Atherosclerotic plaque burden of middle cerebral artery and extracranial carotid artery characterized by MRI in patients with acute ischemic stroke in China: association and clinical relevance

Objectives: This study sought to compare the atherosclerotic plaque burden between middle cerebral artery (MCA) and extracranial carotid artery (ECA) in ischemic stroke patients using high-resolution, black-blood (HR BB) MRI and to investigate the relationship between plaque burden found in both arteries and stroke severity.

Methods: All subjects with recent ischemic stroke underwent MCA and ECA HR BB MRI at 3.0 Tesla. For each artery segment, the thickness, area and signal intensities of plaques were recorded. Plaque burden, as measured by normalized wall index (NWI = wall area/total vessel area × 100%) were calculated. All patients received a clinical stroke severity score as measured by the National Institutes of Health Stroke Scale (NIHSS) scores at the time of admission.

Results: A total of 65 stroke subjects were included in the final analysis. MCA exhibited significantly greater NWI than the ipsilateral ECA (symptomatic MCA vs. ECA: 58.04 ± 8.19 vs. 37.53 ± 10.25, p < 0.001; asymptomatic MCA vs. ECA: 53.80 ± 4.49 vs. 34.85 ± 4.27, p < 0.001, respectively). NWI in symptomatic MCA and ECA were significantly associated with NIHSS scores (r = 0.779 vs. 0.645; p < 0.001 respectively). Moreover, stronger statistical correlations between NIHSS scores and NWI were found in MCA, as compared with ECA during multivariate linear regression analysis.

Conclusion: Greater atherosclerotic plaque burden and a closer association with stroke severity were found for the MCA as compared to the ipsilateral ECA. Identification of MCA plaque lesions by MRI may be helpful for developing more aggressive strategies for stroke prevention.     

Chronic remote ischemic conditioning for symptomatic internal carotid or middle cerebral artery occlusion: A prospective cohort study

AimsRemote ischemic conditioning (RIC) has been demonstrated to reduce recurrent stroke in patients with intracranial artery stenosis. This study aimed to evaluate the effects of RIC in patients with the symptomatic internal carotid artery (ICA) or middle cerebral artery (MCA) occlusion.MethodsThis study is based on a high‐volume single‐center prospective cohort study in China, which included patients with symptomatic ICA or MCA occlusion with impaired hemodynamics and receiving chronic RIC. Clinical follow‐up visits were performed regularly, and cardio‐cerebrovascular events were assessed.ResultsIn total, 131 patients (68 with ICA occlusion and 63 with MCA occlusion; mean age, 52.6 ± 13.7 years; stroke, 73.5%; transient ischemic attack TIA, 26.5%) qualified for the analysis; the mean follow‐up period was 8.8 years (range, 3–14 years). The compliance of RIC was 95.6 ± 3.7%, and no associated severe adverse events happened. The annual risk of ischemic stroke and ischemic cerebrovascular events was 2.4% and 3.3%, respectively. The cumulative probabilities of ischemic cerebrovascular events and major adverse cardiovascular and cerebrovascular events were 32.8% and 44.8% at 14 years, respectively.ConclusionIn patients with symptomatic ICA or MCA occlusion with impaired hemodynamics, chronic RIC is well‐tolerated, and it appears to be associated with a low annual risk of ischemic stroke and cardio‐cerebrovascular events.     

Efficacy of transcranial alternating current stimulation over bilateral mastoids (tACSbm) on enhancing recovery of subacute post-stroke patients

Background and aims: Transcranial alternating current stimulation (tACS) offers another method of non-invasive brain stimulation in post-stroke rehabilitation. Because it is not known if tACS over bilateral mastoids (tACS_bm) can promote the functional recovery in subacute post-stroke patients, we wish to learn the effect of tACS_bm on improving neurological function and intracranial hemodynamics of subacute post-stroke patients.

Methods: Sixty subacute post-stroke patients (mean age: 65.4 ± 9.8 years), 15 to 60 days after the onset, were randomly assigned to receiving 15 sessions of usual rehabilitation program without (n = 30) or with tACS_bm (20 Hz and < 400 μA for 30-min; n = 30). The outcome measures included the NIH Stroke Scale (NIHSS) and measures of intracranial hemodynamics before and after treatment.

