Effect of glycerol on cerebral blood flow in chronic cerebral ischemic disease

The change of cerebral blood flow (CBF) after glycerol infusion was analyzed in 10 cases of lacunar infarction and 11 cases of ischemic disease of major artery: 6 cases of internal carotid artery occlusion and 5 cases of middle cerebral artery occlusion. In lacunar infarction, CBF increased generally except for the corona radiata and the increased ratio was about 20%. In cases with ischemic disease of a major artery, the CBF tended to increase in the non-affected hemisphere after glycerol infusion. But CBF did not always increase in the affected hemisphere; rather it decreased in the temporal and parietal lobes and especially in the corona radiata. The blood flow of the affected hemisphere might be stealed to the non-affected hemisphere after glycerol infusion. This phenomenon might be caused by a poor cerebrovascular reserve capacity of the maximally dilated vessels in the affected side.     

Effects of hyperoxia, glycerol and ventricular drainage on ICP and CBF in patients with increased ICP due to CSF circulatory-absorbance disturbance

The effects of hyperoxia, glycerol and ventricular drainage on intracranial pressure (ICP) and cerebral blood flow (CBF) were studied in cases with cerebrospinal fluid (CSF) circulatory-absorbance disturbance due to subarachnoid hemorrhage (SAH) or intraventricular hematoma. Ventricular fluid pressure (VFP) was monitored through a controlled ventricular drainage (CVD) tube using a Statham P-50 pressure transducer. CBF was measured by the 10mCi133Xe intravenous injection method using a Valmet BI-1400 rCBF analyzer. ISI (initial slope index) was used for the CBF value. Studied cases were 19 SAH patients and 2 hypertensive intracerebral hematoma cases with intraventricular hematoma. Hyperoxia included hyperbaric oxygen (HBO), reduced ICP and CBF. During pure oxygen inhalation at atmospheric pressure (1ATA . O2), there was a tendency toward a relationship showing that the higher the resting state ICP, the lesser the likelihood of a CBF decrease. This may indicate that increased ICP impairs cerebral vascular reactivity to hyperoxia in relation to the degree of elevation. The effects of hyperoxia on ICP and CBF were temporary and they promptly returned to the resting state after cessation of oxygen inhalation. In some cases, there was a rebound phenomenon in ICP after HBO. Glycerol administration reduced ICP and increased CBF. There was no clear correlation between resting state ICP and CBF increase after glycerol administration. The effects of glycerol were also temporary. ICP control by opening CVD increased CBF. There was a correlation between the level of resting state ICP and the CBF increase after the opening of CVD. In cases with CSF circulatory-absorbance disturbance, elevated ICP reduced CBF and may further worsen the cerebral damage.(ABSTRACT TRUNCATED AT 250 WORDS)     

The effect of low dose dopamine on CBF in patients with subarachnoid hemorrhage

Cerebral blood flow was measured in 10 patients with subarachnoid hemorrhage using the 133Xe inhalation methods. Regional cerebral blood flow (r-CBF) values were calculated with initial slope index, their values were compared with the blood flow response to the administration of low dose dopamine (DA). CBF values of just after and continuous administration of DA were compared with control values. The measurement of r-CBF was performed immediately after the infusion of 5 micrograms/kg/min DA for 30 min. The focal ischemic lesions decreased, bi-hemispheric mean CBF value (7 cases without A-Com patients) increased by 10.3% significantly (paired T test), affected hemispheric mean CBF value increased by 8.7% significantly and non-affected hemispheric mean CBF value increased by 16.6% significantly. The PaCO2 value didn't change but the mean systemic blood pressure increased by 5.1% significantly. The CBF values of continuous administration of DA for 10 days to 2 weeks were measured. The CBF values increased during the administration of DA. The mean CBF values increased without the steal phenomenon and the mean arterial blood pressure increased slightly after the administration of DA. These phenomena were observed more significantly in non affected side than affected side. We suggest that the administration of DA increase the CBF values in patients with subarachnoid hemorrhage due to the stimulation of DA receptor.     

