional cerebral blood flow in schizophrenia

    International Nuclear Information System (INIS)

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

    1982-01-01

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

  12. 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...

  13. 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...

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

    Energy Technology Data Exchange (ETDEWEB)

    Yasui, Nobuyuki; Asakura, Ken

    1987-12-01

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

  15. Cerebral blood flow variations in CNS lupus

    International Nuclear Information System (INIS)

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

    1990-01-01

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

  16. Cerebral blood flow variations in CNS lupus

    Energy Technology Data Exchange (ETDEWEB)

    Kushner, M.J.; Tobin, M.; Fazekas, F.; Chawluk, J.; Jamieson, D.; Freundlich, B.; Grenell, S.; Freemen, L.; Reivich, M. (Univ. of Pennsylvania Medical Center, Philadelphia (USA))

    1990-01-01

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

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

    International Nuclear Information System (INIS)

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

    1988-01-01

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

  18. 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 ...

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

    International Nuclear Information System (INIS)

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

    1986-01-01

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

  20. Cerebral blood flow tomography with xenon-133

    DEFF Research Database (Denmark)

    Lassen, N A

    1985-01-01

    Cerebral blood flow (CBF) can be measured tomographically by inhalation of Xenon-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...... of other tracers for CBF tomography using SPECT is summarized with emphasis on the 99mTc 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....

  1. Methodological appraisal of SPECT measurements of cerebral blood volume and cerebral tissue hematocrit. Chapter 25

    International Nuclear Information System (INIS)

    Sakai, Fumihiko

    1988-01-01

    In this communication a critical appraisal is given of the method for measuring cerebral blood volume (CBV) and cerebral hematocrit employing single-photon emission computed tomography (SPECT). 2 refs

  2. Low cerebral blood flow in hypotensive perinatal distress

    DEFF Research Database (Denmark)

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

    1977-01-01

    understood. Arterial hypoxia has been taken as the obvious mechanism but this does not fully explain the patho-anatomical findings. In the present investigation we have examined the arterial blood pressure and the cerebral blood flow in eight infants a few hours after birth. The 133Xe clearance technique...... was used for the cerebral blood flow measurements. The study confirmed that perinatal distress may be associated with low arterial blood pressure, and it was shown that cerebral blood flow is very low, 20 ml/100 g/min or less, in hypotensive perinatal distress. It is concluded that cerebral ischaemia plays...

  3. 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...... most distant from the capillaries, whereas other studies point to a shift toward a higher degree of non-oxidative glucose consumption during activation. In this review, we argue that the key mechanism responsible for the regional CBF (rCBF) increase during functional activation is a tight coupling...... between rCBF and glucose metabolism. We assert that uncoupling of rCBF and oxidative metabolism is a consequence of a less pronounced increase in oxygen consumption. On the basis of earlier studies, we take into consideration the functional recruitment of capillaries and attempt to accommodate...

  4. Cerebral blood flow and metabolism during sleep

    DEFF Research Database (Denmark)

    Madsen, Peter Lund; Vorstrup, S

    1991-01-01

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

  5. 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...... whatsoever. This is probably related to the functional nature of the rCBF method: subnormal flow values and lack of the normal flow increase during function tests apparently may disclose functionally inactivated but structurally intact cortex....

  6. Excessive oral intake caffeine altered cerebral cortex ...

    African Journals Online (AJOL)

    Caffeine is commonly consumed in an effort to enhance speed in performance and wakefulness. However, little is known about the deleterious effects it can produce on the brain, this study aimed at determining the extents of effects and damage that can be caused by excessive consumption of caffeine on the cerebral cortex ...

  7. Regional cerebral blood flow in diabetic patients

    International Nuclear Information System (INIS)

    Nagamachi, Shigeki; Ono, Shinnichi; Nishikawa, Takushi

    1993-01-01

    N-isopropyl-p- 123 I-iodoamphetamine (IMP) was used to quantify the regional cerebral blood flow (r-CBF) in 11 diabetic patients (average age; 67.9 years) and 12 non-diabetic subjects (average age; 67.4 years), none of whom had (cerebrovascular disease (CVD) on CT studies. A reference sampling method by continuous arterial blood sampling was used to quantify r-CBF. There were no significant differences in physiological or laboratory data between diabetic and non-diabetic groups except for fasting plasma glucose and HbA 1c levels. The average of r-CBF in each region of cerebrum and cerebellum was significantly lower in diabetic group than that in the control group (p<0.01). These observations show that r-CBF of diabetic patients is reduced, even in the absence of findings of CVD on a CT study. (author)

  8. 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....

  9. Gender differences in regional cerebral blood flow

    International Nuclear Information System (INIS)

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

    1990-01-01

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

  10. Regional cerebral blood flow in schizophrenia

    International Nuclear Information System (INIS)

    Kanoh, Masayuki

    1989-01-01

    Regional cerebral blood flow (rCBF) was measured at rest using the 133 Xe inhalation technique in 40 DSM-III-diagnosed schizophrenics (22 males, 18 females: mean age 35.0 years, range 20-49 years) and 31 age-and sex-matched normal controls (16 males, 15 females: mean age 34.3 years, range 21-49 years). The absolute value (AV) and the percent value (PV) of the rCBF in schizophrenics were compared with those in controls. Correlations between rCBF and the Brief Psychiatric Rating Scale (BPRS) scores or the performance of Wisconsin Card Sorting Test (WCST) were examined in schizophrenics. Schizophrenics showed significantly lower AVs in all brain regions examined and a significantly lower PV in the left superior frontal region than controls. The hyperfrontal rCBF distribution which was found in both hemispheres in controls, was absent in the left hemisphere in schizophrenics. In schizophrenics, superior frontal blood flows were significantly negatively correlated with the negative symptom scores of the BPRS but not with the total scores and the positive symptom scores of the BPRS. In schizophrenics, inferior frontal blood flows were significantly correlated with the number of sorting categories achieved. These results indicate that rCBF in schizophrenia is reduced in the whole brain and especially in the left superior frontal region. These findings suggest a frontal lobe dysfunction in schizophrenia. (author)

  11. Daily rhythm of cerebral blood flow velocity

    Directory of Open Access Journals (Sweden)

    Spielman Arthur J

    2005-03-01

    Full Text Available Abstract Background CBFV (cerebral blood flow velocity is lower in the morning than in the afternoon and evening. Two hypotheses have been proposed to explain the time of day changes in CBFV: 1 CBFV changes are due to sleep-associated processes or 2 time of day changes in CBFV are due to an endogenous circadian rhythm independent of sleep. The aim of this study was to examine CBFV over 30 hours of sustained wakefulness to determine whether CBFV exhibits fluctuations associated with time of day. Methods Eleven subjects underwent a modified constant routine protocol. CBFV from the middle cerebral artery was monitored by chronic recording of Transcranial Doppler (TCD ultrasonography. Other variables included core body temperature (CBT, end-tidal carbon dioxide (EtCO2, blood pressure, and heart rate. Salivary dim light melatonin onset (DLMO served as a measure of endogenous circadian phase position. Results A non-linear multiple regression, cosine fit analysis revealed that both the CBT and CBFV rhythm fit a 24 hour rhythm (R2 = 0.62 and R2 = 0.68, respectively. Circadian phase position of CBT occurred at 6:05 am while CBFV occurred at 12:02 pm, revealing a six hour, or 90 degree difference between these two rhythms (t = 4.9, df = 10, p Conclusion In conclusion, time of day variations in CBFV have an approximately 24 hour rhythm under constant conditions, suggesting regulation by a circadian oscillator. The 90 degree-phase angle difference between the CBT and CBFV rhythms may help explain previous findings of lower CBFV values in the morning. The phase difference occurs at a time period during which cognitive performance decrements have been observed and when both cardiovascular and cerebrovascular events occur more frequently. The mechanisms underlying this phase angle difference require further exploration.

  12. Application of Blood-Brain Barrier Permeability Imaging in Global Cerebral Edema.

    Science.gov (United States)

    Ivanidze, J; Kallas, O N; Gupta, A; Weidman, E; Baradaran, H; Mir, D; Giambrone, A; Segal, A Z; Claassen, J; Sanelli, P C

    2016-09-01

    Blood-brain barrier permeability is not routinely evaluated in the clinical setting. Global cerebral edema occurs after SAH and is associated with BBB disruption. Detection of global cerebral edema using current imaging techniques is challenging. Our purpose was to apply blood-brain barrier permeability imaging in patients with global cerebral edema by using extended CT perfusion. Patients with SAH underwent CTP in the early phase after aneurysmal rupture (days 0-3) and were classified as having global cerebral edema or nonglobal cerebral edema using established noncontrast CT criteria. CTP data were postprocessed into blood-brain barrier permeability quantitative maps of PS (permeability surface-area product), K(trans) (volume transfer constant from blood plasma to extravascular extracellular space), Kep (washout rate constant of the contrast agent from extravascular extracellular space to intravascular space), VE (extravascular extracellular space volume per unit of tissue volume), VP (plasmatic volume per unit of tissue volume), and F (plasma flow) by using Olea Sphere software. Mean values were compared using t tests. Twenty-two patients were included in the analysis. Kep (1.32 versus 1.52, P cerebral edema compared with nonglobal cerebral edema while VE (0.81 versus 0.39, P cerebral edema. Kep is an important indicator of altered blood-brain barrier permeability in patients with decreased blood flow, as Kep is flow-independent. Further study of blood-brain barrier permeability is needed to improve diagnosis and monitoring of global cerebral edema. © 2016 by American Journal of Neuroradiology.

  13. A rat model of reproducible cerebral infarction using thrombotic blood clot emboli

    DEFF Research Database (Denmark)

    Overgaard, K.; Sereghy, T.; Boysen, G.

    1992-01-01

    Neuropathology, experimental thromboembolism, stroke, blood flow, in vitro thrombotic clotting, cerebral infarction, rat......Neuropathology, experimental thromboembolism, stroke, blood flow, in vitro thrombotic clotting, cerebral infarction, rat...

  14. Regional cerebral blood perfusion SPECT imaging in brain ischemic injury due to cerebral hemorrhage

    International Nuclear Information System (INIS)

    Zhang Chunyin; Chen Yue; Li Zuoxiao; Tan Hua; Li Xiaohong

    2006-01-01

    Objective: To explore the clinical value of SPECT perfusion imaging in brain ischemic injury due to cerebral hemorrhage before and after treatment. Methods: Sixty cases of cerebral hemorrhage were randomly divided into nimodipine treated group and routine treated group. The volume of primary ischemic focus, changes of regional cerebral blood perfusion around hematoma and other cerebral areas were observed by SPECT imaging. Results: Volume of the primary focus was reduced apparently in both groups, but much more in nimodipine treated group (P<0.01). Also the regional cerebral blood flow in ischemic focus and remote areas increased much more in nimodipine treated group than routine treated group (P< 0.01). Conclusions: Brain SPECT imaging can sensitively reflect the regional cerebral blood flow before and after treatment. Thereby, it is useful for therapeutic monitoring. (authors)

  15. 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...

  16. Intensive Blood Pressure Control Affects Cerebral Blood Flow in Type 2 Diabetes Mellitus Patients

    NARCIS (Netherlands)

    Kim, Yu-Sok; Davis, Shyrin C. A. T.; Truijen, Jasper; Stok, Wim J.; Secher, Niels H.; van Lieshout, Johannes J.

    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

  17. Effect of hematocrit and systolic blood pressure on cerebral blood flow in newborn infants

    International Nuclear Information System (INIS)

    Younkin, D.P.; Reivich, M.; Jaggi, J.L.; Obrist, W.D.; Delivoria-Papadopoulos, M.

    1987-01-01

    The effects of hematocrit and systolic blood pressure on cerebral blood flow were measured in 15 stable, low birth weight babies. CBF was measured with a modification of the xenon-133 ( 133 Xe) clearance technique, which uses an intravenous bolus of 133 Xe, an external chest detector to estimate arterial 133 Xe concentration, eight external cranial detectors to measure cephalic 133 Xe clearance curves, and a two-compartmental analysis of the cephalic 133 Xe clearance curves to estimate CBF. There was a significant inverse correlation between hematocrit and CBF, presumably due to alterations in arterial oxygen content and blood viscosity. Newborn CBF varied independently of systolic blood pressure between 60 and 84 mm Hg, suggesting an intact cerebrovascular autoregulatory mechanism. These results indicate that at least two of the factors that affect newborn animal CBF are operational in human newborns and may have important clinical implications

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

    DEFF Research Database (Denmark)

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

    1991-01-01

    We measured cerebral blood flow (CBF) and cerebral metabolic rate of oxygen (CMRO2) during light sleep (stage 2) in 8 young healthy volunteers using the Kety-Schmidt technique with 133Xe as the inert gas. Measurements were performed during wakefulness and light sleep as verified by standard....... They differ in respect of arousal threshold as a stronger stimulus is required to awaken a subject from deep sleep as compared to light sleep. Our results suggest that during non-rapid eye movement sleep cerebral metabolism and thereby cerebral synaptic activity is correlated to cerebral readiness rather than...

  19. Preclinical Arterial Spin Labeling Measurement of Cerebral Blood Flow.

    Science.gov (United States)

    Muir, Eric R

    2018-01-01

    Magnetic resonance imaging has been utilized as a quantitative and noninvasive method to image blood flow. Arterial spin labeling (ASL) is an MRI technique that images blood flow using arterial blood water as an endogenous tracer. Herein we describe the use of ASL to measure cerebral blood flow completely noninvasively in rodents, including methods, analysis, and important considerations when utilizing this technique.

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

    International Nuclear Information System (INIS)

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

    1989-01-01

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

  1. Relationship between blood uric and acute cerebral infarction

    International Nuclear Information System (INIS)

    Yin Zhanxia; Zhao Danyang

    2011-01-01

    Objective: To study the relationship between blood uric acid and acute cerebral infarction. Methods: The level of blood uric acid and prevalence of hyperuricemia (HUA) were compared in 360 patients with acute cerebral infarction and 300 patients without it. According to the level of blood uric acid, 360 acute cerebral infarction patients were divided into HUA and normouricemia (NUA) groups. Age, sex, body mass index (BMI), blood glucose and total cholesterol were compared between the HUA and NUA group. The degree of neurological functional defection was compared between the two groups when patients were attacked by acute cerebral infarction. After a recovery treatment, the neurological functional defection of the two groups was compared a second time. Results: (1)The average blood uric acid level and prevalence of HUA were higher in patients with acute cerebral infarction. (2) The BMI, blood glucose and total cholesterol were higher in HUA group than in NUA group. (3) The neurological functional defection was more serious in HUA group when patients were attacked by acute cerebral infarction and after a recovery treatment. Conclusion: Hyperuricemia is related to acute cerebral infarction. (authors)

  2. Hemodilution increases cerebral blood flow in acute ischemic stroke

    International Nuclear Information System (INIS)

    Vorstrup, S.; Andersen, A.; Juhler, M.; Brun, B.; Boysen, G.

    1989-01-01

    We measured cerebral blood flow in 10 consecutive, but selected, patients with acute ischemic stroke (less than 48 hours after onset) before and after hemodilution. Cerebral blood flow was measured by xenon-133 inhalation and emission tomography, and only patients with focal hypoperfusion in clinically relevant areas were included. Hemodilution was done according to the hematocrit level: for a hematocrit greater than or equal to 42%, 500 ml whole blood was drawn and replaced by the same volume of dextran 40; for a hematocrit between 37% and 42%, only 250 ml whole blood was drawn and replaced by 500 cc of dextran 40. Mean hematocrit was reduced by 16%, from 46 +/- 5% (SD) to 39 +/- 5% (SD) (p less than 0.001). Cerebral blood flow increased in both hemispheres by an average of 20.9% (p less than 0.001). Regional cerebral blood flow increased in the ischemic areas in all cases, on an average of 21.4 +/- 12.0% (SD) (p less than 0.001). In three patients, a significant redistribution of flow in favor of the hypoperfused areas was observed, and in six patients, the fractional cerebral blood flow increase in the hypoperfused areas was of the same magnitude as in the remainder of the brain. In the last patient, cerebral blood flow increased relatively less in the ischemic areas. Our findings show that cerebral blood flow increases in the ischemic areas after hemodilution therapy in stroke patients. The marked regional cerebral blood flow increase seen in some patients could imply an improved oxygen delivery to the ischemic tissue

  3. Cerebral Blood Flow and Metabolism in the Wernicke-Korsakoff Syndrome*

    Science.gov (United States)

    Shimojyo, Sadatomo; Scheinberg, Peritz; Reinmuth, Oscar

    1967-01-01

    Cerebral blood flow and metabolism were measured by the iodoantipyrine-4-131I method in nine patients and by the nitrous oxide method in three patients with the Wernicke-Korsakoff syndrome. Cerebral blood flow and cerebral oxygen and glucose consumption were strikingly reduced from the normal, whereas cerebral vascular resistance was increased. Total cerebral metabolism and blood flow may be greatly reduced even though the cerebral metabolic defect is confined to circumscribed anatomical areas. Profound reduction in brain metabolism is not necessarily reflected in alterations of consciousness or awareness as has been previously suggested, or in electroencephalographic abnormalities. This appears to provide cogent support for the neurophysiological principle that disturbance of consciousness is a function of the location of the lesion, not the over-all degree of metabolic defect. The absence of improvement of cerebral metabolic functions in two patients who were restudied after an additional 2 to 3 weeks of treatment confirms the clinical impression of incomplete recovery in many such patients. PMID:6025486

  4. Regional cerebral blood flow in neuropediatrics

    International Nuclear Information System (INIS)

    Junik, R.

    2001-01-01

    Single photon emission computed tomography can effectively and non-invasively measure regional blood flow. Mostly used 99mTc-HMPAO is a safe brain imaging agent for pediatric applications. The radiation dose is acceptable. Knowledge of the normal rCBF pattern, including normal asymmetries and variations due to age, is necessary prerequisite for the evaluation and reporting of the results of 99mTc-HMPAO brain SPECT studies in clinical practice. The interpretation of he rCBF study in a child requires knowledge of normal brain maturation. The aim of the present review is to focus on the contribution to clinical developmental neurology of SPECT The clinical use of SPECT in developmental neurology are epilepsy, brain death, acute neurological loss including stroke, language disorders, cerebral palsy, high-risk neonates, hypertension due to renovascular disease, traumatic brain injury, migraine, anorexia nervosa, autism, Gilles de la Tourette syndrome, attention deficit disorder-hyperactivity, and monitoring therapy. Sedation is not routinely used, rather each child is evaluated. However, drug sedation is mandatory in some uncooperative children. (author)

  5. 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.

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

    International Nuclear Information System (INIS)

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

    1995-01-01

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

  7. Brain region-selective mechanisms contribute to the progression of cerebral alterations in acute liver failure in rats.

    Science.gov (United States)

    Cauli, Omar; López-Larrubia, Pilar; Rodrigo, Regina; Agusti, Ana; Boix, Jordi; Nieto-Charques, Laura; Cerdán, Sebastián; Felipo, Vicente

    2011-02-01

    Patients with acute liver failure (ALF) often die of intracranial pressure (IP) and cerebral herniation. Main contributors to increased IP are ammonia, glutamine, edema, and blood flow. The sequence of events and underlying mechanisms, as well as the temporal pattern, regional distribution, and contribution of each parameter to the progression of neurologic deterioration and IP, are unclear. We studied rats with ALF to follow the progression of changes in ammonia, glutamine, grade and type (vasogenic or cytotoxic) of edema, blood-brain barrier permeability, cerebral blood flow, and IP. We assessed whether the changes in these parameters were similar between frontal cortex and cerebellum and evaluated the presence, type, and progression of edema in 12 brain areas. ALF was induced by injection of galactosamine. The grade and type of edema was assessed by measuring the apparent diffusion coefficient by magnetic resonance imaging. Cerebral blood flow was measured by magnetic resonance and blood-brain barrier permeability by Evans blue-albumin extravasation. Increased IP arises from an early increase of blood-brain barrier permeability in certain areas (including cerebellum but not frontal cortex) followed by vasogenic edema. Ammonia and glutamine then increase progressively, leading to cytotoxic edema in many areas. Alterations in lactate and cerebral blood flow are later events that further increase IP. Different mechanisms in specific regions of the brain contribute, with different temporal patterns, to the progression of cerebral alterations and IP in ALF. Copyright © 2011 AGA Institute. Published by Elsevier Inc. All rights reserved.

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

    International Nuclear Information System (INIS)

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

    2006-01-01

    alter regional cerebral blood flow and hence the final results of a radionuclide cerebral blood flow study. Therefore it is recommended that body temperature should be considered as one of the factors while interpreting a cerebral blood flow study, and as far as possible such studies should be conducted on patients in normothermic conditions to avoid misleading results. It is hoped that the results of our study would encourage researchers to carry out further studies on humans. (author)

  9. 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...... and metabolism was originally performed using the Kety-Schmidt method and this method still represent the gold standard by which subsequent methods have been evaluated. However, in its classical setting, the method overestimates cerebral blood flow. Studies of metabolic changes during activation must take...... difficulties due to limitation in resolution and partial volume effects. In contrast to the tight coupling between regional glucose metabolism and cerebral blood flow, there is an uncoupling between flow and oxygen consumption as the latter only increases to a limited extend. The excess glucose uptake is thus...

  10. Cerebral blood flow is an earlier indicator of perfusion abnormalities than cerebral blood volume in Alzheimer's disease

    OpenAIRE

    Lacalle-Aurioles, María; Mateos-Pérez, José M; Guzmán-De-Villoria, Juan A; Olazarán, Javier; Cruz-Orduña, Isabel; Alemán-Gómez, Yasser; Martino, María-Elena; Desco, Manuel

    2014-01-01

    The purpose of this study was to elucidate whether cerebral blood flow (CBF) can better characterize perfusion abnormalities in predementia stages of Alzheimer's disease (AD) than cerebral blood volume (CBV) and whether cortical atrophy is more associated with decreased CBV or with decreased CBF. We compared measurements of CBV, CBF, and mean cortical thickness obtained from magnetic resonance images in a group of healthy controls, patients with mild cognitive impairment (MCI) who converted t...

  11. 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.

  12. Cerebral blood flow: Physiologic and clinical aspects

    International Nuclear Information System (INIS)

    Wood, J.H.

    1987-01-01

    This book contains 46 chapters divided among nine sections. The section titles are: Historical Perspectives; Cerebrovascular Anatomy; Cerebrovascular Physiology; Methods of Clinical Measurement; Experimental Methods; Imaging of Cerebral Circulation; Cerebrovascular Pathophysiology; Cerebrovascular Pharmacology; and Surgical and Interventional Augmentation

  13. 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; pbrain tissue oxygenation and other parameters of brain perfusion.

  14. Whole blood viscosity and cerebral blood flow velocities in obese hypertensive or obese normotensive adolescents.

    Science.gov (United States)

    Akcaboy, Meltem; Nazliel, Bijen; Goktas, Tayfun; Kula, Serdar; Celik, Bülent; Buyan, Necla

    2018-01-26

    Obesity affects all major organ systems and leads to increased morbidity and mortality. Whole blood viscosity is an important independent regulator of cerebral blood flow. The aim of the present study was to evaluate the effect of whole blood viscosity on cerebral artery blood flow velocities using transcranial Doppler ultrasound in pediatric patients with obesity compared to healthy controls and analyze the effect of whole blood viscosity and blood pressure status to the cerebral artery blood flow velocities. Sixty patients with obesity diagnosed according to their body mass index (BMI) percentiles aged 13-18 years old were prospectively enrolled. They were grouped as hypertensive or normotensive according to their ambulatory blood pressure monitoring. Whole blood viscosity and middle cerebral artery velocities by transcranial Doppler ultrasound were studied and compared to 20 healthy same aged controls. Whole blood viscosity values in hypertensive (0.0619±0.0077 poise) and normotensive (0.0607±0.0071 poise) groups were higher than controls (0.0616±0.0064 poise), with no significance. Middle cerebral artery blood flow velocities were higher in the obese hypertensive (73.9±15.0 cm/s) and obese normotensive groups (75.2±13.5 cm/s) than controls (66.4±11.5 cm/s), but with no statistical significance. Physiological changes in blood viscosity and changes in blood pressure did not seem to have any direct effect on cerebral blood flow velocities, the reason might be that the cerebral circulation is capable of adaptively modulating itself to changes to maintain a uniform cerebral blood flow.

  15. 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.

  16. Cerebral lactate production and blood flow in acute stroke

    DEFF Research Database (Denmark)

    Henriksen, O; Gideon, P; Sperling, B

    1992-01-01

    Eight stroke patients were examined serially in the acute phase and 1 week and 2-4 weeks after stroke with water-suppressed proton magnetic resonance spectroscopy. The time courses of lactate level and regional cerebral blood flow were studied. A high lactate level was found in the acute phase....... The lactate content decreased to barely detectable levels during the following 3 weeks, while regional blood flow increased during this period. The inverse relationship between lactate level and cerebral blood flow suggests that lactate plays no substantial role in the vasodilatation underlying the hyperemia...

  17. 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 st...

  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...

  19. Elevated arteriolar cerebral blood volume in prodromal Huntington's disease.

    Science.gov (United States)

    Hua, Jun; Unschuld, Paul G; Margolis, Russell L; van Zijl, Peter C M; Ross, Christopher A

    2014-03-01

    Neurovascular alterations have been implicated in the pathophysiology of Huntington's disease (HD). Because arterioles are most responsive to metabolic alterations, arteriolar cerebral blood volume (CBVa) is an important indicator of cerebrovascular regulation. The objective of this pilot study was to investigate potential neurovascular (CBVa ) abnormality in prodromal-HD patients and compare it with the widely used imaging marker: brain atrophy. CBVa and brain volumes were measured with ultra-high-field (7.0-Telsa) magnetic resonance imaging in seven prodromal-HD patients and nine age-matched controls. Cortical CBVa was elevated significantly in prodromal-HD patients compared with controls (relative difference, 38.5%; effect size, 1.48). Significant correlations were found between CBVa in the frontal cortex and genetic measures. By contrast, no significant brain atrophy was detected in the prodromal-HD patients. CBVa may be abnormal in prodromal-HD, even before substantial brain atrophy occurs. Further investigation with a larger cohort and longitudinal follow-up is merited to determine whether CBVa could be used as a potential biomarker for clinical trials. © 2013 International Parkinson and Movement Disorder Society.

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

    DEFF Research Database (Denmark)

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

    1991-01-01

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

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

    NARCIS (Netherlands)

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

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

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

    NARCIS (Netherlands)

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

    2014-01-01

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

  3. 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.

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

    International Nuclear Information System (INIS)

    Li Yuge; Gao Qinyi; Wang Shuang; Zhao Yong

    2008-01-01

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

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

    DEFF Research Database (Denmark)

    Sestoft, D; Meden, P; Hemmingsen, R

    1993-01-01

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

  6. 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...... and thereby elevate Vmean at a given volume flow. To evaluate transcranial Doppler-determined Vmean at high plasma catecholamine levels, seven elite cyclists performed a maximal performance test on a bicycle ergometer. Results were compared with those elicited during five incremental exercise bouts and during...

  7. Cerebral blood flow in asymptomatic individuals

    International Nuclear Information System (INIS)

    Isaka, Yoshinari; Iiji, Osamu; Ashida, Keiichi; Imaizumi, Masatoshi

    1993-01-01

    We studied the relationship between cortical grey matter flow (CBF) and age, cerebrovascular risk factors and the severity of subcortical hypersignals (HS, hyperintensity score in MRI) in 47 asymptomatic subjects with cerebrovascular risk factors. Multiple regression analysis revealed that HS was most strongly related to CBF, and that hematocrit, age and evidence of ischemic change detected in the electrocardiogram also appeared to be independent determinants of CBF. Both the severity and location of hypersignals were correlated with CBF. The most significant negative correlation observed was that between CBF and HS in the basal ganglia-thalamic region, where the degree of signal abnormality was modest. Decreased CBF in asymptomatic subjects with cerebrovascular risk factors may be related to microcirculatory disturbance associated with elevated hematocrit and an increase in the number of risk factors, and functional suppression of cerebral cortex due to the neuronal disconnection associated with subcortical lesions. In addition, impaired cerebral circulation may be related to MRI signal abnormalities. (author)

  8. Regional cerebral blood flow in Angelman syndrome

    Energy Technology Data Exchange (ETDEWEB)

    Guecueyener, K. (Dept. of Pediatric Neurology, Faculty of Medicine, Gazi Univ., Ankara (Turkey)); Goekcora, N. (Dept. of Nuclear Medicine, Faculty of Medicine, Gazi Univ., Ankara (Turkey)); Ilgin, N. (Dept. of Nuclear Medicine, Faculty of Medicine, Gazi Univ., Ankara (Turkey)); Buyan, N. (Dept. of Pediatric Neurology, Faculty of Medicine, Gazi Univ., Ankara (Turkey)); Sayli, A. (Dept. of Molecular Biology and Genetics, Faculty of Medicine, Gazi Univ., Ankara (Turkey))

    1993-07-01

    A patient with typical features of Angelman syndrome - a genetically inherited disorder involving developmental delay, ataxia, episodes of paroxysmal laughter and brachiocephaly - was studied with single-photon emission tomography. Hyperfusion found in the left frontal and left temporoparietal regions can provide insights into the functional cerebral pathology, which may be due to a disturbance of the developmental process related to a chromosomal abnormality. (orig.)

  9. Blood pressure gradients in cerebral arteries: a clue to pathogenesis of cerebral small vessel disease.

    Science.gov (United States)

    Blanco, Pablo J; Müller, Lucas O; Spence, J David

    2017-09-01

    The role of hypertension in cerebral small vessel disease is poorly understood. At the base of the brain (the 'vascular centrencephalon'), short straight arteries transmit blood pressure directly to small resistance vessels; the cerebral convexity is supplied by long arteries with many branches, resulting in a drop in blood pressure. Hypertensive small vessel disease (lipohyalinosis) causes the classically described lacunar infarctions at the base of the brain; however, periventricular white matter intensities (WMIs) seen on MRI and WMI in subcortical areas over the convexity, which are often also called 'lacunes', probably have different aetiologies. We studied pressure gradients from proximal to distal regions of the cerebral vasculature by mathematical modelling. Blood flow/pressure equations were solved in an Anatomically Detailed Arterial Network (ADAN) model, considering a normotensive and a hypertensive case. Model parameters were suitably modified to account for structural changes in arterial vessels in the hypertensive scenario. Computations predict a marked drop in blood pressure from large and medium-sized cerebral vessels to cerebral peripheral beds. When blood pressure in the brachial artery is 192/113 mm Hg, the pressure in the small arterioles of the posterior parietal artery bed would be only 117/68 mm Hg. In the normotensive case, with blood pressure in the brachial artery of 117/75 mm Hg, the pressure in small parietal arterioles would be only 59/38 mm Hg. These findings have important implications for understanding small vessel disease. The marked pressure gradient across cerebral arteries should be taken into account when evaluating the pathogenesis of small WMIs on MRI. Hypertensive small vessel disease, affecting the arterioles at the base of the brain should be distinguished from small vessel disease in subcortical regions of the convexity and venous disease in the periventricular white matter.

  10. Patient state index and cerebral blood flow changes during shoulder arthroscopy in beach chair position.

    Science.gov (United States)

    Buget, Mehmet Ilke; Atalar, Ata Can; Edipoglu, Ipek Saadet; Sungur, Zerrin; Sivrikoz, Nukhet; Karadeniz, Meltem; Saka, Esra; Kucukay, Suleyman; Senturk, Mert N

    2016-01-01

    The aim of the study were to demonstrate the possible hemodynamic changes and cerebral blood flow alterations in patients who were positioned from supine to beach chair position; and to detect if the position change causes any cortical activity alteration as measured by the 4-channeled electroencephalography monitor. 35 patients were included. Before the induction, mean arterial pressure and patient state index values were recorded (T0). After the intubation, doppler-ultrasonography of the patients' internal carotid and vertebral arteries were evaluated to acquire cerebral blood flow values from the formula. In supine position, mean arterial pressure, patient state index and cerebral blood flow values were recorded (T1) and the patient was positioned to beach chair position. After 5min all measurements were repeated (T2). Measurements of patient state index and mean arterial pressure were repeated after 20 (T3), and 40 (T4)min. There was a significant decrease between T0 and T1 in heart rate (80.5±11.6 vs. 75.9±14.4beats/min), MAP (105.8±21.9 vs. 78.9±18.4mmHg) and PSI (88.5±8.3 vs. 30.3±9.7) (all pchair position. Beach chair position was associated with a decrease in cerebral blood flow and patient state index values. Patient state index was affected by the gravitational change of the cerebral blood flow; however, both factors were not directly correlated to each other. Moreover, the decrease in patient state index value was transient and returned to normal values within 20min. Copyright © 2015 Sociedade Brasileira de Anestesiologia. Published by Elsevier Editora Ltda. All rights reserved.

  11. [Patient state index and cerebral blood flow changes during shoulder arthroscopy in beach chair position].

    Science.gov (United States)

    Buget, Mehmet Ilke; Atalar, Ata Can; Edipoglu, Ipek Saadet; Sungur, Zerrin; Sivrikoz, Nukhet; Karadeniz, Meltem; Saka, Esra; Kucukay, Suleyman; Senturk, Mert N

    2016-01-01

    The aim of the study were to demonstrate the possible hemodynamic changes and cerebral blood flow alterations in patients who were positioned from supine to beach chair position; and to detect if the position change causes any cortical activity alteration as measured by the 4-channeled electroencephalography monitor. 35 patients were included. Before the induction, mean arterial pressure and patient state index values were recorded (T0). After the intubation, doppler-ultrasonography of the patients' internal carotid and vertebral arteries were evaluated to acquire cerebral blood flow values from the formula. In supine position, mean arterial pressure, patient state index and cerebral blood flow values were recorded (T1) and the patient was positioned to beach chair position. After 5min all measurements were repeated (T2). Measurements of patient state index and mean arterial pressure were repeated after 20 (T3), and 40 (T4)min. There was a significant decrease between T0 and T1 in heart rate (80.5±11.6 vs. 75.9±14.4beats/min), MAP (105.8±21.9 vs. 78.9±18.4mmHg) and PSI (88.5±8.3 vs. 30.3±9.7) (all pchair position. Beach chair position was associated with a decrease in cerebral blood flow and patient state index values. Patient state index was affected by the gravitational change of the cerebral blood flow; however, both factors were not directly correlated to each other. Moreover, the decrease in patient state index value was transient and returned to normal values within 20min. Copyright © 2015 Sociedade Brasileira de Anestesiologia. Publicado por Elsevier Editora Ltda. All rights reserved.

  12. 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 2.4 l min(-1) m(-2), respectively, in females. No effects of cardiac output or cardiac index on CBF or structural signs of brain ageing were observed. However, fractional brain flow defined as the ratio of total brain flow to cardiac output was inversely correlated with cardiac index (r(2) = 0.22, P...... = 0.008) and furthermore lower in males than in females (8.6% versus 12.5%, P = 0.003). Fractional brain flow was also inversely correlated with cerebral white matter lesion grade, although this effect was not significant when adjusted for age. Frequency analysis of heart rate variability showed...

  13. 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.

  14. Modelling Cerebral Blood Flow Autoregulation in Humans

    National Research Council Canada - National Science Library

    Panerai, R

    2001-01-01

    ...% of CBF regulatory,' mechanisms and their interaction with other haemodynamic variables such as intracranial pressure and blood gases, Mathematical models have been able to reproduce many known...

  15. 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....

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

    NARCIS (Netherlands)

    Zeeman, Gerda G.; 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

  17. 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…

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

    DEFF Research Database (Denmark)

    Sestoft, D; Meden, P; Hemmingsen, R

    1993-01-01

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

  19. A New Technology for Detecting Cerebral Blood Flow

    DEFF Research Database (Denmark)

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

    2012-01-01

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

  20. Regional cerebral blood flow in primary degenerative dementia

    International Nuclear Information System (INIS)

    Kawakatsu, Shinobu; Totsuka, Shiro; Shinohara, Masao; Koyama, Hideki; Sagawa, Katsuo; Morinobu, Shigeru; Oiji, Arata; Komatani, Akio

    1991-01-01

    Regional cerebral blood flow (rCBF) was examined, using SPECT by Xe-133 inhalation, in patients with primary degenerative dementia who were subgrouped according to predominant symptoms with respect to amnesia, apraxia, agnosia, aphasia, and personality changes. Also the effect of sex and age at dementia onset on the rCBF patterns was assessed. (author). 26 refs.; 1 fig.; 7 tabs

  1. 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...

  2. Determinants of resting cerebral blood flow in sickle cell disease

    NARCIS (Netherlands)

    Bush, Adam M.; Borzage, Matthew T.; Choi, Soyoung; Václavů, Lena; Tamrazi, Benita; Nederveen, Aart J.; Coates, Thomas D.; Wood, John C.

    2016-01-01

    Stroke is common in children with sickle cell disease and results from an imbalance in oxygen supply and demand. Cerebral blood flow (CBF) is increased in patients with sickle cell disease to compensate for their anemia, but adequacy of their oxygen delivery has not been systematically demonstrated.

  3. Effect of pregnancy on regional cerebral blood flow

    International Nuclear Information System (INIS)

    Nagamachi, Shigeki; Hoshi, Hiroaki; Jinnouchi, Seishi; Ohnishi, Takashi; Futami, Shigemi; Watanabe, Katsushi; Ikeda, Tomoaki; Mori, Norimasa

    1993-01-01

    Regional cerebral blood flow (r-CBF) of 10 pregnant women were quantified by 133 Xe SPECT study with inhalation method before and after artificial abortion. During pregnancy, value of r-CBF in each region except occipital lobe was significantly higher than that of the post abortion. Arterial blood gas was analyzed after SPECT procedure. P co2 concentration increased significantly after artificial abortion. Although its mechanism is unknown, our preliminary work demonstrates that r-CBF increased by pregnancy. (author)

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

    International Nuclear Information System (INIS)

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

    2011-01-01

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

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

    Science.gov (United States)

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

    2005-01-01

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

  6. 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.)

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

    International Nuclear Information System (INIS)

    Cermik, Tevfik F.; Kaya, Meryem; Bedel, Deniz; Berkarda, Sakir; Yigitbasi, Oemer N.; Ugur-Altun, Betuel

    2007-01-01

    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.)

  8. 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 catech...... cerebral flux of TNF-alpha, interleukin (IL)-1beta, and IL-6 did not differ significantly from zero. Thus, high circulating levels of TNF-alpha during human endotoxemia do not induce a direct reduction in cerebral oxidative metabolism.......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...... of a reference endotoxin. Arterial TNF-alpha peaked at 90 minutes, coinciding with a peak in subjective symptoms. At this time, CBF and Paco were significantly reduced compared to baseline; the CBF decrease was readily explained by hypocapnia. The cerebral metabolic rate of oxygen remained unchanged, and the net...

  9. 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.

  10. Altered protein mannosylation in developing cerebral cortex by streptomycin.

    Science.gov (United States)

    Alperin, M D; Calandria, J M; Carminatti, H; Idoyaga-Vargas, V P

    2000-11-09

    Our research objective was to characterize the biochemical effect of streptomycin during postnatal rat cerebral cortex development using a sensitive method that preserves the in situ topological relationship. We found a decrease in the mannosylation of asparagine-linked oligosaccharides without affecting polypeptide synthesis, DNA synthesis or glucose and mannose disappearance from the medium in mini-tissue units derived from P5. In addition, the rate of Dolp-GlcNAc2 Man9 Glc3 synthesis and the oligosaccharide protein transferase activity did not change in the presence of the aminoglycoside. These findings strongly suggested that the alteration of protein mannosylation occurred downstream of G3 transfer to nascent polypeptides. Further, the mini-tissue units may be useful for the assessment of neurological toxicity of antibacterial agents.

  11. Cerebral blood flow links insulin resistance and baroreflex sensitivity.

    Science.gov (United States)

    Ryan, John P; Sheu, Lei K; Verstynen, Timothy D; Onyewuenyi, Ikechukwu C; Gianaros, Peter J

    2013-01-01

    Insulin resistance confers risk for diabetes mellitus and associates with a reduced capacity of the arterial baroreflex to regulate blood pressure. Importantly, several brain regions that comprise the central autonomic network, which controls the baroreflex, are also sensitive to the neuromodulatory effects of insulin. However, it is unknown whether peripheral insulin resistance relates to activity within central autonomic network regions, which may in turn relate to reduced baroreflex regulation. Accordingly, we tested whether resting cerebral blood flow within central autonomic regions statistically mediated the relationship between insulin resistance and an indirect indicator of baroreflex regulation; namely, baroreflex sensitivity. Subjects were 92 community-dwelling adults free of confounding medical illnesses (48 men, 30-50 years old) who completed protocols to assess fasting insulin and glucose levels, resting baroreflex sensitivity, and resting cerebral blood flow. Baroreflex sensitivity was quantified by measuring the magnitude of spontaneous and sequential associations between beat-by-beat systolic blood pressure and heart rate changes. Individuals with greater insulin resistance, as measured by the homeostatic model assessment, exhibited reduced baroreflex sensitivity (b = -0.16, p baroreflex sensitivity was statistically mediated by cerebral blood flow in central autonomic regions, including the insula and cingulate cortex (mediation coefficients baroreflex sensitivity. Our observations may help to characterize the neural pathways by which insulin resistance, and possibly diabetes mellitus, relates to adverse cardiovascular outcomes.

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

    International Nuclear Information System (INIS)

    Kitamura, Shin

    1983-01-01

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

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

    International Nuclear Information System (INIS)

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

    1984-01-01

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

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

    International Nuclear Information System (INIS)

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

    1982-01-01

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

  15. Cerebral blood flow asymmetries in headache-free migraineurs

    International Nuclear Information System (INIS)

    Levine, S.R.; Welch, K.M.; Ewing, J.R.; Joseph, R.; D'Andrea, G.