Results: At the fifteenth session, when compared with the baseline, the mean NIHSS scores of the patients in the tACS_bm group had significantly a larger decrease [18.3 ± 2.6 vs. 10.8 ± 2.7; p < 0.001] than that of the control group [19.1 ± 2.7 vs. 13.0 ± 2.4] [F(1,54) = 4.29, p = 0.043]. After both the first and fifteenth sessions, compared with the control group, the mean blood flow velocity (MFVs) of the tACS_bm group had significantly larger increase in the MCA, ACA, and PCA (p < 0.001), the Gosling pulsatility index (PI) of the tACS_bm group had also significantly larger decline in the MCA, ACA, and PCA than that of the control group (p < 0.001). The best predictor of the changes in the NIHSS scores was the decline in the pulsatility index in the vascular territory of both lesional and non-lesional MCA measured by the end of the last treatment session.

Conclusions: tACS_bm appeared to be effective for enhancing patients’ functional recovery and cerebral hemodynamics in the subacute phase. The extent of recovery seems to be associated with the decline of the resistance in vascular bed of the main cerebral arteries. The mechanisms behind this effect should be explored further through research.     

Effects of uncomplicated carotid endarterectomy on cognitive function and brain perfusion in patients with unilateral asymptomatic severe stenosis of the internal carotid artery by comparison with unoperated patients

Objective: The purpose of the present exploratory study was to evaluate the effects of uncomplicated carotid endarterectomy (CEA) on cognitive function and brain perfusion in patients with unilateral asymptomatic severe stenosis of the internal carotid artery (ICA) by comparison with unoperated patients.

Methods: Patients with age ≤75 years and unilateral asymptomatic severe stenosis (≥70%) of the cervical ICA underwent CEA with antiplatelet therapy (surgically treated group: 116 patients) or antiplatelet therapy alone or neither (medically treated group: 45 patients). For the surgically treated group, neuropsychological testing and brain perfusion measurement using single-photon emission computed tomography were performed within one month before surgery and one month after surgery. For the medically treated group, the same testing and measurement were performed twice at an interval of 1 to 2 months.

Results: None of the operated patients developed new major ischemic events after surgery or intraoperative cerebral hyperperfusion. None of the patients in the medically treated group experienced neurological deficits including transient ischemic attacks during the study period. The incidence of patients with interval cognitive improvement was significantly greater in the surgically treated group (11 patients: 9%) than in the medically treated group (0%) (p = 0.0352). The incidence of patients with interval brain perfusion improvement in the ipsilateral cerebral hemisphere was significantly greater in the surgically treated group (24 patients: 21%) than in the medically treated group (0%) (p = 0.0003).

Conclusions: Uncomplicated CEA may improve cognitive function and brain perfusion in patients with unilateral asymptomatic severe stenosis of the ICA when compared with unoperated patients.     

Dynamic cross-sectional changes of the middle cerebral artery in atherosclerotic stenosis detected by 3·0-Tesla MRI

Abstract

Objectives:

Atherosclerotic stenosis of the middle cerebral artery (MCA) is one of the causes of ischemic stroke, but aside from investigations using magnetic resonance angiography (MRA), studies evaluating stenosis are rare. The purpose of this study was to assess dynamic changes of MCA cross section between the systolic and diastolic phases in patients with cerebral infarction using 3·0-Tesla magnetic resonance imaging (3T MRI).

Methods:

We assessed 12 stroke patients with M1 stenosis in the MCA and 12 healthy volunteers. We measured MCA cross sections (proximal/distal to stenosis and on the stenosis) in the systolic and diastolic phases by synchronizing imaging with heartbeats, as well as the maximum flow velocity by using cine-phase contrast (PC) MRI. Each patient also underwent conventional MRA.

Results:

Differences in cross sections between systolic and diastolic phases were significantly smaller in the stenosed artery compared to the distal (P < 0·05) and proximal areas (P < 0·01) in stroke patients. The difference in maximal blood velocity between systolic and diastolic phases at the M1 stenosis was significantly larger than that in the area proximal to the stenosis (P < 0·05).