Dynamic single-section CT demonstrates reduced cerebral blood flow in acute intracerebral hemorrhage

Optimum blood pressure (BP) management in acute intracerebral hemorrhage (ICH) remains controversial. BP reduction may limit hematoma expansion, but may also exacerbate ischemia. Reduced regional cerebral blood flow (rCBF) has been reported in ICH. Its extent and precise pattern, however, remain uncertain. Dynamic single-section CT perfusion (CTP) is rapid, easily performed and offers superior spatial resolution to PET, SPECT and MRI. It may be the most applicable method for assessing the effects of BP management on rCBF in ICH. We sought to assess whether CTP can identify rCBF abnormalities in acute ICH in 5 patients with ICH who underwent CTP within 24 h of symptom onset. rCBF was measured in serially expanded 2-mm rings around the hematoma and compared with rCBF in the uninvolved hemisphere. Mean time to CTP was 9 h (range 3-23). Mean ICH volume was 25 ml (range 9-64). Perihematoma perfusion was reduced in all patients compared with contralateral hemisphere rCBF. rCBF reduction was most pronounced immediately adjacent to the hematoma (p < 0.05 at 2 mm, p = 0.084 at 4 mm, p > 0.2 at 6 and 8 mm). Perihematoma rCBF increased as a function of the distance from hematoma perimeter. Rate of rCBF increase over distance correlated with time from onset (p = 0.006). We conclude that CTP identifies a rim of reduced rCBF in ICH. A gradient of hypoperfusion appears to extend at least 4 mm beyond the hematoma edge and may be time dependent. Whether reduced CBF is associated with perihematoma ischemia requires additional study.     

Clinical study of cerebral blood flow in bilateral chronic subdural hematoma measured by 99mTc-HMPAO SPECT]

Cerebral blood flow(CBF) in 34 patients with bilateral chronic subdural hematoma was measured by 99mTc-HMPAO SPECT before operation. The regional CBF was measured in 26 regions of the 10 cortical regions, putamen, thalamus and cerebellar hemisphere on both sides. According to the thickness of subdural hematoma, the thicker hematoma side was measured and examined as the thick hematoma side, and the other side as the thin hematoma side. Thirty four cases with bilateral chronic subdural hematoma were classified into four groups on the basis of clinical symptoms: 13 cases with headache(headache group), 10 cases with hemiparesis(hemiparesis group), 5 cases with tetraparesis(tetraparesis group) and 6 cases with consciousness disturbance or dementia(consciousness disturbance group), and into two groups according to the degree of midline brain shift on MRI: 14 cases of non-shifted group and 20 cases of shifted group. The average CBF of 34 patients in each region indicated a regional CBF reduction in the frontal, parietal and occipital cortices on the thin hematoma side, and in the putamen on the thick hematoma side. In the headache group, the regional CBF reduction on the thin hematoma side was found in the frontal, parietal and occipital cortices compared with the corresponding regions on the thick hematoma side, and in thalamus on the thick hematoma side. In the hemiparesis and tetraparesis groups, there was no statistically significant CBF reduction between the thick and thin hematoma sides. In the consciousness disturbance group, the CBF reduction in whole brain was remarkably significant. By the degree of the midline brain shift, the CBF reductions between the thick and thin hematoma sides were observed. Namely, in the shifted group, the CBF reductions were noted in the frontal, parietal and occipital cortices in the thin hematoma side, and in the putamen in the thick hematoma side. We concluded that the CBF reduction of bilateral chronic subdural hematoma was bilaterally found in the hemiparesis and tetraparesis groups, and which was finally observed in whole brain in the consciousness disturbance group.     

Hemodynamics of hypertensive putaminal hemorrhage evaluated by Xenon-enhanced computed tomography and acetazolamide test

Cerebral blood flow (CBF) is usually decreased in patients with hypertensive putaminal hemorrhage (HPH). However, there are few reports concerning cerebrovascular reserve capacity (CRC) in these cases. This study evaluated cerebral hemodynamics in patients with HPH by measuring CBF and CRC. CBF and CRC were measured by stable xenon enhanced computed tomography (Xe-CT) in 11 patients with HPH (HPH group) and 11 patients with essential hypertension without intracerebral hematoma (non-HPH group). CBFs of the hemisphere and thalamus in the HPH group were lower than those in the non-HPH group. And the CBF of the hemisphere was increased transiently after the surgical evacuation of the hematoma. Thereafter, it fell gradually. The CRCs were also lower in acute stage of the HPH group. The CRC recovered during the chronic stage. Hemodynamics in patients with HPH can be modulated by surgical removal of hematoma. However, some adjunct therapies are necessary to prevent delayed neuronal inactivity. Stable Xe-CT with acetazolamide test is useful to evaluate hemodynamics in the HPH patients.     

