The Experts below are selected from a list of 12303 Experts worldwide ranked by ideXlab platform
Tatsuya Higashi - One of the best experts on this subject based on the ideXlab platform.
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misery perfusion and amyloid deposition in atherosclerotic major Cerebral Artery Disease
NeuroImage: Clinical, 2019Co-Authors: Hiroshi Yamauchi, Shinya Kagawa, Masaaki Takahashi, Naoya Oishi, Masahiro Ono, Tatsuya HigashiAbstract:Abstract Although experimental studies have shown that global Cerebral hypoperfusion leads to amyloid deposition in the hemisphere with carotid Artery occlusion in rodents, the results of such occurrence are controversial in humans. Hence, we aim to determine whether global Cerebral hypoperfusion leading to decreased blood flow relative to metabolic demand [increased oxygen extraction fraction (OEF), misery perfusion] is associated with increases in amyloid deposition in the hemisphere with atherosclerotic major Cerebral Artery Disease in patients. We evaluated the distribution of β-amyloid plaques using positron emission tomography and a [18F]-pyridylbenzofuran derivative (18F-FPYBF-2) in 13 patients with unilateral atherosclerotic Disease of the internal carotid Artery (ICA) or middle Cerebral Artery (MCA) Disease and no cortical infarction. The distribution volume ratio (DVR) of 18F- FPYBF-2 was calculated using dynamic data and Logan graphical analysis with reference tissue and was correlated with the Cerebral blood flow (CBF), Cerebral metabolic rate of oxygen (CMRO2), and OEF, obtained from 15O-gas PET. The mean cortical value was calculated as the mean value within the frontal, posterior cingulate, precuneus, parietal, and lateral temporal cortical regions. Significant reductions in CBF and CMRO2 and increases in OEF were found in the hemisphere ipsilateral to the arterial lesion compared with the contralateral hemisphere. There was no significant difference for 18F-FPYBF-2 DVR between hemispheres. The ipsilateral to contralateral ratio of the 18F- FPYBF-2 DVR was increased in 3 patients, while the ipsilateral to contralateral OEF ratio was increased in 4 patients. The incidence of an increased hemispheric DVR ratio was significantly higher in patients with an increased hemispheric OEF ratio (3/4) than in patients without (0/9) (p
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progressive cortical neuronal damage and chronic hemodynamic impairment in atherosclerotic major Cerebral Artery Disease
Stroke, 2016Co-Authors: Hiroshi Yamauchi, Shinya Kagawa, Yoshihiko Kishibe, Masaaki Takahashi, Tatsuya HigashiAbstract:Background and Purpose— Cross-sectional studies suggest that chronic hemodynamic impairment may cause selective cortical neuronal damage in patients with atherosclerotic internal carotid Artery or middle Cerebral Artery occlusive Disease. The purpose of this longitudinal study was to determine whether the progression of cortical neuronal damage, evaluated as a decrease in central benzodiazepine receptors (BZRs), is associated with hemodynamic impairment at baseline or hemodynamic deterioration during follow-up. Methods— We evaluated the distribution of BZRs twice using positron emission tomography and 11 C-flumazenil over time in 80 medically treated patients with atherosclerotic internal carotid Artery or middle Cerebral Artery occlusive Disease that had no ischemic episodes during follow-up. Using 3D stereotactic surface projections, we quantified abnormal decreases in the BZRs in the Cerebral cortex within the middle Cerebral Artery distribution and correlated changes in the BZR index with the mean hemispheric values of hemodynamic parameters obtained from 15 O gas positron emission tomography. Results— In the hemisphere affected by arterial Disease, the BZR index in 40 patients (50%) was increased during follow-up (mean 26±20 months). In multivariable logistic regression analyses, increases in the BZR index were associated with the decreased Cerebral blood flow at baseline and an increased oxygen extraction fraction during follow-up. Increases in the oxygen extraction fraction during follow-up were associated with a lack of statin use. Conclusions— In patients with atherosclerotic internal carotid Artery or middle Cerebral Artery Disease, the progression of cortical neuronal damage was associated with hemodynamic impairment at baseline and hemodynamic deterioration during follow-up. Statin use may be beneficial against hemodynamic deterioration and therefore neuroprotective.
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increase in 18f fluoroacetate uptake in patients with chronic hemodynamic Cerebral ischemia
Stroke, 2015Co-Authors: Hiroshi Yamauchi, Shinya Kagawa, Yoshihiko Kishibe, Masaaki Takahashi, Ryuichi Nishii, Hiroshi Mizuma, Kazuhiro Takahashi, Hirotaka Onoe, Tatsuya HigashiAbstract:Background and Purpose—[18F]-fluoroacetate (18F-FACE) can be used for evaluating glial cell metabolism. Experimental studies have shown an increase in 18F-FACE uptake in rodent models of Cerebral ischemia. The aim of this study was to determine whether 18F-FACE uptake is increased in the noninfarcted Cerebral cortex in patients with hemodynamic ischemia owing to atherosclerotic internal carotid Artery or middle Cerebral Artery Disease. Methods—We evaluated 9 symptomatic patients with unilateral atherosclerotic internal carotid Artery or middle Cerebral Artery Disease and no cortical infarction using positron emission tomography with 18F-FACE and 15O-gases. 18F-FACE uptake during 40 to 60 minutes after injection was compared with the Cerebral blood flow, Cerebral metabolic rate of oxygen, oxygen extraction fraction, and Cerebral blood volume in the middle Cerebral Artery distributions. Results—Significant decreases of Cerebral blood flow and Cerebral metabolic rate of oxygen and increases of oxygen extract...