    1987-01-01

    Regional cerebral blood flow (rCBF) asymmetries were studied in controls and patients with common and classic/complicated migraine using 133 Xe inhalation with 8 homologously situated external collimators over each cerebral hemisphere. Migraine patients as a group more frequently had posterior rCBF asymmetries than controls (p less than 0.03). Although there were no differences in the number of anterior rCBF asymmetries, migraine patients had 2 or more asymmetric probe pairs more often than controls (p less than 0.02). The posterior rCBF asymmetries, consistent with the site of activation of many migraine attacks, may be related to more labile control of the cerebral circulation

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

    DEFF Research Database (Denmark)

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

    2008-01-01

    During exercise: the Kety-Schmidt-determined cerebral blood flow (CBF) does not change because the jugular vein is collapsed in the upright position. In contrast, when CBF is evaluated by (133)Xe clearance, by flow in the internal carotid artery, or by flow velocity in basal cerebral arteries......, a approximately 25% increase is detected with a parallel increase in metabolism. During activation, an increase in cerebral O(2) supply is required because there is no capillary recruitment within the brain and increased metabolism becomes dependent on an enhanced gradient for oxygen diffusion. During maximal......, and data support the theory that glycogen depletion in astrocytes limits the ability of the brain to accelerate its metabolism during activation. The release of interleukin-6 from the brain when exercise is prolonged may represent a signaling pathway in matching the metabolic response of the brain...

  17. 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

  18. Regional cerebral blood flow in fibromyalgia

    International Nuclear Information System (INIS)

    Kwiatek, R.; Barnden, L.; Rowe, C.; McKinnon, J.; Pile, K.

    1998-01-01

    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

  19. Cerebral blood flow, blood volume, and brain tissue hematocrit during isovolemic hemodilution with hetastarch in rats.

    Science.gov (United States)

    Todd, M M; Weeks, J B; Warner, D S

    1992-07-01

    The influence of isovolemic hemodilution with 6% hetastarch [hematocrits (Hct) ranging from 43 to 20%] on cerebral blood flow (CBF), cerebral red blood cell and plasma volumes, total cerebral blood volume (CBV), and cerebral Hct was examined in normothermic, normocarbic, halothane-anesthetized Sprague-Dawley rats. CBF was measured via the indicator-fractionation method ([3H]nicotine), red blood cell volume was measured using 99mTc-labeled red blood cells, while plasma volume was measured using [14C]dextran. Brain tissue was fixed in situ by microwave irradiation. All data plots (e.g., CBF vs. Hct) were fitted by linear regression methods. Hemodilution was associated with a progressive increase in forebrain CBF (from a fitted value of 78 ml.100 g-1.min-1 at Hct = 43%, to 171 ml.100 g-1.min-1 at 20%). Cerebral plasma volume also rose, while red blood cell volume decreased. Total CBV (i.e., the sum of red blood cell and plasma volumes) increased in parallel with CBF (from 2.51 ml/100 g at Hct = 43 to 4.94 ml/100 g at Hct = 20%). This increase is larger than can be explained by a simple increase in the diameter of arterial/arteriolar resistance vessels and may be due to either capillary recruitment or to an increase in the volume of postarteriolar structures. Calculated cerebral tissue hematocrit decreased. The magnitude of this decrease was larger than the reduction in arterial Hct; the ratio of cerebral to arterial Hct decreased from 0.780 at an arterial Hct equaling 43% to 0.458 at Hct equaling 20%.(ABSTRACT TRUNCATED AT 250 WORDS)

  20. Cerebral blood oxygenation measurements in neonates with optoacoustic technique

    Science.gov (United States)

    Herrmann, Stephen; Petrov, Irene Y.; Petrov, Yuriy; Richardson, C. Joan; Fonseca, Rafael A.; Prough, Donald S.; Esenaliev, Rinat O.

    2017-03-01

    Cerebral hypoxia is a major contributor to neonatal/infant mortality and morbidity including severe neurological complications such as mental retardation, cerebral palsy, motor impairment, and epilepsy. Currently, no technology is capable of accurate monitoring of neonatal cerebral oxygenation. We proposed to use optoacoustics for this application by probing the superior sagittal sinus (SSS), a large central cerebral vein. We developed and built a multi-wavelength, optical parametric oscillator (OPO) and laser diode optoacoustic systems for measurement of SSS blood oxygenation in the reflection mode through open anterior or posterior fontanelles and in the transmission mode through the skull in the occipital area. In this paper we present results of initial tests of the laser diode system for neonatal cerebral oxygenation measurements. First, the system was tested in phantoms simulating neonatal SSS. Then, using the data obtained in the phantoms, we optimized the system's hardware and software and tested it in neonates admitted in the Neonatal Intensive Care Unit. The laser diode system was capable of detecting SSS signals in the reflection mode through the open anterior and posterior fontanelles as well as in the transmission mode through the skull with high signal-to-noise ratio. Using the signals measured at different wavelengths and algorithms developed for oxygenation measurements, the laser diode system provided real-time, continuous oxygenation monitoring with high precision at all these locations.

  1. Quantification of cerebral blood flow via Duplex sonography

    International Nuclear Information System (INIS)

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

    1987-01-01

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

  2. Cerebral blood flow in Binswanger's disease

    International Nuclear Information System (INIS)

    Kawabata, Keita; Tachibana, Hisao; Sugita, Minoru

    1991-01-01

    Eight patients with a clinical diagnosis of Binswanger's disease (BD) were evaluated with I-123 IMP SPECT. The SPECT findings were compared with those in 7 other patients with Alzheimer's disease (AD) and 9 normal subjects. The ratios of I-123 IMP in the temporal cortex, thalamus, and basal ganglia to that in the cerebellum were lower in the BD group than the normal group. The BD group had a higher ratio of the occipital cortex/the cerebellum than the control group, suggesting a decreased blood flow in the cerebellum. When I-123 IMP ratio in various areas to that in the occipital cortex was examined, both the BD and AD groups seemed to have a decreased blood flow over the whole cerebrum. The BD group had a lower I-123 IMP uptake in the thalamus and basal ganglia, and the AD group had it in the parietal cortex, relative to the occipital cortex. Blood flow patterns for BD were found to be different from those for AD. This suggests the difference in areas responsible for etiology between BD and AD. (N.K.)

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

    Energy Technology Data Exchange (ETDEWEB)

    Nemoto, Akio [Toho Univ., Tokyo (Japan). School of Medicine

    2003-01-01

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

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

    International Nuclear Information System (INIS)

    Herscovitch, P.; Powers, W.J.

    1987-01-01

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

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

    International Nuclear Information System (INIS)

    Lenart-Jankowska, D.; Junik, R.; Sowinski, J.; Gembicki, M.; Wender, M.

    1997-01-01

    The purpose of our work was to compare the regional cerebral blood flow (rCBF) in SPECT examination in Parkinson's disease with (17 cases) and without (7 cases) dementia and in various clinical stages of the disease. The patients underwent SPECT examination 5-40 min after intravenous application of HMPAO (Ceretec, Amersham) with 740 Mbq (20 mCi) pertechnate 99m Tc. SPECT was performed with a Siemens Diacam single-head rotating gamma camera coupled to a high resolution collimator and Icon computer system provided by the manufacturer. The results were defined in relative values of ROI in relation to cerebellum. Patients with Parkinson's disease showed hypoperfusion in cerebral lobes and in deep cerebral structures including the basal ganglia. Regional perfusion deficit in SPECT was seen with and without associated dementia and already in early stage of the disease. Parkinson's disease is provoked by the lesions of dopaminergic neurons of the central nervous system leading to domination of extrapyramidal symptoms. There are many indications that also the neurotransmitters associated with cognitive functions as acetylcholine demonstrate some abnormalities. However, only in some cases of Parkinson's disease dementia is the dominating symptom. Our results of regional cerebral blood flow testify that in Parkinson's disease the dysfunction of the central nervous system is more diffuse than has previously been suggested. (author)

  6. 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...... · s-1). Cognitive function did not change during the 6 months. Static cerebrovascular autoregulation appears to be impaired in type 2 diabetes mellitus, with a transient reduction in CBFV in uncomplicated diabetic patients on tight BP control, but with a progressive reduction in CBFV in diabetic...... 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...

  7. The effect of enalapril maleate on cerebral blood flow in chronic cerebral infarction.

    Science.gov (United States)

    Kobayashi, S; Yamaguchi, S; Okada, K; Suyama, N; Bokura, K; Murao, M

    1992-05-01

    The influence of long-term oral administration of enalapril maleate (an angiotensin II-converting enzyme inhibitor) on regional cerebral blood flow (rCBF) was studied in 10 patients with chronic cerebral infarction. The rCBF was measured by a 133Xe inhalation method before and after a mean of sixty-five days' administration of 5 mg of enalapril. Mean arterial blood pressure (MABP) was mildly decreased in 6 patients, but the average change in MABP was not significant (Endtidal partial pressure of carbon dioxide (PeC02) was not changed significantly. The mean rCBF was increased by 8% after administration of enalapril (0.05 less than p less than 0.1) There was no significant correlation between percent change in MABP and the percent change in rCBF. These results indicate that enalapril has not only antihypertensive action but also a beneficial effect on the cerebral circulation in patients with chronic cerebral infarction.

  8. Regional cerebral blood flow and oxygen metabolism in patient with cerebral stroke studied by positron tomography

    International Nuclear Information System (INIS)

    Uemura, Kazuo

    1987-01-01

    After the CT-era, tomographic measurement has been required for regional cerebral blood flow and metabolism. This paper descrives results on the quontitative studies of regional cerebral blood flow and oxygen metabolism in patients with cerebral stroke, studied using the 0 - 15 labelled gas steady-stete method and HEAD-TOME III by the PET-group of Akita. The results were summarized as follows. 1) Cerebral infarct with acute onset: 33 PET studies were carried out on the 16 subjects. Most of the lesions revealed considerable flow-metabolism mismatch: misery perfusion within the initial day, and then luxury perfusion up to 2 months. Threthold CBF causing tissue necrosis estimated at 17 ml/100 ml/min by PET. 2) Thrombosis of carotid artery with or without small infarct: Isodense tissues of the 31 patients were examined, Most of the subjects showed coupled decrease of flow/metabolism. Only 4 revealed critical reduction of flow and maintained metabolism with increased oxygen extraction. That would indicates that only a few of the patients could be indicated to EC/IC bypass surgery. 3) Hypertensive intracerbral hemorrhage: The 26 subjects were studied. A markedly ischemic zone was limitted just around a hematoma and luxury perfusion appeared only in 3 cases. Increased intracranial pressure seemes to affect flow and metabolism of the patients with a hematoma lager than 4.5 - 5 cm in max, diameter. That should be considered for indication of surgical evacuation of a hematoma. (author)

  9. Regional cerebral blood flow and oxygen metabolism in patient with cerebral stroke studied by positron tomography

    Energy Technology Data Exchange (ETDEWEB)

    Uemura, Kazuo

    1987-12-01

    After the CT-era, tomographic measurement has been required for regional cerebral blood flow and metabolism. This paper descrives results on the quontitative studies of regional cerebral blood flow and oxygen metabolism in patients with cerebral stroke, studied using the 0 - 15 labelled gas steady-stete method and HEAD-TOME III by the PET-group of Akita. The results were summarized as follows. 1) Cerebral infarct with acute onset: 33 PET studies were carried out on the 16 subjects. Most of the lesions revealed considerable flow-metabolism mismatch: misery perfusion within the initial day, and then luxury perfusion up to 2 months. Threthold CBF causing tissue necrosis estimated at 17 ml/100 ml/min by PET. 2) Thrombosis of carotid artery with or without small infarct: Isodense tissues of the 31 patients were examined, Most of the subjects showed coupled decrease of flow/metabolism. Only 4 revealed critical reduction of flow and maintained metabolism with increased oxygen extraction. That would indicates that only a few of the patients could be indicated to EC/IC bypass surgery. 3) Hypertensive intracerbral hemorrhage: The 26 subjects were studied. A markedly ischemic zone was limitted just around a hematoma and luxury perfusion appeared only in 3 cases. Increased intracranial pressure seemes to affect flow and metabolism of the patients with a hematoma lager than 4.5 - 5 cm in max, diameter. That should be considered for indication of surgical evacuation of a hematoma.

  10. Middle cerebral artery blood flow velocity in elite power athletes during maximal weight-lifting.

    Science.gov (United States)

    Dickerman, R D; McConathy, W J; Smith, G H; East, J W; Rudder, L

    2000-06-01

    Cerebral blood flow velocity (CBFV) has been shown to significantly increase during dynamic exercise (running) secondary to increases in cardiac output. Static exercise (weight-lifting) induces supraphysiological arterial pressures up to 450/380 mmHg, and thus may alter CBFV. Catastrophic brain injuries such as stroke, cerebral hemorrhage, subarachnoid hemorrhage, retinal hemorrhage and retinal detachment have been associated with weight-lifting. A recent study has shown that intra-ocular pressure (IOP), which is an indirect measure of intracranial pressure, elevates to pathophysiologic levels during weight-lifting. Recent CBFV studies instituting Valsalva have demonstrated decreases in CBFV from 21%-52%. To date, no studies have examined CBFV during maximal weight-lifting to elucidate the cerebrovascular responses to extreme pressure alterations. We recruited nine elite power athletes, including a multi-world record holder in powerlifting, for a transcranial Doppler study of middle cerebral artery blood flow velocity at rest and during maximal weight-lifting. All subjects' resting blood flow velocities were within normal ranges (mean 64.4 +/- 9.5 cm sec2). Blood flow velocities were significantly (p < 0.0001) decreased in all subjects during maximal lifting (mean 48.4 +/- 10.1 cm sec2). Linear regression analysis demonstrated a significant inverse linear relationship in the net change of blood velocities from rest to maximal lift for each subject (r = 0.8585, p < 0.001). This study demonstrates that blood flow velocities are significantly decreased during heavy resistance training. The drop in CBFV during weight-lifting was significantly less than previous Valsalva studies, which likely reveals the cardiovascular, baroreflex, and cerebrovascular system adaptations occurring in these elite power athletes.

  11. Transcranial Doppler estimation of cerebral blood flow and cerebrovascular conductance during modified rebreathing.

    NARCIS (Netherlands)

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

    2007-01-01

    Clinical transcranial Doppler assessment of cerebral vasomotor reactivity (CVMR) uses linear regression of cerebral blood flow velocity (CBFV) vs. end-tidal CO(2) (Pet(CO(2))) under steady-state conditions. However, the cerebral blood flow (CBF)-Pet(CO(2)) relationship is nonlinear, even for

  12. THE INFLUINCE OF THE STAPHYLOCOCCUS INFECTION TO THE STRUCTURAL ORGANIZATION OF WISTAR RATS BRAIN AND CEREBRAL BLOOD VESSELS

    Directory of Open Access Journals (Sweden)

    Torianik I. I.

    2013-12-01

    Full Text Available In this article there are a dates about the influence of thestaphylococcus infection to the structural organization of Wistar rats brain and cerebral blood vessels in experiment. The purpose of the experiment’s are achieving by the seding staphylococcus infection means of the characterical structures of the brain and cerebralblood damages, that similar with the such in a human in a case of the development of a traditional clinic pathology.The results are evaluated to character of the morphological changes (brain cortex and cerebral blood vessels destructive and degenerative alterations,inflammatory processes.

  13. Sport-Related Concussion Alters Indices of Dynamic Cerebral Autoregulation

    Directory of Open Access Journals (Sweden)

    Alexander D. Wright

    2018-03-01

    Full Text Available Sport-related concussion is known to affect a variety of brain functions. However, the impact of this brain injury on cerebral autoregulation (CA is poorly understood. Thus, the goal of the current study was to determine the acute and cumulative effects of sport-related concussion on indices of dynamic CA. Toward this end, 179 elite, junior-level (age 19.6 ± 1.5 years contact sport (ice hockey, American football athletes were recruited for preseason testing, 42 with zero prior concussions and 31 with three or more previous concussions. Eighteen athletes sustained a concussion during that competitive season and completed follow-up testing at 72 h, 2 weeks, and 1 month post injury. Beat-by-beat arterial blood pressure (BP and middle cerebral artery blood velocity (MCAv were recorded using finger photoplethysmography and transcranial Doppler ultrasound, respectively. Five minutes of repetitive squat–stand maneuvers induced BP oscillations at 0.05 and 0.10 Hz (20- and 10-s cycles, respectively. The BP–MCAv relationship was quantified using transfer function analysis to estimate Coherence (correlation, Gain (amplitude ratio, and Phase (timing offset. At a group level, repeated-measures ANOVA indicated that 0.10 Hz Phase was significantly reduced following an acute concussion, compared to preseason, by 23% (−0.136 ± 0.033 rads at 72 h and by 18% (−0.105 ± 0.029 rads at 2 weeks post injury, indicating impaired autoregulatory functioning; recovery to preseason values occurred by 1 month. Athletes were cleared to return to competition after a median of 14 days (range 7–35, implying that physiologic dysfunction persisted beyond clinical recovery in many cases. When comparing dynamic pressure buffering between athletes with zero prior concussions and those with three or more, no differences were observed. Sustaining an acute sport-related concussion induces transient impairments in the capabilities of the cerebrovascular

  14. 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...... edema/high ICP. Nor does portacaval shunting or hyperammonemia impair autoregulation. Rather, massive liver necrosis and reduced liver mass are associated with loss of CBF autoregulation Udgivelsesdato: 2008/5...

  15. Aging, regional cerebral blood flow, and neuropsychological functioning

    International Nuclear Information System (INIS)

    MacInnes, W.D.; Golden, C.J.; Gillen, R.W.; Sawicki, R.F.; Quaife, M.; Uhl, H.S.; Greenhouse, A.J.

    1984-01-01

    Previous studies found changes in regional cerebral blood flow (rCBF) patterns related to both age and various cognitive tasks. However, no study has yet demonstrated a relationship between rCBF and performance on the Luria-Nebraska Neuropsychological Battery (LNNB) in an elderly group. Seventy-nine elderly volunteers (56-88 years old), both healthy and demented, underwent the 133 xenon inhalation rCBF procedure and were given the LNNB. The decrements in the gray-matter blood flow paralleled decrements in performance on the LNNB. Using partial correlations, a significant proportion of shared variance was observed between gray-matter blood flow and the LNNB scales. However, there was much less of a relationship between white-matter blood flow and performance on the LNNB. This study suggests that even within a restricted age sample rCBF is related in a global way to neuropsychological functioning

  16. 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

    . 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...

  17. Influence of hemodialysis on the mean blood flow velocity in the middle cerebral artery.

    Science.gov (United States)

    Stefanidis, I; Bach, R; Mertens, P R; Liakopoulos, V; Liapi, G; Mann, H; Heintz, B

    2005-08-01

    Several effects of hemodialysis, including hemoconcentration, alterations of hemostasis or hemorheology and endothelial activation, could potentially interfere with cerebral blood flow (CBF) regulation. These treatment-specific changes may also be crucial for the enhanced incidence of stroke in uremic patients. Nevertheless, the influence of hemodialysis on CBF has not been yet adequately studied. We registered mean blood flow velocity (MFV) in the middle cerebral artery (MCA) during hemodialysis treatment in order to evaluate its contribution on CBF changes. Transcranial Doppler ultrasonography (TCD) of the MCA was performed continuously during hemodialysis treatment in 18 stable patients (10 males and 8 females, mean age 62 +/- 11 years) with end-stage renal disease of various origin. Blood pressure (mmHg), heart rate (/min), ultrafiltration volume (ml), BV changes (deltaBV by hemoglobinometry, %), arterial blood gases (pO2, blood oxygen content, pCO2), hemostasis activation (thrombin-antithrombin III complex, ELISA) and fibrinogen (Clauss) were measured simultaneously at the beginning of treatment and every hour thereafter. Before the hemodialysis session the MFV in the MCA was within normal range (57.5 +/- 13.0 cm/s, ref. 60 +/- 12) and was mainly dependent on the patients' age (r = -0.697, p delta%MFV) were interrelated to the ultrafiltration volume (r = -0.486, p delta%acO2, r = -0.420, p delta%fibrinogen, r = 0.244, p < 0.05). A significant continuous decrease of the MFV in the MCA was observed during hemodialysis treatment, which inversely correlated both with ultrafiltration volume, BV changes and changes of plasma fibrinogen. The ultrafiltration-induced hemoconcentration with concomitant rise of hematocrit and oxygen transport capacity, may partly explain the alterations in the cerebral MFV observed during hemodialysis.

  18. 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...

  19. 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.

  20. 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....

  1. Regional cerebral blood flow in the patient with brain tumor

    Energy Technology Data Exchange (ETDEWEB)

    Tsuchida, Shohei (Okayama Univ. (Japan). School of Medicine)

    1993-06-01

    Regional cerebral blood flow (rCBF) was measured with xenon-enhanced CT (Xe-CT) in 21 cases of intracranial tumors (13 meningiomas, 5 gliomas, 3 metastatic brain tumors). Peritumoral edema was graded as mild, moderate or severe based on the extent of edema on CT and MRI. According to intratumoral blood flow distribution patterns, three patterns were classified as central type with relatively high blood flow at the center of the tumor, homogeneous type with an almost homogeneous blood flow distribution, and marginal type with relatively high blood flow at the periphery of the tumor. High grade astrocytoma and metastatic brain tumor showed marginal type blood flow and moderate or severe edema except in one case. Five meningiomas with severe peritumoral edema revealed marginal type blood flow and four with mild peritumoral edema showed central type blood flow, except for one case. No correlation was found between the extent of peritumoral edema and histological subtype, tumor size, location, duration of clinical history, vascularization on angiogram, and mean blood flow in the tumor. These results suggest that blood flow distribution patterns within the tumor may affect the extension of peritumoral edema. Pre- and postoperative rCBFs were evaluated with Xe-CT and IMP-SPECT in 7 cases, mean rCBF of peritumoral edema was 6.2 ml/100 g/min preoperatively, and discrepancy between rCBF on Xe-CT and that on IMP-SPECT was shown in the remote cortical region ipsilateral to the tumor. Postoperative rCBF revealed an improved blood flow in both adjacent and remote areas, suggesting that the decreased blood flow associated with brain tumors might be relieved after surgery. (author) 53 refs.

  2. Regional cerebral blood flow in the patient with brain tumor

    International Nuclear Information System (INIS)

    Tsuchida, Shohei

    1993-01-01

    Regional cerebral blood flow (rCBF) was measured with xenon-enhanced CT (Xe-CT) in 21 cases of intracranial tumors (13 meningiomas, 5 gliomas, 3 metastatic brain tumors). Peritumoral edema was graded as mild, moderate or severe based on the extent of edema on CT and MRI. According to intratumoral blood flow distribution patterns, three patterns were classified as central type with relatively high blood flow at the center of the tumor, homogeneous type with an almost homogeneous blood flow distribution, and marginal type with relatively high blood flow at the periphery of the tumor. High grade astrocytoma and metastatic brain tumor showed marginal type blood flow and moderate or severe edema except in one case. Five meningiomas with severe peritumoral edema revealed marginal type blood flow and four with mild peritumoral edema showed central type blood flow, except for one case. No correlation was found between the extent of peritumoral edema and histological subtype, tumor size, location, duration of clinical history, vascularization on angiogram, and mean blood flow in the tumor. These results suggest that blood flow distribution patterns within the tumor may affect the extension of peritumoral edema. Pre- and postoperative rCBFs were evaluated with Xe-CT and IMP-SPECT in 7 cases, mean rCBF of peritumoral edema was 6.2 ml/100 g/min preoperatively, and discrepancy between rCBF on Xe-CT and that on IMP-SPECT was shown in the remote cortical region ipsilateral to the tumor. Postoperative rCBF revealed an improved blood flow in both adjacent and remote areas, suggesting that the decreased blood flow associated with brain tumors might be relieved after surgery. (author) 53 refs

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

    International Nuclear Information System (INIS)

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

    1987-01-01

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

  4. 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).

  5. Effect of carotid ligation on cerebral blood flow in baboons

    Science.gov (United States)

    Sengupta, D.; Harper, Murray; Jennett, Bryan

    1974-01-01

    Cerebral blood flow (CBF) measurements were carried out in two groups of anaesthetized normocapnic baboons. In the first group of five animals the effect of hypoxia on the CBF before and after ipsilateral carotid artery ligation was studied. The results showed that, although after ipsilateral carotid ligation there was little change in the CBF at normal PaO2, at hypoxia there was only 20% rise in the CBF as compared with an 80% rise before the carotid ligation. In the second group of 10 animals, effects of haemorrhagic hypotension on the CBF after ipsilateral carotid artery ligation were estimated. The results indicated impairment of autoregulatory response of the cerebral circulation. PMID:4836753

  6. Cerebral Blood and CSF Flow Patterns in Patients Diagnosed for Cerebral Venous Thrombosis - An Observational Study

    Directory of Open Access Journals (Sweden)

    Souraya ElSankari

    2012-01-01

    Full Text Available Background and Purpose: Recent studies of the organization of the cerebral venous system in healthy subjects using phase contrast magnetic resonance imaging (PC-MRI show its structural complexity and inter-individual variations. Our objective was to study the venous blood and CSF flows in cerebral venous thrombosis (CVT. Materials and Methods: PC-MRI sequences were added to brain MRI conventional protocol in 19 patients suspected of CVT, among whom 6 patients had CVT diagnosis confirmed by MR venography. Results were compared with 18 healthy age-matched volunteers (HV. Results: In patients without CVT (NoCVT confirmed by venography, we found heterogeneous individual venous flows, and variable side dominance in paired veins and sinuses, comparable to those in healthy volunteers. In CVT patients, PC-MRI detected no venous flow in the veins and/or sinuses with thrombosis. Arterial flows were preserved. CSF aqueductal and cervical stroke volumes were increased in a patient with secondary cerebral infarction, and decreased in 4 patients with extended thrombosis in the superior sagittal and transverse sinuses. These results suggest the main role of the venous system in the regulation of the dynamic intracranial equilibrium. Conclusions: CVT produces highly individualized pattern of disturbance in venous blood drainage. Complementary to MRI venography, PC-MRI provides non-invasive data about venous blockage consequences on CSF flow disturbances.

  7. Impact of Cardiac Contractility during Cerebral Blood Flow in Ischemia

    Directory of Open Access Journals (Sweden)

    Silver, Brian

    2011-05-01

    Full Text Available Objective: In cerebral regions affected by ischemia, intrinsic vascular autoregulation is often lost. Blood flow delivery depends upon cardiac function and may be influenced by neuro-endocrine mediated myocardial suppression. Our objective is to evaluate the relation between ejection fraction (EF and transcranial doppler (TCD peak systolic velocities (PSV in patients with cerebral ischemic events.Methods: We conducted a retrospective cohort study from an existing TCD registry. We evaluated patients admitted within 24 hours of onset of a focal neurological deficit who had an echocardiogram and TCD performed within 72 hours of admission.Results: We identified 58 patients from March to October 2003. Eighty-one percent (n=47 had a hospital discharge diagnosis of ischemic stroke and 18.9% (n=11 had a diagnosis of transient ischemic attack. Fourteen patients had systolic dysfunction (EF50% compared to those with systolic dysfunction (EF<50% was as follows: middle cerebral artery 62.0 + 28.6 cm/s vs. 51.0 + 23.3 cm/s, p=0.11; anterior cerebral artery 52.1 + 21.6 cm/s vs. 45.9 + 22.7 cm/s, p=0.28; internal carotid artery 56.5 + 20.1 cm/s vs. 46.4 + 18.4 cm/s, p=0.04; ophthalmic artery 18.6 + 7.2 cm/s vs. 15.3 + 5.2 cm/s, p=0.11; vertebral artery 34.0 + 13.9 cm/s vs. 31.6 + 15.0 cm/s, p=0.44.Conclusion: Cerebral blood flow in the internal carotid artery territory appears to be higher in cerebral ischemia patients with preserved left ventricular contractility. Our study was unable to differentiate pre-existing cardiac dysfunction from neuro-endocrine mediated myocardial stunning. Future research is necessary to better understand heart-brain interactions in this setting and to further explore the underlying mechanisms and consequences of neuro-endocrine mediated cardiac dysfunction. [West J Emerg Med. 2011;12(2:227-232.

  8. Regional cerebral blood flow during comprehension and speech (in cerebrally healthy subjects)

    International Nuclear Information System (INIS)

    Lechevalier, B.; Petit, M.C.; Eustache, F.; Lambert, J.; Chapon, F.; Viader, F.

    1989-01-01

    Regional cerebral blood flow (rCBF) was measured by the xenon-133 inhalation method in 10 cerebrally healthy subjects at rest and during linguistic activation tests. These consisted of a comprehension test (binaural listening to a narrative text) and a speech test (making sentences from a list of words presented orally at 30-s intervals). The comprehension task induced a moderate increase in the mean right CBF and in both inferior parietal areas, whereas the speech test resulted in a diffuse increase in the mean CBF of both hemispheres, predominating regionally in both inferior parietal, left operculary, and right upper motor and premotor areas. It is proposed that the activation pattern induced by linguistic stimulation depends on not only specific factors, such as syntactic and semantic aspects of language, but also the contents of the material proposed and the attention required by the test situation

  9. Chronicity and a low anteroposterior gradient of cerebral blood flow in schizophrenia

    International Nuclear Information System (INIS)

    Mathew, R.J.; Wilson, W.H.

    1990-01-01

    Regional cerebral blood flow (CBF) was measured with the 133xenon inhalation technique in 27 patients with schizophrenia of less than 5 years' duration and in 27 patients with schizophrenia of more than 12 years' duration, under resting conditions. Similar measurements were also performed in 54 normal control subjects matched for age and sex. Patients with schizophrenia of long duration had lower anteroposterior gradients of CBF than patients with schizophrenia of short duration and matched control subjects. Covarying out age and end-tidal levels of CO2 did not alter the results

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

    International Nuclear Information System (INIS)

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

    1989-01-01

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

  11. Single photon emission computed tomography imaging of cerebral blood flow, blood-brain barrier disruption, and apoptosis time course after focal cerebral ischemia in rats.

    Science.gov (United States)

    Garrigue, Philippe; Giacomino, Laura; Bucci, Chiara; Muzio, Valeria; Filannino, Maria A; Sabatier, Florence; Dignat-George, Françoise; Pisano, Pascale; Guillet, Benjamin

    2016-01-01

    Cerebral ischemia is a leading cause of disability worldwide and no other effective therapy has been validated to date than intravenous thrombolysis. In this context, many preclinical models have been developed and recent advances in preclinical imaging represent promising tools. Thus, we proposed here to characterize in vivo time profiles of cerebral blood flow, blood-brain barrier disruption and apoptosis following a transient middle cerebral artery occlusion in rats using SPECT/CT imaging. Rats underwent a 1-h middle cerebral artery occlusion followed by reperfusion. Cerebral blood flow, blood-brain barrier disruption and apoptosis were evaluated by SPECT/CT imaging using respectively (99m)Tc-HMPAO, (99m)Tc-DTPA and the experimental (99m)Tc-Annexin V-128, up to 14 days after middle cerebral artery occlusion. Histological evaluation of apoptosis has been performed using TUNEL method to validate the (99m)Tc-Annexin V-128 uptake. (99m)Tc-HMPAO cerebral blood flow evaluation showed hypoperfusion during occlusion, partially restored on days 4 and 7 and sustained up to 14 days after middle cerebral artery occlusion. (99m)Tc-DTPA SPECT/CT showed a blood-brain barrier disruption starting on day 1 post-middle cerebral artery occlusion, peaking on day 2, with barrier integrity totally restored on day 7. (99m)Tc-Annexin V-128 SPECT/CT imaging showed significant positive correlation with TUNEL immunohistochemistry and allowed ischemic-induced apoptosis to be detected from day 2 to day 7, peaking on day 3 after middle cerebral artery occlusion. Using SPECT/CT imaging, we showed that after transient middle cerebral artery occlusion in rat there was a sustained decrease in cerebral blood flow followed by blood-brain barrier disruption preceding meanwhile apoptosis. Rodent SPECT/CT imaging of cerebral blood flow, blood-brain barrier disruption and apoptosis appears to be an efficient tool for evaluating neuroprotective drugs and regenerative therapies against cerebral ischemia

  12. 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......-parieto-temporal CBF reduction is highly diagnostic for AD, despite the fact that a similar CBF pattern could also be observed in other types of dementia. Many AD patients with parieto-temporal flow reduction also have a diffuse flow reduction in the frontal cortical areas, particularly in advanced stages...

  13. Decreased cerebral blood flow in renal transplant recipients

    International Nuclear Information System (INIS)

    Kamano, Chisako; Komaba, Yuichi; Sakayori, Osamu; Iino, Yasuhiko; Katayama, Yasuo

    2002-01-01

    We performed single-photon emission computed tomography (SPECT) to investigate the influence of renal transplantation on cerebral blood flow (CBF). Fifteen renal transplant recipients and twelve normal subjects underwent cerebral SPECT with N-isopropyl-p-[ 123 I] iodoamphetamine ( 123 I-IMP). All transplant recipients received prednisolone and cyclosporine (CyA). Regional CBF (rCBF) was measured by defining regions of interest in the cerebral cortex, deep white matter, striatum, thalamus, and cerebellum. In transplant recipients, correlations to the mean overall cortical CBF were assessed using the interval from transplantation to measurement of SPECT, as well as the serum creatinine concentration. Moreover, to investigate the influence of CyA on CBF, the correlation between mean overall cortical CBF and CyA trough concentrations was assessed. In all regions, CBF in renal transplant recipients was significantly lower than in normal subjects. No significant correlation was seen between serum creatinine, interval from transplantation, or CyA trough concentrations and mean overall cortical CBF. Renal transplant recipients demonstrated a decrease in CBF, that can have an associated secondary pathology. Therefore, renal transplant recipients may benefit from post-operative MRI or CT. (author)

  14. In vivo cerebral blood flow autoregulation studies using rheoencephalography

    Science.gov (United States)

    Bodo, M.; Pearce, F.; Garcia, A.; Van Albert, S.; Settle, T.; Szebeni, J.; Baranyi, L.; Hartings, J.; Armonda, R.

    2010-04-01

    Acute management of patients with traumatic brain/blast injury is a challenge. To minimize secondary injury and improve outcome, it is critical to detect neurological deterioration early, when it is potentially reversible. One potential monitoring method is cerebral electrical impedance (rheoencephalography-REG) because of its non-invasiveness and good time resolution. Reported here are the results of cerebral blood flow (CBF) manipulations comparing electroencephalogram (EEG) with REG (both intra-cerebral) and measuring with surface and skull REG electrodes. Our hypothesis was that REG would reflect spreading depression and CBF autoregulation. Animal experiments were performed using one rat (four trials with intracerebral electrodes), monkeys (n=8, with surface electrodes) and pigs (n = 24 pigs with skull electrodes; 57 trials, 19 types of liposomes). Challenges included intracranial pressure (ICP) elevation, liposome infusion, and hemorrhage. Data were stored on a PC and evaluated off line. CBF autoregulation was evaluated both by visual inspection and by a Matlab script. These studies confirmed that REG reflects CBF autoregulation and that REG is useful for detecting spreading depression (SD), vasospasm and the lower limit of CBF autoregulation. These findings have clinical relevance for use in noninvasive neuro-monitoring in the neurosurgery intensive care and during transportation of patients with brain injury.

  15. 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

    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...... 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...

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

    International Nuclear Information System (INIS)

    Mraovitch, S.; Calando, Y.; Goadsby, P.J.; Seylaz, J.

    1992-01-01

    Changes in cerebral cortical perfusion (CBF 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 α-chloralose. CBF LDF was recorded with laser Doppler flowmetry, while lCBF and lCGU were measured by the quantitative autoradiographic ( 14 C)iodoantipyrine and ( 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

  17. 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.

  18. 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.

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

    Science.gov (United States)

    Bassani, Mariana Almada; Caldas, Jamil Pedro Siqueira; Netto, Abimael Aranha; Marba, Sérgio Tadeu Martins

    2016-06-01

    To assess the impact of respiratory therapy with the expiratory flow increase technique on cerebral hemodynamics of premature newborns. 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 5minutes. Cerebral blood flow velocity and resistance and pulsatility indices in the pericallosal artery were assessed. 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. The expiratory flow increase technique did not affect cerebral blood flow in clinically-stable preterm infants. Copyright © 2015 Sociedade de Pediatria de São Paulo. Publicado por Elsevier Editora Ltda. All rights reserved.

  20. 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.

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

    International Nuclear Information System (INIS)

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

    1985-01-01

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

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

    DEFF Research Database (Denmark)

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

    1978-01-01

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

  3. 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......In the course of our studies on cerebral blood flow in newborn infants, we have observed a striking depressing effect of sodium bicarbonate infusion on cerebral blood flow which in some cases may severely aggravate cerebral ischemia. We measured cerebral blood flow before and after the treatment...... to the bicarbonate infusion. In one case an extreme reduction occurred: cerebral blood flow was reduced to 3 ml/100 g/min, well below the level compatible with tissue survival. The results are discussed with regard to the optimal treatment of the acidotic newborn....

  4. Effects of smoking on regional cerebral blood flow in cerebral vascular disease patients and normal subjects

    International Nuclear Information System (INIS)

    Kubota, Kazuo; Yamaguchi, Tatsuo; Fujiwara, Takehiko; Matsuzawa, Taiju

    1987-01-01

    The chronic effect of smoking on the regional cerebral blood flow (r-CBF) was studied by 133-Xenon inhalation method and described with the Initial Slope Index (ISI). Fifty-two patients as the control group who had no abnormality neurologically or with CT scan, 32 patients with old cerebral infarction and 20 patients with old cerebral hemorrhage were introduced to the present study, and these patients were divided into smokers and non-smokers in each group. Those whose smoking index of 200 or more [(number of cigarettes/day) x (years of smoking history) ≥ 200] were designated as smokers. ISI values were decreased significantly in smokers than non-smokers in all groups. Mean ISI value of unaffected hemisphere in smokers decreased by 16 % in the infarction group and 22 % in the hemorrhage group comparing to the non-smokers', respectively. In the control group, mean ISI value of right hemisphere decreased by 15 % and left 14 % in smokers compared to the non-smokers. The r-CBF values in 44 of the 47 smokers were found to be lower than the expected age matched values in non-smokers. Serum high density lipoprotein cholesterol value in smokers was significantly lower than that in non-smokers. We demonstrated preliminarily that the smoking chronically reduced the r-CBF. Advanced atherosclerosis associated with the smoker was suggested to affect the CBF. (author)

  5. Impact of mydriatic eye drops on neonatal cerebral blood flow

    Directory of Open Access Journals (Sweden)

    Atef Alshafei

    2017-11-01

    Full Text Available Retinopathy of prematurity (ROP screening is a common routine procedure carried out on preterm infants in neonatal intensive care units (NICUs. Mydriatic eye drops containing phenylephrine hydrochloride 2.5% (a sympathomimetic agent and tropicamide 0.5% (a cycloplegic medication are readily absorbed from the conjunctiva and produce systemic responses in various organs. To our knowledge, no studies have investigated the direct effects of these medications on cerebral blood flow velocities (CBFVs in preterm infants. To evaluate the systemic effects of locally instilled mydriatic eye drops (phenylephrine hydrochloride 2.5% and tropicamide 0.5% used for ROP screening, on cerebral blood flow velocity in preterm infants, a prospective observational study was conducted among preterm infants with gestational age (GA < 31 weeks admitted to the NICU at Dubai Hospital between February 20, 2017 and June 20, 2017. The infants (at a post-menstrual age of 31-34 weeks underwent duplex ultrasound evaluation of CBFV before and after mydriatic eye drops administration.Pulsed-wave Doppler ultrasound studies were performed 1 h before and 1 h after eye mydriasis. We measured peak systolic velocity (PSV and end diastolic velocity (EDV for both the anterior cerebral artery (ACA and middle cerebral artery (MCA and calculated the resistive index (RI, defined as PSV – EDV/PSV. Mean arterial blood pressure (MAP, heart rate, oxygen saturation and pain score were assessed before and 1 h after ROP examination.A paired t-test and McNemar’s test were used to assess the statistical significance of the difference between pairs of means and the qualitative variables measured twice for the same study group.Among the 42 eligible preterm infants, the mean (SD GA was 27 (2.68 weeks (range, 24-31 weeks. The mean (SD RI of ACA before and 1 h after eye drops administration was 0.84 (0.06 and 0.83 (0.07 respectively (p = 0.453. The mean (SD RIs of MCA before and then 1 h after

  6. Tomographic cerebral blood flow measurement during carotid surgery

    DEFF Research Database (Denmark)

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

    1994-01-01

    surgery and performing single photon emission computer tomography (SPECT) scanning shortly after the operation thereby pictures rCBF at the time of injection. DESIGN: Ongoing prospective study. SETTINGS: Departments of Vascular Surgery, Neurology and Anaesthesiology, University Hospital, Rigshospitalet......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......, Copenhagen, Denmark. MATERIAL: 15 patients who during a period of 4 months underwent carotid endarterectomy. CHIEF OUTCOME MEASURES: Prior to surgery rCBF was determined using 133Xe and SPECT. Intraoperatively stump pressure was measured and a bolus of TcHMPAO was injected for later SPECT measurement. MAIN...

  7. 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

    2017-09-01

    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 (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.

  8. [Correlation between indices of 24-h monitoring of blood pressure and disturbed venous cerebral outflow in hypertensive patients].

    Science.gov (United States)

    Afanas'eva, N L; Mordovin, V F; Semke, G V; Luk'ianenok, P I

    2008-01-01

    To study relations between disturbances of cerebral venous circulation and parameters of 24-h blood pressure monitoring in hypertensive patients. A total of 72 patients aged 28 to 60 years with essential hypertension of stage II have undergone 24-h blood pressure monitoring and MR-venography of the brachiocephalic veins on a low-field MR-tomograph using 2D TOF angiography. Symptoms of disturbed cerebral venous circulation were found in 60% patients. Major venous collectors were asymmetric in 79.2% patients, 40.3% had marked asymmetry, 14% had severe asymmetry. Disturbances of venous outflow significantly more frequently occurred in non-dippers and night-peakers as well as in high variability of blood pressure. Patients with marked asymmetry of venous collectors had elevated nocturnal systolic and diastolic blood pressure, high load indices of nocturnal systolic and diastolic pressure, a low degree of nocturnal fall of blood pressure. Disturbance of venous cerebral outflow in hypertensive patients is closely related with alterations of a circadian profile of blood pressure: circadian index of blood pressure, variability of blood pressure.

