Regional cerebral blood flow changes after bilateral external carotid artery ligation in acute experimental infarction.

Regional cerebral blood flow (rCBF) was measured in baboons by intracarotid injection of 133Xe and a gamma camera after acute cerebral infarction was induced by occlusion of the middle cerebral artery (MCA). A steady state of rCBF was measured four hour after MCA occlusion and was followed by bilateral ligation of the external cartoid arteries (ECA). Subsequent rCBF measurements were obtained at 30, 60, and 120 minutes. After bilateral ECA ligation, flow in ischaemic and non-ischaemic areas was greatly enhanced and flow in the hyperaemic areas significantly reduced, presumably since they had provided collateral circulation to the ischaemic zone with a favourable redistribution.     

Clinical implications of collateral middle cerebral artery flow in acute ischaemic stroke with internal carotid artery occlusion

Background and purpose: The presence of collateral middle cerebral artery (MCA) flow via the primary collateral pathway is thought to protect against the progression of cerebral ischaemia. However, there have been few reports on early clinical outcomes according to the presence of collateral MCA flow in acute ischaemic stroke (AIS) with internal carotid artery (ICA) occlusion. Therefore, we sought to investigate the early clinical outcomes and lesion patterns according to the presence of collateral MCA flows in AIS with ICA occlusion. Methods: This is a retrospective study of patients with AIS with ICA occlusion consecutively admitted to our stroke center between October 2008 and March 2010. Patients were included if they were admitted within 12 h of symptom onset with AIS and symptomatic ICA occlusion. Collateral MCA flow was defined as the presence of MCA signals from proximal M1 to distal MCA branches ipsilateral to the ICA occlusion by magnetic resonance angiography. Early neurological deterioration (END) was defined as a 4‐point increase in the National Institutes of Health Stroke Scale (NIHSS) score and persistent neurological deterioration for at least 24 h or newly developed neurological symptoms within 7 days. Results: Sixty‐five patients (42 men, 23 women) were finally included. Initial NIHSS scores were significantly lower, and favorable outcomes at 3 months were better in patients with collateral MCA flow than in those without (P < 0.001). Initial lesion patterns were different according to the collateral MCA flow. However, patients with mild AIS might more frequently deteriorate than those with moderate to severe AIS. Conclusions: In our study, collateral MCA flow reduced initial stroke severity and was associated with favorable outcomes at 3 months but did not seem to protect against END in mild AIS patients with ICA occlusion. Therefore, the results of this study suggest that mild AIS patients with ICA occlusion should be carefully managed because their conditions may deteriorate.     

Changes in cerebral blood flow pattern after carotid endarterectomy

A comparison was made between pre- and postoperative cerebral blood flow measurements in 20 patients who underwent endarterectomy. Most patients showed no difference between both studies. However in 4 of the series an increase in blood flow was observed while in another 4 patients a decrease occurred. Especially patients with a low preoperative flow seemed to have profited from the endarterectomy.     

Regional cerebral blood flow after long-term exposure to carbon disulfide

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.     

颈动脉超声应用筛查颈动脉狭窄及脑卒中高危因素分析

目的分析广西壮族自治区梧州市角嘴社区颈动脉超声应用筛查颈动脉狭窄结果及脑卒中的高危因素。方法选择2013年1月~2015年3月广西壮族自治区梧州市角嘴社区5789名居民为研究对象,对其采用问卷调查及体格检查,统计分析颈动脉超声检查的结果及脑卒中高危因素。结果调查的5789名居民中,≥60岁居民内膜增厚发生率26.65%,斑块形成率为13.67%;40~60岁居民内膜增厚发生率9.20%,斑块形成率为4.42%。≥60岁居民的内膜增厚发生率和斑块发生率均比40~60岁居民高(P0.05)。男性内膜增厚发生率27.89%,斑块形成率为11.38%,女性内膜增厚发生率8.06%,斑块形成率为7.37%。男性内膜增厚发生率和斑块发生率均比女性居民高(P0.05)。居民的脑卒中高危因素分析表明,吸烟史、高血压病、明显超重或肥胖、缺乏运动所占比例高,分别为14.32%、16.02%、16.02%、35.13%,与其他因素相比差异具有统计学意义(P0.05);高血压病、明显超重或肥胖、缺乏运动与脑卒中的发生关联较大(P0.05)。结论广西壮族自治区梧州市角嘴社区脑卒中高危人群的干预的重点方向应为降低血压、控制饮食和多运动。通过开展颈动脉血管超声检查,实现居民脑卒中前期患者的早发现、早干预、早治疗。     