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misery perfusion blood pressure control and 5 year stroke risk in symptomatic major Cerebral Artery Disease
Stroke, 2015Co-Authors: Hiroshi Yamauchi, Shinya Kagawa, Yoshihiko Kishibe, Masaaki Takahashi, Tatsuya HigashiAbstract:Background and Purpose—The benefit of strict blood pressure (BP) control in high-risk patients with symptomatic major Cerebral Artery Disease and misery perfusion (MP) is controversial. Our purposes were (1) to determine whether MP is a predictor of a 5-year risk of subsequent stroke and (2) to investigate the relationships among BP during follow-up, MP, and the stroke risk. Methods—We studied 130 nondisabled patients with symptomatic major Cerebral Artery Disease. Baseline hemodynamic measurements were obtained from 15O-gas positron emission tomography, and patients received medical treatment and they were followed for 5 years or until stroke recurrence or death. Results—During 5 years, strokes occurred in 6 of 16 patients with MP and in 15 of 114 without MP (log-rank test; P<0.01). There were 4 (25%) ipsilateral ischemic strokes in patients with MP and 4 in those without MP (P<0.001). The risk of ipsilateral ischemic stroke declined markedly after 2 years, and there was only 1 ipsilateral ischemic strok...
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impaired perfusion modifies the relationship between blood pressure and stroke risk in major Cerebral Artery Disease
Journal of Neurology Neurosurgery and Psychiatry, 2013Co-Authors: Hiroshi Yamauchi, Shinya Kagawa, Yoshihiko Kishibe, Tatsuya Higashi, Masaaki TakahashiAbstract:Objective Blood pressure (BP) lowering may increase stroke risk in patients with symptomatic major Cerebral Artery Disease and impaired perfusion. To investigate the relationships among BP, impaired perfusion and stroke risk. Methods We retrospectively analysed data from 130 non-disabled, medically treated patients with either symptomatic extracranial carotid occlusion or intracranial stenosis or occlusion of the carotid Artery or middle Cerebral arteries. All patients had baseline haemodynamic measurements with 15 O-gas positron emission tomography and were followed for 2 years or until stroke recurrence or death. Results There was a negative linear relationship between systolic BP (SBP) and risk of stroke in the territory of the Diseased Artery. The 2-year incidence of ischaemic stroke in the territory in patients with normal SBP ( Conclusions Impaired perfusion modified the relationship between blood pressure and stroke risk, although this study had limitations including the retrospective analysis, the potentially biased sample, the small number of critical events and the fact that BP was measured only as a snapshot in clinic.
Hiroshi Yamauchi - One of the best experts on this subject based on the ideXlab platform.
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misery perfusion and amyloid deposition in atherosclerotic major Cerebral Artery Disease
NeuroImage: Clinical, 2019Co-Authors: Hiroshi Yamauchi, Shinya Kagawa, Masaaki Takahashi, Naoya Oishi, Masahiro Ono, Tatsuya HigashiAbstract:Abstract Although experimental studies have shown that global Cerebral hypoperfusion leads to amyloid deposition in the hemisphere with carotid Artery occlusion in rodents, the results of such occurrence are controversial in humans. Hence, we aim to determine whether global Cerebral hypoperfusion leading to decreased blood flow relative to metabolic demand [increased oxygen extraction fraction (OEF), misery perfusion] is associated with increases in amyloid deposition in the hemisphere with atherosclerotic major Cerebral Artery Disease in patients. We evaluated the distribution of β-amyloid plaques using positron emission tomography and a [18F]-pyridylbenzofuran derivative (18F-FPYBF-2) in 13 patients with unilateral atherosclerotic Disease of the internal carotid Artery (ICA) or middle Cerebral Artery (MCA) Disease and no cortical infarction. The distribution volume ratio (DVR) of 18F- FPYBF-2 was calculated using dynamic data and Logan graphical analysis with reference tissue and was correlated with the Cerebral blood flow (CBF), Cerebral metabolic rate of oxygen (CMRO2), and OEF, obtained from 15O-gas PET. The mean cortical value was calculated as the mean value within the frontal, posterior cingulate, precuneus, parietal, and lateral temporal cortical regions. Significant reductions in CBF and CMRO2 and increases in OEF were found in the hemisphere ipsilateral to the arterial lesion compared with the contralateral hemisphere. There was no significant difference for 18F-FPYBF-2 DVR between hemispheres. The ipsilateral to contralateral ratio of the 18F- FPYBF-2 DVR was increased in 3 patients, while the ipsilateral to contralateral OEF ratio was increased in 4 patients. The incidence of an increased hemispheric DVR ratio was significantly higher in patients with an increased hemispheric OEF ratio (3/4) than in patients without (0/9) (p