  9. 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

    . Global cerebral blood flow at rest and during exercise on a bicycle ergometer was measured by the Kety-Schmidt technique. Cerebral metabolic rates of oxygen, glucose, and lactate were calculated by the Fick principle. Cerebral function was assessed by a computer-based measurement of reaction time...... and cerebral metabolic rates of oxygen and glucose also remained unchanged, whereas cerebral metabolic rates of lactate increased slightly but nonsignificantly at high altitude during exercise compared with high altitude at rest. Reaction time was unchanged. The data indicate that cerebral blood flow......The authors investigated the effect of acclimatization to high altitude on cerebral blood flow and oxidative metabolism at rest and during exercise. Nine healthy, native sea-level residents were studied 3 weeks after arrival at Chacaltaya, Bolivia (5,260 m) and after reacclimatization to sea level...

  10. 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

    Cilostazol, an inhibitor of phosphodiesterase (PDE) type 3, is used clinically in peripheral artery disease. PDE3 inhibitors may be clinically useful in the treatment of delayed cerebral vasospasm after subarachnoid hemorrhage. The authors present the first results on the effect of cilostazol...... on cerebral hemodynamics in normal participants. In this double-blind, randomized, crossover study, 200 mg cilostazol or placebo was administered orally to 12 healthy participants. Cerebral blood flow was measured using 133Xe inhalation and single photon emission computerized tomography. Mean flow velocity...... 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...

  11. 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...... cerebral artery blood flow velocity. Cerebral oxygenation and metabolism were evaluated from the arterial-to-venous differences for oxygen, glucose, and lactate. Blood pressure was comparable during exercise between the two groups. However, the partial pressure of arterial carbon dioxide was lower...

  12. Modelling of impaired cerebral blood flow due to gaseous emboli

    International Nuclear Information System (INIS)

    Hague, J P; Banahan, C; Chung, E M L

    2013-01-01

    Bubbles introduced to the arterial circulation during invasive medical procedures can have devastating consequences for brain function but their effects are currently difficult to quantify. Here we present a Monte Carlo simulation investigating the impact of gas bubbles on cerebral blood flow. For the first time, this model includes realistic adhesion forces, bubble deformation, fluid dynamical considerations, and bubble dissolution. This allows investigation of the effects of buoyancy, solubility, and blood pressure on embolus clearance. Our results illustrate that blockages depend on several factors, including the number and size distribution of incident emboli, dissolution time and blood pressure. We found it essential to model the deformation of bubbles to avoid overestimation of arterial obstruction. Incorporation of buoyancy effects within our model slightly reduced the overall level of obstruction but did not decrease embolus clearance times. We found that higher blood pressures generate lower levels of obstruction and improve embolus clearance. Finally, we demonstrate the effects of gas solubility and discuss potential clinical applications of the model. (paper)

  13. Heterogeneity of cerebral blood flow: a fractal approach

    International Nuclear Information System (INIS)

    Kuikka, J.T.; Hartikainen, P.

    2000-01-01

    Aim: We demonstrate the heterogeneity of regional cerebral blood flow using a fractal approach and single-photon emission computed tomography (SPECT). Method: Tc-99m-labelled ethylcysteine dimer was injected intravenously in 10 healthy controls and in 10 patients with dementia of frontal lobe type. The head was imaged with a gamma camera and transaxial, sagittal and coronal slices were reconstructed. Two hundred fifty-six symmetrical regions of interest (ROIs) were drawn onto each hemisphere of functioning brain matter. Fractal analysis was used to examine the spatial heterogeneity of blood flow as a function of the number of ROIs. Results: Relative dispersion (=coefficient of variation of the regional flows) was fractal-like in healthy subjects and could be characterized by a fractal dimension of 1.17±0.05 (mean±SD) for the left hemisphere and 1.15±0.04 for the right hemisphere, respectively. The fractal dimension of 1.0 reflects completely homogeneous blood flow and 1.5 indicates a random blood flow distribution. Patients with dementia of frontal lobe type had a significantly lower fractal dimension of 1.04±0.03 than in healthy controls. (orig.) [de

  14. 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

    2017-01-01

    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....... The proteomic profile of the isolated cerebral microvasculature 72 h after GCI (compared to sham) indicated that the main expressional changes could be divided into nine categories: (1) cellular respiration, (2) remodelling of the extracellular matrix, (3) decreased contractile phenotype, (4) clathrin...... categories. Flow cytometry confirmed key findings from the proteome such as upregulation of the extracellular proteins lamininβ2 and nidogen2 (p expressional changes in the cerebral microvasculature after GCI...

  15. Middle cerebral artery blood velocity depends on cardiac output during exercise with a large muscle mass

    NARCIS (Netherlands)

    Ide, K.; Pott, F.; van Lieshout, J. J.; Secher, N. H.

    1998-01-01

    We tested the hypothesis that pharmacological reduction of the increase in cardiac output during dynamic exercise with a large muscle mass would influence the cerebral blood velocity/perfusion. We studied the relationship between changes in cerebral blood velocity (transcranial Doppler), rectus

  16. Cerebral blood flow during anticipation of public speaking in social phobia: a PET study.

    Science.gov (United States)

    Tillfors, Maria; Furmark, Tomas; Marteinsdottir, Ina; Fredrikson, Mats

    2002-12-01

    The aim was to examine the neural correlates of anxiety elicited by the anticipation of public speaking in individuals with social phobia. Positron emission tomography and (15)O-water was used to measure regional cerebral blood flow in subjects with DSM-IV defined social phobia during anxiety anticipation. Heart rate and subjective anxiety were also recorded. While being scanned, subjects were speaking alone either before or after speaking in public. To evaluate anticipatory anxiety we compared individuals speaking alone before they were speaking in front of an audience with those who did the reverse. Heart rate and subjective anxiety measures confirmed anticipatory anxiety in social phobics who performed their private speech before their public. This was accompanied by enhanced cerebral blood flow in the right dorsolateral prefrontal cortex, left inferior temporal cortex, and in the left amygdaloid-hippocampal region. Brain blood flow was lower in the left temporal pole and bilaterally in the cerebellum in the anticipation group. Brain regions with altered perfusion presumably reflect changes in neural activity associated with worry about anticipated public performance. We speculate that anticipatory anxiety in social phobics originates in an affect sensitive fear network encompassing the amygdaloid-hippocampal region, prefrontal, and temporal areas.

  17. 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.

  18. Cerebral blood volume, blood flow, and oxygen metabolism in cerebral ischaemia and subarachnoid haemorrhage: An in-vivo study using positron emission tomography

    International Nuclear Information System (INIS)

    Martin, W.R.W.; Baker, R.P.; Grubb, R.L.; Raichle, M.E.

    1984-01-01

    A characteristic sequence of metabolic and haemodynamic changes has been shown to occur in the brain as cerebral perfusion pressure is reduced in experimental animals. Increased cerebral blood volume (CBV) occurs initially, followed by a fall in blood flow (CBF) and, finally, a fall in oxygen metabolism (CMRO 2 ). By measuring CBV, CBF, and CMRO 2 with positron emission tomography in patients with vasospasm associated with subarachnoid haemorrhage and in patients with arteriosclerotic occlusion or stenosis of extraparenchymal cerebral arteries, we have demonstrated the presence of similar changes distal to such lesions in man. These findings suggest the presence of a local decrease in perfusion pressure. This study demonstrates the utility of positron emission tomography in the assessment of cerebral circulation and metabolism in man. Measurements of regional CBV must be included for a complete assessment of the dynamics of the cerebral circulation. (Author)

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

    Energy Technology Data Exchange (ETDEWEB)

    Schroeck, H.K.; Kuschinsky, W. (Univ. of Bonn (Germany, F.R.))

    1989-10-01

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

  20. Cerebral blood flow in sickle cell cerebrovascular disease

    International Nuclear Information System (INIS)

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

    1984-01-01

    Cerebral blood flow (CBF) has been studied by the xenon-133 ( 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 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 133 Xe CBF method may be useful for following up children with sickle cell disease who are at high risk for recurrent stroke

  1. Heterogeneity of muscarinic receptor subtypes in cerebral blood vessels

    International Nuclear Information System (INIS)

    Garcia-Villalon, A.L.; Krause, D.N.; Ehlert, F.J.; Duckles, S.P.

    1991-01-01

    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

  2. Cerebral blood flow in normal and abnormal sleep and dreaming

    International Nuclear Information System (INIS)

    Meyer, J.S.; Ishikawa, Y.; Hata, T.; Karacan, I.

    1987-01-01

    Measurements of regional or local cerebral blood flow (CBF) by the xenon-133 inhalation method and stable xenon computerized tomography CBF (CTCBF) method were made during relaxed wakefulness and different stages of REM and non-REM sleep in normal age-matched volunteers, narcoleptics, and sleep apneics. In the awake state, CBF values were reduced in both narcoleptics and sleep apneics in the brainstem and cerebellar regions. During sleep onset, whether REM or stage I-II, CBF values were paradoxically increased in narcoleptics but decreased severely in sleep apneics, while in normal volunteers they became diffusely but more moderately decreased. In REM sleep and dreaming CBF values greatly increased, particularly in right temporo-parietal regions in subjects experiencing both visual and auditory dreaming

  3. Cerebral blood flow changes in Parkinson's disease associated with dementia

    International Nuclear Information System (INIS)

    Derejko, M.; Lass, P.; Slawek, J.; Nyka, W.M.

    2001-01-01

    Dementia is one of the main non-motor symptoms of Parkinson's disease (PD) and it is diagnosed in about 30% of cases. Its aetiology remains unclear and contributing factors are controversial. Dementia may be more common in old patients with severe motor symptoms and mild cognitive impairment. Clinico-pathological studies show the association between dementia in PD and the age-related group of dementias, such as AD and VaD. A valuable aid in the assessment of dementia in PD is cerebral blood flow (CBF) brain SPECT scanning. It shows three different patterns of rCBF reduction, including frontal lobe hypoperfusion, iu Alzheimer-likel type of hypoperfusion and multiple, vascular defects. The heterogeneity of rCBF reduction may reflect the multifactorial pathophysiology of dementia in PD. It may result from concomitant AD pathology, cerebrovascular disease, destruction of nigro-striato-frontal projection or may be a distinct disease of different aetiology. (author)

  4. Cerebral blood flow SPECT scanning in cortico-basal degeneration

    International Nuclear Information System (INIS)

    Slawek, J.; Walczak, A.; Krupa-Olchawa, J.; Lass, P.; Dubaniewicz, M.

    1999-01-01

    Idiopathic Parkinson's disease accounts for ca. 75% of all cases of Parkinsonism. Corticobasal degeneration is a relatively rare example of the so-called ''Parkinson-plus'' syndrome. The authors present the case of a 56-year-old woman with rigidity and atypical tremor of upper extremity followed by gait apraxia, dysarthria, bilateral pyramidal signs and myoclonus. There was no improvement after treatment with L-dopa. The disease has progressed, but the patient is still alive. On the basis of clinical data a diagnosis of corticobasal degeneration has been established. Cerebral blood flow SPECT scanning revealed diffuse hypoperfusion of left frontal lobe, antero-inferior part of the left temporal lobe and left basal ganglia. The case illustrates the usefulness of brain SPECT in atypical forma of Parkinson's disease. (author)

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

    Directory of Open Access Journals (Sweden)

    Ming Xiao

    2017-01-01

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

  6. Cerebral Blood Flow Responses to Aquatic Treadmill Exercise.

    Science.gov (United States)

    Parfitt, Rhodri; Hensman, Marianne Y; Lucas, Samuel J E

    2017-07-01

    Aquatic treadmills are used as a rehabilitation method for conditions such as spinal cord injury, osteoarthritis, and stroke, and can facilitate an earlier return to exercise training for athletes. However, their effect on cerebral blood flow (CBF) responses has not been examined. We tested the hypothesis that aquatic treadmill exercise would augment CBF and lower HR compared with land-based treadmill exercise. Eleven participants completed incremental exercise (crossover design) starting from walking pace (4 km·h, immersed to iliac crest [aquatic], 6 km·h [land]) and increasing 1 km·h every 2 min up to 10 km·h for aquatic (maximum belt speed) or 12 km·h for land. After this, participants completed two 2-min bouts of exercise immersed to midthigh and midchest at constant submaximal speed (aquatic), or were ramped to exhaustion (land; increased gradient 2° every min). Middle cerebral artery blood flow velocity (MCAv) and HR were measured throughout, and the initial 10 min of each protocol and responses at each immersion level were compared. Compared with land-based treadmill, MCAvmean increased more from baseline for aquatic exercise (21% vs 12%, P aquatic walking compared with land-based moderate intensity running (~10 cm·s, P = 0.56). Greater water immersion lowered HR (139 vs 178 bpm for midchest vs midthigh), whereas MCAvmean remained constant (P = 0.37). Findings illustrate the potential for aquatic treadmill exercise to enhance exercise-induced elevations in CBF and thus optimize shear stress-mediated adaptation of the cerebrovasculature.

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

    International Nuclear Information System (INIS)

    Matsuda, Hiroshi

    2001-01-01

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

  8. MRI of cerebral blood flow under hyperbaric conditions in rats.

    Science.gov (United States)

    Cardenas, Damon P; Muir, Eric R; Duong, Timothy Q

    2016-07-01

    Hyperbaric oxygen (HBO) therapy has a number of clinical applications. However, the effects of acute HBO on basal cerebral blood flow (CBF) and neurovascular coupling are not well understood. This study explored the use of arterial spin labeling MRI to evaluate changes in baseline and forepaw stimulus-evoked CBF responses in rats (n = 8) during normobaric air (NB), normobaric oxygen (NBO) (100% O2 ), 3 atm absolute (ATA) hyperbaric air (HB) and 3 ATA HBO conditions. T1 was also measured, and the effects of changes in T1 caused by increasing oxygen on the CBF calculation were investigated. The major findings were as follows: (i) increased inhaled oxygen concentrations led to a reduced respiration rate; (ii) increased dissolved paramagnetic oxygen had significant effects on blood and tissue T1 , which affected the CBF calculation using the arterial spin labeling method; (iii) the differences in blood T1 had a larger effect than the differences in tissue T1 on CBF calculation; (iv) if oxygen-induced changes in blood and tissue T1 were not taken into account, CBF was underestimated by 33% at 3 ATA HBO, 10% at NBO and 0.05) and all were higher than CBF under NB by ~40% (p masks oxygen-induced vasoconstriction, although blood gas was not measured; and (vi) substantial stimulus-evoked CBF increases were detected under HBO, similar to NB, supporting the notion that activation-induced CBF regulation in the brain does not operate through an oxygen-sensing mechanism. CBF MRI provides valuable insights into the effects of oxygen on basal CBF and neurovascular coupling under hyperbaric conditions. Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons, Ltd.

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

    International Nuclear Information System (INIS)

    Yokoyama, Eriko; Nagata, Ken; Uemura, Kazuo

    1997-01-01

    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)

  10. 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)

  11. Spaceflight on the Bion-M1 biosatellite alters cerebral artery vasomotor and mechanical properties in mice.

    Science.gov (United States)

    Sofronova, Svetlana I; Tarasova, Olga S; Gaynullina, Dina; Borzykh, Anna A; Behnke, Bradley J; Stabley, John N; McCullough, Danielle J; Maraj, Joshua J; Hanna, Mina; Muller-Delp, Judy M; Vinogradova, Olga L; Delp, Michael D

    2015-04-01

    Conditions during spaceflight, such as the loss of the head-to-foot gravity vector, are thought to potentially alter cerebral blood flow and vascular resistance. The purpose of the present study was to determine the effects of long-term spaceflight on the functional, mechanical, and structural properties of cerebral arteries. Male C57BL/6N mice were flown 30 days in a Bion-M1 biosatellite. Basilar arteries isolated from spaceflight (SF) (n = 6), habitat control (HC) (n = 6), and vivarium control (VC) (n = 16) mice were used for in vitro functional and mechanical testing and histological structural analysis. The results demonstrate that vasoconstriction elicited through a voltage-gated Ca(2+) mechanism (30-80 mM KCl) and thromboxane A2 receptors (10(-8) - 3 × 10(-5) M U46619) are lower in cerebral arteries from SF mice. Inhibition of Rho-kinase activity (1 μM Y27632) abolished group differences in U46619-evoked contractions. Endothelium-dependent vasodilation elicited by acetylcholine (10 μM, 2 μM U46619 preconstriction) was virtually absent in cerebral arteries from SF mice. The pressure-diameter relation was lower in arteries from SF mice relative to that in HC mice, which was not related to differences in the extracellular matrix protein elastin or collagen content or the elastin/collagen ratio in the basilar arteries. Diameter, medial wall thickness, and medial cross-sectional area of unpressurized basilar arteries were not different among groups. These results suggest that the microgravity-induced attenuation of both vasoconstrictor and vasodilator properties may limit the range of vascular control of cerebral perfusion or impair the distribution of brain blood flow during periods of stress. Copyright © 2015 the American Physiological Society.

  12. Associations between total cerebral blood flow and age related changes of the brain.

    Directory of Open Access Journals (Sweden)

    Adriaan C G M van Es

    Full Text Available BACKGROUND AND PURPOSE: Although total cerebral blood flow (tCBF is known to be related to age, less is known regarding the associations between tCBF and the morphologic changes of the brain accompanying cerebral aging. The purpose of this study was to investigate whether total cerebral blood flow (tCBF is related to white matter hyperintensity (WMH volume and/or cerebral atrophy. Furthermore, we investigate whether tCBF should be expressed in mL/min, as was done in all previous MR studies, or in mL/100 mL/min, which yielded good results in precious SPECT, PET and perfusion MRI studies investigating regional cerebral blood flow. MATERIALS AND METHODS: Patients were included from the nested MRI sub-study of the PROSPER study. Dual fast spin echo and FLAIR images were obtained in all patients. In addition, single slice phase contrast MR angiography was used for flow measurements in the internal carotids and vertebral arteries. tCBF was expressed in both mL/min and mL/100 mL/min. RESULTS: We found a significant correlation between tCBF in mL/min and both age (r = -.124; p = palterations due to various pathologies, tCBF should in mL/100 mL/min instead of mL/min. Furthermore, changes or differences in WMH volume should be accounted for.

  13. [Contingent negative variation and regional cerebral blood flow in senile dementia and cerebral aging].

    Science.gov (United States)

    Uytdenhoef, P; Depauw, Y; Van Wettere, J P; Godaux, E; Bernier, J; Jacquy, J

    1988-12-01

    Relationships between contingent negative variation (CNV) amplitude, regional cerebral blood flow (CBF), mini mental status examination score (MMSE) and reaction time (RT) have been studied in young subjects, non-demented old subjects and patients with primary degenerative senile dementia. Significant correlations have been found between CNV amplitude and global CBF, MMSE score and reaction time. Factorial analysis has shown 3 factors weighted respectively by MMSE and CNV, antero-posterior ratio fort left hemispheric CBF and age, and antero-posterior ratio for right hemispheric CBF and reaction time. Discriminant analysis has shown 2 discriminant functions differentiating young from old subjects with 90% accuracy and demented from non-demented patients with 75% accuracy.

  14. SPECT measurements of cerebral blood volume before and after acetazolamide in occlusive cerebrovascular diseases

    International Nuclear Information System (INIS)

    Inoue, Yusuke; Momose, Toshimitsu; Machida, Kikuo; Honda, Norinari; Nishikawa, Junichi; Sasaki, Yasuhito.

    1994-01-01

    Cerebral blood volume before and after acetazolamide was measured by SPECT to evaluate cerebral vasodilatory capacity in eight patients with cerebrovascular disease and five control subjects. Two SPECT measurements were performed serially, and acetazolamide was administered between them. The ratio of increase in hemispheric blood volume was calculated, and it was compared with the results of cerebral blood flow and cerebral blood volume measurements. A cerebral vasodilatory capacity map, the image after acetazolamide minus the baseline image, was also produced. Acetazolamide increased hemispheric blood volume in all subjects. The ratio of increase was lower in the involved hemispheres of the patients with unilateral carotid disease than in the uninvolved hemispheres of the patients and control subjects. The ratio of concordance with blood flow and blood volume measurements was approximated at 80%. Cerebral vasodilatory capacity mapping revealed three defects compatible with the clinical data. SPECT measurements of cerebral blood volume after acetazolamide can be performed following baseline SPECT with no additional radiotracer, and may be helpful to assess hemodynamic status. (author)

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

    DEFF Research Database (Denmark)

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

    2002-01-01

    The authors investigated the effect of acclimatization to high altitude on cerebral blood flow and oxidative metabolism at rest and during exercise. Nine healthy, native sea-level residents were studied 3 weeks after arrival at Chacaltaya, Bolivia (5,260 m) and after reacclimatization to sea level....... Global cerebral blood flow at rest and during exercise on a bicycle ergometer was measured by the Kety-Schmidt technique. Cerebral metabolic rates of oxygen, glucose, and lactate were calculated by the Fick principle. Cerebral function was assessed by a computer-based measurement of reaction time...

  16. The effect of sodium salicylate on cerebral blood flow and metabolism.

    OpenAIRE

    Pickard, J. D.; Rose, J. E.; Shaw, M. D.; Strathdee, A.

    1980-01-01

    1 The effect of intravenous sodium salicylate on cerebral oxygen consumption and cerebral blood flow and its response to hypercapnia was measured by the 133Xenon intracarotid injection technique in ten baboons. 2 After an initial peak, the plasma salicylate level maintained a stable value for 2 h of 1 mmol/l with 50 mg/kg sodium salicylate and 2.5 mmol/l with 200 mg/kg sodium salicylate. 3 Sodium salicylate (50 mg/kg) produced no change in baseline cerebral blood flow (CBF) or cerebral oxygen...

  17. Cerebral blood flow in migraine and cortical spreading depression

    International Nuclear Information System (INIS)

    Lauritzen, M.

    1987-01-01

    In a series of migraine patients, carotid arteriography was carried out as part of the clinical evaluation. 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 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 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 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 whether this phenomenon could explain the blood flow changes in migraine. ( 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 λ. (EG)

  18. Placental ischemia in pregnant rats impairs cerebral blood flow autoregulation and increases blood–brain barrier permeability

    Science.gov (United States)

    Warrington, Junie P.; Fan, Fan; Murphy, Sydney R.; Roman, Richard J.; Drummond, Heather A.; Granger, Joey P.; Ryan, Michael J.

    2014-01-01

    Abstract Cerebrovascular events contribute to ~40% of preeclampsia/eclampsia‐related deaths, and neurological symptoms are common among preeclamptic patients. We previously reported that placental ischemia, induced by reducing utero‐placental perfusion pressure, leads to impaired myogenic reactivity and cerebral edema in the pregnant rat. Whether the impaired myogenic reactivity is associated with altered cerebral blood flow (CBF) autoregulation and the edema is due to altered blood–brain barrier (BBB) permeability remains unclear. Therefore, we tested the hypothesis that placental ischemia leads to impaired CBF autoregulation and a disruption of the BBB. CBF autoregulation, measured in vivo by laser Doppler flowmetry, was significantly impaired in placental ischemic rats. Brain water content was increased in the anterior cerebrum of placental ischemic rats and BBB permeability, assayed using the Evans blue extravasation method, was increased in the anterior cerebrum. The expression of the tight junction proteins: claudin‐1 was increased in the posterior cerebrum, while zonula occludens‐1, and occludin, were not significantly altered in either the anterior or posterior cerebrum. These results are consistent with the hypothesis that placental ischemia mediates anterior cerebral edema through impaired CBF autoregulation and associated increased transmission of pressure to small vessels that increases BBB permeability leading to cerebral edema. PMID:25168877

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

    Science.gov (United States)

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

    2017-05-01

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

  20. A report of cerebral malaria treated with automated red blood cell exchange.

    Science.gov (United States)

    Anani, Waseem Q; Smith, Gerald P; Irani, Mehraboon; Puca, Kathleen E

    2017-04-01

    Adjunctive automated whole blood or red blood cell exchange (RBCEx) can rapidly decrease malarial hyperparasitemia. Several case reports and series suggest improvement in clinical symptomatology; however, recent Centers of Disease Control and Prevention (CDC) recommendations concluded that RBCEx has no efficacy as an adjunctive therapy. We present a case of mental status changes secondary to cerebral malaria treated with automated RBCEx resulting in rapid and dramatic neurologic improvement. An 84-year-old Somali woman presented with a 3-day history of altered mental status, spiking fevers, chills, bilateral leg pain and weakness, and intermittent diarrhea. Her travel history included a recent trip to Kenya for 1 month without antimalarial chemoprophylaxis. During the hospital stay, her health declined, and she became obtunded. Physical examination revealed fever, tachypnea, hypertension, hypoxia, and no response to verbal or physical stimuli. Her hemoglobin decreased from 12.6 to 6.5 g/dL with 12% intraerythrocytic parasitemia by thin smear. Intraerythrocytic trophozoites and banana-shaped gametocytes were present consistent with Plasmodium falciparum. An emergent 1.5-volume RBC mass automated RBCEx and quinidine infusion decreased her parasitemia to 2%. The patient's mental status improved throughout the procedure, and after the 2½-hour procedure, the patient was alert, oriented, and speaking coherently. The patient continued to receive quinidine and artesunate 1 day later from CDC. Automated RBCEx transfusion reduced the parasite burden and restored neurologic functioning in a patient with cerebral malaria while awaiting definitive treatment with artesunate. © 2017 AABB.

  1. Cerebral blood flow (CBF) with 133Xe inhalation method

    International Nuclear Information System (INIS)

    Kusunoki, Tadaki; Masumura, Michio; Tamaki, Norihiko; Matsumoto, Satoshi; Yamashita, Hideyuki.

    1982-01-01

    The effects of CO 2 inhalation on the cerebral blood flow (CBF) were examined with 133 Xe inhalation method (Novo Inhalation Cerebrograph) on 9 normal peoples and 20 patients. Nine normal peoples were divided into 3 groups consisting of each 3 peoples, namely young age group, middle age group, and old age group. Each increased CBF (%) by CO 2 inhalation was 40 -- 44 in young age group, 36 -- 37 in middle age group, and 35 -- 36 in old age group in the blood flow of the first compartment (F 1 ), and 27 -- 28 in young age group, 30 -- 31 in middle age group and 23 -- 24 in old age group in the initial slope index (ISI). Each CO 2 reactivity factor (RF) was 5.5 -- 5.8 in young age group, 3.8 -- 4.0 in middle age group and 3.3 in old age group in F 1 , and 3.1 -- 3.2 in young age group, 2.0 -- 3.3 in middle age group, and 1.2 -- 1.3 in old age group in ISI. Twenty patients consisted of 15 patients of occlusive cerebrovascular disease, 2 patients of head injury, 2 patients of normal pressure hydrocephalus and one patient of subarachnoid hemorrhage. RF was abnormally lower than normal value in 5 patients in F 1 , but in 7 in ISI. Clinical benefits of CBF study during CO 2 inhalation with 133 Xe inhalation method were discussed. (author)

  2. Imaging of Neuronal Activity in Awake Mice by Measurements of Flavoprotein Autofluorescence Corrected for Cerebral Blood Flow

    Directory of Open Access Journals (Sweden)

    Manami Takahashi

    2018-01-01

    Full Text Available Green fluorescence imaging (e.g., flavoprotein autofluorescence imaging, FAI can be used to measure neuronal activity and oxygen metabolism in living brains without expressing fluorescence proteins. It is useful for understanding the mechanism of various brain functions and their abnormalities in age-related brain diseases. However, hemoglobin in cerebral blood vessels absorbs green fluorescence, hampering accurate assessments of brain function in animal models with cerebral blood vessel dysfunctions and subsequent cerebral blood flow (CBF alterations. In the present study, we developed a new method to correct FAI signals for hemoglobin-dependent green fluorescence reductions by simultaneous measurements of green fluorescence and intrinsic optical signals. Intrinsic optical imaging enabled evaluations of light absorption and scatters by hemoglobin, which could then be applied to corrections of green fluorescence intensities. Using this method, enhanced flavoprotein autofluorescence by sensory stimuli was successfully detected in the brains of awake mice, despite increases of CBF, and hemoglobin interference. Moreover, flavoprotein autofluorescence could be properly quantified in a resting state and during sensory stimulation by a CO2 inhalation challenge, which modified vascular responses without overtly affecting neuronal activities. The flavoprotein autofluorescence signal data obtained here were in good agreement with the previous findings from a condition with drug-induced blockade of cerebral vasodilation, justifying the current assaying methodology. Application of this technology to studies on animal models of brain diseases with possible changes of CBF, including age-related neurological disorders, would provide better understanding of the mechanisms of neurovascular coupling in pathological circumstances.

  3. Exercise-induced oxidative-nitrosative stress is associated with impaired dynamic cerebral autoregulation and blood-brain barrier leakage.

    Science.gov (United States)

    Bailey, Damian M; Evans, Kevin A; McEneny, Jane; Young, Ian S; Hullin, David A; James, Philip E; Ogoh, Shigehiko; Ainslie, Philip N; Lucchesi, Céline; Rockenbauer, Antal; Culcasi, Marcel; Pietri, Sylvia

    2011-11-01

    The present study examined whether dynamic cerebral autoregulation and blood-brain barrier function would become compromised as a result of exercise-induced oxidative-nitrosative stress. Eight healthy men were examined at rest and after an incremental bout of semi-recumbent cycling exercise to exhaustion. Changes in a dynamic cerebral autoregulation index were determined during recovery from continuous recordings of blood flow velocity in the middle cerebral artery (MCAv) and mean arterial pressure during transiently induced hypotension. Electron paramagnetic resonance spectroscopy and ozone-based chemiluminescence were employed for direct detection of spin-trapped free radicals and nitric oxide metabolites in venous blood. Neuron-specific enolase, S100β and 3-nitrotyrosine were determined by ELISA. While exercise did not alter MCAv, it caused a mild reduction in the autoregulation index (from 6.9 ± 0.6 to 5.5 ± 0.9 a.u., P brain barrier permeability without causing structural brain damage subsequent to a free radical-mediated impairment in dynamic cerebral autoregulation.

  4. Type of aphasia and regional cerebral blood flow

    International Nuclear Information System (INIS)

    Tagawa, Koichi; Sugimoto, Keiko; Minematsu, Kazuo; Yamaguchi, Takenori; Naritomi, Hiroaki; Sawada, Tohru

    1982-01-01

    In 40 patients with aphasia due to cerebral infarction, regional cerebral blood flow (rCBF) was measured after 2 months of ictus with 133 Xe inhalation method. There were 18 cases with motor aphasia and 22 with sensory aphasia. On the measurements of rCBF, 3 detectors were placed over frontal region (group F), 3 over temporal region (group T), and remaining 3 over parietal region (group P), of the dominant hemisphere. The flow values were compared with the rCBF values obtained from 21 control subjects who had no abnormality in CT scan and on neurological examinations. The control subjects revealed the hyperfrontal pattern of flow distribution; rCBF values in groups F, T and P, which were expressed as an initial slope index, were 50.0 +- 4.8, 48.0 +- 5.1 and 47.4 +- 4.5, respectively. The hyperfrontal pattern was absent in cases with motor aphasia. In this group, rCBF in groups F, T and P were 42.0 +- 8.3, 44.7 +- 8.4 and 41.0 +- 8.5, respectively, and rCBF in frontal region was significantly reduced compared with that in the control group. In sensory aphasia, rCBF values in groups F, T and P were all significantly reduced compared to the controls showing 44.0 +- 5.7, 42.8 +- 5.1 and 40.6 +- 5.4, respectively. In this group, the hyperfrontal pattern was maintained at a low flow level. When absolute rCBF values were compared between motor and sensory aphasia, there was no significant difference between these 2 groups. However, regional flow distribution in motor aphasia was significantly different from that of sensory aphasia, and the cases having the lowest value in group F were more frequently found in the former than in the latter. (J.P.N.)

  5. Regional cerebral blood flow and P300 in neurosurgical disorders

    Energy Technology Data Exchange (ETDEWEB)

    Funahashi, Kazuyoshi; Hyoutani, Genhachi; Maeshima, Shinichirou; Miyamoto, Kazuki; Kuwata, Toshikazu; Terada, Tomoaki; Komai, Norihiko (Wakayama Medical Coll. (Japan))

    1990-08-01

    Changes in regional cerebral blood flow (rCBF), P300 and higher brain function were studied in neurosurgical patients with localized lesions on computed tomography (CT). Twenty-five patients ranging in age from 30 to 81 were studied. Nineteen of these suffered from cerebrovascular disease and six had tumors. Using the oddball paradigm, P300 components were elicited by rate tones (2 KHz) and recorded at Cz and Pz referred to linked ear-lobe electorodes. The P300 latencies of the patients were statistically compared with those of 27 normal subjects. Higher brain function was evaluated with the following psychological tests: a rating scale for psychological function (Sano and Tanemura), Mini-Mental State (MMS), Hasegawa's Dementia Scale (HDS) and the 'Kanahiroi' test. Regional CBF was measured in the bilateral cerebral cortices (the frontal, temporal and occipital lobes), thalamus and basal ganglia by means of a cold xenon CT method. The laterality indices of rCBF (Rt. rCBF/Lt. rCBF) in the bilateral symmetrical areas of the patients were compared to those of 8 normal subjects. Of the 25 patients, 12 revealed prolongation of P300 latency. Ten (86%) of the 12 with prolonged P300 latency showed reduction of rCBF in the right cerebral hemisphere (rt. frontal lobe, rt. thalamus and rt. basal ganglia). Significant correlations (P<0.025) were recognized between the P300 latencies and the laterality indices of rCBF in the frontal lobe and thalamus. There was a significant correlation (P<0.05) between the scores of MMS and HDS and the laterality indicies of rCBF in the frontal lobe only. In the 13 patients with normal P300 latency, 6 (46%) displayed no reduction in rCBF. The remaining 7 patients with normal P300 showed reduction of rCBF in the left hemisphere. Both right frontal lobe and right thalamus have an important role affecting the prolongation of P300 latency and disturbance of cognitive functions. (author).

  6. Regional cerebral blood flow and P300 in neurosurgical disorders

    International Nuclear Information System (INIS)

    Funahashi, Kazuyoshi; Hyoutani, Genhachi; Maeshima, Shinichirou; Miyamoto, Kazuki; Kuwata, Toshikazu; Terada, Tomoaki; Komai, Norihiko

    1990-01-01

    Changes in regional cerebral blood flow (rCBF), P300 and higher brain function were studied in neurosurgical patients with localized lesions on computed tomography (CT). Twenty-five patients ranging in age from 30 to 81 were studied. Nineteen of these suffered from cerebrovascular disease and six had tumors. Using the oddball paradigm, P300 components were elicited by rate tones (2 KHz) and recorded at Cz and Pz referred to linked ear-lobe electorodes. The P300 latencies of the patients were statistically compared with those of 27 normal subjects. Higher brain function was evaluated with the following psychological tests: a rating scale for psychological function (Sano and Tanemura), Mini-Mental State (MMS), Hasegawa's Dementia Scale (HDS) and the 'Kanahiroi' test. Regional CBF was measured in the bilateral cerebral cortices (the frontal, temporal and occipital lobes), thalamus and basal ganglia by means of a cold xenon CT method. The laterality indices of rCBF (Rt. rCBF/Lt. rCBF) in the bilateral symmetrical areas of the patients were compared to those of 8 normal subjects. Of the 25 patients, 12 revealed prolongation of P300 latency. Ten (86%) of the 12 with prolonged P300 latency showed reduction of rCBF in the right cerebral hemisphere (rt. frontal lobe, rt. thalamus and rt. basal ganglia). Significant correlations (P<0.025) were recognized between the P300 latencies and the laterality indices of rCBF in the frontal lobe and thalamus. There was a significant correlation (P<0.05) between the scores of MMS and HDS and the laterality indicies of rCBF in the frontal lobe only. In the 13 patients with normal P300 latency, 6 (46%) displayed no reduction in rCBF. The remaining 7 patients with normal P300 showed reduction of rCBF in the left hemisphere. Both right frontal lobe and right thalamus have an important role affecting the prolongation of P300 latency and disturbance of cognitive functions. (author)

  7. Cerebral Blood Flow and Glucose Metabolism in Appetite-Related Brain Regions in Type 1 Diabetic Patients After Treatment With Insulin Detemir and NPH Insulin A randomized controlled crossover trial

    NARCIS (Netherlands)

    van Golen, L.W.; IJzerman, R.G.; Huisman, M.C.; Hensbergen, J.F.; Hoogma, R.P.; Drent, M.L.; Lammertsma, A.A.; Diamant, M.

    2013-01-01

    Objective-To test the hypothesis that insulin detemir, which is associated with less weight gain than other basal insulin formulations, exerts its weight-modulating effects by acting on brain regions involved in appetite regulation, as represented by altered cerebral blood flow (CBF) or cerebral

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

    DEFF Research Database (Denmark)

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

    1991-01-01

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

  9. 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

    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...... to standing. The mathematical model uses a compartmental approach to describe pulsatile blood flow and pressure in a number of compartments representing the systemic circulation. Our model includes compartments representing the trunk and upper extremities, the lower extremities, the brain, the atria......, 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...

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

    International Nuclear Information System (INIS)

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

    1989-01-01

    To investigate the relationship between anxiety and regional cerebral blood flow, we administered behavioral challenges to 10 patients with obsessive-compulsive disorder while measuring regional cerebral blood flow with the xenon 133 inhalation technique. Each patient was studied under three conditions: relaxation, imaginal flooding, and in vivo (actual) exposure to the phobic stimulus. Subjective anxiety, obsessive-compulsive ratings, and autonomic measures (heart rate, blood pressure) increased significantly, but respiratory rate and PCO 2 did not change across the three conditions. Regional cerebral blood flow increased slightly (in the temporal region) during imaginal flooding, but decreased markedly in several cortical regions during in vivo exposure, when anxiety was highest by subjective and peripheral autonomic measures. These results demonstrate that intense anxiety can be associated with decreased rather than increased cortical perfusion and that ostensibly related states of anxiety (eg, anticipatory and obsessional anxiety) may be associated with opposite effects on regional cerebral blood flow

  11. 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.

  12. 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-linearities......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...... 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...

  13. Hemodilution, cerebral O2 delivery, and cerebral blood flow: a study using hyperbaric oxygenation.

    Science.gov (United States)

    Tomiyama, Y; Jansen, K; Brian, J E; Todd, M M

    1999-04-01

    Hemodilution reduces blood viscosity and O2 content (CaO2) and increases cerebral blood flow (CBF). Viscosity and CaO2 may contribute to increasing CBF after hemodilution. However, because hematocrit is the major contributor to blood viscosity and CaO2, it has been difficult to assess their relative importance. By varying blood viscosity without changing CaO2, prior investigation in hemodiluted animals has suggested that both factors play roughly equal roles. To further investigate the relationship of hemodilution, blood viscosity, CaO2, and CBF, we took the opposite approach in hemodiluted animals, i.e., we varied CaO2 without changing blood viscosity. Hyperbaric O2 was used to restore CaO2 to normal after hemodilution. Pentobarbital sodium-anesthetized rats underwent isovolumic hemodilution with 6% hetastarch, and forebrain CBF was measured with [3H]nicotine. One group of animals did not undergo hemodilution and served as controls (Con). In the three experimental groups, hematocrit was reduced from 44% to 17-19%. Con and hemodiluted (HDil) groups were ventilated with 40% O2 at 101 kPa (1 atmosphere absolute), which resulted in CaO2 values of 19.7 +/- 1.3 and 8.1 +/- 0.7 (SD) ml O2/dl, respectively. A second group of hemodiluted animals (HBar) was ventilated with 100% O2 at 506 kPa (5 atmospheres absolute) in a hyperbaric chamber, which restored CaO2 to an estimated 18.5 +/- 0.5 ml O2/dl by increasing dissolved O2. A fourth group of hemodiluted animals (HCon) served as hyperbaric controls and were ventilated with 10% O2 at 506 kPa, resulting in CaO2 of 9.1 +/- 0.6 ml O2/dl. CBF was 79 +/- 19 ml. 100 g-1. min-1 in the Con group and significantly increased to 123 +/- 9 ml. 100 g-1. min-1 in the HDil group. When CaO2 was restored to baseline with dissolved O2 in the HBar group, CBF decreased to 104 +/- 20 ml. 100 g-1. min-1. When normoxia was maintained during hyperbaric exposure in the HCon group, CBF was 125 +/- 18 ml. 100 g-1. min-1, a value indistinguishable from

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

    International Nuclear Information System (INIS)

    Kinoshita, Hirofumi

    1987-01-01

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

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

    International Nuclear Information System (INIS)

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

    1984-01-01

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

  16. Changes in Cerebral Blood Flow in Presymptomatic Mutation Carriers of Familial Frontotemporal Dementia (FTD-3), Measured with MRI

    DEFF Research Database (Denmark)

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

    in the presymptomatic stage of the disease as indicated by local changes in cerebral blood flow (CBF). Methods: Presymptomatic mutation carriers and first-degree related non-carriers were MRI-scanned with a spin-echo sequence sensitive mainly to CBF in capillaries. CBF images were co-registered to structural T1-images...... decreased mean CBF values at the capillary level in all ROIs, with significant changes in capillary CBF in the parietal (mean change 14 %; p = 0.03) and occipital (mean change 9 %; p = 0.02) lobes. Conclusions: Decreased cerebral blood flow can be measured in presymptomatic CHMP2B mutation carriers...... with statistically significant differences in the occipital- and parietal lobes. Alterations in CBF possibly affect the whole brain. Data indicate that FTD-3 pathology might involve brain capillaries. This may impact the understanding of the pathogenesis involving endosomal dysfunction and implicates involvement...

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

    International Nuclear Information System (INIS)

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

    1989-01-01

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

  18. Cerebral blood flow effects of yoga training: preliminary evaluation of 4 cases.

    Science.gov (United States)

    Cohen, Debbie L; Wintering, Nancy; Tolles, Victoria; Townsend, Raymond R; Farrar, John T; Galantino, Mary Lou; Newberg, Andrew B

    2009-01-01

    Experienced practitioners of yoga have been shown to alter brain function, but this case series measured cerebral blood flow before and after a 12-week training program in Iyengar yoga (IY) for naïve subjects. On the first day, each of the 4 subjects listened to the teacher speaking on the history and background of the yoga program while they were injected with 250 MBq of (99m)Tc-bicisate and received a single photon emission computed tomography scan (pre-program baseline). Subjects then had their first IY training and were injected and scanned with 925 MBq bicisate while they did their first meditation (pre-program meditation). Subjects then underwent a 12-week training program in IY and then underwent the same imaging protocol with a postprogram baseline and postprogram meditation scan. Baseline and meditation scans, before and after training, were compared using paired t tests. There were significant decreases (p IY training.