Discussion:

We clearly demonstrated dynamic cross-sectional changes in the stenotic areas by 3T MRI, suggesting hemodynamic shear stress, which may further enhance MCA atherosclerosis.     

颞浅动脉-大脑中动脉分流术治疗大脑中动脉狭窄性脑卒中的疗效观察

目的 探讨颞浅动脉（STA）-大脑中动脉（MCA）分流术治疗大脑中动脉狭窄致缺血性卒中的安全性和有效性。方法 回顾性分析2013年1月至2016年12月STA-MCA分流术治疗的75例大脑中动脉狭窄引起的缺血性卒中的临床资料。结果 术中B超探查显示71例吻合口血流通畅满意,4例血流缓慢。术后3 d死亡2例,其余73例术后CT灌注成像检查显示脑血流灌注明显改善。术后7、14 d神经功能评分较治疗前明显改善（P<0.05）,术后6、12个月神经功能评分进一步好转（P<0.05）。术后随访12个月,73例未出现因搭桥血管狭窄或闭塞引起的新发脑梗死及TIA;67例CTA检查显示血管显影良好。结论 STA-MCA分流术是预防和治疗大脑中动脉狭窄性卒中安全、有效的手段。     

Impaired dynamic cerebral autoregulation in middle cerebral artery stenosis

Abstract

Background and purpose: Analysis of dynamic cerebral autoregulation during transient falls in blood pressure is considered a sensitive and convenient method for evaluating patients with carotid artery stenosis. To this point, there have been few reports on the efficacy of using the thigh cuffs technique to analyse middle cerebral artery (MCA) stenosis. If it could be determined whether cerebral blood flow can be maintained (autoregulated) during sudden falls in arterial blood pressure (ABP), then it might be possible to identify patients with MCA stenosis who are at risk of stroke.

Methods: We used the thigh cuff technique to estimate dynamic cerebral autoregulation in 57 patients with MCA stenosis and 72 normal controls. After a stepwise fall in arterial blood pressure, we determined the rate of the rise of MCA blood velocity and compared it with the rate of the rise of arterial blood pressure. In this manner, the dynamic cerbral autoregulation of 11 patients undergoing MCA M1 stent angioplasty was estimated both pre- and post-operation.

Results: The autoregulatory index (ARI) was significantly reduced in patients with stenosed/occluded MCA (3.24 ± 1.52), as compared with normal controls (5.25 ± 1.39; p<0.001) (results reported as mean ± SD). Poor ARI values are usually observed in patients with a higher degree of stenosis and particularly in patients with insufficient collateral compensation. ARI was significantly reduced in severe stroke patients (modified ranking scale≥1), as compared with asymptomatic or TIA patients (p<0.05). After MCA stent angioplasty was performed, there was a significant improvement in ARI in 11 subjects, which caused a mean increase in ARI from 2.08 ± 1.10 to 3.80 ± 1.36 (p=0.008).

Conclusions: Dynamic cerebral autoregulation is impaired in patients with middle cerebral artery stenosis. Assessing dynamic cerebral autoregulation may allow a subgroup of patients with MCA stenosis who are at risk of hemodynamic stroke to be identified. Dynamic cerebral disautoregulation in patients with severe MCA stenosis is mostly remedied by stent angioplasty.     

Clinical and neuroradiological features of internal watershed infarction and the occlusive diseases of carotid artery system

Abstract

Background: To describe the clinical and neuroradiological features of internal watershed (IWS) infarction and to analyze the relationship between IWS infarction and occlusive diseases of carotid artery system.

Methods: We identified 27 IWS infarction patients with diffusion-weighted magnetic resonance imaging by commonly used templates within 10 days after the onset. Patients with potential cardiac sources of embolism were excluded. Occlusive diseases of carotid arteries were assessed by magnetic resonance angiography or digital subtraction angiography. Baseline characteristics, clinical course, prognosis, neuroradiological features and symptomatic arteries were analyzed.