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progressive cortical neuronal damage and chronic hemodynamic impairment in atherosclerotic major Cerebral Artery Disease
Stroke, 2016Co-Authors: Hiroshi Yamauchi, Shinya Kagawa, Yoshihiko Kishibe, Masaaki Takahashi, Tatsuya HigashiAbstract:Background and Purpose— Cross-sectional studies suggest that chronic hemodynamic impairment may cause selective cortical neuronal damage in patients with atherosclerotic internal carotid Artery or middle Cerebral Artery occlusive Disease. The purpose of this longitudinal study was to determine whether the progression of cortical neuronal damage, evaluated as a decrease in central benzodiazepine receptors (BZRs), is associated with hemodynamic impairment at baseline or hemodynamic deterioration during follow-up. Methods— We evaluated the distribution of BZRs twice using positron emission tomography and 11 C-flumazenil over time in 80 medically treated patients with atherosclerotic internal carotid Artery or middle Cerebral Artery occlusive Disease that had no ischemic episodes during follow-up. Using 3D stereotactic surface projections, we quantified abnormal decreases in the BZRs in the Cerebral cortex within the middle Cerebral Artery distribution and correlated changes in the BZR index with the mean hemispheric values of hemodynamic parameters obtained from 15 O gas positron emission tomography. Results— In the hemisphere affected by arterial Disease, the BZR index in 40 patients (50%) was increased during follow-up (mean 26±20 months). In multivariable logistic regression analyses, increases in the BZR index were associated with the decreased Cerebral blood flow at baseline and an increased oxygen extraction fraction during follow-up. Increases in the oxygen extraction fraction during follow-up were associated with a lack of statin use. Conclusions— In patients with atherosclerotic internal carotid Artery or middle Cerebral Artery Disease, the progression of cortical neuronal damage was associated with hemodynamic impairment at baseline and hemodynamic deterioration during follow-up. Statin use may be beneficial against hemodynamic deterioration and therefore neuroprotective.
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increase in 18f fluoroacetate uptake in patients with chronic hemodynamic Cerebral ischemia
Stroke, 2015Co-Authors: Hiroshi Yamauchi, Shinya Kagawa, Yoshihiko Kishibe, Masaaki Takahashi, Ryuichi Nishii, Hiroshi Mizuma, Kazuhiro Takahashi, Hirotaka Onoe, Tatsuya HigashiAbstract:Background and Purpose—[18F]-fluoroacetate (18F-FACE) can be used for evaluating glial cell metabolism. Experimental studies have shown an increase in 18F-FACE uptake in rodent models of Cerebral ischemia. The aim of this study was to determine whether 18F-FACE uptake is increased in the noninfarcted Cerebral cortex in patients with hemodynamic ischemia owing to atherosclerotic internal carotid Artery or middle Cerebral Artery Disease. Methods—We evaluated 9 symptomatic patients with unilateral atherosclerotic internal carotid Artery or middle Cerebral Artery Disease and no cortical infarction using positron emission tomography with 18F-FACE and 15O-gases. 18F-FACE uptake during 40 to 60 minutes after injection was compared with the Cerebral blood flow, Cerebral metabolic rate of oxygen, oxygen extraction fraction, and Cerebral blood volume in the middle Cerebral Artery distributions. Results—Significant decreases of Cerebral blood flow and Cerebral metabolic rate of oxygen and increases of oxygen extract...
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misery perfusion blood pressure control and 5 year stroke risk in symptomatic major Cerebral Artery Disease
Stroke, 2015Co-Authors: Hiroshi Yamauchi, Shinya Kagawa, Yoshihiko Kishibe, Masaaki Takahashi, Tatsuya HigashiAbstract:Background and Purpose—The benefit of strict blood pressure (BP) control in high-risk patients with symptomatic major Cerebral Artery Disease and misery perfusion (MP) is controversial. Our purposes were (1) to determine whether MP is a predictor of a 5-year risk of subsequent stroke and (2) to investigate the relationships among BP during follow-up, MP, and the stroke risk. Methods—We studied 130 nondisabled patients with symptomatic major Cerebral Artery Disease. Baseline hemodynamic measurements were obtained from 15O-gas positron emission tomography, and patients received medical treatment and they were followed for 5 years or until stroke recurrence or death. Results—During 5 years, strokes occurred in 6 of 16 patients with MP and in 15 of 114 without MP (log-rank test; P<0.01). There were 4 (25%) ipsilateral ischemic strokes in patients with MP and 4 in those without MP (P<0.001). The risk of ipsilateral ischemic stroke declined markedly after 2 years, and there was only 1 ipsilateral ischemic strok...