  19. 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

  20. The effect of phenylephrine on arterial and venous cerebral blood flow in healthy subjects

    DEFF Research Database (Denmark)

    Ogoh, Shigehiko; Sato, Kohei; Fisher, James P

    2011-01-01

    Sympathetic regulation of the cerebral circulation remains controversial. Although intravenous phenylephrine (PE) infusion reduces the near-infrared spectroscopy (NIRS)-determined measure of frontal lobe oxygenation (S(c) O(2) ) and increases middle cerebral artery mean blood velocity (MCA V...

  1. 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 CB...

  2. Association of Automatically Quantified Total Blood Volume after Aneurysmal Subarachnoid Hemorrhage with Delayed Cerebral Ischemia

    NARCIS (Netherlands)

    Zijlstra, I. A.; Gathier, C. S.; Boers, A. M.; Marquering, H. A.; Slooter, A. J.; Velthuis, B. K.; Coert, B. A.; Verbaan, D.; van den Berg, R.; Rinkel, G. J.; Majoie, C. B.

    2016-01-01

    The total amount of extravasated blood after aneurysmal subarachnoid hemorrhage, assessed with semiquantitative methods such as the modified Fisher and Hijdra scales, is known to be a predictor of delayed cerebral ischemia. However, prediction rates of delayed cerebral ischemia are moderate, which

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

    International Nuclear Information System (INIS)

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

    1987-01-01

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

  4. Cerebral Oedema, Blood-Brain Barrier Breakdown and the Decrease in Na(+),K(+)-ATPase Activity in the Cerebral Cortex and Hippocampus are Prevented by Dexamethasone in an Animal Model of Maple Syrup Urine Disease.

    Science.gov (United States)

    Rosa, Luciana; Galant, Leticia S; Dall'Igna, Dhébora M; Kolling, Janaina; Siebert, Cassiana; Schuck, Patrícia F; Ferreira, Gustavo C; Wyse, Angela T S; Dal-Pizzol, Felipe; Scaini, Giselli; Streck, Emilio L

    2016-08-01

    Maple syrup urine disease (MSUD) is a rare metabolic disorder associated with acute and chronic brain dysfunction. This condition has been shown to lead to macroscopic cerebral alterations that are visible on imaging studies. Cerebral oedema is widely considered to be detrimental for MSUD patients; however, the mechanisms involved are still poorly understood. Therefore, we investigated whether acute administration of branched-chain amino acids (BCAA) causes cerebral oedema, modifies the Na(+),K(+)-ATPase activity, affects the permeability of the blood-brain barrier (BBB) and alters the levels of cytokines in the hippocampus and cerebral cortex of 10-day-old rats. Additionally, we investigated the influence of concomitant administration of dexamethasone on the alterations caused by BCAA. Our results showed that the animals submitted to the model of MSUD exhibited an increase in the brain water content, both in the cerebral cortex and in the hippocampus. By investigating the mechanism of cerebral oedema, we discovered an association between H-BCAA and the Na(+),K(+)-ATPase activity and the permeability of the BBB to small molecules. Moreover, the H-BCAA administration increases Il-1β, IL-6 and TNF-α levels in the hippocampus and cerebral cortex, whereas IL-10 levels were decreased in the hippocampus. Interestingly, we showed that the administration of dexamethasone successfully reduced cerebral oedema, preventing the inhibition of Na(+),K(+)-ATPase activity, BBB breakdown and the increase in the cytokines levels. In conclusion, these findings suggest that dexamethasone can improve the acute cerebral oedema and brain injury associated with high levels of BCAA, either through a direct effect on brain capillary Na(+),K(+)-ATPase or through a generalized effect on the permeability of the BBB to all compounds.

  5. Effects of bee venom acupuncture on heart rate variability, pulse wave, and cerebral blood flow for types of Sasang Constitution

    Directory of Open Access Journals (Sweden)

    Lee Sang-min

    2009-03-01

    Full Text Available 1. Objectives: To evaluate effects of bee venom acupuncture on cardiovascular system and differences according to each constitution. 2. Methods: Heart rate variability, pulse wave and the velocity of cerebral blood flow were measured before bee venom acupuncture(BVA, right after and after 30 minuets, had been applied to 20 subjects. 3. Results: 1. BVA did not have effects on measurement variables of heart rate variability. 2. BVA had effects on pulse wave, showing total time, radial augmentation index up and height of percussion wave, time to percussion wave, sum of pulse pressure down. 3. BVA did not have effects on the cerebral blood flow velocity when considering not Sasang Constitution 4. Considering Sasang Constitution, BVA demonstrates different responses in time to preincisura wave, mean blood flow velocity, peak systolic velocity and end diastolic velocity. 4.Conclusion: From those results, the following conclusions are obtained. Cause BVA alters pulse wave and makes differences in the cerebral blood flow velocity according to Sasang Constitution. Various methods of BVA treatment are needed considering Sasang Constitution.

  6. 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...

  7. 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.

    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

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

    Indian Academy of Sciences (India)

    Newtonian fluid. Abstract. 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 ...

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

    International Nuclear Information System (INIS)

    Lindner, P.; Nickel, O.

    1985-01-01

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

  10. 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...

  11. Alterations in autonomic function and cerebral hemodynamics to orthostatic challenge following a mountain marathon.

    Science.gov (United States)

    Murrell, Carissa; Wilson, Luke; Cotter, James D; Lucas, Samuel; Ogoh, Shigehiko; George, Keith; Ainslie, Philip N

    2007-07-01

    We examined potential mechanisms (autonomic function, hypotension, and cerebral hypoperfusion) responsible for orthostatic intolerance following prolonged exercise. Autonomic function and cerebral hemodynamics were monitored in seven athletes pre-, post- (marathon [42.2 km; cumulative gain approximately 1,000 m; approximately 15 degrees C; completion time, 261 +/- 27 (SD) min]. In each condition, middle cerebral artery blood velocity (MCAv), blood pressure (BP), heart rate (HR), and cardiac output (Modelflow) were measured continuously before and during a 6-min stand. Measurements of HR and BP variability and time-domain analysis were used as an index of sympathovagal balance and baroreflex sensitivity (BRS). Cerebral autoregulation was assessed using transfer-function gain and phase shift in BP and MCAv. Hypotension was evident following the marathon during supine rest and on standing despite increased sympathetic and reduced parasympathetic control, and elevations in HR and cardiac output. On standing, following the marathon, there was less elevation in normalized low-frequency HR variability (P marathon. These findings indicate that following prolonged exercise, hypotension and postural reductions in autonomic function or baroreflex control, or both, rather than a compromise in cerebral autoregulation, may place the brain at risk of hypoperfusion. Such changes may be critical factors in collapse following prolonged exercise.

  12. Correlation of severity of aphasia with cerebral blood flow

    International Nuclear Information System (INIS)

    Tagawa, Koichi; Sugimoto, Keiko; Sone, Noriaki; Yamaguchi, Takenori; Naritomi, Hiroaki; Sawada, Tohru

    1982-01-01

    In 46 patients with aphasia due to cerebral infarction, regional cerebral blood flow (rCBF) was measured by 133 Xe inhalation method, and relationship between severity of aphasia and degree of rCBF reduction was investigated. Measurements of rCBF were performed after 2 months of ictus in all patients. At the time of rCBF measurements, the severity of aphasia was mild in 13, moderate in 16 and severe in the other 17 patients. Control rCBF values were obtained from 16 subjects who had neither neurological deficits nor abnormal findings on CT scan. In control group, mean hemispheric rCBF values (mCBF), which were calculated from initial slope index, were 49.1 +- 3.8 and 49.4 +- 3.9 respectively in the right and left hemisphere. In all aphasic patients but two who had mild aphasia, mCBF in the left hemisphere showed lower values as compared to that in the right hemisphere. The mCBF in the left hemisphere was 46.5 +- 5.3 in the mild group, 41.3 +- 5.8 in the moderate group and 34.3 +- 5.0 in the severe group. The values in the moderate and severe groups were significantly reduced as compared to the control or those in the mild group. The mCBF in the severe group was also significantly lower than those in the moderate group. The mCBF in the right hemisphere was 48.4 +- 6.3 in the mild group, 45.6 +- 6.1 in the moderate group and 38.6 +- 4.9 in the severe group. The values in the severe group were significantly reduced as compared to those in the other groups as well as the control. The present study suggests that measurements of rCBF by 133 Xe inhalation method are valid for the evaluation of severity of aphasia in stroke patients. (author)

  13. 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.

  14. Cerebral blood flow during delirium tremens and related clinical states studied with xenon-133 inhalation tomography

    International Nuclear Information System (INIS)

    Hemmingsen, R.; Vorstrup, S.; Clemmesen, L.; Holm, S.; Tfelt-Hansen, P.; Sorensen, A.S.; Hansen, C.; Sommer, W.; Bolwig, T.G.

    1988-01-01

    The regional cerebral blood flow of 12 patients with severe alcohol withdrawal reactions (delirium tremens or impending delirium tremens) was measured during the acute state before treatment and after recovery. Greater cerebral blood flow was significantly correlated with visual hallucinations and agitation during the acute withdrawal reaction. The results suggest that delirium tremens and related clinical states represent a type of acute brain syndrome mainly characterized by CNS hyperexcitability

  15. 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, hypertension 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.

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

    International Nuclear Information System (INIS)

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

    1984-01-01

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

  17. Significance of preoperative cerebral blood flow measurements in endovascular occlusion of the internal carotid and middle cerebral arteries

    International Nuclear Information System (INIS)

    Laurent, A.; Weitzner, I.; Luft, A.; Merland, J.J.

    1988-01-01

    Cerebral blood flow (CBF) measurements during 12 endovascular balloon occlusions (ten internal carotid and two middle cerebral arteries) with good clinical and angiographic tolerance were done with repeated boluses of Xe-133 injected directly into the ipsi- and contralateral carotid systems, during the occlusion and repeated measurements with detectors on both sides (before occlusion and 5-30 minutes after occlusion). In two cases of unchanged and four of increased CBF, one reversible deficit was probably due to an embolus. In six cases of decreased CBF, two deficits occurred, characterized by a greater than 25% decrease. It seems to represent a good predictive value for intolerance to occlusion

  18. Time-related changes in cerebral blood flow in subarachnoid hemorrhage due to ruptured cerebral aneurysm

    Energy Technology Data Exchange (ETDEWEB)

    Fukuda, Tadaharu; Hasue, Masamichi; Ko, Meishyu; Hasegawa, Kouichi; Nakamura, Tatsuya (Tokyo Medical Coll. (Japan). Hachiouji Medical Center); Miwa, Tetsurou

    1992-04-01

    Cerebral blood flow (CBF) was determined by the {sup 123}I-IMP SPECT reference sample method in 39 patients with subarachnoid hemorrahge (SAH) due to ruptured cerebral aneurysm, who were referred to a medical center within 36 hours after the onset. SAH and ruptured aneurysm were diagnosed by CT scan and angiography, respectively. By regarding the day of onset as day 0, SAH was divided into three stages: the acute stage during day 0-4, the subacute stage during day 5-20, and the chronic stage during day 21 or more. The prognosis was evaluated with the Glasgow outcome scale (GOS). Average CBFs were 33.39, 29.44, and 33.15 in the acute, subacute, and chronic stages, respectively. The values were all lower than the reference sample value, 43.39. Only a small number of cases, however, had vasospasm on angiography conducted in the acute stage. There was correlation between CT severity in the acute stage and decreased CBF. When low denisty area was seen on CT in the subacute stage, average CBFs were 28.28 and 23.95 in the acute and subacute stages, respectively, in contrast to 35.97 and 32.45 without evidence of low density in the subacute stage. CBF decreased by 0.79 in a group of cisternal drainage from the acute stage to the subacute stage, being smaller than the value (7.15) in a group without drainage. When ventricular-peritoneal shunt was conducted for hydrocepharus in the chronic stage, CBF was increased after surgery. CBF associated with an improvement of the GOS was higher in both the acute and the subacute stages than in severely disabled or death cases. Prognosis was better in a group with acute CBF of 30 or more than a group of less than 30. Serial determination of CBF in SAH was useful for evaluating the condition of SAH, selecting therapeutic methods, and estimating the prognosis. (N.K.).

  19. 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.

  20. 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...

  1. Cerebral blood flow changes during sodium-lactate-induced panic attacks

    International Nuclear Information System (INIS)

    Stewart, R.S.; Devous, M.D. Sr.; Rush, A.J.; Lane, L.; Bonte, F.J.

    1988-01-01

    Dynamic single-photon emission computed axial tomography (CAT) with inhaled xenon-133 was used to measure regional cerebral blood flow in 10 drug-free patients with DSM-III-diagnosed panic disorder and in five normal control subjects. All subjects underwent regional cerebral blood flow studies while at rest or during normal saline infusion and during sodium lactate infusion. Six of the 10 patients and none of the control subjects experienced lactate-induced panic attacks. Lactate infusion markedly raised hemispheric blood flow levels in both control subjects and patients who did not panic. Patients who did panic experienced either a minimal increase or a decrease in hemispheric blood flow

  2. Noninvasive 133Xe inhalation method for cerebral blood flow measurement

    International Nuclear Information System (INIS)

    Takagi, Shigeharu; Kobatake, Keitaro; Shinohara, Yukito

    1991-01-01

    Recent development of the 133 Xe inhalation technique has made it possible to measure cerebral blood flow (CBF) noninvasively. Recording of the head curves from the frontal and temporal areas during inhalation of 133 Xe, however, is contaminated by the artifact from the air passages. A method based on Fourier transforms was reported to be able to eliminate air passage artifact (APA) effectively. However, it was pointed out that such an algorithm does not give a complete correction if the artifact seen by the head detectors differs in shape from that recorded from the airways at the mouth, which may happen when there is a slow isotope convection in the nasal and sinus cavities. The purpose of this study was to compare the CBF values calculated by the Fourier method with those by the conventional method of Obrist (VM method). Mean hemispheric gray matter flow (F 1 ) calculated by the VM method in 11 subjects, including normal volunteers and patients with various neurological diseases, was 69.2±13.2 mg/100 g brain/ min, whereas F 1 calculated by the Fourier method in the same subjects was 64.4±13.5, indicating that APA can be effectively eliminated by the Fourier method. The F 1 values calculated by the Fourier method from the frontal and temporal regions were relatively high, and closer to the F 1 values calculated by the VM method. The size of the APA was large in these regions. It was concluded that the deformed APA contaminated the results in these regions, and could not be eliminated effectively by the Fourier method. It is suggested that the shape of the head curve and the size of APA should be carefully examined to ensure that CBF data are reliable. (author)

  3. BOLD-specific cerebral blood volume and blood flow changes during neuronal activation in humans.

    Science.gov (United States)

    Chen, J Jean; Pike, G Bruce

    2009-12-01

    To understand and predict the blood-oxygenation level-dependent (BOLD) fMRI signal, an accurate knowledge of the relationship between cerebral blood flow (DeltaCBF) and volume (DeltaCBV) changes is critical. Currently, this relationship is widely assumed to be characterized by Grubb's power-law, derived from primate data, where the power coefficient (alpha) was found to be 0.38. The validity of this general formulation has been examined previously, and an alpha of 0.38 has been frequently cited when calculating the cerebral oxygen metabolism change (DeltaCMRo(2)) using calibrated BOLD. However, the direct use of this relationship has been the subject of some debate, since it is well established that the BOLD signal is primarily modulated by changes in 'venous' CBV (DeltaCBV(v), comprising deoxygenated blood in the capillary, venular, and to a lesser extent, in the arteriolar compartments) instead of total CBV, and yet DeltaCBV(v) measurements in humans have been extremely scarce. In this work, we demonstrate reproducible DeltaCBV(v) measurements at 3 T using venous refocusing for the volume estimation (VERVE) technique, and report on steady-state DeltaCBV(v) and DeltaCBF measurements in human subjects undergoing graded visual and sensorimotor stimulation. We found that: (1) a BOLD-specific flow-volume power-law relationship is described by alpha = 0.23 +/- 0.05, significantly lower than Grubb's constant of 0.38 for total CBV; (2) this power-law constant was not found to vary significantly between the visual and sensorimotor areas; and (3) the use of Grubb's value of 0.38 in gradient-echo BOLD modeling results in an underestimation of DeltaCMRo(2).

  4. Experimental Cerebral Malaria Pathogenesis—Hemodynamics at the Blood Brain Barrier

    Science.gov (United States)

    Nacer, Adéla; Movila, Alexandru; Sohet, Fabien; Girgis, Natasha M.; Gundra, Uma Mahesh; Loke, P'ng; Daneman, Richard; Frevert, Ute

    2014-01-01

    Cerebral malaria claims the lives of over 600,000 African children every year. To better understand the pathogenesis of this devastating disease, we compared the cellular dynamics in the cortical microvasculature between two infection models, Plasmodium berghei ANKA (PbA) infected CBA/CaJ mice, which develop experimental cerebral malaria (ECM), and P. yoelii 17XL (PyXL) infected mice, which succumb to malarial hyperparasitemia without neurological impairment. Using a combination of intravital imaging and flow cytometry, we show that significantly more CD8+ T cells, neutrophils, and macrophages are recruited to postcapillary venules during ECM compared to hyperparasitemia. ECM correlated with ICAM-1 upregulation on macrophages, while vascular endothelia upregulated ICAM-1 during ECM and hyperparasitemia. The arrest of large numbers of leukocytes in postcapillary and larger venules caused microrheological alterations that significantly restricted the venous blood flow. Treatment with FTY720, which inhibits vascular leakage, neurological signs, and death from ECM, prevented the recruitment of a subpopulation of CD45hi CD8+ T cells, ICAM-1+ macrophages, and neutrophils to postcapillary venules. FTY720 had no effect on the ECM-associated expression of the pattern recognition receptor CD14 in postcapillary venules suggesting that endothelial activation is insufficient to cause vascular pathology. Expression of the endothelial tight junction proteins claudin-5, occludin, and ZO-1 in the cerebral cortex and cerebellum of PbA-infected mice with ECM was unaltered compared to FTY720-treated PbA-infected mice or PyXL-infected mice with hyperparasitemia. Thus, blood brain barrier opening does not involve endothelial injury and is likely reversible, consistent with the rapid recovery of many patients with CM. We conclude that the ECM-associated recruitment of large numbers of activated leukocytes, in particular CD8+ T cells and ICAM+ macrophages, causes a severe restriction in

  5. Two dynamic pictures of regional cerebral blood flow by the Xenon 133 inhalation method (application to cerebral infarction)

    International Nuclear Information System (INIS)

    Philippon, B.L.; Compingt, D.L.; Boussert, F.; Hajlani, M.

    1981-01-01

    Measurement of regional cerebral blood flow (rCBF) have been carried out with a gamma-camera and according to the xenon 133 inhalation method. The rCBF measurements are based on the initial part of corrected cerebral curves for recirculation and computed through deconvolution with the expired air curve. Hence an initial slope index corrected for recirculation can be determined by deconvolution. The calculation also allows us to estimate the regional partition coefficient of xenon between brain and blood. Reproductibility of this method of calculation is +-10% for regional cerebral area. Two rCBF pictures are given by the computer. The first type of picture represents the regional inequalities of rCBF when taking into consideration the local values of the partition coefficient. Second type of image is based on a constant value of the partition coefficient for the whole hemisphere. We make a comparison between the two types of pictures. 28 of the 50 patients studied after cerebral infarct shown significant falls of partition coefficient (from 5 to 43%) (mean value 28%+-11%) [fr

  6. 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

    2017-06-01

    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.

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

    International Nuclear Information System (INIS)

    Lindner, P.; Nickel, O.

    1984-01-01

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

  8. The influence of the non-Newtonian properties of blood on blood-hammer through the posterior cerebral artery.

    Science.gov (United States)

    Tazraei, Pedram; Riasi, Alireza; Takabi, Behrouz

    2015-06-01

    This work investigates a two dimensional numerical analysis of blood hammer through the posterior cerebral artery. The non-Newtonian and usual Newtonian blood models are compared in the case of blood hammer through the posterior cerebral artery to quantify the differences between the models. In this way, a validated CFD simulation is used to study non-Newtonian shear-thinning effects of blood. The governing equations for the modeling of two-dimensional transient flow are solved using a combination of characteristics and central finite difference methods, respectively for the hyperbolic and parabolic parts. Herein, the non-Newtonian viscosity characteristic of blood is incorporated by using the Carreau model. To convert the nonlinear terms available in the characteristics equation into the linear ones, the Newton-Kantorovich method is implemented. The verification and validation of the numerical results are carried out in detail. Hemodynamic characteristics of blood hammer through the posterior cerebral artery are derived with both the Newtonian and non-Newtonian models, and the results are meticulously compared and discussed. The results show that when blood hammer occurs, the non-Newtonian properties greatly influence the velocity and shear stress profiles. At the early stages of blood hammer, there is a 64% difference between magnitudes of wall shear stress in these two models, and the magnitude of the wall shear stress for the shear-thinning blood flow is lower than the Newtonian one. Copyright © 2015 Elsevier Inc. All rights reserved.

  9. Cerebral blood flow and oximetry response to blood transfusion in relation to chronological age in preterm infants.

    Science.gov (United States)

    Banerjee, J; Leung, T S; Aladangady, N

    2016-06-01

    Preterm infants frequently receive blood transfusion (BT) and the aim of this study was to measure the effect of BT on cerebral blood flow and oxygenation in preterm infants in relation to chronological age. Preterm infants undergoing intensive care recruited to three chronological age groups: 1 to 7 (Group 1; n=20), 8 to 28 (Group 2; n=21) & ≥29days of life (Group 3; n=18). Pre and post-BT anterior cerebral artery (ACA) time averaged mean velocity (TAMV) and superior vena cava (SVC) flow were measured. Cerebral Tissue Haemoglobin Index (cTHI) and Oxygenation Index (cTOI) were measured from 15-20min before to 15-20min post-BT using NIRS. Vital parameters and blood pressure were measured continuously. Mean BP increased significantly, and there was no significant change in vital parameters following BT. Pre-BT ACA TAMV was higher in Group 2 and 3 compared to Group 1 (pBlood transfusion increased cTOI and cTHI and decreased ACA TAMV in all groups. PDA had no impact on the baseline cerebral oximetry and blood flow as well as changes following blood transfusion. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

  10. 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...

  11. 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.

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

    International Nuclear Information System (INIS)

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

    1988-01-01

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

  13. Increased cerebral blood flow during hypercapnia is not affected by lesion of the nucleus locus ceruleus

    International Nuclear Information System (INIS)

    Harik, S.I.; Prado, R.; Busto, R.; Ginsberg, M.D.

    1986-01-01

    To test the hypothesis that the putative noradrenergic innervation of intraparenchymal cerebral blood vessels from the nucleus locus ceruleus mediates the vasodilatory response to hypercapnia, regional cerebral blood flow was measured by iodo-[ 14 C]antipyrine autoradiography in awake and restrained rats with unilateral 6-hydroxydopamine lesion of the nucleus locus ceruleus and in unlesioned control rats. Hypercapnia, induced by the inhalation of 5% or 8% CO 2 in air for 8 minutes caused a 2 to 5-fold increase in regional cerebral blood flow. However, despite a marked reduction of about 90% in cortical norepinephrine levels ipsilateral to the lesion, blood flow to the frontal and parietal cortex, hippocampus, striatum and cerebellum increased to the same extent in ipsilateral and contralateral regions. Thus, lesion of the locus ceruleus and the resultant depletion of endogenous cortical and hippocampal norepinephrine, does not influence the cerebrovascular response to hypercapnia

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

    International Nuclear Information System (INIS)

    Tamaru, Fuyuhiko

    1997-01-01

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

  15. 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

    Rats were injected with iodoamphetamine synthesized and labeled with 125I or with 125I- isopropyliodoamphetamine , a molecule of established value for the determination of local cerebral blood flow. The blood kinetics, tissue distribution, and brain uptake index for each tracer exhibited...

  16. 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 baboo...

  17. 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...

  18. Regulation of cerebral blood flow in patients with autonomic dysfunction and severe postural hypotension

    DEFF Research Database (Denmark)

    Hesse, Birger; Mehlsen, Jesper; Boesen, Finn

    2002-01-01

    Whether cerebral blood flow (CBF) autoregulation is maintained in autonomic dysfunction has been debated for a long time, and the rather sparse data available are equivocal. The relationship between CBF and mean arterial blood pressure (MABP) was therefore tested in eight patients with symptoms...

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

    Indian Academy of Sciences (India)

    of blood through an artery with saccular cerebral aneurysm is reported. The flow is unsteady but is ... aneurysms with and without a coil insert considering blood as a non-Newtonian fluid. The simulation is carried out ..... Instantaneous flow patterns confirm that the coil creates a bypass that stabilizes wall loading of the bulge.

  20. Regional cerebral blood flow changes in chronic polidrug abusers

    International Nuclear Information System (INIS)

    Quintana, J.C.; Olea, E.; Seijas, D.; Haydn, V.

    2002-01-01

    Chronic exposure to cocaine and other drugs are in clear association with a variety of medical complications, involving many organ systems. The Central Nervous System (CNS) is particularly sensitive to such exposures: permanent behavioral, psychiatric and neurological complications are common in this group of patients. Regional cerebral blood perfusion (rCBF) analysis has been used to study these conditions with PET and SPECT for a long time. According to the literature, it is clear that drug exposure (particularly cocaine) does produce significant changes over rCBF, nevertheless the vast majority of SPECT and some PET studies are difficult to reproduce because they were analyzed using subjective (visual) and/or ROI's to address the changes. Aim: To study the pattern of rCBF change of chronic cocaine and other drugs (polidrug) users/abusers population using brain SPECT and SPM (Statistical Parametric Mapping). Material and Methods: From a population of 163 addicted patients, 55 chronic cocaine and other drugs users/abuser were selected. A pre-treatment brain SPECT under basal conditions was performed in all of them. 99mTc-ECD was used as rCBF tracer and SPM (Statistical Parametric Mapping) as a framework to address statistically significant rCBF variations of change. The whole group was compared with a population of normal patients (both sexes, aged between 20 and 40 y.o., no history of trauma, drug exposure, neurological or psychiatric disorders). Results: Significant areas of reduced (hypoperfusion) and increased (hyperperfusion) rCBF were identified in the patients group. The hypoperfusion areas involve mainly the left insula region and the surrounding frontal and temporal lobe and a smaller area in the anterior and inferior portion of the right frontal lobe. The increased perfusion areas were identified at the left thalamus and the right fronto-parietal cortical region. Conclusion: Our results suggest that chronic cocaine exposure produce activation/damage to

  1. Changes in regional cerebral blood flow during auditory cognitive tasks

    International Nuclear Information System (INIS)

    Ohyama, Masashi; Kitamura, Shin; Terashi, Akiro; Senda, Michio.

    1993-01-01

    In order to investigate the relation between auditory cognitive function and regional brain activation, we measured the changes in the regional cerebral blood flow (CBF) using positron emission tomography (PET) during the 'odd-ball' paradigm in ten normal healthy volunteers. The subjects underwent 3 tasks, twice for each, while the evoked potential was recorded. In these tasks, the auditory stimulus was a series of pure tones delivered every 1.5 sec binaurally at 75 dB from the earphones. Task A: the stimulus was a series of tones with 1000 Hz only, and the subject was instructed to only hear. Task B: the stimulus was a series of tones with 1000 Hz only, and the subject was instructed to push the button on detecting a tone. Task C: the stimulus was a series of pure tones delivered every 1.5 sec binaurally at 75 dB with a frequency of 1000 Hz (non-target) in 80% and 2000 Hz (target) in 20% at random, and the subject was instructed to push the button on detecting a target tone. The event related potential (P300) was observed in task C (Pz: 334.3±19.6 msec). At each task, the CBF was measured using PET with i.v. injection of 1.5 GBq of O-15 water. The changes in CBF associated with auditory cognition was evaluated by the difference between the CBF images in task C and B. Localized increase was observed in the anterior cingulate cortex (in all subjects), the bilateral associate auditory cortex, the prefrontal cortex and the parietal cortex. The latter three areas had a large individual variation in the location of foci. These results suggested the role of those cortical areas in auditory cognition. The anterior cingulate was most activated (15.0±2.24% of global CBF). This region was not activated in the condition of task B minus task A. The anterior cingulate is a part of Papez's circuit that is related to memory and other higher cortical function. These results suggested that this area may play an important role in cognition as well as in attention. (author)

  2. Effects of cardiopulmonary bypass on cerebral blood flow in neonates, infants, and children

    International Nuclear Information System (INIS)

    Greeley, W.J.; Ungerleider, R.M.; Kern, F.H.; Brusino, F.G.; Smith, L.R.; Reves, J.G.

    1989-01-01

    Cardiopulmonary bypass (CPB) management in neonates, infants, and children requires extensive alterations in temperature, pump flow rate, and perfusion pressure, with occasional periods of circulatory arrest. The effect of these alterations on cerebral blood flow (CBF) are unknown. This study was designed to determine the relation of temperature and mean arterial pressure to CBF during hypothermic CPB (18-32 degrees C), with and without periods of total circulatory arrest. CBF was measured before, during, and after hypothermic CPB with xenon-clearance techniques in 67 pediatric patients, aged 1 day-16 years. Patients were grouped based on different CPB techniques: group A, repair during moderate-hypothermic bypass at 25-32 degrees C; group B, repair during deep-hypothermic bypass at 18-22 degrees C; and group C, repair with total circulatory arrest at 18 degrees C. There was a significant correlation of CBF with temperature during CPB. CBF significantly decreased under hypothermic conditions in all groups compared with prebypass levels under normothermia. In groups A and B, CBF returned to baseline levels in the rewarming phase of CPB and exceeded baseline levels after bypass. In group C, no significant increase in CBF was observed during rewarming after total circulatory arrest (32 ± 12 minutes) or after weaning from CPB. During moderate-hypothermic CPB (25-32 degrees C), there was no association between CBF and mean arterial pressure. However, during deep-hypothermic CPB (18-22 degrees C), there was a association between CBF and mean arterial pressure

  3. Beagle puppy model of intraventricular hemorrhage: effect of indomethacin on cerebral blood flow

    International Nuclear Information System (INIS)

    Ment, L.R.; Stewart, W.B.; Duncan, C.C.; Scott, D.T.; Lambrecht, R.

    1983-01-01

    The newborn beagle puppy has been demonstrated to provide a good model for neonatal intraventricular hemorrhage (IVH). A study was designed to determine if indomethacin can prevent IVH and if indomethacin would produce changes in cerebral blood flow (CBF). Newborn beagle puppies were randomized by computer into two groups: one was pretreated with indomethacin, a known inhibitor of prostaglandin synthetase, and the other was saline. The dogs in both groups were then assigned either to undergo hemorrhagic hypotension/volume reexpansion insult or to receive no insult. Twenty percent of all pups receiving indomethacin and undergoing the insult experienced IVH, compared to 71% of the pups undergoing insult that had been pretreated with saline. Significant alterations in the blood pressure responses to the hemorrhagic hypotension/volume reexpansion insult were noted in the former group compared to the saline-pretreated pups subjected to insult. Finally, employing carbon-14 autoradiography for the determination of CBF, it was demonstrated that indomethacin decreases resting CBF of the newborn beagle pups and, in indomethacin-pretreated animals subjected to insult, prevents the increases in CBF seen in the saline-pretreated traumatized pups. 62 references, 1 figure, 3 tables

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

    Directory of Open Access Journals (Sweden)

    Noboru Toda

    2016-08-01

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

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

    International Nuclear Information System (INIS)

    Lindner, P.; Nickel, O.

    1984-01-01

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

  6. The study of SPECT cerebral blood flow and neuroreceptor imaging in depressive disorders

    International Nuclear Information System (INIS)

    Yuan Ling; Liu Jianzhong; Wu Zhifang

    2007-01-01

    The imaging methods of depressive disorders include structural imaging and functional imaging, the abnormal of cerebral structure in CT and MRI is neither significant nor specific, while the use of PET and SPECT provides depression study in-vivo about regional cerebral blood flow and central neurotransmitter and receptor's structure and function, which further have advanced research on aetiology, pathogenesis and therapy of' depressive disorders. (authors)

  7. 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....

  8. Cerebral blood velocity and other cardiovascular responses to 2 days of head-down tilt

    Science.gov (United States)

    Frey, Mary A. B.; Mader, Thomas H.; Bagian, James P.; Charles, John B.; Meehan, Richard T.

    1993-01-01

    Spaceflight induces a cephalad redistribution of fluid volume and blood flow within the human body, and space motion sickness, which is a problem during the first few days of space flight, could be related to these changes in fluid status and in blood flow of the cerebrum and vestibular system. To evaluate possible changes in cerebral blood flow during simulated weightlessness, we measured blood velocity in the middle cerebral artery (MCA) along with retinal vascular diameters, intraocular pressure, impedance cardiography, and sphygmomanometry on nine men (26.2 +/- 6.6 yr) morning and evening for 2 days during continuous 10 deg head-down tilt (HDT). When subjects went from seated to head-down bed rest, their heart rate and retinal diameters decreased, and intraocular pressures increased. After 48 h of HDT, blood flow velocity in the MCA was decreased and thoracic impedance was increased, indicating less fluid in the thorax. Percent changes in blood flow velocities in the MCA after 48 h of HDT were inversely correlated with percent changes in retinal vascular diameters. Blood flow velocities in the MCA were inversely correlated (intersubject) with arterial pressures and retinal vascular diameters. Heart rate, stroke volume, cardiac output, systolic arterial pressure, and at times pulse pressure and blood flow velocities in the MCA were greater in the evening. Total peripheral resistance was higher in the morning. Although cerebral blood velocity is reduced after subjects are head down for 2 days, the inverse relationship with retinal vessel diameters, which have control analogous to that of cerebral vessels, indicates cerebral blood flow is not reduced.

  9. 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....

  10. Cerebral blood flow determination within the first 8 hours of cerebral infarction using stable xenon-enhanced computed tomography

    Energy Technology Data Exchange (ETDEWEB)

    Hughes, R.L.; Yonas, H.; Gur, D.; Latchaw, R.

    1989-06-01

    Cerebral blood flow mapping with stable xenon-enhanced computed tomography (Xe/CT) was performed in conjunction with conventional computed tomography (CT) within the first 8 hours after the onset of symptoms in seven patients with cerebral infarction. Six patients had hemispheric infarctions, and one had a progressive brainstem infarction. Three patients with very low (less than 10 ml/100 g/min) blood flow in an anatomic area appropriate for the neurologic deficit had no clinical improvement by the time of discharge from the hospital; follow-up CT scans of these three patients confirmed infarction in the area of very low blood flow. Three patients with moderate blood flow reductions (15-45 ml/100 g/min) in the appropriate anatomic area had significant clinical improvement from their initial deficits and had normal follow-up CT scans. One patient studied 8 hours after stroke had increased blood flow (hyperemia) in the appropriate anatomic area and made no clinical recovery.

  11. 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.

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

    International Nuclear Information System (INIS)

    Herold, S.

    1985-01-01

    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. (orig.) [de

  13. Doppler study of middle cerebral artery blood flow velocity and cerebral autoregulation during a simulated ascent of Mount Everest.

    Science.gov (United States)

    Ter Minassian, A; Beydon, L; Ursino, M; Gardette, B; Gortan, C; Richalet, J P

    2001-01-01

    To explore cerebral hemodynamics in 8 healthy volunteers in a hypobaric chamber up to the altitude of Mount Everest after a progressive stepwise decompression to 8,848 m. Physiological, clinical, and transcranial Doppler data were collected after at least 3 days at 5,000, 6,000, and 7,000 m and within 4 hours of reaching 8,000 m and returning to sea level. Three subjects were excluded at 8,000 and 8,848 m because of acute neurological deficits. Heart rate increased; mean arterial pressure remained stable; PaO2 and PaCO2 decreased with altitude; hemoglobin (Hb) and hematocrit (Ht) increased; arterial O2 content decreased over 6,000 m; middle cerebral artery blood flow velocity (MCAv) increased only during acute exposure to 8,000 m; and the corresponding pulsatility (PI) and resistivity indices (RI) decreased over 5,000 m. PI and RI correlated with heart rate. The transient hyperemic response (THR) of MCAv to common carotid compression was depressed at 8,000 m. At 8,000 m, the increase in MCAv seemed to reflect the normal hemodynamic response to acute hypoxia. The decrease of THR at this altitude could be an indication of impaired cerebral autoregulation. The role of impaired cerebral autoregulation in the genesis of acute neurologic deficits, observed at 8,000 m and above in 3 subjects, remains speculative.

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

    Energy Technology Data Exchange (ETDEWEB)

    Kitamura, Shin (Nippon Medical School, Tokyo)

    1983-04-01

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

  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. Cholinergic receptor alterations in the cerebral cortex of spinal cord injured rat

    Directory of Open Access Journals (Sweden)

    R. Chinthu

    2017-07-01

    Full Text Available Many areas of the cerebral cortex process sensory information or coordinate motor output necessary for control of movement. Disturbances in cortical cholinergic system can affect locomotor coordination. Spinal cord injury causes severe motor impairment and disturbances in cholinergic signalling can aggravate the situation. Considering the impact of cortical cholinergic firing in locomotion, we focussed the study in understanding the cholinergic alterations in cerebral cortex during spinal cord injury. The gene expression of key enzymes in cholinergic pathway - acetylcholine esterase and choline acetyl transferase showed significant upregulation in the cerebral cortex of spinal cord injured group compared to control with the fold increase in expression of acetylcholine esterase prominently higher than cholineacetyl transferase. The decreased muscarinic receptor density and reduced immunostaining of muscarinic receptor subtypes along with down regulated gene expression of muscarinic M1 and M3 receptor subtypes accounts for dysfunction of metabotropic acetylcholine receptors in spinal cord injury group. Ionotropic acetylcholine receptor alterations were evident from the decreased gene expression of alpha 7 nicotinic receptors and reduced immunostaining of alpha 7 nicotinic receptors in confocal imaging. Our data pin points the disturbances in cortical cholinergic function due to spinal cord injury; which can augment the locomotor deficits. This can be taken into account while devising a proper therapeutic approach to manage spinal cord injury.

  17. Low cerebral blood flow in hypotensive perinatal distress

    DEFF Research Database (Denmark)

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

    1977-01-01

    Hypoxic brain injury is the most important neurological problem in the neonatal period and accounts for more neurological deficits in children than any other lesion. The neurological deficits are notably mental retardation, epilepsy and cerebral palsy. The pathogenesis has hitherto been poorly...

  18. Tomographic cerebral blood flow measurement during carotid surgery

    DEFF Research Database (Denmark)

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

    1994-01-01

    surgery and performing single photon emission computer tomography (SPECT) scanning shortly after the operation thereby pictures rCBF at the time of injection. DESIGN: Ongoing prospective study. SETTINGS: Departments of Vascular Surgery, Neurology and Anaesthesiology, University Hospital, Rigshospitalet...... carotid surgery. This method may serve as a reference tool in future research on intraoperative cerebral haemodynamics....

  19. Cerebral blood flow and oxygen metabolism of peritumorous edema measured with PET

    International Nuclear Information System (INIS)

    Tomura, N.; Kato, T.; Kanno, I.; Shishido, F.; Murakami, M.; Vemura, K.; Ogawa, T.; Mineura, K.

    1989-01-01

    The purpose of this paper is to study the cerebral blood flow and metabolism of peritumorous edema to evaluate its basic mechanism and reversibility. The cerebral blood flow (CBF), oxygen metabolism (CMRO 2 ), and cerebral blood volume (CBV) of peritumorous edema in seven cases of glioma were studied and compared with those of acute ischemic brain edema in nine cases. In peritumorous edema, the CBF (27.3 mL/100 mL/min ± 5.4) and the CMRO 2 (2.17 mL/100mL/min ± 0.62) both remained above 1.5 mL/100 mL/min, that is, above the reversible threshold in ischemic brain tissue. It has been shown that the peritumorous edema was of the vasogenic type and might be reversible tissue if tumor was removed

  20. Change of blood glucose level and its possible mechanism in patients with cerebral stroke

    International Nuclear Information System (INIS)

    Chen Weizhen; Zhang Yong; Zhang Zikang; Mo Congjian

    2003-01-01

    To study the mechanism of the change of blood glucose levels in patients with cerebral stroke, the levels of blood glucose, cortisol, glucogen, insulin, growth hormone, triiodothyronine (T 3 ), thyroxine (T 4 ) and adrenocorticotropic hormone (ACTH) were dynamically measured in 90 patients with cerebral stroke. The circumstances of brain middle line movement, lateral ventricle oppression and entrance brain ventricle of burst hematoma of the patients were examines by CT scan. The total incidence of hyperglycemia in the patients was 42.22%. The blood glucose level was positively related to the cortisol and glucogen levels, and negatively related to the T 3 level. The changed level of blood glucose and its related hormones both returned to normal range in 10 days. Both the ACTH level and the rate of cerebral pathological change in hyperglycemia group were significantly higher than that in normoglycemia and control groups. The rate of cerebral pathological change in elevated ACTH level group was higher than that in normal ACTH level group. The mechanism of hyperglycemia in the patients with cerebral stroke might be related to the stimulation of the hypothalamus, which may induce the discharge of ACTH and glucagon releasing factor, and to that the level of cortisol and glucagon increased, the level of T 3 decreased

  1. Blood-brain barrier and cerebral blood flow: Age differences in hemorrhagic stroke

    Directory of Open Access Journals (Sweden)

    Semyachkina-Glushkovskaya Oxana

    2015-11-01

    Full Text Available Neonatal stroke is similar to the stroke that occurs in adults and produces a significant morbidity and long-term neurologic and cognitive deficits. There are important differences in the factors, clinical events and outcomes associated with the stroke in infants and adults. However, mechanisms underlying age differences in the stroke development remain largely unknown. Therefore, treatment guidelines for neonatal stroke must extrapolate from the adult data that is often not suitable for children. The new information about differences between neonatal and adult stroke is essential for identification of significant areas for future treatment and effective prevention of neonatal stroke. Here, we studied the development of stress-induced hemorrhagic stroke and possible mechanisms underlying these processes in newborn and adult rats. Using histological methods and magnetic resonance imaging, we found age differences in the type of intracranial hemorrhages. Newborn rats demonstrated small superficial bleedings in the cortex while adult rats had more severe deep bleedings in the cerebellum. Using Doppler optical coherent tomography, we found higher stress-reactivity of the sagittal sinus to deleterious effects of stress in newborn vs. adult rats suggesting that the cerebral veins are more vulnerable to negative stress factors in neonatal vs. adult brain in rats. However, adult but not newborn rats demonstrated the stroke-induced breakdown of blood brain barrier (BBB permeability. The one of possible mechanisms underlying the higher resistance to stress-related stroke injures of cerebral vessels in newborn rats compared with adult animals is the greater expression of two main tight junction proteins of BBB (occludin and claudin-5 in neonatal vs. mature brain in rats.