显微血管减压术后颅内出血的原因及应对策略

目的 探讨显微血管减压(MVD)术后颅内出血的原因及应对策略.方法 对12例面肌痉挛、三叉神经痛MVD术后颅内出血患者的临床资料进行回顾性分析,并对相关文献进行复习.结果 本组患者中,小脑半球实质内血肿者3例,小脑出血破入脑室3例,蛛网膜下腔出血2例,脑室出血2例,后颅窝硬膜外血肿1例,幕上硬膜下血肿1例.1例脑室出血...     

Bi-hemispheric CBF and its CO2 reactivity of TIAs and completed strokes in ICA occlusions

Bi-hemispheric cerebral blood flow (CBF) measurements during rest and hyperventilation, with intra-arterial 133Xe injection method, were investigated in 19 cases, angiographically diagnosed as unilateral internal carotid artery (ICA) occlusion, including 8 cases with TIAs and 11 cases with completed strokes as the onset. Indices of cerebral vascular resistance and CO2 reactivity with decreasing arterial PCO2 were also investigated. A significant decrease (P less than 0.05) of hemispheric mean CBF was noted in the ischemic hemisphere, but normal flow values in the unaffected hemisphere and preserved CO2 responsiveness during hyperventilation were observed in both the affected and unaffected hemispheres in patients with TIAs. Moreover, a direct relationship between CBF and blood pressure, observed in 11 cases with completed strokes, was not recognized in 8 cases with TIAs. A degree of the abnormalities of the affected hemisphere in cerebral circulation was suggested to be somewhat different between TIAs and completed strokes in ICA occlusions, and bi-hemispheric CBF measurements would be an useful method for evaluating the various indices of the CBF in ICA occlusions.     

Clinical study of cerebral blood flow in unilateral chronic subdural hematoma measured by 99mTc-HMPAO SPECT]

Cerebral blood flow (CBF) measured by 99mTc-HMPAO SPECT before operation was studied in 60 patients with unilateral chronic subdural hematoma. The regional CBF was measured in 26 regions of the fronto-occipital 10 cortices, putamen, thalamus and cerebellar hemisphere on both sides. Sixty cases with unilateral chronic subdural hematoma were classified into four groups on the basis of clinical symptoms: 17 cases with headache (headache group), 34 cases with hemiparesis (hemiparesis group) and 9 cases with consciousness disturbance or dementia (consciousness disturbance group), and into three groups on the basis of the degree of midline brain shift on MRI: 7 cases of mild shift group, 24 cases of moderate shift group and 29 cases of severe shift group. The average CBF in 60 patients in each region indicated that the regional CBF was reduced in frontal, occipital cortices and cerebellum on the non-hematoma side, and in putamen and thalamus on the hematoma side. In the headache group, the regional CBF reduction on the non-hematoma side was found in only frontal and occipital cortices compared with the corresponding regions on the hematoma side. In the hemiparesis group, the regional CBF was reduced in frontal and occipital cortices on the non-hematoma side and in putamen and thalamus on the hematoma side. The part of CBF reduction in both hemispheres was also noted in the hemiparesis group. In the consciousness disturbance group, the CBF reduction was markedly noted in whole brain. The CBF reductions in frontal and occipital cortices on the non-hematoma side and in putamen, thalamus and cerebellum on the hematoma side was not mutually related with the degree of midline brain shift. We concluded that the disturbance of CBF in chronic subdural hematoma was started from frontal and occipital cortices on the non-hematoma side observed in the headache group, and which was extended to putamen and thalamus on the hematoma side and a part of both hemispheres observed in the hemiparesis group. And such disturbance was finally observed as the CBF reductions in whole brain in the consciousness disturbance group.     