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impaired perfusion modifies the relationship between blood pressure and stroke risk in major Cerebral Artery Disease
Journal of Neurology Neurosurgery and Psychiatry, 2013Co-Authors: Hiroshi Yamauchi, Shinya Kagawa, Yoshihiko Kishibe, Tatsuya Higashi, Masaaki TakahashiAbstract:Objective Blood pressure (BP) lowering may increase stroke risk in patients with symptomatic major Cerebral Artery Disease and impaired perfusion. To investigate the relationships among BP, impaired perfusion and stroke risk. Methods We retrospectively analysed data from 130 non-disabled, medically treated patients with either symptomatic extracranial carotid occlusion or intracranial stenosis or occlusion of the carotid Artery or middle Cerebral arteries. All patients had baseline haemodynamic measurements with 15 O-gas positron emission tomography and were followed for 2 years or until stroke recurrence or death. Results There was a negative linear relationship between systolic BP (SBP) and risk of stroke in the territory of the Diseased Artery. The 2-year incidence of ischaemic stroke in the territory in patients with normal SBP ( Conclusions Impaired perfusion modified the relationship between blood pressure and stroke risk, although this study had limitations including the retrospective analysis, the potentially biased sample, the small number of critical events and the fact that BP was measured only as a snapshot in clinic.
Shinya Kagawa - One of the best experts on this subject based on the ideXlab platform.
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misery perfusion and amyloid deposition in atherosclerotic major Cerebral Artery Disease
NeuroImage: Clinical, 2019Co-Authors: Hiroshi Yamauchi, Shinya Kagawa, Masaaki Takahashi, Naoya Oishi, Masahiro Ono, Tatsuya HigashiAbstract:Abstract Although experimental studies have shown that global Cerebral hypoperfusion leads to amyloid deposition in the hemisphere with carotid Artery occlusion in rodents, the results of such occurrence are controversial in humans. Hence, we aim to determine whether global Cerebral hypoperfusion leading to decreased blood flow relative to metabolic demand [increased oxygen extraction fraction (OEF), misery perfusion] is associated with increases in amyloid deposition in the hemisphere with atherosclerotic major Cerebral Artery Disease in patients. We evaluated the distribution of β-amyloid plaques using positron emission tomography and a [18F]-pyridylbenzofuran derivative (18F-FPYBF-2) in 13 patients with unilateral atherosclerotic Disease of the internal carotid Artery (ICA) or middle Cerebral Artery (MCA) Disease and no cortical infarction. The distribution volume ratio (DVR) of 18F- FPYBF-2 was calculated using dynamic data and Logan graphical analysis with reference tissue and was correlated with the Cerebral blood flow (CBF), Cerebral metabolic rate of oxygen (CMRO2), and OEF, obtained from 15O-gas PET. The mean cortical value was calculated as the mean value within the frontal, posterior cingulate, precuneus, parietal, and lateral temporal cortical regions. Significant reductions in CBF and CMRO2 and increases in OEF were found in the hemisphere ipsilateral to the arterial lesion compared with the contralateral hemisphere. There was no significant difference for 18F-FPYBF-2 DVR between hemispheres. The ipsilateral to contralateral ratio of the 18F- FPYBF-2 DVR was increased in 3 patients, while the ipsilateral to contralateral OEF ratio was increased in 4 patients. The incidence of an increased hemispheric DVR ratio was significantly higher in patients with an increased hemispheric OEF ratio (3/4) than in patients without (0/9) (p
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progressive cortical neuronal damage and chronic hemodynamic impairment in atherosclerotic major Cerebral Artery Disease
Stroke, 2016Co-Authors: Hiroshi Yamauchi, Shinya Kagawa, Yoshihiko Kishibe, Masaaki Takahashi, Tatsuya HigashiAbstract:Background and Purpose— Cross-sectional studies suggest that chronic hemodynamic impairment may cause selective cortical neuronal damage in patients with atherosclerotic internal carotid Artery or middle Cerebral Artery occlusive Disease. The purpose of this longitudinal study was to determine whether the progression of cortical neuronal damage, evaluated as a decrease in central benzodiazepine receptors (BZRs), is associated with hemodynamic impairment at baseline or hemodynamic deterioration during follow-up. Methods— We evaluated the distribution of BZRs twice using positron emission tomography and 11 C-flumazenil over time in 80 medically treated patients with atherosclerotic internal carotid Artery or middle Cerebral Artery occlusive Disease that had no ischemic episodes during follow-up. Using 3D stereotactic surface projections, we quantified abnormal decreases in the BZRs in the Cerebral cortex within the middle Cerebral Artery distribution and correlated changes in the BZR index with the mean hemispheric values of hemodynamic parameters obtained from 15 O gas positron emission tomography. Results— In the hemisphere affected by arterial Disease, the BZR index in 40 patients (50%) was increased during follow-up (mean 26±20 months). In multivariable logistic regression analyses, increases in the BZR index were associated with the decreased Cerebral blood flow at baseline and an increased oxygen extraction fraction during follow-up. Increases in the oxygen extraction fraction during follow-up were associated with a lack of statin use. Conclusions— In patients with atherosclerotic internal carotid Artery or middle Cerebral Artery Disease, the progression of cortical neuronal damage was associated with hemodynamic impairment at baseline and hemodynamic deterioration during follow-up. Statin use may be beneficial against hemodynamic deterioration and therefore neuroprotective.