Results: Two patterns were identified: 14 patients had confluent IWS (C-IWS) infarction, and 13 patients had partial IWS (P-IWS) infarction. Twelve patients in C-IWS group and 10 patients in P-IWS group had severe stenosis (>70%) or occlusion in either the internal carotid artery (ICA) or middle cerebral artery (MCA). Occlusive diseases of ICA and non-lacunar syndrome were more prevalent in C-IWS group, while occlusive diseases of MCA and lacunar syndrome were more prevalent in P-IWS group. Concomitant small cortical lesions ipsilateral to IWS infarcts were more common in C-IWS group than in P-IWS group, and were significantly associated with ICA diseases. Clinical deterioration during the first seven days after admission and poor outcome assessed by the Modified Rankin Score 3 months after stroke were more prevalent in C-IWS group than in P-IWS group.

Conclusions: There is a relatively definite relationship between IWS infarction and occlusive diseases of carotid arteries. The distribution of symptomatic arteries (ICA or MCA) in C-IWS group is significantly different from that in P-IWS group. Both hypoperfusion and microembolism are probable mechanisms. There may be some differences in their roles in pathogenesis of C-IWS and P-IWS infarction. Microembolism may contribute C-IWS infarction in addition to hypoperfusion, which is the major pathogenesis of P-IWS infarction.     

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.     

High incidence of hyponatremia in patients with ruptured anterior communicating artery aneurysms

Abstract

We studied the incidence and timing of hyponatremia (Na < 135 mEq l~¹) after subarachnoid hemorrhage (SAH) with special reference to ruptured anterior communicating artery (A-com) aneurysms. Hunt and Kosnik (HK) grading, symptomatic vasospasm in A-com aneurysm, and hydrocephalus were analyzed for connections to hyponatremia in 55 patients with ruptured A-com aneurysms, 65 with ruptured internal cerebral artery (ICA) aneurysms, and 49 with ruptured middle cerebral artery (MCA) aneurysms. Hyponatremia occurred in 28 (51%) of 55 patients with A-com aneurysms and in nine (18%) of 49 patients with MCA aneurysms. Severe hyponatremia (Na < 130 mEq^-1) occurred in 16 patients (29%) in the A-com group, four patients (6%) in the ICA group, and three patients (6%) in the MCA group. The A-com aneurysm group had a significantly higher incidence of mild hyponatremia (p < 0.01) and severe hyponatremia (p< 0.001) than other groups. Among A-com cases, hyponatremia occurred significantly more often in HK grade III and IV cases (p < 0.05), in cases with vasospasm (p < 0.001), and in cases with hydrocephalus (p < 0.01). Respective days of onset for symptomatic vasospasm and for hyponatremia were day 7.6 ±4.4 and day 10.6± 5.8 following SAH, representing a 3-day delay for hyponatremia (p<0.05). In most patients hyponatremia resolved within 28 days following SAH. Hyponatremia occurred more often with A-com aneurysms, possibly because of vasospasm around the A-com or hydrocephalus causing hypothalamic dysfunction. Since hypervolemic therapy can cause hyponatremia, particularly careful observation is required during such therapy in patients with A-com aneurysm. [Neurol Res 2000; 22: 151-155     

A new clinically relevant model for intracranial atherosclerosis in rats

Introduction: Intracranial atherosclerotic stenosis (ICAS) is one of the most common causes of stroke worldwide and, in particular, has been implicated as a leading cause of recurrent ischemic stroke. We developed a new rat model to study intracranial atherosclerosis.

Methods: Twelve-week-old male Sprague-Dawley rats were divided into a control (on a maintain diet) and a high-cholesterol group (on a daily 1% cholesterol diet) for up to 6 weeks. During the first two weeks, NG-nitro-L-arginine methylester (L-NAME, 3 mg/mL) was added to the drinking water in the high-cholesterol group to induce intimal changes making the rats susceptible to atherosclerosis. Blood lipids, including low-density lipoprotein (LDL), cholesterol (CHO), triglycerides (TG), and high-density lipoprotein (HDL), were measured after 3 and 6 weeks. Histological sections of the brains, including internal carotid artery (ICA), middle cerebral artery (MCA), and basilar artery (BA), were prepared to study intracranial artery morphometry and intimal thickening. The levels of CD68, an inflammatory marker, within the vessel walls as determined by immunohistochemistry were also measured.