用凝血功能综合评分法分析高血压脑出血急性期血肿扩大的相关因素

目的旨在用凝血功能综合评分法(CFCS)分析高血压脑出血急性期血肿扩大的相关因素。方法收集2010年3月至2012年3月收治的高血压脑出血患者152例,其中男90例、女62例;年龄平均(54.7±11.3)岁。应用头颅CT观察患者急性期血肿扩大的情况。参照国际血栓和止血协会制定的凝血功能检测指标设计CFCS进行评分;对包括CFCS在内的多个血肿扩大危险因素进行单因素χ2检验及多因素Logistic回归分析。结果共入组152例患者,血肿体积平均(26.2±12.1)mL;入院时GCS评分平均(9.8±3.7)分。入选病例在急性期出现血肿扩大57例(37.5%)。χ2检验发现起病时血肿部位、入院时血压情况、CFCS评分等是血肿扩大的候选危险因素(P0.05)。将上述因素引入Logistic回归方程,逐步前进法分析得出入院时收缩压、CFCS评分、早期使用甘露醇是高血压脑出血急性期血肿扩大的独立危险因素。结论CFCS评分与高血压脑出血急性期血肿扩大以及预后密切相关,可以作为临床判断血肿扩大因素的参考指标,有利于早期发现血肿扩大并及时进行干预。     

Changes in cerebral blood flow during cerebrospinal fluid pressure manipulation in patients with normal pressure hydrocephalus: a methodological study.

The combination of cerebral blood flow measurement using (15)O-water positron emission tomography with magnetic resonance coregistration and CSF infusion studies was used to study the global and regional changes in CBF with changes in CSF pressure in 15 patients with normal pressure hydrocephalus. With increases in CSF pressure, there was a variable increase in arterial blood pressure between individuals and global CBF was reduced, including in the cerebellum. Regionally, mean CBF decreased in the thalamus and basal ganglia, as well as in white matter regions. These reductions in CBF were significantly correlated with changes in the CSF pressure and with proximity to the ventricles. A three-dimensional finite-element analysis was used to analyze the effects on ventricular size and the distribution of stress during infusion. To study regional cerebral autoregulation in patients with possible normal pressure hydrocephalus, a sensitive CBF technique is required that provides absolute, not relative normalized, values for regional CBF and an adequate change in cerebral perfusion pressure must be provoked.     

Cerebral blood flow abnormalities in cerebral palsied children with a normal CT scan

Cerebral palsy (CP) is often a consequence of a hypoxic-ischemic encephalopathy and/or intracerebral hemorrhage secondary to pre- and peri-natal asphyxia. Hypodense lesions on the CT-scan are found in about 70 to 80% of CP-patients. In the present study, regional cerebral blood flow (CBF) was measured in CP-patients having a normal CT-scan. The aim was to correlate the CBF changes with the clinical and the etiologic findings. CBF was measured by xenon-133 inhalation and single photon emission computer tomography. The mean CBF value in 20 CP-patients, age 6-19 years, was 67 +/- 11 (1 SD) ml/100g/min, the same value as found in the 9 normal children. However, 16 of the 20 CP-patients had focal hypoperfused areas on the tomographic flow map. In the preterm infants (n = 7) the hypoperfused areas were mainly located in the posterior watershed areas, often in one hemisphere only. In the term infants (n = 13) both asymmetrical and symmetrical hypoperfused areas were observed in the anterior and posterior watershed areas. In addition, several children had larger low flow areas in the frontal and fronto-parietal lobes. In both groups, a relatively poor concordance was observed between the clinical findings and the expected location of the low flow area.     