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increase in 18f fluoroacetate uptake in patients with chronic hemodynamic Cerebral ischemia
Stroke, 2015Co-Authors: Hiroshi Yamauchi, Shinya Kagawa, Yoshihiko Kishibe, Masaaki Takahashi, Ryuichi Nishii, Hiroshi Mizuma, Kazuhiro Takahashi, Hirotaka Onoe, Tatsuya HigashiAbstract:Background and Purpose—[18F]-fluoroacetate (18F-FACE) can be used for evaluating glial cell metabolism. Experimental studies have shown an increase in 18F-FACE uptake in rodent models of Cerebral ischemia. The aim of this study was to determine whether 18F-FACE uptake is increased in the noninfarcted Cerebral cortex in patients with hemodynamic ischemia owing to atherosclerotic internal carotid Artery or middle Cerebral Artery Disease. Methods—We evaluated 9 symptomatic patients with unilateral atherosclerotic internal carotid Artery or middle Cerebral Artery Disease and no cortical infarction using positron emission tomography with 18F-FACE and 15O-gases. 18F-FACE uptake during 40 to 60 minutes after injection was compared with the Cerebral blood flow, Cerebral metabolic rate of oxygen, oxygen extraction fraction, and Cerebral blood volume in the middle Cerebral Artery distributions. Results—Significant decreases of Cerebral blood flow and Cerebral metabolic rate of oxygen and increases of oxygen extract...
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misery perfusion blood pressure control and 5 year stroke risk in symptomatic major Cerebral Artery Disease
Stroke, 2015Co-Authors: Hiroshi Yamauchi, Shinya Kagawa, Yoshihiko Kishibe, Masaaki Takahashi, Tatsuya HigashiAbstract:Background and Purpose—The benefit of strict blood pressure (BP) control in high-risk patients with symptomatic major Cerebral Artery Disease and misery perfusion (MP) is controversial. Our purposes were (1) to determine whether MP is a predictor of a 5-year risk of subsequent stroke and (2) to investigate the relationships among BP during follow-up, MP, and the stroke risk. Methods—We studied 130 nondisabled patients with symptomatic major Cerebral Artery Disease. Baseline hemodynamic measurements were obtained from 15O-gas positron emission tomography, and patients received medical treatment and they were followed for 5 years or until stroke recurrence or death. Results—During 5 years, strokes occurred in 6 of 16 patients with MP and in 15 of 114 without MP (log-rank test; P<0.01). There were 4 (25%) ipsilateral ischemic strokes in patients with MP and 4 in those without MP (P<0.001). The risk of ipsilateral ischemic stroke declined markedly after 2 years, and there was only 1 ipsilateral ischemic strok...
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impaired perfusion modifies the relationship between blood pressure and stroke risk in major Cerebral Artery Disease
Journal of Neurology Neurosurgery and Psychiatry, 2013Co-Authors: Hiroshi Yamauchi, Shinya Kagawa, Yoshihiko Kishibe, Tatsuya Higashi, Masaaki TakahashiAbstract:Objective Blood pressure (BP) lowering may increase stroke risk in patients with symptomatic major Cerebral Artery Disease and impaired perfusion. To investigate the relationships among BP, impaired perfusion and stroke risk. Methods We retrospectively analysed data from 130 non-disabled, medically treated patients with either symptomatic extracranial carotid occlusion or intracranial stenosis or occlusion of the carotid Artery or middle Cerebral arteries. All patients had baseline haemodynamic measurements with 15 O-gas positron emission tomography and were followed for 2 years or until stroke recurrence or death. Results There was a negative linear relationship between systolic BP (SBP) and risk of stroke in the territory of the Diseased Artery. The 2-year incidence of ischaemic stroke in the territory in patients with normal SBP ( Conclusions Impaired perfusion modified the relationship between blood pressure and stroke risk, although this study had limitations including the retrospective analysis, the potentially biased sample, the small number of critical events and the fact that BP was measured only as a snapshot in clinic.
Masaaki Takahashi - One of the best experts on this subject based on the ideXlab platform.