颈动脉支架置入术对大脑皮质血流灌注量的影响

目的 研究颈动脉狭窄支架置入术对脑皮质血流灌注量的影响.方法 应用单光子发射计算机断层扫描(SPECT)对18例单侧颈动脉狭窄患者颈动脉支架置入术前后脑皮质血流灌注量进行检测.结果 患者术后双侧大脑前动脉、大脑中动脉、大脑后动脉供血区脑皮质血流灌注量均显著增加(均P<0.05);同时支架置入侧术后大脑中动脉、大脑后动脉供血区脑皮质血流灌注量比值较术前增加更明显(均P<0.05),但大脑前动脉供血区差异无统计学意义.结论 颈动脉狭窄支架置入术可使狭窄侧及对侧脑皮质血流灌注量增加,而狭窄侧大脑中动脉、后动脉增加幅度更明显.     

High rate of restenosis after carotid artery stenting in patients with high-grade internal carotid artery stenosis

OBJECTIVE: Carotid endarterectomy (CEA) is the gold-standard procedure for the majority of patients with high-grade symptomatic internal carotid artery stenosis and also for specified high-grade asymptomatic stenoses; however, a proportion of patients are treated with carotid endovascular therapy. We aimed to document medium-term clinical and neurosonographical outcome after carotid artery stenting (CAS). METHODS: 53 patients (mean age: 65 +/- 8 years) with high-grade (> or = 70 % by means of duplex sonography) carotid artery stenosis were enrolled into the study. Nineteen patients had asymptomatic, 34 patients had symptomatic stenoses. All patients had a pre-interventional CT, Doppler and duplex sonography, and digital subtraction angiography (DSA) or magnetic resonance angiography (MRA) prior to the procedural DSA. All patients were offered CEA as the gold-standard procedure and as an alternative to CAS. Both clinical and Duplex sonographical follow-up was obtained at day 1 and 7, month 1, month 3, month 6, month 12, and every subsequent 6 months after the procedure. Mean follow-up time was 22 +/- 1.6 months (+/- SEM). RESULTS: 2/53 patients suffered from stroke. A further 2 patients suffered from carotid artery occlusion shortly after CAS. The cumulative rate of restenosis during follow-up was 24.5 % (13/53). Four of these (7.5 %) were of high-grade and led to further interventional or surgical therapy. CONCLUSIONS: A high rate of restenosis was found during follow-up after CAS. Our analysis of non-selected patients emphasizes that CEA remains the gold-standard procedure for the treatment of symptomatic internal carotid artery stenosis. The frequently performed endovascular treatment of carotid stenosis outside the setting of a randomized controlled trial is not supported by our data.     

Markers of lacunar stroke in patients with moderate internal carotid artery stenosis

The benefits of surgical correction of moderate internal carotid artery stenosis have been demonstrated only in symptomatic subjects. It is debatable whether patients with lacunar infarct ipsilateral to a moderate carotid stenosis may be considered symptomatic like those with large–artery stroke. The aim of the study was to seek markers capable of differentiating patients with lacunar or non–lacunar stroke ipsilateral to a moderate internal carotid artery stenosis.We enrolled 95 patients with a first stroke ipsilateral to a moderate (50–69 %) stenosis of the internal carotid artery and divided them into lacunar and non–lacunar stroke based on clinical presentation and neuroradiological findings; 34 subjects with asymptomatic moderate carotid stenosis and 31 normal individuals were also studied. Baseline characteristics; risk factors, cerebrovascular reactivity to hypercapnia evaluated by means of the breath–holding index (BHI), the presence and severity of carotid stenosis and intimamedia thickness (IMT) of the common carotid arteries were determined. There were 36 patients with lacunar and 59 with non–lacunar stroke. Degree of stenosis, and IMT and BHI ipsilateral to symptomatic stenosis were found to be significant independent predictors as each 10 % increase of stenosis carried a 4.3 higher probability of non–lacunar stroke (95 % CI: 1.91–9.51); each decimillimeter increment in IMT increased this probability by 1.45 (95 % CI: 1.10–1.92); and the risk odds ratio associated with each 0.1 increase in BHI was 1.88 (95 % CI: 1.33–2.66). A decrease in BHI of 0.1 thus carried a 90% greater probability of having a lacunar stroke. The results show that patients with moderate internal carotid artery stenosis and lacunar stroke can be differentiated from those with non–lacunar stroke on the basis of distinctive ultrasonographic findings. Further studies are needed to clarify whether our findings have pathogenetic implications and may be of help for the planning of different therapeutic strategies in patients with moderate internal carotid stenosis and lacunar or non–lacunar ipsilateral stroke.     