An experimental study on the effects of DMSO and indomethacin on cerebral circulation and intracranial pressure

Albino rabbits with a cryogenic lesion to the left parieto-occipital cortex had cerebral blood flow studies (CBF) with the hydrogen clearance technique 24 hours after the insult. Similar subgroups were treated with DMSO (1 g/kg) bolus, DMSO (2 g/kg) infusion, indomethacin (20 mg/kg) bolus, and indomethacin followed by DMSO. Following DMSO bolus administration there was an immediate rise in CBF over both hemispheres, with a significant paradoxical decrease at 30 minutes, followed by a second smaller rise at 60 minutes. With DMSO infusion, the rise in CBF was sustained throughout the infusion period with no paradoxical decrease. With indomethacin there was an initial decrease immediately following the drug, and at 60 minutes there was a rise in the insulted left hemisphere, more than the right one. Indomethacin administration 15 minutes prior to DMSO failed to halt the immediate increase in CBF noted following DMSO bolus injection. These results, together with the changes that occurred in intracranial pressure and brain water content, are analyzed.     

Effects of dopamine on cortical blood flow and somatosensory evoked potentials in the acute stages of cerebral ischemia

Effects of intravenous infusion of dopamine on local cortical blood flow (CBF) and somatosensory evoked potentials (SEP) was evaluated using canine cerebral ischemia, which was produced by middle cerebral artery occlusion. CBF was monitored with a H2 clearance method and SEP. P1 to N1 peak to peak amplitude (V1) was recorded by stimulating the sciatic nerve on the contralateral side. CBF and SEP recovered at doses of 5 and 10 gamma, despite almost no increase of systemic arterial pressure. CBF and SEP were restored at doses of dopamine of 20 and 30 gamma, with an increase of mean systemic arterial pressure 5 to 15 mm Hg and similar results were obtained at doses of 25 gamma. Recovery of SEP was slight at extremely high doses of dopamine (65 gamma), despite a definite increase of mean systemic arterial pressure (MSAP) and CBF.     

高血压性脑出血局部组织血流量变化的CT灌注研究

目的 利用CT灌注成像的方法探讨高血压脑出血血肿周围及其远隔区域脑血流变化情况。方法 对20例高血压脑出血患者行治疗后2周颅脑CT灌注扫描及计算机辅助系统制作颅脑CT灌注参数图,对血肿周围局部脑血流量（regional cerebral blood flow,rCBF）、局部脑血容量（regional cerebralblood volume,rCBV）和对比剂平均通过时间（mean transit time,MTT）脑血流动力学参数进行定量测量,并与正常侧对应参照点进行比较。结果 血肿周围存在不同程度低灌注,血肿边缘区rCBF、rCBV显著低于血肿外层区,血肿边缘区MTT较血肿外层区明显延长（P <0.05）,血肿边缘区及外层区rCBF、rCBV、MTT较相应镜像点均有统计学差异（P <0.05）。结论 血肿周围局部脑血流显著降低,CT灌注成像可显示血肿周围异常的脑血流动力学变化, 可为脑出血临床救治提供有价值信息。     

Bi-hemispheric CBF and Its CO2 Reactivity of TIAs and Completed Strokes in ICA Occlusions

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Bi-hemispheric cerebral blood flow (CBF) measurements during rest and hyperventilation, with intra-arteria1 ¹³³Xe injection method, were investigated in 19 cases, angiographically diagnosed as unilateral internal carotid artery (ICA) occlusion, including 8 cases with TIAs and 11 cases with completed strokes as the onset. Indices of cerebral vascular resistance and CO₂ reactivity with decreasing arterial\PCO₂ were also investigated.

A significant decrease (P < 0.05) of hemispheric mean CBF was noted in the ischemic hemisphere, but normal flow values in the unaffected hemisphere and preserved CO₂ responsiveness during hyperventilation were observed in both the affected and unaffected hemispheres in patients with TIAs. Moreover, a direct relationship between CBF and blood pressure, observed in 11 cases with completed strokes, was not recognized in 8 cases with TIAs.

A degree of the abnormalities of the affected hemisphere in cerebral circulation was suggested to be somewhat different between TIAs and completed strokes in ICA occlusions, and bi-hemispheric CBF measurements would be an useful method for evaluating the various indices of the CBF in ICA occlusions.     