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misery perfusion and amyloid deposition in atherosclerotic major Cerebral Artery Disease
NeuroImage: Clinical, 2019Co-Authors: Hiroshi Yamauchi, Shinya Kagawa, Masaaki Takahashi, Naoya Oishi, Masahiro Ono, Tatsuya HigashiAbstract:Abstract Although experimental studies have shown that global Cerebral hypoperfusion leads to amyloid deposition in the hemisphere with carotid Artery occlusion in rodents, the results of such occurrence are controversial in humans. Hence, we aim to determine whether global Cerebral hypoperfusion leading to decreased blood flow relative to metabolic demand [increased oxygen extraction fraction (OEF), misery perfusion] is associated with increases in amyloid deposition in the hemisphere with atherosclerotic major Cerebral Artery Disease in patients. We evaluated the distribution of β-amyloid plaques using positron emission tomography and a [18F]-pyridylbenzofuran derivative (18F-FPYBF-2) in 13 patients with unilateral atherosclerotic Disease of the internal carotid Artery (ICA) or middle Cerebral Artery (MCA) Disease and no cortical infarction. The distribution volume ratio (DVR) of 18F- FPYBF-2 was calculated using dynamic data and Logan graphical analysis with reference tissue and was correlated with the Cerebral blood flow (CBF), Cerebral metabolic rate of oxygen (CMRO2), and OEF, obtained from 15O-gas PET. The mean cortical value was calculated as the mean value within the frontal, posterior cingulate, precuneus, parietal, and lateral temporal cortical regions. Significant reductions in CBF and CMRO2 and increases in OEF were found in the hemisphere ipsilateral to the arterial lesion compared with the contralateral hemisphere. There was no significant difference for 18F-FPYBF-2 DVR between hemispheres. The ipsilateral to contralateral ratio of the 18F- FPYBF-2 DVR was increased in 3 patients, while the ipsilateral to contralateral OEF ratio was increased in 4 patients. The incidence of an increased hemispheric DVR ratio was significantly higher in patients with an increased hemispheric OEF ratio (3/4) than in patients without (0/9) (p
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progressive cortical neuronal damage and chronic hemodynamic impairment in atherosclerotic major Cerebral Artery Disease
Stroke, 2016Co-Authors: Hiroshi Yamauchi, Shinya Kagawa, Yoshihiko Kishibe, Masaaki Takahashi, Tatsuya HigashiAbstract:Background and Purpose— Cross-sectional studies suggest that chronic hemodynamic impairment may cause selective cortical neuronal damage in patients with atherosclerotic internal carotid Artery or middle Cerebral Artery occlusive Disease. The purpose of this longitudinal study was to determine whether the progression of cortical neuronal damage, evaluated as a decrease in central benzodiazepine receptors (BZRs), is associated with hemodynamic impairment at baseline or hemodynamic deterioration during follow-up. Methods— We evaluated the distribution of BZRs twice using positron emission tomography and 11 C-flumazenil over time in 80 medically treated patients with atherosclerotic internal carotid Artery or middle Cerebral Artery occlusive Disease that had no ischemic episodes during follow-up. Using 3D stereotactic surface projections, we quantified abnormal decreases in the BZRs in the Cerebral cortex within the middle Cerebral Artery distribution and correlated changes in the BZR index with the mean hemispheric values of hemodynamic parameters obtained from 15 O gas positron emission tomography. Results— In the hemisphere affected by arterial Disease, the BZR index in 40 patients (50%) was increased during follow-up (mean 26±20 months). In multivariable logistic regression analyses, increases in the BZR index were associated with the decreased Cerebral blood flow at baseline and an increased oxygen extraction fraction during follow-up. Increases in the oxygen extraction fraction during follow-up were associated with a lack of statin use. Conclusions— In patients with atherosclerotic internal carotid Artery or middle Cerebral Artery Disease, the progression of cortical neuronal damage was associated with hemodynamic impairment at baseline and hemodynamic deterioration during follow-up. Statin use may be beneficial against hemodynamic deterioration and therefore neuroprotective.
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increase in 18f fluoroacetate uptake in patients with chronic hemodynamic Cerebral ischemia
Stroke, 2015Co-Authors: Hiroshi Yamauchi, Shinya Kagawa, Yoshihiko Kishibe, Masaaki Takahashi, Ryuichi Nishii, Hiroshi Mizuma, Kazuhiro Takahashi, Hirotaka Onoe, Tatsuya HigashiAbstract:Background and Purpose—[18F]-fluoroacetate (18F-FACE) can be used for evaluating glial cell metabolism. Experimental studies have shown an increase in 18F-FACE uptake in rodent models of Cerebral ischemia. The aim of this study was to determine whether 18F-FACE uptake is increased in the noninfarcted Cerebral cortex in patients with hemodynamic ischemia owing to atherosclerotic internal carotid Artery or middle Cerebral Artery Disease. Methods—We evaluated 9 symptomatic patients with unilateral atherosclerotic internal carotid Artery or middle Cerebral Artery Disease and no cortical infarction using positron emission tomography with 18F-FACE and 15O-gases. 18F-FACE uptake during 40 to 60 minutes after injection was compared with the Cerebral blood flow, Cerebral metabolic rate of oxygen, oxygen extraction fraction, and Cerebral blood volume in the middle Cerebral Artery distributions. Results—Significant decreases of Cerebral blood flow and Cerebral metabolic rate of oxygen and increases of oxygen extract...