  2. Changes in cerebral blood flow and blood brain barrier in the gerbil hippocampal CA1 region following repeated brief cerebral ischemia.

    Science.gov (United States)

    Jingtao, J.; Sato, S.; Yamanaka, N.

    1999-12-01

    Neuronal damage and changes in cerebral blood flow (CBF) and the permeability of the blood-brain barrier (BBB) following repeated brief periods of ischemia were studied in Mongolian gerbils. The cerebral ischemia was produced by three repeated occlusions of bilateral common carotid arteries for 3 min at 1-h intervals. CBF and permeability of the BBB were examined with tracers (China ink and silver nitrate) at 1, 3, and 7 days post ischemia using light and electron microscopy. Three days after the reperfusion, significant extravasation of tracers, consequential reduction of CBF, extensive neuronal destruction, and intravascular platelet aggregation were observed. Such vascular changes in the CA1 region were more severe than those in the frontal cortex. These findings strongly support the view that microcirculatory disturbance may be a mechanism responsible for delayed neuronal death in the CA1 region of the hippocampus.

  3. Cerebral blood-flow measurements with Tc-99m HMPAO and I-123 HIPDM in patients with cerebral tumors

    International Nuclear Information System (INIS)

    Maier-Hauff, K.; Cordes, M.; Sprung, Ch.; Gerlach, L.; Baerwald, R.

    1988-01-01

    In a study of 47 patients with brain tumors (12 meningiomas, 29 gliomas, four metastases, two lymphomas), the cerebral uptake of Tc-99m HMPAO and I-123 HIPDM were measured within the tumor and edema area. The meningioma, lymphoma, and metastases group showed increased regional cerebral blood flow (rCBF) with both methods in contrast to the low-grade gliomas, with a decreased tracer uptake. In high-grade gliomas, hypoperfusion was seen in ten of 18 cases with HMPAO and four of 18 with HIPDM. The rCBF in perifocal edema showed a low perfusion rate in all cases. In contrast to other investigators, the authors found a typical perfusion pattern in grade III and IV gliomas. The recent results demonstrate that the SPECT methods play an important role in the planning of radiation therapy and chemotherapy for malignant brain tumors

  4. 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

    It has been disputed whether or not large intracranial arteries are dilated during migraine attacks. In order to answer this question the present transcranial Doppler study focused on side-to-side differences of middle cerebral artery blood velocity during unilateral attacks of migraine without...... 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...

  5. No effect of angiotensin II AT(2)-receptor antagonist PD 123319 on cerebral blood flow autoregulation

    DEFF Research Database (Denmark)

    Estrup, T M; Paulson, O B; Strandgaard, S

    2001-01-01

    Blockade of the renin-angiotensin system with angiotensin-converting enzyme inhibitors (ACE-I) or angiotensin AT1-receptor antagonists shift the limits of autoregulation of cerebral blood flow (CBF) towards lower blood pressure (BP). The role of AT2-receptors in the regulation of the cerebral...... group. CBF was measured by the intracarotid 133xenon injection method and BP was raised by noradrenaline infusion and lowered by controlled haemorrhage in separate groups of rats. The limits of autoregulation were determined by computed least-sum-of-squares analysis. PD 123319 did not influence baseline...

  6. Regional cerebral blood flow in dialysis encephalopathy and primary degenerative dementia

    International Nuclear Information System (INIS)

    Mathew, R.J.; Rabin, P.; Stone, W.J.; Wilson, W.H.

    1985-01-01

    Regional cerebral blood flow (CBF) was measured in patients with dialysis encephalopathy, primary degenerative dementia, dialysis patients with no central nervous system (CNS) complications, and normal controls. Both groups of dialysis patients (with and without CNS complications) demonstrated higher CBF values, and the dementia patients, lower CBF values than the controls. The dialysis patients had lower hematocrit, which correlated inversely with the cerebral blood flow. No such correlations were present in normals and patients with primary degenerative dementia. The dialysis patients and controls obtained similar CBF when the flow values were adjusted for the differences in hematocrit

  7. Aging alters mRNA expression of amyloid transporter genes at the blood-brain barrier.

    Science.gov (United States)

    Osgood, Doreen; Miller, Miles C; Messier, Arthur A; Gonzalez, Liliana; Silverberg, Gerald D

    2017-09-01

    Decreased clearance of potentially toxic metabolites, due to aging changes, likely plays a significant role in the accumulation of amyloid-beta (Aβ) peptides and other macromolecules in the brain of the elderly and in the patients with Alzheimer's disease (AD). Aging is the single most important risk factor for AD development. Aβ transport receptor proteins expressed at the blood-brain barrier are significantly altered with age: the efflux transporters lipoprotein receptor-related protein 1 and P-glycoprotein are reduced, whereas the influx transporter receptor for advanced glycation end products is increased. These receptors play an important role in maintaining brain biochemical homeostasis. We now report that, in a rat model of aging, gene transcription is altered in aging, as measured by Aβ receptor gene messenger RNA (mRNA) at 3, 6, 9, 12, 15, 20, 30, and 36 months. Gene mRNA expression from isolated cerebral microvessels was measured by quantitative polymerase chain reaction. Lipoprotein receptor-related protein 1 and P-glycoprotein mRNA were significantly reduced in aging, and receptor for advanced glycation end products was increased, in parallel with the changes seen in receptor protein expression. Transcriptional changes appear to play a role in aging alterations in blood-brain barrier receptor expression and Aβ accumulation. Copyright © 2017 Elsevier Inc. All rights reserved.

  8. 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 og...... iskæmi under episoder med lavt MAP, og for cerebral hyperperfusion og vasogent ødem ved højt MAP. CBF autoregulationen undersøgtes hos tyve voksne patienter med akut bakteriel meningitis i den tidlige sygdomsfase (... meningitis, men retableres ved klinisk restitution. Autoregulationen kan endvidere delvis retableres ved akut hyperventilation. Fundene har potentiel betydning for valg af supportiv terapi hos patienter med meningitis....

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

    International Nuclear Information System (INIS)

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

    1988-01-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1988-10-01

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

  11. Mechanical muscle and tendon properties of the plantar flexors are altered even in highly functional children with spastic cerebral palsy.

    Science.gov (United States)

    Kruse, Annika; Schranz, Christian; Svehlik, Martin; Tilp, Markus

    2017-12-01

    Recent ultrasound studies found increased passive muscle stiffness and no difference in tendon stiffness in highly impaired children and young adults with cerebral palsy. However, it is not known if muscle and tendon mechanical properties are already altered in highly functional children with cerebral palsy. Therefore, the purpose of this study was to compare the mechanical and material properties of the plantar flexors in highly functional children with cerebral palsy and typically developing children. Besides strength measurements, ultrasonography was used to assess gastrocnemius medialis and Achilles tendon elongation and stiffness, Achilles tendon stress, strain, and Young's modulus in twelve children with cerebral palsy (GMFCS levels I and II) and twelve typically developing peers during passive dorsiflexion rotations as well as maximum voluntary contractions. Despite no difference in ankle joint stiffness (P>0.05) between groups, passive but not active Achilles tendon stiffness was significantly decreased (-39%) and a tendency of increased passive muscle stiffness was observed even in highly functional children with cerebral palsy. However, material properties of the tendon were not altered. Maximum voluntary contraction showed reduced plantar flexor strength (-48%) in the cerebral palsy group. Even in children with mild spastic cerebral palsy, muscle and tendon mechanical properties are altered. However, it appears that the Achilles tendon stiffness is different only when low forces act on the tendon during passive movements. Although maximum voluntary force is already decreased, forces acting on the Achilles tendon during activity appear to be sufficient to maintain typical material properties. Copyright © 2017 Elsevier Ltd. All rights reserved.

  12. 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

    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

  13. Quantification of modulated blood oxygenation levels in single cerebral veins by investigating their MR signal decay

    Energy Technology Data Exchange (ETDEWEB)

    Sedlacik, Jan [St. Jude Children' s Research Hospital, Memphis, TN (United States). Div. of Translational Imaging Research; University Clinics Jena (Germany). Medical Physics Group; Rauscher, Alexander [University Clinics Jena (Germany). Medical Physics Group; British Columbia Univ., Vancouver (Canada). MRI Research Centre; Reichenbach, Juergen R. [University Clinics Jena (Germany). Medical Physics Group

    2009-07-01

    The transverse magnetization of a single vein and its surrounding tissue is subject to spin dephasing caused by the local magnetic field inhomogeneity which is induced by the very same vessel. This phenomenon can be approximated and simulated by applying the model of an infinitely long and homogeneously magnetized cylinder embedded in a homogeneous tissue background. It is then possible to estimate the oxygenation level of the venous blood by fitting the simulated magnetization-time-course to the measured signal decay. In this work we demonstrate the ability of this approach to quantify the blood oxygenation level (Y) of small cerebral veins in vivo, not only under normal physiologic conditions (Y{sub native}=0.5-0.55) but also during induced changes of physiologic conditions which affect the cerebral venous blood oxygenation level. Changes of blood's oxygenation level induced by carbogen (5% CO{sub 2}, 95% O{sub 2}) and caffeine were observed and quantified, resulting in values of Y{sub carbogen}=0.7 and Y{sub caffeine}=0.42, respectively. The proposed technique may ultimately help to better understand local changes in cerebral physiology during neuronal activation by quantifying blood oxygenation in veins draining active brain areas. It may also be beneficial in clinical applications where it may improve diagnosis of cerebral pathologies as well as monitoring of responses to therapy. (orig.)

  14. 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...

  15. Comparative studies of D2 receptors and cerebral blood flow in hemi-Parkinsonism rats

    International Nuclear Information System (INIS)

    Lin Yansong; Lin Xiangtong

    2000-01-01

    Objective: To study the relationship between dopamine D 2 receptors and cerebral blood flow in hemi-Parkinsonism rats. Methods: Hemi-Parkinsonism rats were made by stereotaxic 6-hydroxy dopamine (6-OH-DA) lesions in substantia nigra and ventral tegmental area, apomorphine (Apo) which could induce the successful model rat to rotate toward the intact side was used to select the rat models, 125 I-IBZM in vivo autoradiography and 99 Tc m -HMPAO regional cerebral biodistribution analysis were used to study D 2 receptors and cerebral blood flow. The HPLC-ECD was used to measure striatum DA and its metabolite content . Results: the lesioned side striatum DA and its metabolites homovanillic acid (HVA) 3,4-dihyroxy-phenylacetic acid (DOPAC) reduced significantly than that of the intact side and pseudo-operated group, striatum/cerebellum 125 I-IBZM uptake ratio was 8.04 +- 0.71 in lesioned side of hemi-Parkinsonism rats, significantly increased compared with the intact side and the pseudo-operated group (P 0.05). Conclusions: the 6-OH-DA lesioned side DA content decreased significantly and thus induced a compensative up-regulation of striatum D 2 receptor binding sites in hemi-Parkinsonism rats, which show good correlation with rotation behavior induced by Apo. Comparing with cerebral blood flow, D 2 receptor reflected by IBZM seems to be more specific and earlier to detect the cerebral functional impairment in experimental hemi-Parkinsonism

  16. 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 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.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.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.

  17. Glutamate Levels and Resting Cerebral Blood Flow in Anterior Cingulate Cortex Are Associated at Rest and Immediately Following Infusion of S-Ketamine in Healthy Volunteers

    OpenAIRE

    Kirsten Borup Bojesen; Kirsten Borup Bojesen; Kasper Aagaard Andersen; Kasper Aagaard Andersen; Kasper Aagaard Andersen; Sophie Nordahl Rasmussen; Sophie Nordahl Rasmussen; Sophie Nordahl Rasmussen; Lone Baandrup; Line Malmer Madsen; Birte Yding Glenthøj; Birte Yding Glenthøj; Egill Rostrup; Brian Villumsen Broberg

    2018-01-01

    Progressive loss of brain tissue is seen in some patients with schizophrenia and might be caused by increased levels of glutamate and resting cerebral blood flow (rCBF) alterations. Animal studies suggest that the normalisation of glutamate levels decreases rCBF and prevents structural changes in hippocampus. However, the relationship between glutamate and rCBF in anterior cingulate cortex (ACC) of humans has not been studied in the absence of antipsychotics and illness chronicity. Ketamine i...

  18. 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.

  19. Exposure to pulse-modulated radio frequency electromagnetic fields affects regional cerebral blood flow.

    Science.gov (United States)

    Huber, R; Treyer, V; Schuderer, J; Berthold, T; Buck, A; Kuster, N; Landolt, H P; Achermann, P

    2005-02-01

    We investigated the effects of radio frequency electromagnetic fields (RF EMF) similar to those emitted by mobile phones on waking regional cerebral blood flow (rCBF) in 12 healthy young men. Two types of RF EMF exposure were applied: a 'base-station-like' and a 'handset-like' signal. Positron emission tomography scans were taken after 30 min unilateral head exposure to pulse-modulated 900 MHz RF EMF (10 g tissue-averaged spatial peak-specific absorption rate of 1 W/kg for both conditions) and sham control. We observed an increase in relative rCBF in the dorsolateral prefrontal cortex on the side of exposure. The effect depended on the spectral power in the amplitude modulation of the RF carrier such that only 'handset-like' RF EMF exposure with its stronger low-frequency components but not the 'base-station-like' RF EMF exposure affected rCBF. This finding supports our previous observation that pulse modulation of RF EMF is necessary to induce changes in the waking and sleep EEG, and substantiates the notion that pulse modulation is crucial for RF EMF-induced alterations in brain physiology.

  20. 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.)

  1. 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

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

    International Nuclear Information System (INIS)

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

    1990-01-01

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

  3. Cerebral blood flow study with 3D-SSP and neuropsychological evaluation by mini-mental state examination (MMSE) before and after clipping of unruptured cerebral aneurysm

    International Nuclear Information System (INIS)

    Takada, Hidekazu; Sasaki, Takehiko; Osato, Toshiaki

    2006-01-01

    We evaluate the influence of surgery for unruptured aneurysms on cerebral blood flow and neuropsychological estimate. We evaluated the cases of 28 consecutive patients with unruptured cerebral aneurysm treated with direct surgery accompanied by craniotomy. Before and after surgery, MRI, 123 I-IMP-SPECT with 3D-SSP analysis and MMSE were performed. There was not a significant decrease in MMSE. In 123 I-IMP-SPECT, it was recognized that the cerebral blood flow was decreased at the frontal operculum of operative site. These results indicate that careful neuropsychological evaluation is essential to make a favorable treatment plan for unruptured aneulysms. (author)

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

    International Nuclear Information System (INIS)

    Furlow, T.W. Jr.

    1982-01-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

    Furlow, T.W. Jr.

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

  6. An analysis of cerebral blood flow from middle cerebral arteries during cognitive tasks via functional transcranial Doppler recordings.

    Science.gov (United States)

    Li, Meng; Huang, Hanrui; Boninger, Michael L; Sejdić, Ervin

    2014-07-01

    Functional transcranial Doppler (fTCD) is a useful medical imaging technique to monitor cerebral blood flow velocity (CBFV) in major cerebral arteries. In this paper, CBFV changes in the right and left middle cerebral arteries (MCA) caused by cognitive tasks, such as word generation tasks and mental rotation tasks, were examined using fTCD. CBFV recordings were collected from 20 healthy subjects (10 females, 10 males). We obtained both the raw CBFV signal and the envelope CBFV signal, which is the maximal velocity to gain more information about the changes and hemisphere lateralization in cognitive tasks compared to the resting state. Time, frequency, time-frequency, and information-theoretic features were calculated and compared. Sex effects were also taken into consideration. The results of our analysis demonstrated that the raw CBFV signal contained more descriptive information than the envelope signals. Furthermore, both types of cognitive tasks produced higher values in most signal features. Geometric tasks were more distinguished from the rest-state than verbal tasks and the lateralization was exhibited in right MCA during geometric tasks. Our results show that the raw CBFV signals provided valuable information when studying the effects of cognitive tasks and lateralization in the MCA. Copyright © 2014 Elsevier Ireland Ltd and the Japan Neuroscience Society. All rights reserved.

  7. Methods for measurement of cerebral blood flow in man

    DEFF Research Database (Denmark)

    Lassen, N A

    1976-01-01

    -cerebral uptake, and insensitive both for detecting regional ischemia and regional hyperemia. The spatial resolution is also much more limited. For these reasons great caution must be exercised in interpreting the results. Methods yielding three-dimensional rCBF data will be needed in order to gain more precise...... information both on spatial localization and, especially, on ischemic areas. The most promising is computer-assisted axial tomography with freely diffusible radioactive isotopes or with x-rays using an intra-arterial injection of contrast. But, the available techniques are still too slow: in order to measure...

  8. Cerebral blood flow and glucose metabolism measured with positron emission tomography are decreased in human type 1 diabetes.

    Science.gov (United States)

    van Golen, Larissa W; Huisman, Marc C; Ijzerman, Richard G; Hoetjes, Nikie J; Schwarte, Lothar A; Lammertsma, Adriaan A; Diamant, Michaela

    2013-08-01

    Subclinical systemic microvascular dysfunction exists in asymptomatic patients with type 1 diabetes. We hypothesized that microangiopathy, resulting from long-standing systemic hyperglycemia and hyperinsulinemia, may be generalized to the brain, resulting in changes in cerebral blood flow (CBF) and metabolism in these patients. We performed dynamic [(15)O]H2O and [(18)F]-fluoro-2-deoxy-d-glucose brain positron emission tomography scans to measure CBF and cerebral glucose metabolism (CMRglu), respectively, in 30 type 1 diabetic patients and 12 age-matched healthy controls after an overnight fast. Regions of interest were automatically delineated on coregistered magnetic resonance images and full kinetic analysis was performed. Plasma glucose and insulin levels were higher in patients versus controls. Total gray matter CBF was 9%, whereas CMRglu was 21% lower in type 1 diabetic subjects versus control subjects. We conclude that at real-life fasting glucose and insulin levels, type 1 diabetes is associated with decreased resting cerebral glucose metabolism, which is only partially explained by the decreased CBF. These findings suggest that mechanisms other than generalized microangiopathy account for the altered CMRglu observed in well-controlled type 1 diabetes.

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

    Directory of Open Access Journals (Sweden)

    Farzaneh A Sorond

    2008-04-01

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

  10. 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.

  11. 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.

  12. Cerebral tissue oxygen saturation and extraction in preterm infants before and after blood transfusion

    NARCIS (Netherlands)

    van Hoften, Jacorina C. R.; Verhagen, Elise A.; Keating, Paul; ter Horst, Hendrik J.; Bos, Arend F.

    Objective Preterm infants often need red blood cell (RBC) transfusions. The aim of this study was to determine whether haemoglobin levels before transfusion were associated with regional cerebral tissue oxygen saturation (r(c)SO(2)) and fractional tissue oxygen extraction (FTOE) and whether RBC

  13. 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 immer...

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

    NARCIS (Netherlands)

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

    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

  15. Monitoring variables affecting positron emission tomography measurements of cerebral blood flow in anaesthetized pigs

    DEFF Research Database (Denmark)

    Alstrup, Aage Kristian Olsen; Zois, Nora Elisabeth; Simonsen, Mette

    2018-01-01

    Background Positron emission tomography (PET) imaging of anaesthetized pig brains is a useful tool in neuroscience. Stable cerebral blood flow (CBF) is essential for PET, since variations can affect the distribution of several radiotracers. However, the effect of physiological factors regulating...

  16. Monitoring variables affecting positron emission tomography measurements of cerebral blood flow in anaesthetized pigs

    DEFF Research Database (Denmark)

    Alstrup, Aage Kristian Olsen; Zois, Nora Elisabeth; Simonsen, Mette

    Background: Positron emission tomography (PET) imaging of anaesthetised pig brains is a useful tool in neuroscience. Stable cerebral blood flow (CBF) is essential for PET, since variations can affect the kinetics of several radiotracers. However, the impact of physiological factors regulating CBF...

  17. 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,

  18. Effects of prone and supine position on cerebral blood flow in preterm infants.

    Science.gov (United States)

    Bembich, Stefano; Oretti, Chiara; Travan, Laura; Clarici, Andrea; Massaccesi, Stefano; Demarini, Sergio

    2012-01-01

    We evaluated the effect of prone and supine position on cerebral blood flow (CBF) in stable preterm infants. CBF, PO(2), and PCO(2) were measured in the two positions. Peripheral oxygenation increased and CBF decreased in prone position. We speculate that CBF autoregulation may compensate for increased peripheral oxygenation, by decreasing CBF. Copyright © 2012 Mosby, Inc. All rights reserved.

  19. 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...

  20. 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.; Keyser, de Jacques

    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

  1. 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 seve...

  2. 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...

  3. 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...

  4. Near-infrared spectroscopy determined cerebral oxygenation with eliminated skin blood flow in young males

    DEFF Research Database (Denmark)

    Hirasawa, Ai; Kaneko, Takahito; Tanaka, Naoki

    2016-01-01

    We estimated cerebral oxygenation during handgrip exercise and a cognitive task using an algorithm that eliminates the influence of skin blood flow (SkBF) on the near-infrared spectroscopy (NIRS) signal. The algorithm involves a subtraction method to develop a correction factor for each subject. ...

  5. Middle cerebral artery blood velocity during intense static exercise is dominated by a Valsalva maneuver

    NARCIS (Netherlands)

    Pott, Frank; van Lieshout, Johannes J.; Ide, Kojiro; Madsen, Per; Secher, Niels H.

    2003-01-01

    Lifting of a heavy weight may lead to "blackout" and occasionally also to cerebral hemorrhage, indicating pronounced consequences for the blood flow through the brain. We hypothesized that especially strenuous respiratory straining (a Valsalva-like maneuver) associated with intense static exercise

  6. 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...

  7. 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...

  8. 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...

  9. Regulation of regional cerebral blood flow during and between migraine attacks

    DEFF Research Database (Denmark)

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

    1983-01-01

    Cerebrovascular reactivity to voluntary hyperventilation, moderate hypertension, and physiological activation was studied in nine patients during induced migraine attacks and in four patients between their attacks. Regional cerebral blood flow was measured by the xenon 133 injection technique in ...... abnormalities to the area of the oligemia supports our suggestion that the blood flow changes are caused by a change in local metabolism. Between attacks of migraine, the patients had normal regulation of brain circulation....

  10. 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....

  11. 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.

  12. 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...... methods, that are based of the use of radioactive tracers, can be applied in the same manner for mapping cortex activity. In particular single photon tomography SPECT is readily applicable to clinical audiology, so that the cortical components of the auditory processing can be more closely investigated....

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

    International Nuclear Information System (INIS)

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

    1979-01-01

    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 13 NH 3 in rhesus monkeys during P/sub a/CO 2 induced changes in CBF, and with dog studies using in vitro tissue counting techniques to examine 13 NH 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 2 . The single pass extraction fraction of 13 NH 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 13 NH 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 13 NH 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 13 NH 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 13 N tissue concentrations with further increases in CBF associated with progressively smaller changes in 13 N concentrations. 13 NH 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

  14. 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...... during incremental reductions in cerebral perfusion pressure (CPP) by controlled hemorrhage. Autoregulation was preserved in all rats without meningitis (groups A and E) and was lost in 24 of 25 meningitis rats (groups B, C, and D) (P...meningitis groups (Pcerebral vasodilation, which right shifts...

  15. Perioperative blood pressure management with clevidipine during coiling of cerebral artery aneurysms

    Directory of Open Access Journals (Sweden)

    Meyer Thomas

    2009-01-01

    Full Text Available The tight control of blood pressure (BP is mandatory during cerebral aneurysm coiling to minimize abrupt changes in the transmural pressure across the aneurysm and thereby decrease the risk of rupture. Critical times during these procedures when significant BP changes may occur include anesthetic induction, endotracheal intubation, and emergence. Clevidipine is a recently introduced, rapidly acting dihydropyridine calcium channel antagonist. Its rapid metabolism by tissue and plasma esterases results in an effective half-life of 1 to 3 minutes. We present our preliminary experience with the use of clevidipine to control BP during the anesthetic care of three patients undergoing coiling of cerebral aneurysms in the interventional radiology suite.

  16. The measurement of blood flow in the cerebral hemispheres using a radioactive tracer

    International Nuclear Information System (INIS)

    Calegaro, J.U.M.; Reis, J.M.M. dos; Lopes, P.G.; Ribeiro, J.I.C.; Mansano, A.

    1978-01-01

    The modified Olendorf technique to measure the passage of a non-diffusible radioactive tracer through the cerebral hemispheres is described. The results given as brain transit time presents the following normal values: right hemisphere = 11,0 +- 2,8s (s.d.); left hemisphere = 11,0 +- 2,9s (s.d.). The equipment used is a two scintillation detectors sistem (with flat field collimation) with simultaneous chard recorder. The values obtained are taken as cerebral blood flow index. From 20 patients studied, 12 have obstructive carotid [pt

  17. Influence of high altitude on cerebral blood flow and fuel utilization during exercise and recovery

    Science.gov (United States)

    Smith, K J; MacLeod, D; Willie, C K; Lewis, N C S; Hoiland, R L; Ikeda, K; Tymko, M M; Donnelly, J; Day, T A; MacLeod, N; Lucas, S J E; Ainslie, P N

    2014-01-01

    We examined the hypotheses that: (1) during incremental exercise and recovery following 4–6 days at high altitude (HA) global cerebral blood flow (gCBF) increases to preserve cerebral oxygen delivery () in excess of that required by an increasing cerebral metabolic rate of oxygen (); (2) the trans-cerebral exchange of oxygen vs. carbohydrates (OCI; carbohydrates = glucose + ½lactate) would be similar during exercise and recovery at HA and sea level (SL). Global CBF, intra-cranial arterial blood velocities, extra-cranial blood flows, and arterial–jugular venous substrate differences were measured during progressive steady-state exercise (20, 40, 60, 80, 100% maximum workload (Wmax)) and through 30 min of recovery. Measurements (n = 8) were made at SL and following partial acclimatization to 5050 m. At HA, absolute Wmax was reduced by ∼50%. During submaximal exercise workloads (20–60% Wmax), despite an elevated absolute gCBF (∼20%, P exercise and recovery at HA serve to maintain . Despite adequate at HA the brain appears to increase non-oxidative metabolism during exercise and recovery. PMID:25362150

  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 Lajord

    2013-01-01

    tomography (PET)/computed tomography (CT). Ten patients with cirrhosis were studied during an acute episode of HE; nine were reexamined after recovery. Nine patients with cirrhosis with no history of HE served as controls. Mean CMRO(2) increased from 0.73 µmol oxygen/mL brain tissue/min during HE to 0......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. Improving Cerebral Blood Flow after Arterial Recanalization: A Novel Therapeutic Strategy in Stroke.

    Science.gov (United States)

    El Amki, Mohamad; Wegener, Susanne

    2017-12-09

    Ischemic stroke is caused by a disruption in blood supply to a region of the brain. It induces dysfunction of brain cells and networks, resulting in sudden neurological deficits. The cause of stroke is vascular, but the consequences are neurological. Decades of research have focused on finding new strategies to reduce the neural damage after cerebral ischemia. However, despite the incredibly huge investment, all strategies targeting neuroprotection have failed to demonstrate clinical efficacy. Today, treatment for stroke consists of dealing with the cause, attempting to remove the occluding blood clot and recanalize the vessel. However, clinical evidence suggests that the beneficial effect of post-stroke recanalization may be hampered by the occurrence of microvascular reperfusion failure. In short: recanalization is not synonymous with reperfusion. Today, clinicians are confronted with several challenges in acute stroke therapy, even after successful recanalization: (1) induce reperfusion, (2) avoid hemorrhagic transformation (HT), and (3) avoid early or late vascular reocclusion. All these parameters impact the restoration of cerebral blood flow after stroke. Recent advances in understanding the molecular consequences of recanalization and reperfusion may lead to innovative therapeutic strategies for improving reperfusion after stroke. In this review, we will highlight the importance of restoring normal cerebral blood flow after stroke and outline molecular mechanisms involved in blood flow regulation.

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

    International Nuclear Information System (INIS)

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

    1985-01-01

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

  1. Improving Cerebral Blood Flow after Arterial Recanalization: A Novel Therapeutic Strategy in Stroke

    Directory of Open Access Journals (Sweden)

    Mohamad El Amki

    2017-12-01

    Full Text Available Ischemic stroke is caused by a disruption in blood supply to a region of the brain. It induces dysfunction of brain cells and networks, resulting in sudden neurological deficits. The cause of stroke is vascular, but the consequences are neurological. Decades of research have focused on finding new strategies to reduce the neural damage after cerebral ischemia. However, despite the incredibly huge investment, all strategies targeting neuroprotection have failed to demonstrate clinical efficacy. Today, treatment for stroke consists of dealing with the cause, attempting to remove the occluding blood clot and recanalize the vessel. However, clinical evidence suggests that the beneficial effect of post-stroke recanalization may be hampered by the occurrence of microvascular reperfusion failure. In short: recanalization is not synonymous with reperfusion. Today, clinicians are confronted with several challenges in acute stroke therapy, even after successful recanalization: (1 induce reperfusion, (2 avoid hemorrhagic transformation (HT, and (3 avoid early or late vascular reocclusion. All these parameters impact the restoration of cerebral blood flow after stroke. Recent advances in understanding the molecular consequences of recanalization and reperfusion may lead to innovative therapeutic strategies for improving reperfusion after stroke. In this review, we will highlight the importance of restoring normal cerebral blood flow after stroke and outline molecular mechanisms involved in blood flow regulation.

  2. Comparative studies of D2 receptors and cerebral blood flow in hemi-parkinsonism rats

    International Nuclear Information System (INIS)

    Lin, Y.; Lin, X.

    2000-01-01

    To study the relationship between dopamine (DA) D 2 receptors and cerebral blood flow in hemiparkinsonism rats. Hemi-parkinsonism rats were made by stereotaxic 6-hydroxy dopamine (6-OH-DA) lesions in substantia nigra and ventral tegmental area, apomorphine (Apo) which could induce the successful model rat rotates toward the intact side was used to screen that rats, 125 I-IBZM in vivo autoradiography and 99m Tc-HM-PAO regional brain biodistribution were used to study D 2 receptors and cerebral blood flow. The HPLC-ECD were used to measure the concentration of DA and it metabolites homovanillic acid (HVA), 3,4-dehydroxyphenyl acetic acid (DOPAC) in bilateral striatum (ST). The lesioned side ST DA and its metabolites HVA DOPAC reduced significantly than that of the intact side and pseudo-operated control group, ST/cerebellum (CB) 125 I-IBZM uptake ratio was 8.04 ±0.71 in lesioned side of hemi-parkinsonism rats, significantly increased compared with the intact side and the pseudo-operated group (p 99m Tc 30.1±4.53% enhancement as compared to the intact side, and also show good correlation with 30 min Apo induced rotation numbers (r=0.98), the regional cerebral blood flow study didn't show significant difference between bilateral brain cortex area (p>0.05). The DA content decreased significantly and induced an up-regulation of ST D 2 receptor binding sites in 6-OH-DA lesioned side in hemi-parkinsonism rats, the increased percentage of lesioned-intact side ST/CB 125 I-IBZM uptake ratio showed good correlation with rotation behavior induced by Apo. Compare with cerebral blood flow, D 2 receptor reflected by IBZM seems to be more specific and earlier to detect the cerebral functional impairment in experimental hemi-parkinsonism

  3. 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 by 44...

  4. Caffeine and human cerebral blood flow: A positron emission tomography study

    International Nuclear Information System (INIS)

    Cameron, O.G.; Modell, J.G.; Hariharan, M.

    1990-01-01

    Positron emission tomography (PET) was used to quantify the effect of caffeine on whole brain and regional cerebral blood flow (CBF) in humans. A mean dose of 250 mg of caffeine produced approximately a 30% decrease in whole brain CBF; regional differences in caffeine effect were not observed. Pre-caffeine CBF strongly influenced the magnitude of the caffeine-induced decrease. Caffeine decreased p a CO 2 and increased systolic blood pressure significantly; the change in p a CO 2 did not account for the change in CBF. Smaller increases in diastolic blood pressure, heart rate, plasma epinephrine and norepinephrine, and subjectively reported anxiety were also observed

  5. A method for calculating regional cerebral blood flow from emission computed tomography of inert gas concentrations

    DEFF Research Database (Denmark)

    Celsis, P; Goldman, T; Henriksen, L

    1981-01-01

    Emission tomography of positron or gamma emitting inert gases allows calculation of regional cerebral blood flow (rCBF) in cross-sectional slices of human brain. An algorithm is presented for rCBF calculations from a sequence of time averaged tomograms using inhaled 133Xe. The approach is designed...... of four 1 min pictures and using a fixed value for the brain:blood partition coefficient, lambda. The method is essentially based on the bolus distribution principle, and it allows the estimation of blood flow in ischemic areas. Application to positron emission tomography is discussed....

  6. 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...

  7. Stable xenon CT measurement of cerebral blood flow in cardiac transplantation candidates: Correlation with cognitive function

    International Nuclear Information System (INIS)

    Bello, J.A.; Fink, M.E.; Hilal, S.K.; Rose, E.A.; Reemtsma, K.

    1987-01-01

    Thirteen consecutive unselected patients with NYHA class 4 cardiac failure referred for cardiac transplantation underwent neurologic examination and cerebral blood flow measurement (rCBF) using the stable xenon enhanced CT method on a GE9800 system. Eleven men and two women were studied (mean age = 43.8 +- 6.1). On neurological examination, six of the patients demonstrated normal mental function; the remaining seven patients demonstrated memory, language, or learning impairment. There was no difference in mean cardiac output between the groups (4.9 L/min +- 1.68 vs. 4.2L/min +- 1.57). rCBF was significantly reduced in the impaired group. Cognitive impairment in patients with cardiac failure can be correlated with cerebral ischemia. Stable xenon CT measurement of rCBF in transplant candidates may help identify patients requiring more rapid transplantation to prevent permanent cerebral injury

  8. 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....... Global and regional CBF was measured by transcranial Doppler ultrasonography, single-photon emission computed tomography, and the Kety-Schmidt method. Cerebral metabolism and net flux were measured by the Fick principle. Interventions included intravenous norepinephrine infusion, acute hyperventilation......, propofol infusion, and mannitol infusion. Global CBF in patients was lower than that of controls; cerebral oxygen extraction and metabolism was lower in patients than in controls. Regional CBF was more heterogeneous in patients than in controls. Norepinephrine infusion increased mean arterial pressure...

  9. 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

    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......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......; control) or when severe hyperthermia had developed (core temperature = 39.5 degrees C; hyperthermia). The gCBF was similar after 15 min in the two trials, and it remained stable throughout control. In contrast, during hyperthermia gCBF decreased by 18% and was therefore lower in hyperthermia compared...

  10. The effect of phosphodiesterase-5 inhibitors on cerebral blood flow in humans

    DEFF Research Database (Denmark)

    Pauls, Mathilde Mh; Moynihan, Barry; Barrick, Thomas R

    2018-01-01

    Agents that augment cerebral blood flow (CBF) could be potential treatments for vascular cognitive impairment. Phosphodiesterase-5 inhibitors are vasodilating drugs established in the treatment of erectile dysfunction (ED) and pulmonary hypertension. We reviewed published data on the effects......, ED, type 2 diabetes, stroke, pulmonary hypertension, Becker muscular dystrophy and subarachnoid haemorrhage. Most studies used middle cerebral artery flow velocity to estimate CBF. Few studies employed direct measurements of tissue perfusion. Resting CBF velocity was unaffected by phosphodiesterase-5...... inhibitors, but cerebrovascular regulation was improved in ED, pulmonary hypertension, diabetes, Becker's and a group of healthy volunteers. This evidence suggests that phosphodiesterase-5 inhibitors improve responsiveness of the cerebral vasculature, particularly in disease states associated...

  11. 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 headache induction. Ten healthy subjects were included in a double-blind, placebo-controlled crossover study where placebo or sildenafil 100 mg (highest therapeutic dose) were administered on two separate days. Blood velocity in the middle cerebral artery (Vmca) was recorded by transcranial Doppler......, 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...

  12. Maintaining cerebral blood flow : From heart to brain

    NARCIS (Netherlands)

    Bronzwaer, A.-S.G.T.

    2017-01-01

    Brain function depends on a continuous provision of oxygen and nutrients. Interruption of blood supply to the brain for only a few seconds results already in loss of consciousness, emphasizing the need for tight regulation of CBF. Although CBF regulation by cerebrovascular control mechanisms (e.g.

  13. 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...

  14. Cocaine abstinence following chronic treatment alters cerebral metabolism in dopaminergic reward regions. Bromocriptine enhances recovery

    International Nuclear Information System (INIS)

    Clow, D.W.; Hammer, R.P. Jr.

    1991-01-01

    2-[14C]deoxyglucose autoradiography was used to determine local cerebral glucose utilization (lCGU) in rats following chronic cocaine treatment and subsequent abstinence. lCGU was examined in 43 discrete brain regions in animals which had received daily injections of cocaine for 14 days (10 mg/kg) followed by 3 days of saline or bromocriptine (10 mg/kg) treatment. Cocaine abstinence following chronic treatment significantly reduced lCGU in several regions including mesocorticolimbic structures such as ventral tegmental area, medial prefrontal cortex, and nucleus accumbens (NAc). Within the NAc, however, only the rostral pole showed significant reduction. In contrast, when bromocriptine treatment accompanied abstinence, lCGU was no longer reduced in mesocorticolimbic and most other regions, implying that metabolic recovery was enhanced by bromocriptine treatment during early abstinence following chronic cocaine treatment. These data suggest that cerebral metabolism is decreased during cocaine abstinence following chronic treatment in critical brain regions, and that this alteration can be prevented by treatment with direct-acting dopamine agonists such as bromocriptine

  15. The feasibility of detecting cerebral blood flow direction using the indocyanine green video angiography.

    Science.gov (United States)

    Murai, Yasuo; Nakagawa, Syunsuke; Matano, Fumihiro; Shirokane, Kazutaka; Teramoto, Akira; Morita, Akio

    2016-10-01

    The intraoperative confirmation of blood flow direction is necessary in cerebral vascular surgery. Using indocyanine green video angiography (ICG-VAG) with the FLOW 800 system, we examined the transit time of the blood vessel of interest and semiquantitatively evaluated the delay time (T1/2max) from indocyanine green (ICG) injection into the donor artery in reconstructive surgery and the middle cerebral artery (MCA) in aneurysmal surgery. The direction of cerebral blood flow (CBF), which can often be confirmed by ICG-VAG, may be more difficult to determine with faster blood flow. Here, we report our findings regarding the feasibility of detecting CBF direction using the FLOW 800 system. Twenty patients undergoing superficial temporal artery (STA) to MCA anastomosis for carotid occlusive disease and 13 patients with a small MCA aneurysm clipping were evaluated using the T1/2max, semiquantitative method with the FLOW 800 system. In STA-MCA anastomosis cases, the regions of interest (ROIs) included: the proximal donor STA and a region more than 10 mm on the distal side of the donor STA near the anastomosis site. In MCA aneurysms, the ROIs included the proximal M1 and distal M2 sides of the MCA aneurysm. T1/2max was significantly shorter for the proximal sites compared to the distal sites for all subjects (ps direction of CBF can be determined using the FLOW 800 system.

  16. 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).

  17. How does the blood leave the brain? A systematic ultrasound analysis of cerebral venous drainage patterns

    International Nuclear Information System (INIS)

    Doepp, Florian; Schreiber, Stephan J.; Muenster, Thomas von; Rademacher, Joerg; Valdueza, Jose M.; Klingebiel, Randolf

    2004-01-01

    The internal jugular veins are considered to be the main pathways of cerebral blood drainage. However, angiographic and anatomical studies show a wide anatomical variability and varying degrees of jugular and non-jugular venous drainage. The study systematically analyses the types and prevalence of human cerebral venous outflow patterns by ultrasound and MRI. Fifty healthy volunteers (21 females; 29 males; mean age 27±7 years) were studied by color-coded duplex sonography. Venous blood volume flow was measured in both internal jugular and vertebral veins in the supine position. Furthermore, the global arterial cerebral blood volume flow was calculated as the sum of volume flows in both internal carotid and vertebral arteries. Three types of venous drainage patterns were defined: a total jugular volume flow of more than 2/3 (type 1), between 1/3 and 2/3 (type 2) and less than 1/3 (type 3) of the global arterial blood flow. 2D TOF MR-venography was performed exemplarily in one subject with type-1 and in two subjects with type-3 drainage. Type-1 drainage was present in 36 subjects (72%), type 2 in 11 subjects (22%) and type 3 in 3 subjects (6%). In the majority of subjects in our study population, the internal jugular veins were indeed the main drainage vessels in the supine body position. However, a predominantly non-jugular drainage pattern was found in approximately 6% of subjects. (orig.)

  18. 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 ... MAP (from 78 ± 3 to 80 ± 2 mmHg) as well as bilateral jugular vein diameters, leaving MCA V(mean) 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 V...