Normal pressure hydrocephalus after subarachnoid hemorrhage--with regard to pathogenesis and factors influencing the efficacy of shunt surgery

Twenty-four adult cases of suspected normal pressure hydrocephalus (NPH) after subarachnoid hemorrhage (SAH) were investigated clinically from the aspect of predicting the efficacy of the shunting procedure. They consisted of 13 men and 11 women, with the mean age of 55-y-o. In addition to checking neurological signs, pre- and postoperative CT scans, RI (or CT) cisternography and bolus infusion test were performed in each of them. Shunt surgery was done, all of which ventriculoperitoneal shunt, in 17 patients. They were divided into three groups, namely, shunt effective group (A), neurologically unchanged group after surgery (B) and worsened group (C). The A group had 8 cases, B had 8 also and C contained only one. Effectiveness of shunt procedure was measured by an improvement in the activity of daily life (ADL). Compared with group B, group A tended to have more cases of delayed onset of NPH (mean days of 112 from SAH attack in group A while 55 days in group B), cases with "trias" (3 against 0) and moderate ventricular dilatation with periventricular lucency (8 against 2). The finding of delayed clearance in cisternogram did not make an accurate judgement in the efficacy of shunt surgery. By using the bolus method of infusion test, the true cause of shunt non-effective ventricular dilatation was suggested to the disturbance of cerebral blood circulation due to elevation of intracranial venous outflow resistance. This suggestion was elicited by the analysis of pressure response curve gained from the bolus injection, in which group A cases mainly reached the baseline pressure within 22 minutes, but on the contrary group B showed more than 22 minutes as a rule.(ABSTRACT TRUNCATED AT 250 WORDS)     

Clinical observations on treating thalamic hemorrhage into ventricle

Objective To investigate the treatment of severe patients with thalamic hemorrhage into ventricles. Method 12 cases with thalamic hemorrhage into ventricular system were studied, 9 male, 3 femaie, with a mean age of 64 years. All patients were unconscious. The average size of hematoma was 65 ml. Besides general comprehensive care, they received ventricular puncture for ingertion of drainage tape into the cerebral ventricle, infusion with urokinase for clotlysis, lumbar puncture for letting out some cerebrospinal fluid and injection of dexemethasone. Result The patients' clinical symptoms and signs were obviously improved.. The CT scan also demonstrated that hematomas were removed faster. The effective rate was 83.3 per cent, with a murtality of 16.7 per cent. Cohclusion This kind of therapy can increase the clinical cure rate. decrease the disability rate and death rete.     

Impaired cerebral autoregulation 24 h after induction of transient unilateral focal ischaemia in the rat

Cerebral blood flow (CBF) and cerebral autoregulation have been investigated 24 h after transient focal ischaemia in the rat. Cerebral blood flow was measured autoradiographically before and during a moderate hypotensive challenge, to test autoregulatory responses, using two CBF tracers, (99m)Tc-d,l-hexamethylproyleneamine oxide and 14C-iodoantipyrine. Prior to induced hypotension, CBF was significantly reduced within areas of infarction; cortex (28 +/- 20 compared with 109 +/- 23 mL/100 g/min contralateral to ischaemic focus, P = 0.001) and caudate (57 +/- 31 compared with 141 +/- 32 mL/100 g/min contralaterally, P = 0.005). The hypotensive challenge (mean arterial pressure reduced to 60 mmHg by increasing halothane concentration) did not compromise grey matter autoregulation in the contralateral hemisphere; CBF data were not significantly different at normotension and during hypotension. However, in the ipsilateral hemisphere, a significant volume of cortex adjacent to the infarct, which exhibited normal flow at normotension, became oligaemic during the hypotensive challenge (e.g. frontal parietal cortex 109 +/- 15% to 65 +/- 15% of cerebellar flow, P < 0.01). This resulted in a 2.5-fold increase in the volume of cortex which fell below 50% cerebellar flow (39 +/- 34 to 97 +/- 46 mm3, P = 0.003). Moderate hypotension induced a significant reduction in CBF in both ipsilateral and contralateral subcortical white matter (P < 0.01). In peri-infarct caudate tissue, CBF was not significantly affected by hypotension. In conclusion, a significant volume of histologically normal cortex within the middle cerebral artery territory was found to have essentially normal levels of CBF but impaired autoregulatory function at 24 h post-ischaemia.