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misery perfusion blood pressure control and 5 year stroke risk in symptomatic major Cerebral Artery Disease
Stroke, 2015Co-Authors: Hiroshi Yamauchi, Shinya Kagawa, Yoshihiko Kishibe, Masaaki Takahashi, Tatsuya HigashiAbstract:Background and Purpose—The benefit of strict blood pressure (BP) control in high-risk patients with symptomatic major Cerebral Artery Disease and misery perfusion (MP) is controversial. Our purposes were (1) to determine whether MP is a predictor of a 5-year risk of subsequent stroke and (2) to investigate the relationships among BP during follow-up, MP, and the stroke risk. Methods—We studied 130 nondisabled patients with symptomatic major Cerebral Artery Disease. Baseline hemodynamic measurements were obtained from 15O-gas positron emission tomography, and patients received medical treatment and they were followed for 5 years or until stroke recurrence or death. Results—During 5 years, strokes occurred in 6 of 16 patients with MP and in 15 of 114 without MP (log-rank test; P<0.01). There were 4 (25%) ipsilateral ischemic strokes in patients with MP and 4 in those without MP (P<0.001). The risk of ipsilateral ischemic stroke declined markedly after 2 years, and there was only 1 ipsilateral ischemic strok...
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impaired perfusion modifies the relationship between blood pressure and stroke risk in major Cerebral Artery Disease
Journal of Neurology Neurosurgery and Psychiatry, 2013Co-Authors: Hiroshi Yamauchi, Shinya Kagawa, Yoshihiko Kishibe, Tatsuya Higashi, Masaaki TakahashiAbstract:Objective Blood pressure (BP) lowering may increase stroke risk in patients with symptomatic major Cerebral Artery Disease and impaired perfusion. To investigate the relationships among BP, impaired perfusion and stroke risk. Methods We retrospectively analysed data from 130 non-disabled, medically treated patients with either symptomatic extracranial carotid occlusion or intracranial stenosis or occlusion of the carotid Artery or middle Cerebral arteries. All patients had baseline haemodynamic measurements with 15 O-gas positron emission tomography and were followed for 2 years or until stroke recurrence or death. Results There was a negative linear relationship between systolic BP (SBP) and risk of stroke in the territory of the Diseased Artery. The 2-year incidence of ischaemic stroke in the territory in patients with normal SBP ( Conclusions Impaired perfusion modified the relationship between blood pressure and stroke risk, although this study had limitations including the retrospective analysis, the potentially biased sample, the small number of critical events and the fact that BP was measured only as a snapshot in clinic.
Yoshihiko Kishibe - One of the best experts on this subject based on the ideXlab platform.
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progressive cortical neuronal damage and chronic hemodynamic impairment in atherosclerotic major Cerebral Artery Disease
Stroke, 2016Co-Authors: Hiroshi Yamauchi, Shinya Kagawa, Yoshihiko Kishibe, Masaaki Takahashi, Tatsuya HigashiAbstract:Background and Purpose— Cross-sectional studies suggest that chronic hemodynamic impairment may cause selective cortical neuronal damage in patients with atherosclerotic internal carotid Artery or middle Cerebral Artery occlusive Disease. The purpose of this longitudinal study was to determine whether the progression of cortical neuronal damage, evaluated as a decrease in central benzodiazepine receptors (BZRs), is associated with hemodynamic impairment at baseline or hemodynamic deterioration during follow-up. Methods— We evaluated the distribution of BZRs twice using positron emission tomography and 11 C-flumazenil over time in 80 medically treated patients with atherosclerotic internal carotid Artery or middle Cerebral Artery occlusive Disease that had no ischemic episodes during follow-up. Using 3D stereotactic surface projections, we quantified abnormal decreases in the BZRs in the Cerebral cortex within the middle Cerebral Artery distribution and correlated changes in the BZR index with the mean hemispheric values of hemodynamic parameters obtained from 15 O gas positron emission tomography. Results— In the hemisphere affected by arterial Disease, the BZR index in 40 patients (50%) was increased during follow-up (mean 26±20 months). In multivariable logistic regression analyses, increases in the BZR index were associated with the decreased Cerebral blood flow at baseline and an increased oxygen extraction fraction during follow-up. Increases in the oxygen extraction fraction during follow-up were associated with a lack of statin use. Conclusions— In patients with atherosclerotic internal carotid Artery or middle Cerebral Artery Disease, the progression of cortical neuronal damage was associated with hemodynamic impairment at baseline and hemodynamic deterioration during follow-up. Statin use may be beneficial against hemodynamic deterioration and therefore neuroprotective.
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increase in 18f fluoroacetate uptake in patients with chronic hemodynamic Cerebral ischemia
Stroke, 2015Co-Authors: Hiroshi Yamauchi, Shinya Kagawa, Yoshihiko Kishibe, Masaaki Takahashi, Ryuichi Nishii, Hiroshi Mizuma, Kazuhiro Takahashi, Hirotaka Onoe, Tatsuya HigashiAbstract:Background and Purpose—[18F]-fluoroacetate (18F-FACE) can be used for evaluating glial cell metabolism. Experimental studies have shown an increase in 18F-FACE uptake in rodent models of Cerebral ischemia. The aim of this study was to determine whether 18F-FACE uptake is increased in the noninfarcted Cerebral cortex in patients with hemodynamic ischemia owing to atherosclerotic internal carotid Artery or middle Cerebral Artery Disease. Methods—We evaluated 9 symptomatic patients with unilateral atherosclerotic internal carotid Artery or middle Cerebral Artery Disease and no cortical infarction using positron emission tomography with 18F-FACE and 15O-gases. 18F-FACE uptake during 40 to 60 minutes after injection was compared with the Cerebral blood flow, Cerebral metabolic rate of oxygen, oxygen extraction fraction, and Cerebral blood volume in the middle Cerebral Artery distributions. Results—Significant decreases of Cerebral blood flow and Cerebral metabolic rate of oxygen and increases of oxygen extract...