Results: The high-cholesterol diet increased the levels of classic blood markers of atherosclerosis, LDL, CHO, and TG as well as decreased HDL, which became progressively more intensive with time. Rats showed increased intimal thickening in the ICA, MCA, and BA. This protocol also increased the levels of CD68 immunoreactivity within the vessel walls.

Conclusions: A rat model of intracranial atherosclerosis was effectively developed by high-cholesterol diet and L-NAME administration. This clinically relevant model would be beneficial for studying ICAS.     

Balloon-mounted versus self-expanding stents for symptomatic intracranial vertebrobasilar artery stenosis combined with poor collaterals

ABSTRACT

Objectives: To compare the technical and 1-year outcomes of balloon-mounted versus self-expanding stents for symptomatic intracranial vertebrobasilar artery stenosis.

Methods: 167 patients with severe intracranial vertebrobasilar artery atherosclerotic stenosis with poor collaterals were enrolled. Both balloon-mounted stenting and self-expanding stent placement were selected to treat patients. The baseline characteristics, cerebral angiography and clinical follow-up were assessed between the two groups.

Results: The overall mean stenosis degree was reduced from 82.8 ± 11.8% pre-stent placement to 9.41 ± 8.20% post-stent placement. Patients treated with self-expanding stent were more likely to undergo general anesthesia (81.2% versus 67.3%; P = 0.048) and have longer operative times (91.0 ± 25.1 min versus 67.9 ± 17.1 min, P = 0.012) than those treated with self-expanding stents. Patients treated with self-expanding stents were more likely to require longer and larger diameter stents (14.99 ± 3.26 mm versus 9.23 ± 2.46 mm, P = 0.000; 3.28 ± 0.57 mm versus 2.74 ± 0.30 mm, P = 0.000, respectively). The degree of residual stenosis in self-expanding stent group was higher than patients treated with balloon-mounted stents (13.39 ± 8.64% versus 6.70 ± 6.62%, P = 0.000). The rates of stroke, transient ischemic attack or death at 1-year follow-up were not significantly different between two groups (P > 0.05).

Conclusions: Stenting for patients with severe symptomatic intracranial vertebrobasilar arterial stenosis with poor collaterals can be performed safely with efficacy. Patients treated with balloon-mounted stents appear to have shorter operative times and lower re-stenosis rates than treated with self-expanding stents.     

颅内动脉狭窄支架成形术后影响分支缺血性事件的临床因素探讨

目的 探讨颅内动脉狭窄支架成形术（ICASS）后支架置入与临床对应分支缺血性事件的相关性及其影响因素.方法 21例24支颅内大动脉狭窄,行血管内支架成形术.其中大脑中动脉（MCA）15支,椎动脉（VA）5支,基底动脉（BA）3支和颈内动脉（ICA）1支.20支血管（MCA 14支,VA 3支,BA 2支和ICA 1支）为症状性重度狭窄、1支（BA）为无症状性重度狭窄;3支血管（MCA 1支和VA 2支）为症状性中度狭窄.比较评价支架成形术对分支缺血性损害、总体预后等方面的影响.结果 无支架置入性相关分支缺血性损害的表现,随访期（6～27个月）内无再狭窄;所有患者均无手术相关性并发症.结论 在围手术期规范化临床干预下,颅内动脉狭窄支架成形术不会导致明显的理论性支架相关性分支缺血性并发症,但这还需要进一步的验证.     