应用rLMC评分预测急性大脑中动脉M1段或颈内动脉闭塞卒中患者临床预后

目的通过基于CTA评价的区域软脑膜评分(rLMC)评估大脑中动脉M1段或颈内动脉闭塞缺血性卒中患者的二级脑侧支循环开放水平,研究其与患者临床表现及中期临床预后的相关性。方法回顾性分析90例大脑中动脉M1段或颈内动脉闭塞急性缺血性卒中患者的临床资料,均在发病9 h内行CTA检查,依据rLMC评分分组,a组:rLMC评分0~10;b组:11~16;c组:17~20,在180 d mRS≤2认定为临床结局良好。研究卒中患者软脑膜侧支循环代偿与临床预后的相关性。结果分析纳入90例患者,拥有差的rLMC评分,共24例,约占26.7%,拥有中等的rLMC评分,共40例,约占44.4%;拥有良好的rLMC评分,共26例,约占28.9%。同时发现侧支循环良好组的早期神经功能缺损程度更轻,早期神经功能恢复及中期临床预后更好,差异均有统计学意义(P0.01)。结论对于急性大脑中动脉M1段或颈内动脉闭塞缺血性卒中患者基于CTA的rLMC评分能够有效预测早期神经功能缺损的改善及中期临床预后。     

The effects of unilateral carotid occlusion on the responses to decapitation in the gerbil brain

The effects of partial ischemia (unilateral carotid artery occlusion) on the metabolic and electrical responses to decapitation were studied in the awake and anesthetized gerbils' brains. The gerbil was connected to the 2 channel fluorometer/reflectometer by flexible light guides implanted above the two hemispheres of the brain. The results show that: (1) the metabolic rate as measured by this present technique is lower in the gerbil than in the rat; (2) the metabolic rate of the ischemic hemisphere is lower as compared to that of the normoxic contralateral hemisphere.     

Observations on distal intravascular pressure changes and cerebral blood flow after common carotid artery ligation in man

Studies of cerebral blood flow and distal intravascular pressure changes were studied in 11 patients at the time of common carotid artery ligation for the treatment of intracranial aneurysm. No neurological deterioration was observed while these patients were under observation. Cerebral blood flow in the ipsilateral hemisphere recovered rapidly while reduction in pressure, and in particular diminution of pulse pressure, persisted affording protection to the aneurysm.     