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misery perfusion blood pressure control and 5 year stroke risk in symptomatic major Cerebral Artery Disease
Stroke, 2015Co-Authors: Hiroshi Yamauchi, Shinya Kagawa, Yoshihiko Kishibe, Masaaki Takahashi, Tatsuya HigashiAbstract:Background and Purpose—The benefit of strict blood pressure (BP) control in high-risk patients with symptomatic major Cerebral Artery Disease and misery perfusion (MP) is controversial. Our purposes were (1) to determine whether MP is a predictor of a 5-year risk of subsequent stroke and (2) to investigate the relationships among BP during follow-up, MP, and the stroke risk. Methods—We studied 130 nondisabled patients with symptomatic major Cerebral Artery Disease. Baseline hemodynamic measurements were obtained from 15O-gas positron emission tomography, and patients received medical treatment and they were followed for 5 years or until stroke recurrence or death. Results—During 5 years, strokes occurred in 6 of 16 patients with MP and in 15 of 114 without MP (log-rank test; P<0.01). There were 4 (25%) ipsilateral ischemic strokes in patients with MP and 4 in those without MP (P<0.001). The risk of ipsilateral ischemic stroke declined markedly after 2 years, and there was only 1 ipsilateral ischemic strok...
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impaired perfusion modifies the relationship between blood pressure and stroke risk in major Cerebral Artery Disease
Journal of Neurology Neurosurgery and Psychiatry, 2013Co-Authors: Hiroshi Yamauchi, Shinya Kagawa, Yoshihiko Kishibe, Tatsuya Higashi, Masaaki TakahashiAbstract:Objective Blood pressure (BP) lowering may increase stroke risk in patients with symptomatic major Cerebral Artery Disease and impaired perfusion. To investigate the relationships among BP, impaired perfusion and stroke risk. Methods We retrospectively analysed data from 130 non-disabled, medically treated patients with either symptomatic extracranial carotid occlusion or intracranial stenosis or occlusion of the carotid Artery or middle Cerebral arteries. All patients had baseline haemodynamic measurements with 15 O-gas positron emission tomography and were followed for 2 years or until stroke recurrence or death. Results There was a negative linear relationship between systolic BP (SBP) and risk of stroke in the territory of the Diseased Artery. The 2-year incidence of ischaemic stroke in the territory in patients with normal SBP ( Conclusions Impaired perfusion modified the relationship between blood pressure and stroke risk, although this study had limitations including the retrospective analysis, the potentially biased sample, the small number of critical events and the fact that BP was measured only as a snapshot in clinic.
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chronic hemodynamic compromise and Cerebral ischemic events in asymptomatic or remote symptomatic large Artery intracranial occlusive Disease
American Journal of Neuroradiology, 2013Co-Authors: Hiroshi Yamauchi, Shinya Kagawa, Yoshihiko Kishibe, Tatsuya Higashi, Masaaki TakahashiAbstract:BACKGROUND AND PURPOSE: In asymptomatic or remote symptomatic LAICOD, the risk of ischemic events is low in general, but there may be a subgroup of higher risk patients who require aggressive medical management. The purpose of this study was to determine whether chronic hemodynamic compromise is a predictor of ischemic events in asymptomatic or remote symptomatic LAICOD. MATERIALS AND METHODS: We prospectively studied 51 asymptomatic, 19 coexistent asymptomatic, and 19 remote (6 months) symptomatic patients with atherosclerotic intracranial internal carotid Artery or middle Cerebral Artery Disease by using 15 O-PET. MP was defined as decreased CBF, increased OEF, and a decreased CBF/CBV ratio. All patients were followed up for 2 years or until occurrence of stroke or TIA or death. RESULTS: Bypass surgery was performed in 4 patients (2 with MP). Three Cerebral ischemic events (1 TIA in an asymptomatic patient, 1 stroke, and 1 TIA in a remote symptomatic patient) occurred in the vascular territory ipsilateral to LAICOD. Kaplan-Meier analysis with censoring at the time of bypass surgery revealed that the incidence of ipsilateral ischemic events in patients with MP (2/5) was significantly higher than that in patients without MP (1/84) (log-rank test; P .0001). The relative risk conferred by MP was 83.1 (95% confidence interval, 6.8 –1017.4; P .001). The incidence of ipsilateral ischemic events in patients with decreased CBF/CBV (2/9) was also significantly higher than that of patients without it (1/80) (P .0001). CONCLUSIONS: Chronic hemodynamic compromise may be a predictor of ischemic events in both asymptomatic and remote symptomatic LAICOD. ABBREVIATIONS: CI confidence interval; CMRO2 Cerebral metabolic rate of oxygen; LAICOD large-Artery intracranial occlusive Disease; MP misery perfusion; OEF oxygen extraction fraction