  19. Cerebral blood flow velocity in migraine and chronic tension-type headache patients

    Directory of Open Access Journals (Sweden)

    Karacay Ozkalayci S

    2018-04-01

    Full Text Available S Karacay Ozkalayci, B Nazliel, HZ Batur Caglayan, C Irkec Department of Neurology, Faculty of Medicine, Gazi University, Ankara, Turkey Introduction: The present study seeks to use transcranial Doppler ultrasound to evaluate cerebral blood flow velocities in anterior and posterior circulation arteries, during an attack-free episode in migraine patients, with and without aura, as well as in chronic tension-type headache patients who were not receiving prophylactic medication. Methods: A total of 50 patients (35 female, 15 male were evaluated during a headache-free episode: 30 migraine patients without aura (mean age: 32±8 years, 10 migraine patients with aura (mean age: 34±4 years, and 10 patients with chronic tension-type headache (mean age: 34±5 years. Results: No significant difference was present between anterior, middle, and posterior cerebral and vertebral arteries’ blood flow velocities between migraine patients, with and without aura, or in patients with a tension-type headache, and normal controls (p>0.05. However, a significant increase in basilar artery cerebral blood flow velocities relative to controls was present in patients with a tension-type headache (p>0.001. Conclusion: It is difficult to predict the main reason for the significant increase in basilar artery blood flow velocities in patients with chronic tension-type headache. It may be due to constriction of conductance or the dilatation of the resistance vessels. Keywords: cerebral blood flow, migraine without aura, migraine with aura, tension-type headache, transcranial Doppler ultrasonography 

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

    Directory of Open Access Journals (Sweden)

    Clare eHowarth

    2014-05-01

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

  1. Cerebral blood flow single-photon emission tomography with 123I-IMP in vascular dementia

    International Nuclear Information System (INIS)

    Kawahata, Nobuya; Gotoh, Chiharu; Yokoyama, Sakura; Daitoh, Nobuyuki

    2001-01-01

    Cerebral blood flow differences between patients with vascular dementia, patients with multiple lacunar infarction without cognitive dysfunction, and age-matched controls were examined. Thirty four patients with vascular dementia (VD) were selected from consecutive referrals to the Memory Clinic at Narita Memorial Hospital. All the patients had routine assessment including history, physical and neurological examinations, neuropsychological assessment, blood tests, EEG, head MRI, and single photon emission computed tomography (SPECT). All of them fulfilled the NINDS-AIREN diagnostic criteria for vascular dementia. Thirty nine patients with multiple lacunar infarction without cognitive dysfunction and 110 age-matched controls were included in this study. Mean cerebral blood flow (mCBF) and regional cerebral blood flow (rCBF) were measured using N-isopropyl-P- 123 I-iodoamphetamine ( 123 I-IMP) and SPECT imager. The mCBF in VD was 27.6±5.3 ml/100 g/min, while those in the control group and multiple lacunar infarction without cognitive dysfunction were 36.6±6.1 ml/100 g/min and 32.5±5.5 ml/100 g/min, respectively. The patients with VD demonstrated significantly reduced mCBF and rCBF in twenty regions including both cerebellar hemispheres as compared with those of the control group. Although there was no significant rCBF differences in bilateral inferior occipital regions and the right cerebellar hemisphere between patients with VD and multiple lacunar infarction without cognitive dysfunction, we could find significant lower rCBF in the remaining brain areas. In spite of the severity of VD, the diffuse decrease of cerebral blood flow was recognized in all patients with VD. (author)

  2. Positron emission tomography in the newborn: extensive impairment of regional cerebral blood flow with intraventricular hemorrhage and hemorrhagic intracerebral involvement

    International Nuclear Information System (INIS)

    Volpe, J.J.; Herscovitch, P.; Perlman, J.M.; Raichle, M.E.

    1983-01-01

    Positron emission tomography (PET) now provides the capability of measuring regional cerebral blood flow with high resolution and little risk. In this study, we utilized PET in six premature infants (920 to 1,200 g) with major intraventricular hemorrhage and hemorrhagic intracerebral involvement to measure regional cerebral blood flow during the acute period (5 to 17 days of age). Cerebral blood flow was determined after intravenous injection of H 2 O, labeled with the positron-emitting isotope, 15 O. Findings were similar and dramatic in all six infants. In the area of hemorrhagic intracerebral involvement, little or no cerebral blood flow was detected. However, in addition, surprisingly, a marked two- to fourfold reduction in cerebral blood flow was observed throughout the affected hemisphere, well posterior and lateral to the intracerebral hematoma, including cerebral white matter and, to a lesser extent, frontal, temporal, and parietal cortex. In the one infant studied a second time, ie, at 3 months of age, the extent and severity of the decreased cerebral blood flows in the affected hemisphere were similar to those observed on the study during the neonatal period. At the three autopsies, the affected left hemisphere showed extensive infarction, corroborating the PET scans. These observations, the first demonstration of the use of PET in the determination of regional cerebral blood flow in the newborn, show marked impairments in regional cerebral blood flow in the hemisphere containing an apparently restricted intracerebral hematoma, indicating that the hemorrhagic intracerebral involvement is only a component of a much larger lesion, ischemic in basic nature, ie, an infarction. This large ischemic lesion explains the poor neurologic outcome in infants with intraventricular hemorrhage and hemorrhagic intracerebral involvement

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

    OpenAIRE

    Mandić Vesna; Miković` Željko; Đukić Milan; Vasiljević Mladenko; Filimonović Dejan; Bogavac Mirjana

    2005-01-01

    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 wom...

  4. Impaired cerebral blood flow and oxygenation during exercise in type 2 diabetic patients.

    Science.gov (United States)

    Kim, Yu-Sok; Seifert, Thomas; Brassard, Patrice; Rasmussen, Peter; Vaag, Allan; Nielsen, Henning B; Secher, Niels H; van Lieshout, Johannes J

    2015-06-01

    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 cerebral artery blood flow velocity. Cerebral oxygenation and metabolism were evaluated from the arterial-to-venous differences for oxygen, glucose, and lactate. Blood pressure was comparable during exercise between the two groups. However, the partial pressure of arterial carbon dioxide was lower 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 < 0.05), and they expressed a higher rating of perceived exertion (P < 0.05). In contrast, CBF increased ~20% during exercise in the control group while the brain uptake of lactate and glucose was similar in the two groups. In conclusion, these results suggest that impaired CBF and oxygenation responses to exercise in T2DM patients may relate to limited ability to increase cardiac output and to reduced vasodilatory capacity and could contribute to their high perceived exertion. © 2015 The Authors. Physiological Reports published by Wiley Periodicals, Inc. on behalf of the American Physiological Society and The Physiological Society.

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

    International Nuclear Information System (INIS)

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

    1987-01-01

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

  6. Cerebral perfusion pressure in women with preeclampsia is elevated even after treatment of elevated blood pressure.

    Science.gov (United States)

    Sonneveld, Milan J; Brussé, Ingrid A; Duvekot, Johannes J; Steegers, Eric A P; Grune, Frank; Visser, Gerhard H

    2014-05-01

    Cerebral perfusion pressure (CPP) is elevated in preeclampsia, and may predispose to cerebrovascular complications and progression to eclampsia. We estimated zero flow pressure (ZFP) and CPP using simultaneously obtained arterial blood pressure and middle cerebral artery blood flow velocity in 10 women with preeclampsia, all treated with methyldopa with or without nifedipine, and 18 healthy pregnant controls. Mean ± SD ZFP was lower in women with preeclampsia than in controls (16.8 ± 10.9 vs. 31.7 ± 15.0 mmHg, p = 0.01) whereas CPP was considerably higher (82.3 ± 17.7 vs. 55.0 ± 11.7 mmHg, p preeclampsia, but not in controls. Women with preeclampsia may have an increased cerebral perfusion due to a reduced ZFP and increased CPP despite treatment with antihypertensive medication. More rigorous antihypertensive therapy, aimed at reducing CPP, could result in a decrease in cerebral complications in women with preeclampsia. © 2014 Nordic Federation of Societies of Obstetrics and Gynecology.

  7. Inhibition of nitric oxide synthesis following severe hypoxia-ischemia restores autoregulation of cerebral blood flow in newborn lambs

    NARCIS (Netherlands)

    Dorrepaal, CA; Steendijk, P; van Bel, F; Baan, J.

    Birth asphyxia impairs the autoregulatory ability of the cerebral blood flow. Inappropriate synthesis of vasodilatory nitric oxide may be important in this respect. We investigated if nitric oxide synthesis inhibition by N-omega-nitro-L-arginine (NLA) could restore cerebral autoregulation after

  8. Ten-minute umbilical cord occlusion markedly reduces cerebral blood flow and heat production in fetal sheep.

    NARCIS (Netherlands)

    Lotgering, F.K.; Bishai, J.M.; Struijk, P.C.; Blood, A.B.; Hunter, C.J.; Power, G.G.; Longo, L.D.

    2003-01-01

    OBJECTIVE: The study was undertaken to determine to what extent a 10-minute total umbilical cord occlusion affects autoregulation of cerebral blood flow and cerebral heat production in the fetus. STUDY DESIGN: In seven chronically catheterized late-gestation fetal sheep (127-131 days' gestation), we

  9. Regional cerebral blood flow and the effects of nicardipine, a new cerebral vasodilator, in patients with neuropsychiatric symptoms

    International Nuclear Information System (INIS)

    Toyoda, Katsuhiro; Motomura, Naoyasu; Murata, Koen; Sakai, Toshiaki; Yoshioka, Michio; Tsutsumi, Shigetoshi.

    1984-01-01

    Regional cerebral blood flow (rCBF) was determined by 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. (Namekawa, K.)

  10. Regional cerebral blood flow during mechanical hyperventilation in patients with acute bacterial meningitis

    DEFF Research Database (Denmark)

    Møller, Kirsten; Høgh, Peter; Larsen, Fin Stolze

    2000-01-01

    Mechanical hyperventilation is often instituted in patients with acute bacterial meningitis when increased intracranial pressure is suspected. However, the effect on regional cerebral blood flow (CBF) is unknown. In this study, we measured regional CBF (rCBF) in patients with acute bacterial...... meningitis before and during short-term hyperventilation. In 17 patients with acute bacterial meningitis, absolute rCBF (in ml/100 g min-1) was measured during baseline ventilation and hyperventilation by single-photon emission computed tomography (SPECT) using intravenous 133Xe bolus injection. Intravenous...... in the frontal and parietal cortex as well as in the basal ganglia. Focal perfusion abnormalities were present in 10 of 12 patients. Regional cerebral blood flow abnormalities are frequent in patients with acute bacterial meningitis. Short-term hyperventilation does not enhance these abnormalities....

  11. Sources of variability of resting cerebral blood flow in healthy subjects

    DEFF Research Database (Denmark)

    Henriksen, Otto Mølby; Kruuse, Christina Rostrup; Olesen, Jes

    2013-01-01

    Measurements of cerebral blood flow (CBF) show large variability among healthy subjects. The aim of the present study was to investigate the relative effect of established factors influencing CBF on the variability of resting CBF. We retrospectively analyzed spontaneous variability in 430 CBF...... measurements acquired in 152 healthy, young subjects using (133)Xe single-photon emission computed tomography. Cerebral blood flow was correlated positively with both end-tidal expiratory PCO2 (PETCO2) and female gender and inversely with hematocrit (Hct). Between- and within-subject CO2 reactivity...... when Hct was also accounted for. The present study confirms large between-subject variability in CBF measurements and that gender, Hct, and PETCO2 explain only a small part of this variability. This implies that a large fraction of CBF variability may be due to unknown factors such as differences...

  12. 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...... tomographic slices through the brain were recorded with a resolution element of 1.7 X 1.7 X 2.0 cm (full width at half maximum). The blood flow distribution showed that the predominantly gray matter areas displayed flow approximately double that of the predominantly white matter regions. The CBF distribution....... This corresponds to random methodological and biological errors of 6.4/square root 2 = 4.6 ml/100 g/min and is a measure of the overall intraindividual variability. Xenon-133 tomography is atraumatic and affords rCBF images free of the superposition artifacts that practically invalidate the nontomographic...

  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 perio...... are implemented using synthetic data of xenon-133 emission computed tomography and some of the difficulties likely to be encountered in practice are stressed.......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. Sub-Clinical Cognitive Decline and Resting Cerebral Blood Flow in Middle Aged Men

    DEFF Research Database (Denmark)

    Henriksen, Otto Mølby; Hansen, Naja Liv; Osler, Merete

    2017-01-01

    of early sub-clinical cognitive decline with CBF. MATERIALS AND METHODS: The study participants were recruited from a cohort of Danish men born in 1953. Based on a regression model we selected men who performed better (Group A, n = 94) and poorer (Group B, n = 95) on cognitive testing at age 57 than...... expected from testing at age 20. Participants underwent supplementary cognitive testing, blood sampling and MRI including measurements of regional and global CBF. RESULTS: Regional CBF was lower in group B than in group A in the posterior cingulate gyrus and the precuneus. The associations were attenuated......BACKGROUND: Although dementia is associated with both global and regional cerebral blood flow (CBF) changes, little is known about cerebral perfusion in the early pre-clinical stages of cognitive decline preceding overt cognitive dysfunction. The aim of this study was to investigate the association...

  15. Effects of prostacyclin on cerebral blood flow and vasospasm after subarachnoid hemorrhage

    DEFF Research Database (Denmark)

    Rasmussen, Rune; Wetterslev, Jørn; Stavngaard, Trine

    2015-01-01

    BACKGROUND AND PURPOSE: Delayed ischemic neurological deficits (DINDs) are a major contributing factor for poor outcome in patients with subarachnoid hemorrhage. In this trial, we investigated the therapeutic potential of prostacyclin, an endogen substance with known effect on vascular tone...... was initiated day 5 after subarachnoid hemorrhage and discontinued day 10. Primary outcome was the difference in change from baseline in global cerebral blood flow. Secondary outcome measures were occurrence of DIND, angiographic vasospasm, and clinical outcome at 3 months. RESULTS: No statistically significant...... parameters or clinical outcome were found between the 3 groups. CONCLUSIONS: Administration of prostacyclin to patients with subarachnoid hemorrhage may be safe and feasible. Global cerebral blood flow after subarachnoid hemorrhage is not markedly affected by administration of prostacyclin in the tested dose...

  16. Cerebral blood flow, fatigue, mental effort, and task performance in offices with two different pollution loads

    DEFF Research Database (Denmark)

    Nishihara, Naoe; Wargocki, Pawel; Tanabe, Shin-ichi

    2014-01-01

    pollution levels created by placing or removing a pollution source (i.e. a used carpet) behind a screen. During the exposure, the subjects performed four different office tasks presented on a computer monitor. The tasks were performed at two paces: normal and maximum. When the pollution source was present......The effects of indoor air quality on symptoms, perceptions, task performance, cerebral blood flow, fatigue, and mental effort of individuals working in an office were investigated. Twenty-four right-handed Danish female subjects in an office were exposed in groups of two at a time to two air......, the air quality was perceived to be worse and more errors were made when subjects typed text at the maximum pace. No other changes in subjective responses, performance, or physiological measurements were associated with different exposures. Although cerebral blood flow and voice analysis did not detect...

  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

    : 2 ng kg(-1) ). Mean arterial blood pressure (MAP, arterial transducer) and middle cerebral artery blood flow velocity (MCAv, transcranial Doppler ultrasound) were recorded continuously during thigh-cuff deflation-induced changes in MAP for the determination of a modified rate of regulation (Ro......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......(-1) ; P = 0·91 versus baseline; P = 0·14 versus LPS]. While our findings support the concept that dynamic cerebral autoregulation is enhanced during the very early stages of sepsis, they remain inconclusive with regard to more advanced stages of disease, because thigh-cuff deflation failed to induce...

  18. Cycloid psychosis: regional cerebral blood flow correlates of a psychotic episode.

    Science.gov (United States)

    Warkentin, S; Nilsson, A; Karlson, S; Risberg, J; Franze'n, G; Gustafson, L

    1992-01-01

    Eight patients meeting Leonhard's criteria for cycloid psychosis were investigated on repeated occasions during a psychotic episode, with regional cerebral blood flow measurements and clinical ratings. The results showed that, at admission to the hospital, when the patients were clinically exacerbated, the mean hemispheric blood flow was significantly elevated compared with values from a normal control group. The hemispheric blood flow level covaried significantly with the degree of clinical symptoms, such that the more elevated the cortical blood flow was, the more behaviorally disturbed was the patient. At discharge from the hospital, the patients had no residual symptoms and the cortical blood flow was normal. These findings differ distinctly from those commonly made in other psychoses, such as schizophrenia.

  19. 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.

  20. Heritability and genome-wide associations studies of cerebral blood flow in the general population.

    Science.gov (United States)

    Ikram, M Arfan; Zonneveld, Hazel I; Roshchupkin, Gennady; Smith, Albert V; Franco, Oscar H; Sigurdsson, Sigurdur; van Duijn, Cornelia; Uitterlinden, André G; Launer, Lenore J; Vernooij, Meike W; Gudnason, Vilmundur; Adams, Hieab Hh

    2017-06-19

    Cerebral blood flow is an important process for brain functioning and its dysregulation is implicated in multiple neurological disorders. While environmental risk factors have been identified, it remains unclear to what extent the flow is regulated by genetics. Here we performed heritability and genome-wide association analyses of cerebral blood flow in a population-based cohort study. We included 4472 persons free of cortical infarcts who underwent genotyping and phase-contrast magnetic resonance flow imaging (mean age 64.8 ± 10.8 years). The flow rate, cross-sectional area of the vessel, and flow velocity through the vessel were measured in the basilar artery and bilateral carotids. We found that the flow rate of the basilar artery is most heritable (h2 (SE) = 24.1 (9.8), p-value = 0.0056), and this increased over age. The association studies revealed two significant loci for the right carotid artery area (rs12546630, p-value = 2.0 × 10 -8 ) and velocity (rs2971609, p-value = 1.4 × 10 -8 ), with the latter showing a concordant effect in an independent sample (N = 1350, p-value = 0.057, meta-analyzed p-value = 2.5 × 10 -9 ). These loci were also associated with other cerebral blood flow parameters below genome-wide significance, and rs2971609 lies in a known migraine locus. These findings establish that cerebral blood flow is under genetic control with potential relevance for neurological diseases.

  1. 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

  2. A study of the acute effect of smoking on cerebral blood flow using 99mTc-ECD SPET

    International Nuclear Information System (INIS)

    Yamamoto, Yuka; Nishiyama, Yoshihiro; Monden, Toshihide; Satoh, Katashi; Ohkawa, Motoomi

    2003-01-01

    Cigarette smoking is known to be associated with atherosclerosis, is an important risk factor for stroke and has other serious effects. The aim of this study was to evaluate the acute effect of cigarette smoking on cerebral blood flow using statistical parametric mapping (SPM). Ten healthy volunteers with a smoking habit were studied using technetium-99m-labelled ethylcysteinate dimer single-photon emission tomography (SPET). We evaluated the regional cerebral blood flow under the smoking and resting states. The regional cerebral blood flow on smoking-activated SPET was significantly decreased in the whole brain as compared with that on resting SPET. Our findings therefore suggest that one of the acute effects of cigarette smoking is to induce a diffuse decrease in cerebral blood flow. (orig.)

  3. Multimodal Pressure-Flow Analysis: Application of Hilbert Huang Transform in Cerebral Blood Flow Regulation

    Directory of Open Access Journals (Sweden)

    Vera Novak

    2008-06-01

    Full Text Available Quantification of nonlinear interactions between two nonstationary signals presents a computational challenge in different research fields, especially for assessments of physiological systems. Traditional approaches that are based on theories of stationary signals cannot resolve nonstationarity-related issues and, thus, cannot reliably assess nonlinear interactions in physiological systems. In this review we discuss a new technique called multimodal pressure flow (MMPF method that utilizes Hilbert-Huang transformation to quantify interaction between nonstationary cerebral blood flow velocity (BFV and blood pressure (BP for the assessment of dynamic cerebral autoregulation (CA. CA is an important mechanism responsible for controlling cerebral blood flow in responses to fluctuations in systemic BP within a few heart-beats. The MMPF analysis decomposes BP and BFV signals into multiple empirical modes adaptively so that the fluctuations caused by a specific physiologic process can be represented in a corresponding empirical mode. Using this technique, we showed that dynamic CA can be characterized by specific phase delays between the decomposed BP and BFV oscillations, and that the phase shifts are significantly reduced in hypertensive, diabetics and stroke subjects with impaired CA. Additionally, the new technique can reliably assess CA using both induced BP/BFV oscillations during clinical tests and spontaneous BP/BFV fluctuations during resting conditions.

  4. Assessment of cerebral blood flow following administration of surfactant in premature newborns

    International Nuclear Information System (INIS)

    Calvo, M.J.; Matias, M.; Serrano, I.; Lubian, S.; Vallejos, E.; Canovas, S.

    1998-01-01

    To assess, by Doppler ultrasound, the possible changes in the patterns of cerebral blood flow after administration of a surfactant. Fifteen newborns with a period of gestation of less than 30 weeks received low-dose surfactant, as prophylaxis in six cases and as treatment in nine, administered slowly via endo tracheal tube with indwelling catheter. The Doppler recordings in anterior cerebral artery (ACA) and descending aorta (DAo) were assessed prior to administration of the surfactant, immediately afterwards and 15 minutes, 30 minutes, one hour and 24 hours later. The findings were correlated with simultaneous oxygen saturation and arterial blood pressure readings. There was little change in the systolic and diastolic velocities, although both tended to rise progressively throughout the 24 hours of the study period. The mean initial resistance index (R I) in ACA was elevated (0.84±0.11), tending in every case to diminish by 24 hours post administration (0.78±0.11) to levels that are considered normal in the newborn. Lower velocities (p<0.001 and higher RI(p<0.001) were recorded when reversed diastolic velocity was observed in the DAo in relation to patent ducts arteriosus. There were no significant changes in the oxygen saturation or mean arterial pressure. One infant presented a grade I germinal matrix hemorrhage. The findings suggest that this treatment does not produce significant changes in the cerebral blood flow under the circumstances described here. (Author) 40 refs

  5. 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

    2017-05-01

    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 (K i ) of 14 C-α-aminoisobutyric acid ( 14 C-AIB) was determined to quantify the degree of BBB disruption. MCA occlusion increased the K i both in the isoflurane and pentobarbital anesthetized rats. However, the value of K i was lower under isoflurane (11.5±6.0μL/g/min) than under pentobarbital (18.3±7.1μL/g/min) anesthesia. The K i 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 K i (+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. Copyright © 2017 Elsevier Inc. All rights reserved.

  6. Clinical study of cerebral blood flow by /sup 133/Xe inhalation with Tomomatic 64

    Energy Technology Data Exchange (ETDEWEB)

    Tanizaki, Yoshio; Makishita, Hideo; Miyasaka, Motomaro; Fujita, Tsutomu (Kakeyu Hospital, Nagano (Japan)); Kasuga, Toshio

    1983-07-01

    The regional cerebral blood flow was determined in 120 cases of cerebrovascular disturbance by single photon emission CT (ECT) by /sup 133/Xe inhalation. ECT detected lesions not visualized by x-ray CT. Since the activation study by induced hypertension or hypercapnia localized sites of abnormal cerebrovascular response, ECT was useful for the diagnosis of lesions and decision of surgical indications. Delayed scan in ECT indicated fast and slow components separately. Thus, the utility for localization and elucidation of the pathologic condition of abnormal blood flow was suggested. Combination of sup(99m)Tc-RBC ECT clarified the anatomical positional relationship on each slice.

  7. Blood transfusion in preterm infants improves intestinal tissue oxygenation without alteration in blood flow.

    Science.gov (United States)

    Banerjee, J; Leung, T S; Aladangady, N

    2016-11-01

    The objective of the study was to investigate the splanchnic blood flow velocity and oximetry response to blood transfusion in preterm infants according to postnatal age. Preterm infants receiving blood transfusion were recruited to three groups: 1-7 (group 1; n = 20), 8-28 (group 2; n = 21) and ≥29 days of life (group 3; n = 18). Superior mesenteric artery (SMA) peak systolic (PSV) and diastolic velocities were measured 30-60 min pre- and post-transfusion using Doppler ultrasound scan. Splanchnic tissue haemoglobin index (sTHI), tissue oxygenation index (sTOI) and fractional tissue oxygen extraction (sFTOE) were measured from 15-20 min before to post-transfusion using near-infrared spectroscopy. The mean pretransfusion Hb in group 1, 2 and 3 was 11, 10 and 9 g/dl, respectively. The mean (SD) pretransfusion SMA PSV in group 1, 2 and 3 was 0·63 (0·32), 0·81 (0·33) and 0·97 (0·40) m/s, respectively, and this did not change significantly following transfusion. The mean (SD) pretransfusion sTOI in group 1, 2 and 3 was 36·7 (19·3), 44·6 (10·4) and 41·3 (10·4)%, respectively. The sTHI and sTOI increased (P transfusion in all groups. On multivariate analysis, changes in SMA PSV and sTOI following blood transfusion were not associated with PDA, feeding, pretransfusion Hb and mean blood pressure. Pretransfusion baseline splanchnic tissue oximetry and blood flow velocity varied with postnatal age. Blood transfusion improved intestinal tissue oxygenation without altering mesenteric blood flow velocity irrespective of postnatal ages. © 2016 International Society of Blood Transfusion.

  8. 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

  9. 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

    International Nuclear Information System (INIS)

    Wirestam, R.; Knutsson, L.; Risberg, J.; Boerjesson, S.; Larsson, E.M.; Gustafson, L.; Passant, U.; Staahlberg, F.

    2007-01-01

    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

  10. A method to quantitate cerebral blood flow using a rotating gamma camera and iodine-123 iodoamphetamine with one blood sampling

    International Nuclear Information System (INIS)

    Iida, Hidehiro; Itoh, Hiroshi; Bloomfield, P.M.; Munaka, Masahiro; Higano, Shuichi; Murakami, Matsutaro; Inugami, Atsushi; Eberl, S.; Aizawa, Yasuo; Kanno, Iwao; Uemura, Kazuo

    1994-01-01

    A method has been developed to quantitate regional cerebral blood blow (rCBF) using iodine-123-labelled N-isopropyl-p-iodoamphetamine (IMP). This technique requires only two single-photon emission tomography (SPET) scans and one blood sample. Based on a two-compartment model, radioactivity concentrations in the brain for each scan time are calculated. A standard input function has been generated by combining the input functions from 12 independent studies prior to this work to avoid frequent arterial blood sampling, and one blood sample is taken at 10 min following IMP administration for calibration of the standard arterial input function. This calibration time was determined such that the integration of the first 40 min of the calibrated, combined input function agreed best with those from 12 individual input functions (the difference was 5.3% on average). This method was applied to eight subjects (two normals and six patients with cerebral infarction), and yielded rCBF values which agreed well with those obtained by a positron emission tomography H 2 15 O autoradiography method. This method was also found to provide rCBF values that were consistent with those obtained by the non-linear least squares fitting technique and those obtained by conventional microsphere model analysis. The optimum SPET scan times were found to be 40 and 180 min for the early and delayed scans, respectively. These scan times allow the use of a conventional rotating gamma camera for clinical purposes. V d values ranged between 10 and 40 ml/g depending on the pathological condition, thereby suggesting the importance of measuring V d for each ROI. In conclusion, optimization of the blood sampling time and the scanning time enabled quantitative measurement of rCBF with two SPET scans and one blood sample. (orig.)

  11. Insights into cerebrospinal fluid and cerebral blood flows in infants and young children.

    Science.gov (United States)

    Capel, Cyrille; Makki, Malek; Gondry-Jouet, Catherine; Bouzerar, Roger; Courtois, Véronique; Krejpowicz, Bénédicte; Balédent, Olivier

    2014-12-01

    This study investigates the craniospinal flows of blood and cerebrospinal fluid using phase-contrast magnetic resonance imaging (MRI) on 23 control neonates and infants (5 d-68 mo old). Mean arterial cerebral blood flow increased with age of infant from 180 mL/min after birth to 1330 mL/min around 6 years of age. This corresponds to 51 mL/min/100 g and 95 mL/min/100 g, respectively. Cervical cerebrospinal fluid stroke volume increased from 38 × 10(-3) mL to 752 × 10(-3) mL per cardiac cycle. After arterial systolic blood inflow, we observed a delay of the venous outflow that was always preceded by cerebrospinal fluid flushing out through the spinal canal. These results highlighted the importance of compliance of the spinal compartment and the interaction of blood and cerebrospinal fluid dynamics. The capacity of the spinal compartment to receive intracranial cerebrospinal fluid in presence of fontanels was demonstrated. We provide reference values to understand the physiology of cerebrospinal fluid and cerebral blood. © The Author(s) 2013.

  12. Measurement of local cerebral blood flow with Indo (14C) antipyrine. [/sup 131/I, rats, cats

    Energy Technology Data Exchange (ETDEWEB)

    Sakurada, O.; Kennedy, C.; Jehle, J.; Brown, J.D.; Carbin, G.L.; Sokoloff, L.

    1978-01-01

    The autoradiographic diffusible tracer technique for the measurement of local cerebral blood flow was originally designed for use with the radioactive, inert gas /sup 131/I-labeled trifluoroiodomethane and is applicable only with tracers that exhibit unrestricted diffusion through the blood-brain barrier. Because of the technical problems associated with the use of gaseous tracers, a suitable nonvolatile tracer has been sought. (/sup 14/C)-antipyrine has been used previously and found to be unsuitable because of limitations in its diffusion through the blood-brain barrier. An analogue of (/sup 14/C)-antipyrine, iodo-(/sup 14/C)-antipyrine, exhibits higher partition coefficients than (/sup 14/C)-antipyrine between nonpolar solvents and water and might, therefore, be expected to diffuse more freely through the barrier. Its use as the tracer in the local blood flow technique leads to values considerably above those obtained with (/sup 14/C)-antipyrine in the rat and cat and essentially the same as those obtained with the gas trifluoro-(/sup 131/I)-iodomethane in the cat. Iodo-(/sup 14/C)-antipyrine appears, therefore, to be a satisfactory nonvolatile tracer for the measurement of local cerebral blood flow.

  13. Regional cerebral blood flow in schizophrenic patients; In relation to the subtypes of the disease

    Energy Technology Data Exchange (ETDEWEB)

    Sagawa, Katsuo; Sibuya, Isoo; Oiji, Arata; Kawakatsu, Sinobu; Morinobu, Shigeru; Totsuka, Shiro (Yamagata Univ. (Japan). School of Medicine); Kinoshita, Osami; Yazaki, Mitsuyasu

    1990-03-01

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

  14. Advances in regional cerebral blood flow measurement and patho-physiological analysis by SPECT

    Energy Technology Data Exchange (ETDEWEB)

    Odano, Ikuo (Niigata Univ. (Japan). School of Medicine)

    1994-04-01

    Recently, two kinds of radiopharmaceuticals have been developed to represent the biodistribution of regional blood flow, which are N-isopropyl-p-[[sup 123]I]iodoamphetamine (IMP) and [sup 99m]Tc-hexamethylpropylene-amine-oxime (HMPAO). The charachteristics, clinical usage and imitation of these two radiolabeled agents are discussed. The advantage of [sup 123]I-IMP is that it has high first-pass extraction and long retention in brain tissue, hence it can be used to measure the absolute values of regional cerebral blood flow (rCBF). When the kinetics of [sup 123]I-IMP is assumed to be freely diffusible in the brain, its behavior is considered by 2-compartment model, especially which is assumed by the microsphere model in the early period after the i.v. injection of [sup 123]I-IMP. Comparing the rCBF measured by [sup 123]I-IMP with that by [sup 133]Xe inhalation SPECT method, we have to consider PaCO[sub 2] when both SPECT studies are performed, because PaCO[sub 2] is one of the big factors which make effects on the alteration of rCBF. [sup 123]I-IMP has an interesting character of the redistribution phenomenon which represrent the degree of ischemia in the cerebrovascular diseases. Distribution volume an important datum obtained by the SPECT study with [sup 123]I-IMP, which represent the degree of retention, i.e. binding potential of [sup 123]I-IMP in the brain tissue. I introduced the usage of the distribution volume of [sup 123]I-IMP, which was constructed in the rate constant square method, in the differential diagnosis of Parkinson's disease and progressive supranuclear palsy (PSP). The clinical usage of [sup 99m] Tc-HMPAT was mentioned, the advantage of which is the rapid fixation in the brain tissue and the distribution does not change for long time after the i.v. injection. Hence [sup 99m]Tc-HMPAO is used for the diagnosis of epileptic foci and certain loading tests such as balloon occlusion test, postural test and acetazolamide loading test. (author).

  15. 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...... cerebral vessels (arterioles) alternating with a normal calibre for these vessels and/or short periods of vasodilatation. It is considered to be a primary pathological condition of the vessels. When vasoconstriction was present the blood flow decreased to values consistent with ischaemia, which...

  16. Analysis of Regional Cerebral Blood Flow Using 99mTc-HMPAO Brain SPECT in Senile Dementia of Alzheimer Type

    International Nuclear Information System (INIS)

    Lee, Myung Hae; Lee, Myung Chul; Koh, Chang Soon; Roh, Jae Kyu; Woo, Chong In

    1988-01-01

    99m Tc-HMPAO brain SPECT studies were performed in 11 patients with Alzheimer's disease, 7 patients with psychological depression and 12 normal controls. Changes of regional cerebral blood flow was semiquantitatively analyzed and the results were as follows. 1) In 11 patients with Alzheimer's disease, significant reduction of regional cerebral blood flow was found In both temporoparietal areas. 2) Relative perfusion between cerebral hemispheres was rather symmetrical in patient with Alzheimer's disease. 3) All patients with depression showed normal SPECT findings. As for conclusion, 99m Tc-HMPAO brain SPECT seemed to be a valuable method for clinical assessment and management of patients with Alzheimer's disease.

  17. 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

  18. 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......) had CBF values of about 40 ml/100 gm/minute. Hypotensive infants with asphyxia at birth or RDS or both had values for CBF of about 20 ml/100 gm/minute, or less. CBF was strongly correlated with the arterial blood pressure, showing a linear relationship that was identical in infants with asphyxia...

  19. Relative Abundance of Proteins in Blood Plasma Samples from Patients with Chronic Cerebral Ischemia.

    Science.gov (United States)

    Kaysheva, Anna L; Kopylov, Artur T; Ponomarenko, Elena A; Kiseleva, Olga I; Teryaeva, Nadezhda B; Potapov, Alexander A; Izotov, Alexander А; Morozov, Sergei G; Kudryavtseva, Valeria Yu; Archakov, Alexander I

    2018-03-01

    A comparative protein profile analysis of 17 blood plasma samples from patients with ischemia and 20 samples from healthy volunteers was carried out using ultra-high resolution mass spectrometry. The analysis of measurements was performed using the proteomics search engine OMSSA. Normalized spectrum abundance factor (NSAF) in the biological samples was assessed using SearchGUI. The findings of mass spectrometry analysis of the protein composition of blood plasma samples demonstrate that the depleted samples are quite similar in protein composition and relative abundance of proteins. By comparing them with the control samples, we have found a small group of 44 proteins characteristic of the blood plasma samples from patients with chronic cerebral ischemia. These proteins contribute to the processes of homeostasis maintenance, including innate immune response unfolding, the response of a body to stress, and contribution to the blood clotting cascade.

  20. Cerebral blood flow reduction in Alzheimer's disease: impact of capillary occlusions on mice and humans

    Science.gov (United States)

    Berg, Maxime; Merlo, Adlan; Peyrounette, Myriam; Doyeux, Vincent; Smith, Amy; Cruz-Hernandez, Jean; Bracko, Oliver; Haft-Javaherian, Mohammad; Nishimura, Nozomi; Schaffer, Chris B.; Davit, Yohan; Quintard, Michel; Lorthois, Sylvie

    2017-11-01

    Alzheimer's disease may be the most common form of dementia, yet a satisfactory diagnosis procedure has still to be found. Recent studies suggest that a significant decrease of cerebral blood flow, probably caused by white blood cells stalling small vessels, may be among the earliest biological markers. To assess this hypothesis we derive a blood flow model, validate it against in vitro controlled experiments and in vivo measurements made on mice. We then investigate the influence of capillary occlusions on regional perfusion (sum of all arteriole flowrates feeding the network) of large mice and humans anatomical networks. Consistent with experiments, we observe no threshold effect, so that even a small percentage of occlusions (2-4%) leads to significant blood flow decrease (5-12%). We show that both species share the same linear dependance, suggesting possible translation from mice to human. ERC BrainMicroFlow GA61510, CALMIP HPC (Grant 2017-1541).

  1. High frequency jet ventilation and intermittent positive pressure ventilation. Effect of cerebral blood flow in patients after open heart surgery

    International Nuclear Information System (INIS)

    Pittet, J.F.; Forster, A.; Suter, P.M.

    1990-01-01

    Attenuation of ventilator-synchronous pressure fluctuations of intracranial pressure has been demonstrated during high frequency ventilation in animal and human studies, but the consequences of this effect on cerebral blood flow have not been investigated in man. We compared the effects of high frequency jet ventilation and intermittent positive pressure ventilation on CBF in 24 patients investigated three hours after completion of open-heart surgery. The patients were investigated during three consecutive periods with standard sedation (morphine, pancuronium): a. IPPV; b. HFJV; c. IPPV. Partial pressure of arterial CO 2 (PaCO 2 : 4.5-5.5 kPa) and rectal temperature (35.5 to 37.5 degree C) were maintained constant during the study. The CBF was measured by intravenous 133 Xe washout technique. The following variables were derived from the cerebral clearance of 133 Xe: the rapid compartment flow, the initial slope index, ie, a combination of the rapid and the slow compartment flows, and the ratio of fast compartment flow over total CBF (FF). Compared to IPPV, HFJV applied to result in the same mean airway pressure did not produce any change in pulmonary gas exchange, mean systemic arterial pressure, and cardiac index. Similarly, CBF was not significantly altered by HFJV. However, important variations of CBF values were observed in three patients, although the classic main determinants of CBF (PaCO 2 , cerebral perfusion pressure, Paw, temperature) remained unchanged. Our results suggest that in patients with normal systemic hemodynamics, the effects of HFJV and IPPV on CBF are comparable at identical levels of mean airway pressure

  2. 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. © 2013 Published by Elsevier B.V.

  3. Wavelet coherence analysis of spontaneous oscillations in cerebral tissue oxyhemoglobin concentrations and arterial blood pressure in elderly subjects.

    Science.gov (United States)

    Cui, Ruofei; Zhang, Ming; Li, Zengyong; Xin, Qing; Lu, Liqian; Zhou, Weiei; Han, Qingyu; Gao, Yuanjin

    2014-05-01

    This study aims to assess the relationship between spontaneous oscillations in changes in cerebral tissue oxyhemoglobin concentrations (Delta [HbO2]) and arterial blood pressure (ABP) signals in healthy elderly subjects during the resting state using wavelet coherence analysis. Continuous recordings of near-infrared spectroscopy (NIRS) and ABP signals were obtained from simultaneous measurements in 33 healthy elderly subjects (age: 70.7±7.9 years) and 27 young subjects (age: 25.2±3.7 years) during the resting state. The coherence between Delta [HbO2] and ABP oscillations in six frequency intervals (I, 0.4-2 Hz; II, 0.15-0.4 Hz; III, 0.05-0.15 Hz; IV, 0.02-0.05 Hz, V, 0.005-0.0095 Hz and VI, 0.005-0.0095 Hz) was analyzed using wavelet coherence analysis. In elderly subjects, the Delta [HbO2] and ABP oscillations were significantly wavelet coherent in interval I, and wavelet phase coherent in intervals I, II and IV. The wavelet coherence in interval I was significantly higher (p=0.040), in elderly subjects than in young subjects whereas that in interval V significantly lower (p=0.015). In addition, the wavelet phase coherence in interval IV was significantly higher in elderly subjects than in young subjects (p=0.028). The difference in the wavelet coherence of the elderly subjects and the young subjects indicates an altered cerebral autoregulation caused by aging. This study provides new insight into the dynamics of Delta [HbO2] and ABP oscillations and may be useful in identifying the risk for dynamic cerebral autoregulation processes. Copyright © 2014 Elsevier Inc. All rights reserved.

  4. Effect of Acute Resistance Exercise on Carotid Artery Stiffness and Cerebral Blood Flow Pulsatility

    Directory of Open Access Journals (Sweden)

    Wesley K Lefferts

    2014-03-01

    Full Text Available Arterial stiffness is associated with cerebral flow pulsatility. Arterial stiffness increases following acute resistance exercise (RE. Whether this acute RE-induced vascular stiffening affects cerebral pulsatility remains unknown. Purpose: To investigate the effects of acute RE on common carotid artery (CCA stiffness and cerebral blood flow velocity (CBFv pulsatility. Methods: Eighteen healthy men (22 ± 1 yr; 23.7 ± 0.5 kg∙m-2 underwent acute RE (5 sets, 5-RM bench press, 5 sets 10-RM bicep curls with 90 s rest intervals or a time control condition (seated rest in a randomized order. CCA stiffness (β-stiffness, Elastic Modulus (Ep and hemodynamics (pulsatility index, forward wave intensity and reflected wave intensity were assessed using a combination of Doppler ultrasound, wave intensity analysis and applanation tonometry at baseline and 3 times post-RE. CBFv pulsatility index was measured with transcranial Doppler at the middle cerebral artery (MCA. Results: CCA β-stiffness, Ep and CCA pulse pressure significantly increased post-RE and remained elevated throughout post-testing (p 0.05. There were significant increases in forward wave intensity post-RE (p0.05. Conclusion: Although acute RE increases CCA stiffness and pressure pulsatility, it may not affect CCA or MCA flow pulsatility. Increases in pressure pulsatility may be due to increased forward wave intensity and not pressure from wave reflections.