Regional cerebral blood flow after occlusion of the middle cerebral artery

Occlusions of the middle cerebral artery (MCA) are mostly of embolic origin (appr. 80%) and give rise to about one third of all ischemic strokes, most of these being major strokes. MCA occlusions lasting for less than 1/2 h are tolerated without occurrence of permanent tissue damage. Occlusions lasting between 1/2 h to 4-8 h lead to permanent tissue damage and neurological deficits that are proportional to the duration of occlusion. Maximal tissue damage is obtained after 4-8 h occlusion. A cerebral blood flow of 8-23 ml/100 gr/min is sufficient for cellular viability but insufficient for normal tissue function ("ischemic penumbra"). Cellular function is completely abolished in the interval 8-16 ml/100 gr/min and flow at that level is tolerated only for 1-3 h before neuronal death ensues. In the interval 18-23 ml/100 gr/min there is some functional activity although it is reduced. Experimental and clinical evidence suggests that flow in this interval may be tolerated for several days, months or even longer ("chronic ischemic penumbra"). After MCA occlusion the blood flow falls below 8 ml/100 gr/min in most cases and permanent MCA occlusion always leads to relatively large areas of frank infarction. The ischemic infarcts may be surrounded by collaterally perfused areas where the blood flow is pressure-dependent (impaired autoregulation) and quite commonly insufficient for normal neuronal function (below 23 ml/100 gr/min). Such collaterally perfused areas may include a "chronic ischemic penumbra". Emboli causing MCA occlusions commonly disintegrate and/or migrate more peripherally within the first few weeks post stroke. This leads to reperfusion and changes of ischemic infarcts into hyperemic infarcts where flow is severely increased. The vascular reactivity is completely abolished in hyperemic infarcts and the hyperemic state lasts for about two weeks. Probably, anemic infarcts are equivalent to ischemic infarcts while the hemorrhagic variety is equivalent to hyperemic infarcts. The "partial infarct" with selective neuronal necrosis occurs in experimental animals after MCA occlusions of less than four h but not after permanent MCA occlusion. The significance of partial infarction in human stroke is not clarified. The extent of irreversible tissue damage can be reduced only if therapy sets in within 4-8 h after the occlusion. If a "chronic penumbra" exists the extension of reversible tissue damage can be reduced if therapy aimed at increasing the blood flow in the penumbra sets in within weeks or even months after the stroke.(ABSTRACT TRUNCATED AT 400 WORDS)     

脑电图空间对称指数在评价颈动脉支架置入术后脑血流灌注中的应用

目的 探讨脑电图空间对称指数(sBSI)在颈动脉支架置入术(CAS)前后的变化. 方法 对31例CAS患者在术前1 d和术后3～5 d内分别行脑电图检查,计算出脑电图sBSI.根据脑血管造影的结果评估患者的术前狭窄程度和术后残余狭窄.采用配对t检验对CAS前后sBSI进行比较分析,同时对脑电图sBSI手术前后改善程度与狭窄改善程度和术前sBSI进行直线相关和回归分析.结果 31例患者CAS术后脑电图sBSI较术前出现明显的降低,差异有统计学意义(P<0.05).将脑电图sBSI手术前后改善程度与狭窄改善程度进行相关分析后发现,两者无显著相关性(P>0.05),脑电图sBSI手术前后改善程度与术前脑电图sBSI具有显著正相关(P<0.05). 结论 CAS术后脑电罔sBSI存在变化.脑电图sBSI检查可作为评价CAS术后脑血流灌注增加的一种安全、有效的方法.     

Regional cerebral blood flow in patients with leuko-araiosis and atherosclerotic carotid artery disease

The relation between white-matter lesions (WMLs), demonstrated with magnetic resonance imaging, and regional cerebral blood flow (CBF), measured with dynamic positron emission tomography and [18F] fluoromethane, was investigated in 20 patients with atherosclerotic disease of the internal carotid artery. There was no correlation between the extent of small patchy WMLs and hemispheric CBF, but hemispheric CBF was significantly reduced in 5 patients with multiple large or confluent lesions. Distinct focal cortical CBF reductions were observed when large WMLs (greater than 5 mm) were located directly beneath the cortex, whereas large WMLs in deeper white matter were associated with a more diffuse decrease of cortical perfusion. There was no evidence of preferential CBF reduction in vascular border zones with increasing severity of WMLs or stenosis of the internal carotid artery. The side of previous transient ischemic symptoms correlated significantly with hemispheric CBF asymmetries, but not with asymmetries of WMLs and internal carotid artery stenosis. It can be concluded from these results that the presence of small patchy WMLs shown by magnetic resonance imaging cannot be used as evidence of impaired cerebral perfusion, while large lesions indicate clinically relevant cerebrovascular disease affecting cortical blood flow.     