  5. Cerebral blood flow and vascular response to hypercapnia in hypertensive patients with leukoaraiosis

    International Nuclear Information System (INIS)

    Kuwabara, Yasuo; Ichiya, Yuichi; Sasaki, Masayuki; Yoshida, Tsuyoshi; Fukumura, Toshimitsu; Masuda, Kouji; Ibayashi, Setsuro; Fujishima, Masatoshi

    1996-01-01

    Both arteriosclerosis and leukoaraiosis have a close relationship with hypertension, but the relationship between cerebral hemodynamics and leukoaraiosis in hypertensive patients has not been fully examined. To clarify this issue, we measured the regional cerebral blood flow (rCBF) and cerebrovascular response to hypercapnia in hypertensive patients with various degrees of leukoaraiosis. The subjects consisted of 7 normotensive normal controls and 17 hypertensive patients. The hypertensive patients were divided into three groups according to the severity of white matter lesions (leukoaraiosis) on MRI and the presence of dementia, namely, negative or mild leukoaraiosis without dementia, moderate to severe leukoaraiosis without dementia and severe leukoaraiosis with dementia. Both the rCBF and the cerebrovascular response to hypercapnia were measured by the O-15 H 2 O bolus-injection method and positron emission tomography. The rCBF in hypertensive patients without dementia did not decrease when compared with the normotensive controls, but the rCBF in hypertensive patients with dementia markedly decreased in the cerebral cortices and white matter. On the other hand, the cerebrovascular response to hypercapnia declined with the severity of leukoaraiosis, and it decreased most severely in patients with severe leukoaraiosis and dementia. Our results indicate that the reduction in the cerebral hemodynamic reserve capacity has a close relationship with the severity of leukoaraiosis in hypertensive patients, although the rCBF is maintained in hypertensive patients without dementia, and suggest that arteriosclerotic change reduces cerebrovascular CO 2 response and causes a leukoaraiosis in hypertensive patients. (author)

  6. Brain edema and blood-brain barrier permeability following quantitative cerebral microembolism

    International Nuclear Information System (INIS)

    Bralet, A.M.; Bdley, A.; Beley, P.; Bralet, J.

    1979-01-01

    Cerebral microemboli were formed in rats by injecting 4000 carbonized microspheres, 50 +- 10 mu in diameter, labelled with 85 Sr, into the internal carotid artery. The use of radioactive microspheres as embolic agents enabled the number of microspheres to be determined in each cerebral hemisphere. The microspheres were mainly distributed in the cerebral hemisphere on the side of the injection. In 61 rats this hemisphere contained 582 +- 20 microspheres against 99 +- 9 in the contralateral hemisphere. Brain edema was assessed by measuring brain content of water, sodium and potassium. Blood-brain barrier (BBB) permeability was determined by brain accumulation of 125 I-albumin. In the ipsilateral hemisphere brain edema and an increase in BBB permeability appeared 6 hours after embolization and progressed up to 48 hours. Twenty-four hours after embolization, significant correlations were observed between the microsphere content of the cerebral hemispheres and (1) increases in water and sodium levels, (2) the decrease in potassium level, (3) the increase in BBB permeability. The study of these correlations should make it possible to ignore the poor reproducibility of embolizations and to analyze with increased accuracy the results of various experiments

  7. Study of regional cerebral blood flow in obsessive compulsive disorder patients with SPM and ROI method

    International Nuclear Information System (INIS)

    Li Peiyong; Jiang Xufeng; Zhang Liying; Guo Wanhua; Zhu Chengmo

    2002-01-01

    Objective: To investigate the alternations in regional cerebral blood flow (rCBF) in obsessive compulsive disorder (OCD) patients using statistical parametric mapping (SPM). Methods: rCBF measurements using 99 Tc m -ethyl cysteinate dimer (ECD) SPECT was performed on 14 OCD patients and 23 age-matched healthy volunteers. The rCBF distribution was compared between these two groups with SPM under the conditions of increased and decreased perfusion, and with regions of interest (ROIs) using cerebral template. P value was set at 0.01 level. Results: SPM analysis showed that rCBF decreased in cerebral areas including bilateral putamen, superior temporal gyrus and precuneus, and right orbital gyrus, superior and middle frontal gyrus, and left temporo-occipital lobule and superior parietal gyrus, and vermis. rCBF was also increased in left inferior frontal gyrus and posterior cingulate gyrus. With ROIs method, rCBF was decreased in right anterior frontal, temporo-parietal lobule and left temporo-occipital lobule. Conclusions: The study supports the viewpoint that rCBF abnormality of fronto-striatal circuits is involved in OCD patients. SPM method is a forceful tool in analyzing cerebral regional characters

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

    Science.gov (United States)

    Alves-Pinto, Ana; Blumenstein, Tobias; Turova, Varvara; Lampe, Renée

    2016-01-01

    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. 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. 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 pattern correlated significantly with the degree of spasticity. This study confirmed the occurrence of altered lower leg muscle activation patterns in patients with CP during cycling on a recumbent ergometer. There is a need to develop feedback systems that can inform patients and therapists of an incorrect muscle activation during cycling and support the training of a more physiological activation

  9. 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.

  10. Excess salt exacerbates blood-brain barrier disruption via a p38/MAPK/SGK1-dependent pathway in permanent cerebral ischemia

    Science.gov (United States)

    Zhang, Tongshuai; Fang, Shaohong; Wan, Cong; Kong, Qingfei; Wang, Guangyou; Wang, Shuangshuang; Zhang, Haoqiang; Zou, Haifeng; Sun, Bo; Sun, Wei; Zhang, Yao; Mu, Lili; Wang, Jinghua; Wang, Jing; Zhang, Haiyu; Wang, Dandan; Li, Hulun

    2015-01-01

    High salt diet (HSD) is one of the most important risk factors that contribute to many vascular diseases including ischemic stroke. One proposed mechanism underlying the disruption of blood-brain barrier (BBB) mediated by HSD is indirectly through enhancing blood pressure. The direct role of HSD on BBB integrity is unclear. Our purpose is to determine whether and how HSD might be involved in BBB breakdown during ischemia. To test that, we induced model of cerebral ischemia by permanent middle cerebral artery ligation (pMCAL) in either normal diet or HSD fed mice. We observed that HSD significantly enhanced ischemic brain damage which was associated with enhanced BBB disruption, increased leukocytes infiltration and loss of tight junction (TJ) proteins expression without apparently altering blood pressure. Our in vitro experiment also revealed that sodium chloride (NaCl) treatment down-regulated TJ protein expression by endothelial cells and substantially increased BBB permeability during starvation. Inhibition of p38/MAPK/SGK1 pathway eliminated the effect of NaCl on BBB permeability in vitro. In addition, we noticed a positive correlation between urinary sodium levels and ischemic lesion size in stroke patients. Together, our study demonstrates a hypertension-independent role of HSD during ischemia and provides rationale for post cerebral ischemic attack management. PMID:26549644

  11. Quantitative activation patterns of cerebral blood flow during mental stimulation after intravenous injection of sup(195m)Au

    International Nuclear Information System (INIS)

    Lindner, P.; Nickel, O.

    1983-01-01

    A previously reported theory for quantitative cerebral blood flow measurement for nondiffusible radiotracers has been applied to patients after stroke and to volunteers undergoing a mental stimulation exercise. Quantitative measurements of cerebral blood flow pattern in p-a and lateral projections of the brain are obtained using the short lived (30s) isotope sup(195m)Au from the recently developed generator. The energy spectrum of the eluate from the generator shows two strong photon peaks, one at an energy level of 68 KeV and a second at 262 KeV. The low-energy peak is suitable for perfusion studies of the cerebral hemispheres in lateral projection, being without ''look through'' effect. The high-energy level is good for studies in p-a-projection. Studies last less than 1 min and can be repeated after 3 min. Parametric images for quantitative regional cerebral blood flow can be generated, in which the avascular region following stroke can be detected. Quantitative activation patterns of cerebral blood flow during mental stimulation can be generated. The results show that it is possible to measure cerebral blood-flow patterns not only with freely diffusible indicators like Xenon but also with nondiffusible indicators. (orig.)

  12. The neurobiology of glucocerebrosidase-associated parkinsonism: a positron emission tomography study of dopamine synthesis and regional cerebral blood flow

    Science.gov (United States)

    Goker-Alpan, Ozlem; Masdeu, Joseph C.; Kohn, Philip D.; Ianni, Angela; Lopez, Grisel; Groden, Catherine; Chapman, Molly C.; Cropp, Brett; Eisenberg, Daniel P.; Maniwang, Emerson D.; Davis, Joie; Wiggs, Edythe; Berman, Karen F.

    2012-01-01

    Mutations in GBA, the gene encoding glucocerebrosidase, the enzyme deficient in Gaucher disease, are common risk factors for Parkinson disease, as patients with Parkinson disease are over five times more likely to carry GBA mutations than healthy controls. Patients with GBA mutations generally have an earlier onset of Parkinson disease and more cognitive impairment than those without GBA mutations. We investigated whether GBA mutations alter the neurobiology of Parkinson disease, studying brain dopamine synthesis and resting regional cerebral blood flow in 107 subjects (38 women, 69 men). We measured dopamine synthesis with 18F-fluorodopa positron emission tomography, and resting regional cerebral blood flow with H215O positron emission tomography in the wakeful, resting state in four study groups: (i) patients with Parkinson disease and Gaucher disease (n = 7, average age = 56.6 ± 9.2 years); (ii) patients with Parkinson disease without GBA mutations (n = 11, 62.1 ± 7.1 years); (iii) patients with Gaucher disease without parkinsonism, but with a family history of Parkinson disease (n = 14, 52.6 ± 12.4 years); and (iv) healthy GBA-mutation carriers with a family history of Parkinson disease (n = 7, 50.1 ± 18 years). We compared each study group with a matched control group. Data were analysed with region of interest and voxel-based methods. Disease duration and Parkinson disease functional and staging scores were similar in the two groups with parkinsonism, as was striatal dopamine synthesis: both had greatest loss in the caudal striatum (putamen Ki loss: 44 and 42%, respectively), with less reduction in the caudate (20 and 18% loss). However, the group with both Parkinson and Gaucher diseases showed decreased resting regional cerebral blood flow in the lateral parieto-occipital association cortex and precuneus bilaterally. Furthermore, two subjects with Gaucher disease without parkinsonian manifestations showed diminished striatal dopamine. In conclusion, the

  13. 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.

  14. Local cerebral blood flow and local oxygen consumption in prolonged hemiplegic migraine

    International Nuclear Information System (INIS)

    Baron, J.C.; Lebrun-Grandie, P.; Serdaru, M.; Bousser, M.G.; Lhermitte, F.; Cabanis, E.

    1982-09-01

    This work gives the results of a study by positron emission tomography of the cerebral blood flow (CBF), oxygen-extraction rate (O 2 E) and oxygen consumption (CMRO 2 ) during severe and prolonged attack of hemiplegic migraine. The salient facts observed are a high (CBF) in the brain hemisphere affected (ruling out the hypothesis of a persistent cerebral ischemia), together with a collapsed O 2 E (''luxury perfusion'') and especially preservation of the CMRO 2 suggesting a decoupling not only between CBF and CMRO 2 but also between CMRO 2 and functional state of the tissue. Some time after the attack a new study showed the recoupling between CBF and CMRO 2 , but with the latter reduced in the affected hemisphere although the clinical and tomodensitometric state had returned to normal. These new observations should not however be improperly generalised to all migraines, given the unusual characteristics of the disorder in our patient [fr

  15. [Regional cerebral blood flow-SPECT "OFF-ON": a case report of catatonia].

    Science.gov (United States)

    Moreno Caballero, M; Corchos González, N; De Antonio Rubio, I; Gómez-Río, M; Guerrero Velázquez, J F; Rodríguez Fernández, A; Llamas Elvira, J M

    2014-01-01

    We report the case of a patient with a long history of dysthymia and major depressive episodes requiring repeated hospitalization. We describe the most recent episode, associated with catatonia symptomatology and features suggestive of cognitive impairment. The absence of a clear initial psychopharmacological response alongside the clinical severity made the patient a potential candidate for electroconvulsive therapy (ECT). A regional cerebral blood flow SPECT (SPECT-rCBF), performed to rule out concomitant Alzheimer disease (AD), revealed a markedly decreased neocortical uptake, with no definitive pattern of concomitant primary cognitive impairment. Because a gradual clinical improvement was observed in the patient, with evidence of enhanced cerebral reperfusion in a second SPECT-rCBF study at two weeks after admission, the application of ECT was discounted and an expectant attitude was adopted. Copyright © 2013 Elsevier España, S.L. y SEMNIM. All rights reserved.

  16. 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......-distribution pattern was determined within the first 12 hours after development of hepatic encephalopathy (HE) stage 4 before and during hyperventilation. Ten consecutive patients (median age 48 [range 33-57] years) with FHF and 9 healthy controls (median age 54 [24-58] years) had rCBF determined by single photon...... emission computed tomography (SPECT) using intravenous injection of 133Xenon. For determination of high resolution CBF pattern, the patients were also studied with 99mTc-hexa-methylpropyleneamine oxime (HMPAO) in the hyperventilation condition. There was no significant difference in the rCBF distribution...

  17. The effect of blood transfusion on cerebral hemodynamics in preterm infants.

    Science.gov (United States)

    Koyano, Kosuke; Kusaka, Takashi; Nakamura, Shinji; Nakamura, Makoto; Konishi, Yukihiko; Miki, Takanori; Ueno, Masaki; Yasuda, Saneyuki; Okada, Hitoshi; Nishida, Tomoko; Isobe, Kenichi; Itoh, Susumu

    2013-07-01

    Anemia of prematurity commonly occurs in infants with very low birth weight; blood transfusion is an important treatment. However, there is no clear evidence to support the criteria currently widely used, based on blood hemoglobin (bHb) and hematocrit indices. Previous studies showed that overtransfusion or a low threshold for transfusion could induce complications or neurologic sequelae, respectively. We hypothesized that a cerebral hemodynamic index may provide an appropriate criterion for determining the need for transfusion in anemic preterm infants. We used near-infrared time-resolved spectroscopy to measure cerebral hemoglobin oxygen saturation (ScO2 ) and cerebral blood volume (CBV) before and after transfusion in 19 infants (24 measurements) with anemia of prematurity. The median gestational age was 27 weeks 0 days, median birth weight was 751 g, and median postconceptual age at transfusion was 30 weeks 4 days. bHb levels before and after transfusion (mean ± SD) were 9.3 ± 1.4 and 13.7 ± 1.3 g/dL, respectively. After transfusion, CBV significantly decreased from 2.63 ± 0.60 to 2.13 ± 0.26 mL/100 g of brain, and ScO2 significantly increased from 72.8 ± 4.3% to 74.7 ± 4.2%. After transfusion, CBV changes were significantly greater with low compared to high pretransfusion Hb levels. This reflected the physiologic response to severe anemia in premature infants, which is to increase CBV and decrease ScO2 . Therefore, CBV and ScO2 may be useful markers for determining the need for transfusion in very-low-birth-weight infants. © 2012 American Association of Blood Banks.

  18. Quantitative Analysis of Regional Cerebral Blood Flow using 99mTc-HMPAO SPECT in Parkinson's Disease

    International Nuclear Information System (INIS)

    Lee, Myung Chul; Bae, Sang Kyun; Chung, June Key; Koh, Chang Soon; Roh, Jae Kyu; Myung, Ho Jin; Lee, Myung Hae

    1992-01-01

    Regional cerebral blood flow were measured in 10 patients with Parkinson's disease and 12 normal persons using 99m Tc-HMPAO SPECT. Reconstructed images were interpreted qualitatively and were compared with those findings of CT. For the quantitative analysis, six pairs of region of interest matched with the perfusion territories of large cerebral arteries and cerebellar hemisphere were determined. From the count values, indices showing the degree of asymmetry between right and left cerebral or cerebellar hemisphere, cerebral asymmetry index (ASI) and percent index of cerebellar asymmetry (PIA), and an index showing change of each region, region to cerebellum ratio (RCR) were obtained. ASI of normal persons and patients were 0.082 ± 0.033 and 0.108 ± 0.062, respectively and PIA were -0.4 ± 0.7% and -0.7 ± 1.0%, respectively, which showed no statistically significant difference between normal persons and patients. Among 10 RCR's, those of both regions of basal ganglia and both regions of anterior cerebral artery were significantly reduced. We concluded that the most significant reduction of regional cerebral blood flow in patients with Parkinson's disease was observed in the regions of basal ganglia and in the regions of anterior cerebral artery, and the degree of change in hemispheric blood flow was similar in both hemisphere.

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

    International Nuclear Information System (INIS)

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

    1995-01-01

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

  20. 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...... reaching CBF values up to 6 times normal at normal MABP of about 60 to 70 mmHg, and severe ischemia reaching CBF values close to zero in large cortical areas at MABP of 30 mmHg. CVP remained essentially unchanged at 10--15 mmHg. The severe and prolonged asphyxia rendered the blood-brain barrier leaky...

  1. Mechanisms of murine cerebral malaria: Multimodal imaging of altered cerebral metabolism and protein oxidation at hemorrhage sites.

    Science.gov (United States)

    Hackett, Mark J; Aitken, Jade B; El-Assaad, Fatima; McQuillan, James A; Carter, Elizabeth A; Ball, Helen J; Tobin, Mark J; Paterson, David; de Jonge, Martin D; Siegele, Rainer; Cohen, David D; Vogt, Stefan; Grau, Georges E; Hunt, Nicholas H; Lay, Peter A

    2015-12-01

    Using a multimodal biospectroscopic approach, we settle several long-standing controversies over the molecular mechanisms that lead to brain damage in cerebral malaria, which is a major health concern in developing countries because of high levels of mortality and permanent brain damage. Our results provide the first conclusive evidence that important components of the pathology of cerebral malaria include peroxidative stress and protein oxidation within cerebellar gray matter, which are colocalized with elevated nonheme iron at the site of microhemorrhage. Such information could not be obtained previously from routine imaging methods, such as electron microscopy, fluorescence, and optical microscopy in combination with immunocytochemistry, or from bulk assays, where the level of spatial information is restricted to the minimum size of tissue that can be dissected. We describe the novel combination of chemical probe-free, multimodal imaging to quantify molecular markers of disturbed energy metabolism and peroxidative stress, which were used to provide new insights into understanding the pathogenesis of cerebral malaria. In addition to these mechanistic insights, the approach described acts as a template for the future use of multimodal biospectroscopy for understanding the molecular processes involved in a range of clinically important acute and chronic (neurodegenerative) brain diseases to improve treatment strategies.

  2. Caffeine and human cerebral blood flow: A positron emission tomography study

    Energy Technology Data Exchange (ETDEWEB)

    Cameron, O.G.; Modell, J.G.; Hariharan, M. (Univ. of Michigan Medical Center, Ann Arbor (USA))

    1990-01-01

    Positron emission tomography (PET) was used to quantify the effect of caffeine on whole brain and regional cerebral blood flow (CBF) in humans. A mean dose of 250 mg of caffeine produced approximately a 30% decrease in whole brain CBF; regional differences in caffeine effect were not observed. Pre-caffeine CBF strongly influenced the magnitude of the caffeine-induced decrease. Caffeine decreased p{sub a}CO{sub 2} and increased systolic blood pressure significantly; the change in p{sub a}CO{sub 2} did not account for the change in CBF. Smaller increases in diastolic blood pressure, heart rate, plasma epinephrine and norepinephrine, and subjectively reported anxiety were also observed.

  3. Cerebral blood volume measured with inhaled C15O and positron emission tomography

    International Nuclear Information System (INIS)

    Martin, W.R.; Powers, W.J.; Raichle, M.E.

    1987-01-01

    Local cerebral blood volume (CBV) has been measured previously with inhaled 11 CO and positron emission tomography (PET). The model used assumes that equilibrium in tracer concentration has occurred between arterial and systemic venous blood before the PET measurement is made. To verify that this model may be used with the much shorter half-lived C 15 O, we have simultaneously measured arterial and venous blood radioactivity following C 15 O inhalation. Equilibrium occurred 95 +/- 39 s after inhalation (n = 7). If the PET measurement is commenced prior to arteriovenous equilibrium, significant errors occur in calculated CBV. These data indicate that C 15 O may be used as a tracer for CBV measurement provided that emission data collection commences at approximately 120 s after inhalation. Strict quality control measures must be maintained to minimize the contamination of administered C 15 O with 15 O-labeled CO 2

  4. Impact of kangaroo mother care on cerebral blood flow of preterm infants.

    Science.gov (United States)

    Korraa, Afaf A; El Nagger, Alyaa A I; Mohamed, Ragaa Abd El-Salam; Helmy, Noha M

    2014-11-13

    Kangaroo mother care (KMC) has been widely used to improve the care of preterms and low birth weight infants. However, very little is known about cerebral hemodynamics responses in preterm infants during KMC intervention. The aim of this study is to evaluate the changes of cerebral blood flow (CBF) in middle cerebral artery, before and after a 30 minute application of KMC in stable preterm infants. It is a prospective, pre-post test without a control group study. CBF flow paremeters were measured with Doppler ultrasonography in one middle cerebral artery. Sixty preterm stable infants were assessed before and after 30 min KMC. CBF indices were assessed in different positions before KMC, forty neonates in supine position and 20 in vertical suspension (baby is held vertically away from the skin of his mother). Other dependent variables heart rate and mean arterial blood pressure and Spo2 were also studied before and after KMC. The mean gestational age of the infants was (32 ± 2 weeks), and mean birth weight was (2080 ± 270 gm). Comparing CBF indices (Pulsatility index and Resistive index) before and after KMC has shown a significant decrease in both Pulsatility index (PI) and Resistive index (RI) after 30 min. KMC, the mean values were (2.0 ± 0.43 vs 1.68 ± 0.33 & 0.81 ± 0.05 vs 0.76 ± 0.06 respectively P < 0.05*) with mean difference (0.32 & 95% CI 0.042-0.41 & 0.05 & 95% CI 0.04 to 0.06 respectively P < 0.05*) and increase in end diastolic velocity & mean velocity 30 min of KMC (10.97 ± 4.63 vs. 15.39 ± 5.66 P < 0.05*& 25.66 ± 10.74 vs. 32.86 ± 11.47 P < 0.05* ) with mean difference (- 4.42 & 95% CI -5.67 to -3.18 and -7.21 & 95% CI - 9.41 to 5.00 respectively). These changes indicate improvement in CBF. No correlation has been found between CBF parameters and studied vital signs or SpO2. Kangaroo mother care improves cerebral blood flow, thus it might influence the structure and promote

  5. Noninvasive quantitative measurement of cerebral blood flow with [sup 123]I-IMP; Lung monitoring method

    Energy Technology Data Exchange (ETDEWEB)

    Oguchi, Kazuhiro; Kasuga, Toshio; Sone, Shusuke; Nakanishi, Fumiko; Ito, Atsuko (Shinshu Univ., Matsumoto, Nagano (Japan). Faculty of Medicine); Tanizaki, Yoshio

    1993-06-01

    In order to perform a less invasive determination of regional cerebral blood flow (rCBF) using N-isopropyl-p-[[sup 123]I] iodoamphetamine (I-123-IMP), we used the lung clearance curve as a substitute for the arterial blood activity curve as an input function. We assumed that a major portion of the intravenously injected I-123-IMP initially accumulates in the lung and then is gradually cleared from the lung pool to enter the systemic circulation. In this case lung clearance could be considered nearly equal to the integral of arterial blood activity shown during the examination. We used a single probe detector to obtain the lung clearance curve as the difference between sequential lung activity and peak lung activity. The absolute value of the sequential change in arterial blood activity was estimated from the differentiated lung clearance curve compared with the arterial blood activity that was estimated by actual blood sampling once during the examination. The rCBF was calculated by the thus estimated arterial blood activity curve and brain activity by SPECT image using the microsphere model. The values of rCBF obtained by this method were similar to those obtained by the continuous arterial sampling method, and this lung monitoring method was thought to be applicable to clinical use. (author).

  6. Comparative Aspects of the Regulation of Cutaneous and Cerebral Microcirculation During Acute Blood Loss

    Directory of Open Access Journals (Sweden)

    I. A. Ryzhkov

    2017-01-01

    Full Text Available Objective. Using laser Doppler flowmetry (LDF and wavelet-analysis of microvascular blood flow oscillations to determine the features of regulation of cutaneous and cerebral microhemocirculation at early stages of acute fixed volume blood loss.Materials and methods.Experiments were carried out on 31 male outbred rats weighing 300 g to 400 g. The animals were anesthetized by intraperitoneal injection of pentobarbital (45 mg/kg. The tail artery was catheterized for invasive measurement of mean blood pressure (BP and blood withdrawal. The LDF method (ЛАКК-02 device, LAZMA, Russia was used to record microvascular blood flow simultaneously in the right ear and the pial vessels of the left parietal region. An acute fixed-volume hemorrhage model was used. The target blood loss volume was 30% of the total blood volume (TBV. Within 10 minutes after the end of hemorrhage (posthemorrhagic period, the blood pressure and the LDF-gram were recorded. The following LDF-gram parameters were analyzed: the mean value of IP; the maximum amplitude of blood flow oscillations (Amax and the corresponding frequency (Fmax in the frequency band 0.01—0.4 Hz. Statistical processing of the data was performed using Statistica 7.0.Results. At baseline, the values of IP, Аmax and Fmax in the brain were higher than in the skin. At posthemorrhagic period, BP decreased, on average, from 105 to 41 mm Hg. Against this background, IP in the skin decreased by 65%, while in the brain it reduced only by 17%, as compared with the baseline values (P0,0001. In the same time these organs were characterized by a unidirectional dynamics of patterns of fluxmotion. In both investigated organs, Amax increased sharply, and Fmax decreased. In posthemorrhagic period, fluxmotion not only «slowed down», but was also synchronized in a relatively narrow frequency band: for the skin Fmax was about 0.04 Hz (at the border of the endothelial and neurogenic band, for the brain about 0.09 Hz

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

    International Nuclear Information System (INIS)

    Jeong, Y. J.; Park, M. J.; Cha, J. G.; Kim, S. H.; Kim, J. W.; Kang, D. Y.

    2005-01-01

    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 PD patients

  8. 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

  9. Time-resolved near-infrared technique for bedside monitoring of absolute cerebral blood flow

    Science.gov (United States)

    Diop, Mamadou; Tichauer, Kenneth M.; Elliott, Jonathan T.; Migueis, Mark; Lee, Ting-Yim; St. Lawrence, Keith

    2010-02-01

    A primary focus of neurointensive care is monitoring the injured brain to detect harmful events that can impair cerebral blood flow (CBF). Since current non-invasive bedside methods can only indirectly assess blood flow, the goal of this research was to develop an optical technique for measuring absolute CBF. A time-resolved near-infrared (NIR) apparatus was built and its ability to accurately measure changes in optical properties was demonstrated in tissue-mimicking phantoms. The time-resolved system was combined with a bolus-tracking method for measuring CBF using the dye indocyanine green (ICG) as an intravascular flow tracer. Cerebral blood flow was measured in newborn piglets and for comparison, CBF was concurrently measured using a previously developed continuous-wave NIR method. Measurements were acquired with both techniques under three conditions: normocapnia, hypercapnia and following occlusion of the carotid arteries. Mean CBF values (N = 3) acquired with the TR-NIR system were 31.9 +/- 11.7 ml/100g/min during occlusion, 39.7 +/- 1.6 ml/100g/min at normocapnia, and 58.8 +/- 9.9 ml/100g/min at hypercapnia. Results demonstrate that the developed TR-NIR technique has the sensitivity to measure changes in CBF; however, the CBF measurements were approximately 25% lower than the values obtained with the CW-NIRS technique.

  10. Cerebral blood flow measured by positron emission tomography during normothermic cardiopulmonary bypass: An experimental porcine study

    DEFF Research Database (Denmark)

    Thomassen, Sisse Anette; Kjaergaard, Benedict; Alstrup, Aage Kristian Olsen

    2018-01-01

    min and, thereafter, all the pigs returned to 60 mL/kg/min for another 60 min. The MAP was measured continuously and the CBF was measured by positron emission tomography (PET) during spontaneous circulation and at each CPB pump flow after 30 min of steady state. Results: Two pigs were excluded due...... emission tomography (PET) using 15O-labelled water with no pharmacological interventions to maintain the MAP. Methods: Eight pigs (69-71 kg) were connected to normothermic CPB. After 60 minutes (min) with a CPB pump flow of 60 mL/kg/min, the pigs were changed to either 35 mL/kg/min or 47.5 mL/kg/min for 60......Background: Mean arterial blood pressure (MAP) and/or pump flow during normothermic cardiopulmonary bypass (CPB) are the most important factors of cerebral perfusion. The aim of this study was to explore the influence of CPB blood flow on cerebral blood flow (CBF) measured by dynamic positron...

  11. Regional cerebral blood flow and brain atrophy in senile dementia of Alzheimer type (SDAT)

    International Nuclear Information System (INIS)

    Okada, Kazunori; Kobayashi, Shoutai; Yamaguchi, Shuhei; Kitani, Mituhiro; Tsunematsu, Tokugoro

    1987-01-01

    To investigate the relationship between the reduction of cerebal blood flow and brain atrophy in SDAT, these were measured in 13 cases of senile dementia of Alzheimer type, and compared to 15 cases of multi-infarct Dementia, 39 cases of lacunar infarction without dementia (non-demented CVD group) and 69 cases of aged normal control. Brain atrophy was evaluated by two-dimensional method on CT film by digitizer and regional cerebral blood flow (rCBF) was measured by 133 Xe inhalation method. The degree of brain atrophy in SDAT was almost similar of that of MID. But it was more severe than that of non-demented group. MID showed the lowest rCBF among these groups. SDAT showed significantly lower rCBF than that of aged control, but rCBF in SDAT was equal to that of lacunar stroke without dementia. Focal reduction of cerebral blood flow in bilateral fronto-parietal and left occipital regions were observed in SDAT. Verbal intelligence score (Hasegawa's score) correlated with rCBF and brain atrophy index in MID, and a tendency of correlation between rCBF and brain atrophy in MID was also observed. However, there was no correlation among those indices in SDAT. These findings suggest that the loss of brain substance dose not correspond to the reduction of rCBF in SDAT and simultaneous measurement of rCBF and brain atrophy was useful to differ SDAT from MID. (author)

  12. Three-dimensional echo-planar cine imaging of cerebral blood supply using arterial spin labeling.

    Science.gov (United States)

    Shrestha, Manoj; Mildner, Toralf; Schlumm, Torsten; Robertson, Scott Haile; Möller, Harald

    2016-12-01

    Echo-planar imaging (EPI) with CYlindrical Center-out spatiaL Encoding (EPICYCLE) is introduced as a novel hybrid three-dimensional (3D) EPI technique. Its suitability for the tracking of a short bolus created by pseudo-continuous arterial spin labeling (pCASL) through the cerebral vasculature is demonstrated. EPICYCLE acquires two-dimensional planes of k-space along center-out trajectories. These "spokes" are rotated from shot to shot about a common axis to encode a k-space cylinder. To track a bolus of labeled blood, the same subset of evenly distributed spokes is acquired in a cine fashion after a short period of pCASL. This process is repeated for all subsets to fill the whole 3D k-space of each time frame. The passage of short pCASL boluses through the vasculature of a 3D imaging slab was successfully imaged using EPICYCLE. By choosing suitable sequence parameters, the impact of slab excitation on the bolus shape could be minimized. Parametric maps of signal amplitude, transit time, and bolus width reflected typical features of blood transport in large vessels. The EPICYCLE technique was successfully applied to track a short bolus of labeled arterial blood during its passage through the cerebral vasculature.

  13. Investigation of regional cerebral blood flow in alcoholic Korsakoff's syndrome with 123I-IMP SPECT

    International Nuclear Information System (INIS)

    Nakamura, Makoto; Nomura, Soichiro; Kato, Motoichiro; Nakazawa, Tsuneyuki.

    1995-01-01

    Regional cerebral blood flow (rCBF) was determined quantitatively by single photon emission computed tomography (SPECT) using N-isopropyl-p-[ 123 I]iodoamphetamine ( 123 I-IMP) in 6 patients with alcoholic Korsakoff's syndrome (A group). The findings were compared with concurrently available findings from 6 alcoholic patients with no evidence of cerebral disordres such as Korsakoff's syndrome and dementia (B group) and 4 healthy persons (C group). In both A and B groups, diffuse decrease in blood flow was significantly observed in the entire brain, as compared with the C group; no significant difference in the decreased blood flow existed between the A and B groups. According to the WAIS results, the patients in the A group were classified as 'typical Korsakoff's syndrome' (full IQ of 90 or more) and as 'serious Korsakoff's syndrome' (full IQ of 89 or less). rCBF in the thalamus was significantly lower in the A group of patients with typical Korsakoff's syndrome than the B group. These findings may reflect the variety of alcoholic Korsakoff's syndrome. This may also have an implication for the possible classification of several types in this syndrome. (N.K.)

  14. 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

    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

  15. 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...... of the entire hemisphere. The focal rCBF increases were localized to the superior part of the temporal regions, the prefrontal regions, the frontal eye fields, and the orbitofrontal regions. Significant asymmetries were found in particular in the superior temporal region with the left side showing a more...

  16. Measurement of cerebral blood flow by means of intravenous injection of 133Xe

    International Nuclear Information System (INIS)

    Hliscs, R.; Franke, W.G.

    1977-01-01

    In administering 133 Xe intravenous injection is an alternative to arterial puncture. After injection the patient breathes into a closed respiratory loop in order to concentrate the activity in the body. Simultaneously, a scintillation camera scans the activity in brain and expired air in fixed time intervals. After opening the respiratory loop the wash process is recorded. The histograms recorded on magnetic tape and core store are corrected with regard to recirculation applying a new procedure. Data for calculating blood flow in grey and white cerebral tissue are obtained from three-compartment analysis

  17. 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...

  18. Cerebral blood flow in acute and chronic ischemic stroke using xenon-133 inhalation tomography

    DEFF Research Database (Denmark)

    Vorstrup, S; Paulson, O B; Lassen, N A

    1986-01-01

    Serial measurements of cerebral blood flow (CBF) were performed in 12 patients with acute symptoms of ischemic cerebrovascular disease. CBF was measured by xenon-133 inhalation and single photon emission computer tomography. Six patients had severe strokes and large infarcts on the CT scan...... in the infarct and peri-infarct tissue. Of the remaining 6 patients, one had a pontine infarct and one had no lesions on the CT scan, both having normal angiograms and CBF maps. Four patients had small deep or subcortical CT lesions, and showed a slight, but persistent CBF reduction of about 6-8% in the parietal...

  19. Monitoring variables affecting positron emission tomography measurements of cerebral blood flow in anaesthetized pigs

    DEFF Research Database (Denmark)

    Alstrup, Aage Kristian Olsen; Zois, Nora Elisabeth; Simonsen, Mette

    2018-01-01

    Background Positron emission tomography (PET) imaging of anaesthetized pig brains is a useful tool in neuroscience. Stable cerebral blood flow (CBF) is essential for PET, since variations can affect the distribution of several radiotracers. However, the effect of physiological factors regulating...... and the monitoring parameters. Results No significant statistical correlations were found between CBF and the nine monitoring variables. However, we found that arterial carbon dioxide tension (PaCO2) and body temperature were important predictors of CBF that should be observed and kept constant. In addition, we...

  20. Effect of axillary blockade on regional cerebral blood flow during static handgrip

    DEFF Research Database (Denmark)

    Friedman, D B; Friberg, L; Mitchell, J H

    1991-01-01

    Regional cerebral blood flow (rCBF) was determined at rest and during static handgrip before and after regional blockade with lidocaine. A fast rotating single photon emission computer tomograph system with 133Xe inhalation was used at orbitomeatal plane (OM) +2.5 and +6.5 cm in eight subjects. M...... static handgrip, there was no increase in rCBF after partial sensory and motor blockade. Thus bilateral activation occurs in the premotor and motor sensory cortex during static handgrip, and this activation requires neural feedback from the contracting muscles....

  1. Regional cerebral blood flow in psychiatry: The resting and activated brains of schizophrenic patients

    International Nuclear Information System (INIS)

    Gur, R.E.

    1984-01-01

    The investigation of regional brain functioning in schizophrenia has been based on behavioral techniques. Although results are sometimes inconsistent, the behavioral observations suggest left hemispheric dysfunction and left hemispheric overreaction. Recent developments in neuroimaging technology make possible major refinements in assessing regional brain function. Both anatomical and physiological information now be used to study regional brain development in psychiatric disorders. This chapter describes the application of one method - the xenon-133 technique for measuring regional cerebral blood flow (rCBF) - in studying the resting and activated brains of schizoprenic patients

  2. 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

  3. Impaired cerebral cortex development and blood pressure regulation in FGF-2-deficient mice.

    Science.gov (United States)

    Dono, R; Texido, G; Dussel, R; Ehmke, H; Zeller, R

    1998-08-03

    Fibroblast growth factor-2 (FGF-2) has been implicated in various signaling processes which control embryonic growth and differentiation, adult physiology and pathology. To analyze the in vivo functions of this signaling molecule, the FGF-2 gene was inactivated by homologous recombination in mouse embryonic stem cells. FGF-2-deficient mice are viable, but display cerebral cortex defects at birth. Bromodeoxyuridine pulse labeling of embryos showed that proliferation of neuronal progenitors is normal, whereas a fraction of them fail to colonize their target layers in the cerebral cortex. A corresponding reduction in parvalbumin-positive neurons is observed in adult cortical layers. Neuronal defects are not limited to the cerebral cortex, as ectopic parvalbumin-positive neurons are present in the hippocampal commissure and neuronal deficiencies are observed in the cervical spinal cord. Physiological studies showed that FGF-2-deficient adult mice are hypotensive. They respond normally to angiotensin II-induced hypertension, whereas neural regulation of blood pressure by the baroreceptor reflex is impaired. The present genetic study establishes that FGF-2 participates in controlling fates, migration and differentiation of neuronal cells, whereas it is not essential for their proliferation. The observed autonomic dysfunction in FGF-2-deficient adult mice uncovers more general roles in neural development and function.

  4. Increased cerebral blood volume and oxygen consumption in neonatal brain injury

    Science.gov (United States)

    Grant, P Ellen; Roche-Labarbe, Nadege; Surova, Andrea; Themelis, George; Selb, Juliette; Warren, Elizabeth K; Krishnamoorthy, Kalpathy S; Boas, David A; Franceschini, Maria Angela

    2009-01-01

    With the increasing interest in treatments for neonatal brain injury, bedside methods for detecting and assessing injury status and evolution are needed. We aimed to determine whether cerebral tissue oxygenation (StO2), cerebral blood volume (CBV), and estimates of relative cerebral oxygen consumption (rCMRO2) determined by bedside frequency-domain near-infrared spectroscopy (FD-NIRS) have the potential to distinguish neonates with brain injury from those with non-brain issues and healthy controls. We recruited 43 neonates ≤ 15 days old and > 33 weeks gestational age (GA): 14 with imaging evidence of brain injury, 29 without suspicion of brain injury (4 unstable, 6 stable, and 19 healthy). A multivariate analysis of variance with Newman–Keuls post hoc comparisons confirmed group similarity for GA and age at measurement. StO2 was significantly higher in brain injured compared with unstable neonates, but not statistically different from stable or healthy neonates. Brain-injured neonates were distinguished from all others by significant increases in CBV and rCMRO2. In conclusion, although NIRS measures of StO2 alone may be insensitive to evolving brain injury, increased CBV and rCMRO2 seem to be useful for detecting neonatal brain injury and suggest increased neuronal activity and metabolism occurs acutely in evolving brain injury. PMID:19675563

  5. Cerebral blood flow imaging by I-123 IMP and Tc-99m HM-PAO

    Energy Technology Data Exchange (ETDEWEB)

    Uno, Koichi; Yoshikawa, Kyosan; Minoshima, Satoshi; Imaseki, Keiko; Arimizu, Noboru; Yamaura, Akira; Uematsu, Sadao

    1988-02-01

    SPECT studies with either N-isopropyl-p-(I-123)iodo- amphetamine (I-123 IMP) or Tc-99m hexamethyl propylene amine oxime (Tc-99m HM-PAO) were cuncurrently performed in 12 patients with brain disorders, comprising cerebral infarction (7), cerebral aneurysm (one), intracranial hemorrhage (3), and subdural hematoma (one). Whereas I-123 IMP was taken up gradually into the brain, the uptake of Tc-99m-HM-PAO in the brain reached the peak immediately after the iv injection, with 90% or more remaining constant by 15 min postinjection. On early SPECT images, a high uptake of I-123 IMP was observed in the lung, and the uptake of Tc-99m HM-PAO was observed as well in the soft tissue of cervical region. In all patients except for one, decreased rCBF was observed in the lesions on both I-123 and Tc-99m SPECT scans. Both of the radiopharmaceuticals were analogous in that decreased blood flow corresponded to cerebral lesions. (Namekawa, K).

  6. 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...

  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...... indicate that FTD-3 vascular pathology might primarily affect brain capillaries....

  8. The baboon model under anaesthesia for in vivo cerebral blood flow studies using single photon emission computed tomographic (SPECT) techniques

    Energy Technology Data Exchange (ETDEWEB)

    Dormehl, I.; Redelinghuys, F.; Hugo, N. [Pretoria Univ. (South Africa); Oliver, D.; Pilloy, W. [Medical Univ. of Southern Africa (MEDUNSA), Pretoria (South Africa)

    1992-12-31

    Single photon computed tomography of the brain can be useful in animal experimentation directed towards cerebral conditions. A well established and understood baboon model, necessarily under anaesthesia, could especially be valuable in such investigations. Six normal baboons were studied under various anesthetic agents and their combinations: ketamine, thiopentone, pentobarbitone and halothane. Cerebral blood flow (CBF) studies were performed with {sup 99m}Tc-HMPAO. CBF effects from various anaesthesia were detected, requiring careful choice of the anaesthesia for cerebral investigations. (author). 13 refs, 4 figs, 3 tabs.

  9. The baboon model under anaesthesia for in vivo cerebral blood flow studies using single photon emission computed tomographic (SPECT) techniques

    International Nuclear Information System (INIS)

    Dormehl, I.; Redelinghuys, F.; Hugo, N.; Oliver, D.; Pilloy, W.

    1992-01-01

    Single photon computed tomography of the brain can be useful in animal experimentation directed towards cerebral conditions. A well established and understood baboon model, necessarily under anaesthesia, could especially be valuable in such investigations. Six normal baboons were studied under various anesthetic agents and their combinations: ketamine, thiopentone, pentobarbitone and halothane. Cerebral blood flow (CBF) studies were performed with 99m Tc-HMPAO. CBF effects from various anaesthesia were detected, requiring careful choice of the anaesthesia for cerebral investigations. (author). 13 refs, 4 figs, 3 tabs

  10. 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 (Pbacterial meningitis, indicating...

  11. Macro- and microrheological parameters of blood in patients with cerebral and peripheral atherosclerosis: the molecular change mechanisms after pentoxifylline treatment.

    Science.gov (United States)

    Muravyov, Alexei V; Bulaeva, Svetlana V; Tikhomirova, Irina A; Zamishlayev, Andrey V; Uzikova, Ekaterina V; Miloradov, Mikhail Ju

    2011-01-01

    This study was designed to evaluate hemorheological changes in patients with cerebrovascular disease (CVD) and peripheral arterial disease (PAD) after 4 weeks of pentoxifylline therapy as well as to study red blood cell microrheological variables after the cell incubation with pentoxifylline and some phosphodiesterase (PDE) activity inhibitors. The patients with CVD (n = 50) and PAD (n = 33) were treated with pentoxifylline (400 mg, thrice a day) for 4 weeks. Before and after drug therapy the hemorheological measurements including plasma and whole blood viscosity, red blood cell aggregation (RBCA) and deformability (RBCD) were completed. In vitro study RBCs were incubated with: 1) Vinpocetine--inhibitor PDE-1, 10 μM; 2) Rolipram--PDE-4, 10 μM; 3) Isobutyl-methylxanthine (IBMX)--nonselective PDE inhibitor, 100 μM and with pentoxifylline, 10 μM The cell incubation was performed at 37 °C for 15 min. There were the positive changes of hemorheological profile after 4 weeks of the pentoxifylline therapy both in CVD and PAD patients. The marked RBCD changes were observed after the in vitro cell pentoxifylline treatment as well. Perhaps it is connected with the inhibition of the phosphodiesterase activity in RBCs. An application of drugs and chemicals that can inhibit the PDE activity resulted in RBCD rise and RBCA decrease. The experiments with the use of selective PDE inhibitors have revealed the similar red cell deformability changes. Vinpocetine increased RBCD significantly (p RBCA, but the most pronounced effect had Vinpocetine (50%; p < 0.05). Thus, administered pentoxifylline, daily (1200 mg), during four weeks improves hemorheological profile and especially its microrheological part as well as the blood transport capacity in subjects with cerebral and peripheral vascular disorders. It is most probably red cell microrheological control mechanisms may be associated with the phosphodiesterase activity alterations.

  12. High-Sodium Diet Has Opposing Effects on Mean Arterial Blood Pressure and Cerebral Perfusion in a Transgenic Mouse Model of Alzheimer's Disease.

    Science.gov (United States)

    Taheri, Saeid; Yu, Jin; Zhu, Hong; Kindy, Mark S

    2016-10-04

    Cerebral ionic homeostasis impairment, especially Ca2+, has been observed in Alzheimer's disease (AD) and also with hypertension. Hypertension and AD both have been implicated in impaired cerebral autoregulation. However, the relationship between the ionic homeostasis impairment in AD and hypertension and cerebral blood flow (CBF) autoregulation is not clear. To test the hypothesis that a high-salt diet regimen influences the accumulation of amyloid-β (Aβand CBF) and CBF, exacerbates cognitive decline, and increases the propensity to AD. Double transgenic mice harboring the amyloid-β protein precursor (APPswe), and presenilin-1 (PSEN1) along with control littermates, 2 months of age at initiation of special diet, were divided into 4 groups: Group A, APP/PS1 and Group B, controls fed a high-sodium (4.00%) chow diet for 3 months; Group C, APP/PS1 and Group D, controls fed a low-sodium (0.08%) regular chow diet for 3 months. Mean arterial blood pressure (MAP) and CBF were measured noninvasively using the tail MAP measurement device and magnetic resonance imaging, respectively. Aβ plaques numbers in the cortex and hippocampus of APP/PS1 were quantified. In contrary to controls, APP/PS1 mice fed a high-salt diet did not show markedly elevated mean systolic and diastolic blood pressure (134±4.8 compared with 162±2.8 mmHg, and 114±5.0 compared with 137±20 mmHg, phigh-salt diet increased CBF in both APP/PS1 and controls and did not alter the cerebral tissue integrity. Aβ plaques were significantly reduced in the cortex and hippocampus of mice fed a high-salt diet. These data suggest that a high-salt diet differently affects MAP and CBF in APP/PS1 mice and controls.

  13. 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

    2017-11-01

    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. © 2016 International Society of

  14. Exercise Training Increases Parietal Lobe Cerebral Blood Flow in Chronic Stroke: An Observational Study

    Directory of Open Access Journals (Sweden)

    Andrew D. Robertson

    2017-09-01

    Full Text Available Exercise is increasingly recommended as an essential component of stroke rehabilitation, yet uncertainty remains with respect to its direct effect on the cerebral vasculature. The current study first demonstrated the repeatability of pseudo-continuous arterial spin labeling (ASL magnetic resonance imaging (MRI in older adults with stroke, and then investigated the change in cerebrovascular function following a 6-month cardiovascular rehabilitation program. In the repeatability study, 12 participants at least 3 months post-stroke underwent two ASL imaging scans 1 month apart. In the prospective observational study, eight individuals underwent ASL imaging and aerobic fitness testing before and after a 6-month cardiovascular rehabilitation program. Cerebral blood flow (CBF and the spatial coefficient of variation of CBF (sCoV were quantified to characterize tissue-level perfusion and large cerebral artery transit time properties, respectively. In repeat scanning, intraclass correlation (ICC indicated moderate test-retest reliability for global gray matter CBF (ICC = 0.73 and excellent reliability for sCoV (ICC = 0.94. In the observational study, gray matter CBF increased after training (baseline: 40 ± 13 vs. 6-month: 46 ± 12 ml·100 g−1·min−1, P = 0.036. The greatest change occurred in the parietal lobe (+18 ± 12%. Gray matter sCoV, however, did not change following training (P = 0.31. This study provides preliminary evidence that exercise-based rehabilitation in chronic stroke enhances tissue-level perfusion, without changing the relative hemodynamic properties of the large cerebral arteries.

  15. Exercise Training Increases Parietal Lobe Cerebral Blood Flow in Chronic Stroke: An Observational Study

    Science.gov (United States)

    Robertson, Andrew D.; Marzolini, Susan; Middleton, Laura E.; Basile, Vincenzo S.; Oh, Paul I.; MacIntosh, Bradley J.

    2017-01-01

    Exercise is increasingly recommended as an essential component of stroke rehabilitation, yet uncertainty remains with respect to its direct effect on the cerebral vasculature. The current study first demonstrated the repeatability of pseudo-continuous arterial spin labeling (ASL) magnetic resonance imaging (MRI) in older adults with stroke, and then investigated the change in cerebrovascular function following a 6-month cardiovascular rehabilitation program. In the repeatability study, 12 participants at least 3 months post-stroke underwent two ASL imaging scans 1 month apart. In the prospective observational study, eight individuals underwent ASL imaging and aerobic fitness testing before and after a 6-month cardiovascular rehabilitation program. Cerebral blood flow (CBF) and the spatial coefficient of variation of CBF (sCoV) were quantified to characterize tissue-level perfusion and large cerebral artery transit time properties, respectively. In repeat scanning, intraclass correlation (ICC) indicated moderate test-retest reliability for global gray matter CBF (ICC = 0.73) and excellent reliability for sCoV (ICC = 0.94). In the observational study, gray matter CBF increased after training (baseline: 40 ± 13 vs. 6-month: 46 ± 12 ml·100 g−1·min−1, P = 0.036). The greatest change occurred in the parietal lobe (+18 ± 12%). Gray matter sCoV, however, did not change following training (P = 0.31). This study provides preliminary evidence that exercise-based rehabilitation in chronic stroke enhances tissue-level perfusion, without changing the relative hemodynamic properties of the large cerebral arteries. PMID:29033829

  16. 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.

  17. [EFFECT OF VOLUNTARY BREATH-HOLDING AND COGNITIVE LOADS ON REGIONAL CEREBRAL BLOOD FLOW AND BIOELECTRIC ACTIVITY OF THE BRAIN].

    Science.gov (United States)

    Moreva, T I; Pasekova, O B; Kriushev, E S; Dobrokvashina, E I; Moreva, O V; Builov, S P; Smirnov, O A; Bragin, L Kh; Voronkov, Iu I

    2015-01-01

    Cerebral blood flow and bioelectric activity were studied in 10 normal volunteers in order to assess cerebrovascular reactivity during different types of functional testing. The transcranial Doppler was used to measure linear blood velocity (LBV) in the middle cerebral artery (MCA) during maximal voluntary breath-holding (apnea), controlled verbal association test and tactile memory test. Simultaneous electroencephalography (EEG) registered the bioelectric activity of the brain cortex. Both investigations were performed continuously in the course of each test. Breath-holding induced a smooth symmetric increase of CMA blood velocity; LBV rose to maximum values in the majority of the volunteered subjects. Two subjects with small focal changes in the brain's white matter displayed an asymmetric blood flow reaction to apnea. Gain in LBV was materially less during the cognitive tests; the verbal test decreased LBV in one half of the subjects and increased LBV in the other. The tactile memory test increased LBV which was particularly high in the left CMA of all subjects. LBV dynamics during the cognitive tests was essentially different from what was observed in apnea. Blood flow variations in the course of equally the verbal and tactile tests had a regular undulatory character. Concurrent LBV and EEG monitoring made it possible to compare and contrast dynamics of the cerebral blood velocity and bioelectric activity directly during testing and thus to reveal peculiar reactions of the cerebral blood flow to cognitive and physiological testing.

  18. Does long-term passive stretching alter muscle-tendon unit mechanics in children with spastic cerebral palsy?

    Science.gov (United States)

    Theis, Nicola; Korff, Thomas; Mohagheghi, Amir A

    2015-12-01

    Cerebral palsy causes motor impairments during development and many children may experience excessive neural and mechanical muscle stiffness. The clinical assumption is that excessive stiffness is thought to be one of the main reasons for functional impairments in cerebral palsy. As such, passive stretching is widely used to reduce stiffness, with a view to improving function. However, current research evidence on passive stretching in cerebral palsy is not adequate to support or refute the effectiveness of stretching as a management strategy to reduce stiffness and/or improve function. The purpose was to identify the effect of six weeks passive ankle stretching on muscle-tendon unit parameters in children with spastic cerebral palsy. Thirteen children (8-14 y) with quadriplegic/diplegic cerebral palsy were randomly assigned to either an experimental group (n=7) or a control group (n=6). The experimental group underwent an additional six weeks of passive ankle dorsiflexion stretching for 15 min (per leg), four days per week, whilst the control group continued with their normal routine, which was similar for the two groups. Measures of muscle and tendon stiffness, strain and resting length were acquired pre- and post-intervention. The experimental group demonstrated a 3° increase in maximum ankle dorsiflexion. This was accompanied by a 13% reduction in triceps surae muscle stiffness, with no change in tendon stiffness. Additionally, there was an increase in fascicle strain with no changes in resting length, suggesting muscle stiffness reductions were a result of alterations in intra/extra-muscular connective tissue. The results demonstrate that stretching can reduce muscle stiffness by altering fascicle strain but not resting fascicle length. Copyright © 2015 Elsevier Ltd. All rights reserved.

  19. ALTERATION OF RHEOLOGICAL PROPERTIES OF BLOOD AT PATIENTS WITH TONSILLITIS

    Directory of Open Access Journals (Sweden)

    I.A. Zaitseva

    2008-09-01

    Full Text Available Complex research of rheological properties of blood at patients with lacunar tonsillitis lead depending on the period of disease. It is shown, that inflammatory process at patients to a great extent defines disturbances of rheological properties of blood. During normalization of a clinical presentation of disease there is no full recovery of rheological properties of blood due to preservation of blood raised viscosity and low deformability of erythrocytes membranes.

  20. Effects of midodrine hydrochloride on blood pressure and cerebral blood flow during orthostasis in persons with chronic tetraplegia.

    Science.gov (United States)

    Wecht, Jill M; Rosado-Rivera, Dwindally; Handrakis, John P; Radulovic, Miroslav; Bauman, William A

    2010-09-01

    To determine the mean arterial pressure (MAP) and middle cerebral artery mean blood flow velocity (MFV) responses to 5 and 10mg midodrine during head-up tilt (HUT) in persons with tetraplegia. Prospective dose-response trial. James J. Peters Veterans Administration Medical Center. Persons (N=10) with chronic tetraplegia (duration of injury=23+/-11 y). A dose titration study was performed over 3 testing days: control (no drug), 5mg midodrine (5mg), or 10mg midodrine (10mg) during 30 minutes of baseline (predrug/no drug), 30 minutes of supine rest postdrug/no drug, 15 minutes of progressive HUT (5 minutes at 15 degrees , 25 degrees , 35 degrees ), and 45 minutes of 45 degrees HUT. MAP and MFV response to midodrine supine and during HUT. Ten milligrams of midodrine significantly increased MAP while supine and during the HUT maneuver. Of note, the mean increase in MAP during HUT with 10mg was a result of a robust effect in 2 persons, with minimal change in the remaining 8 study subjects. The reduction in cerebral MFV during HUT was attenuated with 10mg. These findings suggest that midodrine 10mg may be efficacious for treatment of hypotension and orthostatic hypotension in select persons with tetraplegia. Although midodrine is routinely prescribed to treat orthostatic hypotension, the results of our work suggests limited efficacy of this agent, but additional studies in a larger sample of subjects with spinal cord injury should be performed.

  1. 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...... to study subjects under resting conditions and during performance of the Wisconsin Card Sorting Test. The study is a replication of a previous investigation in an independent series of patients and healthy volunteers. The patients had significantly lower relative blood flow in prefrontal regions during...... activation than did the healthy volunteers. An earlier series of 19 patients and 7 healthy volunteers was studied using exactly the same procedure. Analyses of the combined samples from the two studies (43 patients and 24 healthy volunteers) showed the patients to have significantly lower relative flow...

  2. Regional cerebral blood flow after long-term exposure to carbon disulfide

    International Nuclear Information System (INIS)

    Aaserud, O.; Russell, D.; Nyberg-Hansen, R.; Joergensen, E.B.; Gjerstad, L.; Rootwelt, K.; Nakstad, P.; Hommeren, O.J.; Tvedt, B.

    1992-01-01

    Sixteen former rayon viscose workers were investigated four years after the exposure to carbon disulfide was discontinued. Median age was 58 years (range 43-65 years), median exposure time was 17 years (range 10-35 years). Encephalopathy was diagnosed in altogether 14 workers. To further explore pathophysiological mechanisms, cerebrovascular investigations were employed. Doppler ultrasound examination of the precerebral vessels in 15 workers showed a slight stenosis of the left internal carotid artery in one. Regional cerebral blood flow investigation (rCBF) with single photon emission computerized tomography (SPECT) with Xenon-133 gas was performed in 14. There was no significant difference from a control group. Regional side-to-side asymmetries beyond reference limits were demonstrated in eight workers. The abnormalities were modest, but may indicate a tendency toward focal blood flow disturbances in workers with long-term exposure to carbon disulfide. (au)

  3. Cerebral blood flow studied by 133Xe inhalation technique in parkinsonism: loss of hyperfrontal pattern

    International Nuclear Information System (INIS)

    Bes, A.; Gueell, A.; Fabre, N.; Dupui, P.; Victor, G.; Geraud, G.

    1983-01-01

    Cerebral blood flow (grey matter flow) in parkinsonism requires further investigation. The noninvasive method of 133 Xe inhalation permits study of larger numbers of subjects than previously used invasive techniques such as the intracarotid 133 Xe injection method. Measurements were made in this laboratory in 30 subjects having Parkinson's disease. Mean hemispheric blood flow (F1) values were 70.4 +/- 9.3 ml/100 g/min, compared to 76.3 for a group of age-matched normal subjects, which is a decrease of -7.8%. The most striking difference was the loss of the hyperfrontal distribution in parkinsonism. The prefrontal F1 values were only 1.8% greater than the hemisphere grey matter flow, compared with 8.5% in controls of a similar age group

  4. Quantification of cerebral blood flow and its clinical usefulness. Application of SPECT to psychiatry

    International Nuclear Information System (INIS)

    Matsuda, Hiroshi; Uema, Takeshi; Kogure, Daisuke; Takano, Harumasa; Terada, Tomo

    1998-01-01

    Brain perfusion SPECT using 99m Tc-ethyl-cysteinate dimer ( 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 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 99m Tc-ECD are useful for objective evaluation of regional abnormality in brain function in psychiatric diseases. (author)

  5. 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)

  6. Effects of whole blood viscosity and plasma NOx on cardiac function and cerebral blood flow in children with chronic kidney disease

    Science.gov (United States)

    Buyan, Necla; Akçaboy, Meltem; Göktaş, Tayfun; Kula, Serdar; Nazlıel, Bijen; Çakar, Nilgün; Uncu, Nermin; Çelik, Bülent; Erbaş, Deniz

    2017-11-13

    Background/aim: The aim of the study was to investigate the effects of whole blood viscosity and plasma nitric oxide on cerebral and cardiovascular risks associated with chronic kidney disease. Materials and methods: The study group consisted of 40 pediatric patients and 21 healthy control subjects. Hematologic and biochemical variables, viscosity and plasma nitric oxide levels, echocardiographic findings, and middle cerebral artery blood flow velocity were examined. Results: Viscosity values of patients were significantly lower than those of the control group. Lower values of hematocrit, total protein, and albumin and higher values of ferritin in all patient groups resulted in significantly low viscosity levels. Plasma nitric oxide levels were higher in all patient groups than those in the controls. No statistically significant difference was present in middle cerebral artery blood flow velocity between the patient and control groups. Even when systolic functions were normal, the patient group had significant deterioration in diastolic functions, suggesting morbidity and mortality risks. Conclusions: Cerebral blood flow velocities were not affected by viscosity and nitric oxide levels, suggesting that cerebral circulation has the ability to make adaptive modulation. The metabolism of nitric oxide levels needs further investigation and studies in patients with chronic renal disease.

  7. [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.

  8. Non-linear models for the detection of impaired cerebral blood flow autoregulation.

    Directory of Open Access Journals (Sweden)

    Max Chacón

    Full Text Available The ability to discriminate between normal and impaired dynamic cerebral autoregulation (CA, based on measurements of spontaneous fluctuations in arterial blood pressure (BP and cerebral blood flow (CBF, has considerable clinical relevance. We studied 45 normal subjects at rest and under hypercapnia induced by breathing a mixture of carbon dioxide and air. Non-linear models with BP as input and CBF velocity (CBFV as output, were implemented with support vector machines (SVM using separate recordings for learning and validation. Dynamic SVM implementations used either moving average or autoregressive structures. The efficiency of dynamic CA was estimated from the model's derived CBFV response to a step change in BP as an autoregulation index for both linear and non-linear models. Non-linear models with recurrences (autoregressive showed the best results, with CA indexes of 5.9 ± 1.5 in normocapnia, and 2.5 ± 1.2 for hypercapnia with an area under the receiver-operator curve of 0.955. The high performance achieved by non-linear SVM models to detect deterioration of dynamic CA should encourage further assessment of its applicability to clinical conditions where CA might be impaired.

  9. 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.

  10. Effect of intranasally administered insulin on cerebral blood flow and perfusion

    DEFF Research Database (Denmark)

    Akintola, Abimbola A.; van Opstal, Anna M.; Westendorp, Rudi G.

    2017-01-01

    Insulin, a vasoactive modulator regulating peripheral and cerebral blood flow, has been consistently linked to aging and longevity. In this proof of principle study, using a randomized, double-blinded, placebo-controlled crossover design, we explored the effects of intranasally administered insul.......28±6.75 mL/100g/min versus 63.31±6.84 mL/100g/min, P=0.003). Thus, intranasal insulin improved tissue perfusion of the occipital cortical brain region and the thalamus in older adults.......Insulin, a vasoactive modulator regulating peripheral and cerebral blood flow, has been consistently linked to aging and longevity. In this proof of principle study, using a randomized, double-blinded, placebo-controlled crossover design, we explored the effects of intranasally administered insulin...... labelling. Total flow through the major cerebropetal arteries was unchanged in both young and old. In the older participants, intranasal insulin compared to placebo increased perfusion through the occipital gray matter (65.2±11.0 mL/100g/min vs 61.2±10.1 mL/100g/min, P=0.001), and in the thalamus (68...

  11. Sub-Clinical Cognitive Decline and Resting Cerebral Blood Flow in Middle Aged Men

    Science.gov (United States)

    Henriksen, Otto Mølby; Hansen, Naja Liv; Osler, Merete; Mortensen, Erik Lykke; Hallam, Dorte Merete; Pedersen, Esben Thade; Chappell, Michael; Lauritzen, Martin Johannes; Rostrup, Egill

    2017-01-01

    Background Although dementia is associated with both global and regional cerebral blood flow (CBF) changes, little is known about cerebral perfusion in the early pre-clinical stages of cognitive decline preceding overt cognitive dysfunction. The aim of this study was to investigate the association of early sub-clinical cognitive decline with CBF. Materials and Methods The study participants were recruited from a cohort of Danish men born in 1953. Based on a regression model we selected men who performed better (Group A, n = 94) and poorer (Group B, n = 95) on cognitive testing at age 57 than expected from testing at age 20. Participants underwent supplementary cognitive testing, blood sampling and MRI including measurements of regional and global CBF. Results Regional CBF was lower in group B than in group A in the posterior cingulate gyrus and the precuneus. The associations were attenuated when corrected for global atrophy, but remained significant in regions of interest based analysis adjusting for regional gray matter volume and vascular risk factors. No influence of group on global CBF was observed. Conclusions We conclude that early sub-clinical cognitive decline is associated with reduced perfusion in the precuneus and posterior cingulate gyrus independently of regional atrophy and vascular risk factors, but cannot be statistically separated from an association with global atrophy. PMID:28095458

  12. Effect of enalapril maleate on cerebral blood flow in patients with chronic heart failure.

    Science.gov (United States)

    Kamishirado, H; Inoue, T; Fujito, T; Kase, M; Shimizu, M; Sakai, Y; Takayanagi, K; Morooka, S; Natsui, S

    1997-08-01

    The effect of enalapril on cerebral blood flow (CBF) was studied in 11 patients with chronic heart failure (NYHA II or III, dilated cardiomyopathy in 6 and old myocardial infarction in 5). CBF was evaluated by analyzing the Patlak-Plot curve obtained from radionuclide angiography with technetium-99m hexamethylpropylene amine oxime (99mTC-HM-PAO). Cardiac index (CI) and stroke volume (SV) were simultaneously measured by impedance cardiography. These measurements were performed before and at four weeks after daily administration of 5 mg enalapril. The stroke volume, cardiac index, and heart rate were not significantly changed after four weeks of enalapril administration. However, CBF was increased by 6.5% from 36.72 +/- 4.66 to 39.13 +/- 5.65 mL/100g/min (P < 0.05). These results suggest that enalapril increased cerebral blood flow, which was not related to increased cardiac output in congestive heart failure. Patlak-Plot analysis of radionuclide angiography using 99mTC-HM-PAO may be available for quantitative assessment of brain perfusion.

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

    International Nuclear Information System (INIS)

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

    2007-01-01

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

  14. 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.

  15. 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.

  16. 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)

  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. Blood Pressure Control in Aging Predicts Cerebral Atrophy Related to Small-Vessel White Matter Lesions

    Directory of Open Access Journals (Sweden)

    Kyle C. Kern

    2017-05-01

    Full Text Available Cerebral small-vessel damage manifests as white matter hyperintensities and cerebral atrophy on brain MRI and is associated with aging, cognitive decline and dementia. We sought to examine the interrelationship of these imaging biomarkers and the influence of hypertension in older individuals. We used a multivariate spatial covariance neuroimaging technique to localize the effects of white matter lesion load on regional gray matter volume and assessed the role of blood pressure control, age and education on this relationship. Using a case-control design matching for age, gender, and educational attainment we selected 64 participants with normal blood pressure, controlled hypertension or uncontrolled hypertension from the Northern Manhattan Study cohort. We applied gray matter voxel-based morphometry with the scaled subprofile model to (1 identify regional covariance patterns of gray matter volume differences associated with white matter lesion load, (2 compare this relationship across blood pressure groups, and (3 relate it to cognitive performance. In this group of participants aged 60–86 years, we identified a pattern of reduced gray matter volume associated with white matter lesion load in bilateral temporal-parietal regions with relative preservation of volume in the basal forebrain, thalami and cingulate cortex. This pattern was expressed most in the uncontrolled hypertension group and least in the normotensives, but was also more evident in older and more educated individuals. Expression of this pattern was associated with worse performance in executive function and memory. In summary, white matter lesions from small-vessel disease are associated with a regional pattern of gray matter atrophy that is mitigated by blood pressure control, exacerbated by aging, and associated with cognitive performance.

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

    International Nuclear Information System (INIS)

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

    1986-01-01

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

  20. 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

    2017-09-01

    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 VEGF 165 and SDF-1 in a rat model of cerebral infarction. METHODS An adenoviral vector expressing VEGF 165 and SDF-1 connected via an internal ribosome entry site was constructed (Ad- VEGF 165 -SDF-1). A rat model of middle cerebral artery occlusion (MCAO) was established; either Ad- VEGF 165 -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 VEGF 165 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- VEGF 165 -SDF-1 vector mediated coexpression of VEGF 165 and SDF-1 in multiple sites around the ischemic core, including the cortex, corpus striatum, and hippocampal granular layer. Coexpression of VEGF 165 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 VEGF 165 and SDF-1 gene therapy represents a potential strategy for improving vascular remodeling and recovery of neural function after

  1. Acetazolamide tomoscintigraphic study of the effect on cerebral blood perfusion using 123I isopropyliodoamphetamine (IAMP 123I). Preliminary results

    International Nuclear Information System (INIS)

    Moretti, J.L.; Defer, G.; Delmon, L.; Caillat-Vigneron, N.; Devinoy, A.; Sergent, A.; Safai, N.; Cesaro, P.

    1987-01-01

    The effect of Acetazolamide (Diamox) on cerebral blood perfusion has been studied in ten patients with cerebral ischemia. Previously, the dose and time effects was tested in two independent groups of male Wistar rats. The cerebral blood perfusion was estimated in man by the cerebral distribution of Isopropyliodoamphetamine 123 I (IAMP 123 I) visualised with conventional emission tomography. The study involved two identical examinations, the second one followed an injection of 1 g of Diamox. The biodistribution of IAMP 123 I was studied in rats without or after different doses of Diamox by counting of target organs. In animals, the pulmonary activity curve versus the dose showed a maximum for 100 mg/kg as the cerebral activity curve increased proportional to the dose. The study of time effect indicated that the best conditions for cerebral imaging by IAMP 123 I seems to take place twenty minutes after the injection of Diamox. In man, the results obtained after Diamox confirmed the known effect of decreasing of vascular resistance, especially in brain. The total cerebral activity in IAMP 123 I was increased in all the patients. In six patients of the ten, the activity of the ischemic region was lower than expected because of the high uptake of the controlateral hemisphere. This phenomenon may increase the sensitivity of detecting lightly hypoperfused cerebral regions. In some other patients, a high activity of the ischemic zone seems to proove an early regulation of the regional blood flow and may be an element of good pronostic. Making an Acetazolamide injection before a tomoscintigraphic examination of the brain with IAMP 123 I seems to provide conventional imaging with sensitivity and pronostic value [fr

  2. 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.

  3. Face cooling with mist water increases cerebral blood flow during exercise: Effect of changes in facial skin blood flow

    Directory of Open Access Journals (Sweden)

    Taiki eMiyazawa

    2012-08-01

    Full Text Available Facial cooling (FC increases cerebral blood flow (CBF at rest and during exercise; however, the mechanism of this response remains unclear. The purpose of the present study was to test our hypothesis that FC causes facial vasoconstriction that diverts skin blood flow (SkBFface towards the middle cerebral artery (MCA Vmean at rest and to a greater extent during exercise. Nine healthy young subjects (20 ± 2 yrs. underwent 3 minutes of FC by fanning and spraying the face with a mist of cold water (~4˚C at rest and during steady-state exercise (heart rate of 120 bpm. We focused on the difference between the averaged data acquired from 1 min immediately before FC and last 1 min of FC. SkBFface, MCA Vmean and MAP were higher during exercise than at rest. As hypothesized, FC decreased SkBFface at rest (-32 ± 4 % and to a greater extent during exercise (-64 ± 10%, P=0.012. Although MCA Vmean was increased by FC (Rest, +1.4 ± 0.5 cm/s; Exercise, +1.4 ± 0.6 cm/s, the amount of the FC-evoked changes in MCA Vmean at rest and during exercise differed among subjects. In addition, changes in MCA Vmean with FC did not correlate with concomitant changes in SkBFface (r=0.095, P=0.709. MAP was also increased by FC (Rest, +6.2 ± 1.4 mmHg; Exercise, +4.2 ± 1.2 mmHg. These findings suggest that the FC induced increase in CBF during exercise could not be explained only by change in SkBFface.

  4. Anatomical relationships of the pia mater to cerebral blood vessels in man.

    Science.gov (United States)

    Hutchings, M; Weller, R O

    1986-09-01

    Using scanning and transmission electron microscopy and light microscopy, the authors studied the human pia mater and its relationship to the entry of blood vessels into the normal cerebral cortex. The purpose of this investigation was to examine the long-established concept that the subarachnoid space communicates directly with the perivascular spaces of the cerebral cortex. Brains obtained post mortem from subjects with recent subarachnoid hemorrhage (SAH) and purulent leptomeningitis were studied by light microscopy to determine the permeability of the pia mater to red blood cells and inflammatory cells. Scanning electron microscopy showed that the normal pia mater is a flat sheet of cells that is reflected from the surface of the brain to form the outer coating of the meningeal vessels in the subarachnoid space. Transmission electron microscopy confirmed that the cells of the pia mater are joined by junctional complexes and form a continuous sheet that separates the subarachnoid space on one side from the subpial and perivascular spaces on the other. Thus, neither the pia mater nor the subarachnoid space extends into the brain beside blood vessels as they enter the cerebral cortex. The perivascular spaces were, in fact, found to be confluent with the subpial space and not with the subarachnoid space. In cases of recent SAH, red blood cells did not enter the perivascular spaces from the subarachnoid space; neither did India ink injected post mortem into the subarachnoid space pass into the perivascular spaces. The results of these crude tracer studies suggest that the pia mater is an effective barrier to the passage of particulate matter. Histological examination of brains of patients who had died with purulent leptomeningitis showed that inflammatory cells were present in the cortical perivascular spaces and in the contiguous subpial spaces. The presence of a large number of inflammatory cells in the subarachnoid space suggests that inflammatory cells readily

  5. Postnatal changes in local cerebral blood flow measured by the quantitative autoradiographic [14C]iodoantipyrine technique in freely moving rats

    International Nuclear Information System (INIS)

    Nehlig, A.; Pereira de Vasconcelos, A.; Boyet, S.

    1989-01-01

    The postnatal changes in local cerebral blood flow in freely moving rats were measured by means of the quantitative autoradiographic [ 14 C]iodoantipyrine method. The animals were studied at 10, 14, 17, 21 and 35 days and at the adult stage. At 10 days after birth, rates of blood flow were very low and quite homogeneous in most cerebral structures except in a few posterior areas. From these relatively uniform levels, values of local cerebral blood flow rose notably to reach a peak at 17 days in all brain regions studied. Rates of blood flow decreased between 17 and 21 days after birth and then increased from weaning time to reach the known characteristic distribution of the adult rat. The postnatal evolution of local cerebral blood in the rat is in good agreement with previous studies in other species such as dog and humans that also show higher rates of cerebral blood flow and glucose utilization at immature stages. However, in the rat, local cerebral blood flow and local cerebral glucose utilization are not coupled over the whole postnatal period studied, since blood flow rates reach peak values at 17 days whereas glucose utilization remains still quite low at that stage. The high rate of cerebral blood flow in the 17-day-old rat may reflect the energetic and biosynthetic needs of the actively developing brain that are completed by the summation of glucose and ketone body utilization

  6. 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. Copyright © 2012 Elsevier Inc. All rights reserved.

  7. Attacks of common migraine or hortons headache may not be accompanied by changes in regional cerebral blood flow

    International Nuclear Information System (INIS)

    Henriksen, L.; Aebelholt Krabbe, A.; Tfelt-Hansen, P.; Olesen, J.

    1982-01-01

    Vasospasm and cerebral ischemia, followed by cerebral and extracerebral vasodilation and hyperemia, are generally believed to form the common pathophysiology of the various subtypes of migraine. Mild forms of reactions are thought to result in common migraine (no neurological prodromes or accompaniments), and more severe reactions are thought to induce classical migraine. 8 induced common migraine attacks in 6 patients do not support this unitarian view, as no regional cerebral blood flow changes was found, but suggests a different pathophysiology in common migraine compaired to classical migraine. There are few features in Hortons headache to incriminate the cerebral vessels, and generally patients do not have symptoms attributable to cerebral involvement. In 6 out of 14 patients with known Hortons headache we succesfully induced an attack after alcohol alone or in combination with sublingual nitroglycerine. A slight hyperventilation occurred during the attack, correcting cerebral blood flow for these changes left mean CBF totally unchanged. No regional abnormalities occurred in any of the about 700 regions measured from during each investigation in neither the group with common migraine, nor in the patients with Hortons headache. (Author)

  8. Sufentanil does not increase cerebral blood flow in healthy human volunteers

    International Nuclear Information System (INIS)

    Mayer, N.; Weinstabl, C.; Podreka, I.; Spiss, C.K.

    1990-01-01

    The effect of sufentanil on human cerebral blood flow (CBF) was studied in seven unpremedicated, healthy volunteers 31 +/- 3.5 yr of age (mean +/- SD) and either sex. CBF (ml.100 g-1.min-1) was measured noninvasively with the 133Xe clearance technique and a scintillation camera before and after sufentanil 0.5 micrograms/kg administered intravenously. This technique provides values for global blood flow and for gray and white matter blood flow, and from 13 preselected regions in one hemisphere. After the administration of sufentanil, the volunteers were stimulated verbally in order to prevent their loss of consciousness and hypercarbia. Heart rate (HR), arterial pressure, oxyhemoglobin saturation, and end-tidal CO2 ETCO2 were recorded during the measurements. Neither global CBF (46.1 +/- 1.6 control and 43 +/- 1.9 after sufentanil, mean +/- SEM) nor gray (76.5 +/- 3.2 and 70.9 +/- 6.1) or white (22.7 +/- 1.5 and 24.2 +/- 1.6) matter blood flow changed significantly after sufentanil administration. As well, no significant differences in HR (72 +/- 4 control and 79 +/- 4 beats per min after sufentanil) and ETCO2 (39.8 +/- 1.4 and 41.1 +/- 1.1 mmHg) were observed. It is concluded that sufentanil has no significant effect on CBF in healthy human volunteers

  9. 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.

  10. 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.

  11. 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)

  12. Cerebral blood flow measured by positron emission tomography during normothermic cardiopulmonary bypass: an experimental porcine study.

    Science.gov (United States)

    Thomassen, Sisse Anette; Kjærgaard, Benedict; Alstrup, Aage Kristian Olsen; Munk, Ole Lajord; Frøkiær, Jørgen; Larsson, Anders; Rasmussen, Bodil Steen

    2018-01-01

    Mean arterial blood pressure (MAP) and/or pump flow during normothermic cardiopulmonary bypass (CPB) are the most important factors of cerebral perfusion. The aim of this study was to explore the influence of CPB blood flow on cerebral blood flow (CBF) measured by dynamic positron emission tomography (PET) using 15 O-labelled water with no pharmacological interventions to maintain the MAP. Eight pigs (69-71 kg) were connected to normothermic CPB. After 60 minutes (min) with a CPB pump flow of 60 mL/kg/min, the pigs were changed to either 35 mL/kg/min or 47.5 mL/kg/min for 60 min and, thereafter, all the pigs returned to 60 mL/kg/min for another 60 min. The MAP was measured continuously and the CBF was measured by positron emission tomography (PET) during spontaneous circulation and at each CPB pump flow after 30 min of steady state. Two pigs were excluded due to complications. CBF increased from spontaneous circulation to a CPB pump flow of 60 mL/kg/min. A reduction in CPB pump flow to 47.5 mL/kg/min (n=3) resulted in only minor changes in CBF while a reduction to 35 mL/kg/min (n=3) caused a pronounced change (correlation coefficient (R 2 ) 0.56). A return of CPB pump flow to 60 mL/kg/min was followed by an increase in CBF, except in the one pig with the lowest CBF during low flow (R 2 =0.44). CBF and MAP were not correlated (R 2 =0.20). In this experimental porcine study, a relationship was observed between pump flow and CBF under normothermic low-flow CPB. The effect of low pump flow on MAP showed substantial variations, with no correlation between CBF and MAP.

  13. Effects of cigarette smoking on cerebral blood flow in normal adults

    International Nuclear Information System (INIS)

    Shinohara, Takao

    1997-01-01

    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 2 inhalation and cigarette smoking. Sham smoking was performed during baseline and CO 2 inhalation. To eliminate the effects from PaCO 2 , CBF was adjusted based on the vascular reactivity to CO 2 and PaCO 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)

  14. Alteration in contractile G-protein coupled receptor expression by moist snuff and nicotine in rat cerebral arteries

    DEFF Research Database (Denmark)

    Sandhu, Hardip; Xu, Cang-Bao; Edvinsson, Lars

    2011-01-01

    The cardiovascular risk for users of use of Swedish snus/American snuff (moist tobacco) has been debated for a long time. The present study was designed to examine the effects of water- or lipid-soluble (DMSO-soluble) snus and nicotine, the most important substance in tobacco, on the expression...... of vasocontractile G-protein coupled receptors (GPCR), such as endothelin ET(B), serotonin 5-HT(1B), and thromboxane A(2) TP receptors, in rat cerebral arteries. Studies show that these vasocontractile GPCR show alterations by lipid-soluble cigarette smoke particles via activation of mitogen-activated protein...... kinases (MAPK). However, the effects of moist tobacco on the expression of GPCR are less studied. Rat middle cerebral arteries were isolated and organ cultured in serum-free medium for 24h in the presence of water-soluble snus (WSS), DMSO-soluble snus (DSS), or nicotine. The dose of snus and nicotine...

  15. Study on the alteration of bubaline blood biochemical composition ...

    African Journals Online (AJOL)

    Bubaline blood biochemistry as affected by slaughter was the agenda for this work. Blood samples were collected from 30 buffaloes from abattoirs before and at slaughter. After biochemical and statistical analysis (mean was compared with t-test), it was observed that the albumin, lactate dehydrogenase and creatine kinase ...

  16. Citalopram attenuated neurobehavioral, biochemical, and metabolic alterations in transient middle cerebral artery occlusion model of stroke in male Wistar rats.

    Science.gov (United States)

    Gupta, Sangeetha; Upadhayay, Deepti; Sharma, Uma; Jagannathan, Naranamangalam R; Gupta, Yogendra Kumar

    2018-04-15

    Oxidative stress and inflammation are implicated as cardinal mechanisms of neuronal death following stroke. In the present study citalopram (Cit) was investigated in a 2 h middle cerebral artery occlusion (MCAo) model of stroke in male Wistar rats. Pretreatment, posttreatment (Post Cit) and pre plus posttreatment (Pre + Post Cit) with Cit were evaluated for its neuroprotective effect. In pretreatment protocol, effect of Cit at three doses (2, 4, and 8 mg/kg) administered i.p., 1 h prior to MCAo was evaluated using neurological deficit score (NDS), motor deficit paradigms, and cerebral infarction 24 h post-MCAo. In posttreatment and pre plus posttreatment protocol, the effective dose of Cit (4 mg/kg) was administered i.p., 0.5 h post-reperfusion (Post Cit) only, and 1 h prior to MCAo and again at 0.5 h post-reperfusion (Pre + Post Cit), respectively. These two groups were assessed for NDS and cerebral infarction. Though NDS was significantly reduced in both Post Cit and Pre + Post Cit groups, significant reduction in cerebral infarction was evident only in Pre + Post Cit group. Infarct volume assessed by magnetic resonance imaging was significantly attenuated in Pre + Post Cit group (10.6 ± 1.1%) compared to MCAo control group (18.5 ± 3.0%). Further, Pre + Post Cit treatment significantly altered 17 metabolites along with attenuation of malondialdehyde, reduced glutathione, matrix metalloproteinases, and apoptotic markers as compared to MCAo control. These results support the neuroprotective effect of Cit, mediated through amelioration of oxidative stress, inflammation, apoptosis, and altered metabolic profile. © 2018 Wiley Periodicals, Inc.

  17. Evaluation of cerebral blood flow change after cigarette smoking using quantitative MRA.

    Directory of Open Access Journals (Sweden)

    Yunsun Song

    Full Text Available Changes in cerebral blood flow (CBF immediately after cigarette smoking (CS are still unclear. Our purpose was to evaluate the hemodynamic changes in each intracranial vessel after CS by using quantitative magnetic resonance angiography (MRA.Fifteen healthy male smokers less than 45 years old with more than 3 pack-year smoking history were enrolled in this study. The hemodynamic change in the vessels, represented by cerebral flow rate (CFR, ml/s and flow velocity (FV, cm/s, was quantitatively measured in eleven vascular segments of the brain using phase-contrast MRA. Two sets of data at each vessel before and after CS were statistically analyzed by paired t-test. Three of 15 participants, as a control group, followed all the procedures but did not smoke.Total CFR of the distal intracranial vessels (anterior, middle, and posterior cerebral arteries; ACA, MCA, and PCA was significantly reduced after CS by 7.3% (847 vs. 785 ml/s, p = 0.024. Such flow changes were statistically more significant in the anterior circulation (ACA and MCA compared to the posterior circulation (PCA. All distal intracranial vessels did not have significant FV change while peak systolic velocity and mean velocity dropped 7.4 and 4.3% and pulsatility index decreased 10.9% in the internal carotid artery. Regarding cross-sectional areas, all distal intracranial vessels showed diminished, and only MCA had a statistical significance (9.9 vs. 9.3 mm2, p = 0.016.There was a significant decrease of CFR after CS especially in the anterior circulation of twelve young male smokers. Considering the changes of FV and cross-sectional area all together, it can be suggested that cerebrovascular impedance increased after