颈内动脉狭窄程度和血流速度与颈内动脉支架置入术后高灌注损伤的相关性研究

目的 探讨颈内动脉狭窄程度和血流速度与颈内动脉支架置入术后高灌注损伤的相关性。方法 选取2014年1月-2019年2月本院收治的298例颈内动脉狭窄患者为研究对象,全部患者采取颈内动脉支架置入术治疗,根据术后是否发生高灌注脑出血将其分为高灌注脑出血组(观察组,n=8)与未发生高灌注脑出血组(对照组,n=290); 采用改良RANKIN量表(mRS评分)评估2组受试者手术前、手术30 d后残疾程度,分别于手术前、手术后3 d采用彩色多普勒超声测定2组受试者患侧颈内动脉狭窄程度及血流速度,应用经颅多普勒TCD测定2组受试者患侧大脑中动脉血流速度; 采用NIHSS评分评估2组受试者手术前、手术30 d后神经功能缺损程度,采用LOGSTIC多元回归分析颈内动脉支架置入术后高灌注脑出血的影响因素。结果 观察组手术30 d后mRS评分高于对照组(P<0.05); 观察组手术前患侧颈内动脉狭窄程度高于对照组(P<0.05); 观察组手术前患侧大脑中动脉动脉血流速度(Vm)低于对照组(P<0.05); 观察组手术30 d后NIHSS评分高于对照组(P<0.05); Logistic多因素回归分析显示,颈内动脉支架置入术后高灌注脑出血与术前颈内动脉狭窄程度、血流速度、术后3 d患侧大脑中动脉血流速度(Vm)呈正相关(P<0.05),与术前患侧大脑中动脉血流速度(Vm)呈负相关(P<0.05)。结论 颈内动脉狭窄程度和血流速度是颈内动脉支架置入术后发生高灌注脑出血的独立影响因素。     

Regional cerebral blood flow, diaschisis, and steal after stroke

Regional CBF was measured by 133Xe inhalation in unilateral cerebral infarction, carotid TIAs, and normal volunteers. Regional CBF values were bilaterally and symmetrically reduced in patients measured within 3 weeks after stroke. Later, rCBF values returned toward normal in the contralateral hemisphere of patients with infarction and in both hemispheres with carotid TIAs. In cases with carotid occlusive disease, flow reduction was seen in the contralateral posterior cerebral artery distribution, with hyperemia in ipsilateral occipital lobe caused by interhemispheric steal. Brainstem-cerebellar flow values were increased following acute cerebral infarction if patients were alert but reduced if consciousness was impaired.     

Relationship of deep white matter hyperintensities and cerebral blood flow in severe carotid artery stenosis

Leukoaraiosis (LA) has been associated with abnormalities of both large and small blood vessels. This study attempts to clarify the pathogenesis of LA by testing the hypothesis that increased frequency of LA with occlusive extra-cranial arterial disease results directly from global reduction in cerebral blood flow (CBF). Thirty-five normal subjects and 55 patients with carotid stenosis (>70%) were studied using MR. CBF was measured using phase contrast MR angiography and LA was scored using previously validated scoring system. Patients were divided into those with evidence of previous infarction on MRI and those without. LA was more severe in patients than in normal subjects (P<0.01) and correlated with age in normal subjects but not in patients. CBF in patients with (809+/-214 ml/min) and without infarction (mean 792+/-181 ml/min) was significantly lower than in normal subjects (mean 1073+/-194 ml/min). There was no correlation between the severity of LA and measured CBF in any group. The severity of LA is greater in patients with severe carotid stenosis but is not correlated to reductions in CBF. This suggests that microvascular abnormality is the dominant pathogenetic factor in LA even in the presence of severe stenotic/occlusive large vessel disease.     

颅内外高流量分流联合颈内动脉结扎术治疗的巨大症状性颈内动脉海绵窦段动脉瘤

目的 探讨颅内外高流量分流联合颈内动脉结扎术治疗巨大症状性颈内动脉海绵窦段动脉瘤的临床疗效.方法 回顾性分析2015年5月至2020年5月运用颅内外高流量分流联合颈内动脉结扎术治疗的4例颈内动脉海绵窦段巨大动脉瘤的临床资料.结果 术后症状明显改善.出院后随访1～4年,4例GOS评分均为5分.术后1年复查颅脑CT和CTA...     

Regional cerebral blood flow with age: changes in rCBF in childhood

Changes in cerebral blood flow (CBF) and regional cerebral blood flow (rCBF) throughout the entire age range including childhood were reported. The CBF in grey matter of children was markedly higher than that found in adults and showed a negative correlation with age. In contrast, the blood flow in white matter did not show a notable decrease with age. The regional distribution of CBF in children did not exhibit the frontal lobe dominance typical of adults. The rCBF pattern began to approach that of adults with growth and by 10 yr the rCBF pattern of children was similar to that of adults.