Surgical modulation of the natural course of collateral circulation in chronic ischemic patients

The purpose of this study was to evaluate hemodynamic compromise in terms of baseline CBF and CRC in patients with chronic cerebral occlusive lesions and its modulation by a superficial temporal artery to middle cerebral artery (STA-MCA) anastomosis. The study subjects were 10 healthy volunteers and 49 chronic ischemic patients with stenosis or occlusion of the internal carotid artery (ICA) or middle cerebral artery (MCA) The hemodynamics were measured using stable xenon enhanced computed tomographic CBF measurement with the acetazolamide challenge. The compromised hemodynamics in patients with chronic steno-occlusive lesions did not improve during their natural course after two months. STAMCA bypass modulated hemodynamic compromise in the ischemic patients. We recommend STAMCA bypass for patients with reduced CRC, regardless of whether baseline CBF is reduced or normal. Hemodynamic classification using a combination of baseline CBF values and CRC values is useful for evaluating cerebral hemodynamics and for choosing the best treatment for cerebral ischemia with occlusive lesions.     

Unilateral internal carotid artery absence in trisomy 18

BackgroundInternal carotid artery (ICA) absence (agenesis or aplasia) is a rare congenital anomaly that is usually asymptomatic and found coincidentally. There has been no report showing a specific chromosomal abnormality causes ICA absence.Case reportsMR angiography in a Japanese male infant with trisomy 18 revealed left ICA absence with the left middle cerebral artery (MCA) and anterior cerebral artery (ACA) supplied from the ipsilateral posterior communicating artery and anterior communicating artery (ACoA), respectively, type A in Lie’s classification. Another Japanese male infant with trisomy 18 showed right ICA absence with the right ACA and MCA supplied from the ACoA, that is, type B in Lie’s classification.ConclusionThere have been no pathological or radiological reports of ICA absence in trisomy 18, however, it may be underestimated because the anomaly usually causes no clinical symptoms. It is necessary to evaluate further patients to clarify whether or not unilateral ICA absence is a characteristic congenital malformation.     

颈内和大脑中动脉狭窄与闭塞的梗死类型及卒中机制的研究

目的 研究单侧动脉粥样硬化性MCA/ICA狭窄与闭塞的急性缺血性脑卒中患者在DWI上的梗死类型及发病机制.方法 起病48h内DWI诊断的急性脑梗死伴有动脉粥样硬化性MCA/ICA狭窄与闭塞的131例患者,有潜在心源性栓子患者除外.急性期DWI上梗死病灶分为：（1）单发病灶（小的穿动脉梗死灶;大的穿动脉梗死灶,皮层支梗死,大面积梗死,分水岭梗死）;（2）多发梗死病灶.结果 131例患者,ICA51例,MCA80例.ICA出现最多的梗死类型：穿支动脉伴分水岭梗死,但与MCA比较,皮层支伴分水岭梗死具有统计学意义（8/51,P=0.001）.MCA以穿支动脉伴皮层支梗死最多,且与ICA比较,具有统计学意义（12/80,P=0.003）.MCA中任何皮层支梗死与狭窄程度无关,ICA中任何分水岭梗死与狭窄程度相关.结论 颈内和大脑中动脉狭窄与闭塞在DWI上的梗死类型有明显的不同,提示有着不同的卒中发病机制.     

ASPECTS-Region-Dependent Functional Outcomes after Endovascular Therapy in Patients with Cardioembolic Stroke

ObjectivesCardioembolic stroke has a poor prognosis. We evaluated the region-dependent efficacy of endovascular therapy (EVT) based on diffusion-weighted imaging-Alberta Stroke Program Early CT Score (DWI-ASPECTS).MethodsThis post-hoc analysis of the RELAXED study, which investigated the optimal timing of rivaroxaban to prevent nonvalvular atrial fibrillation (NVAF) recurrence in patients with acute ischemic stroke (AIS), included NVAF patients admitted with AIS or transient ischemic attack in the middle cerebral artery (MCA), with internal carotid artery (ICA), M1, or M2-MCA occlusion. Relationships between DWI-ASPECTS region and functional outcome (modified Rankin Scale [mRS]), mortality, recurrence, and hemorrhagic stroke were compared between patients with and without EVT, and adjusted odds ratios for age, pre-stroke mRS, National Institutes of Health Stroke Scale (NIHSS), ICA occlusion, infarct size, recombinant tissue plasminogen activator (rt-PA) use, and onset-to-hospitalization time were estimated.ResultsEVT patients had significantly lower hemoglobin levels, higher median NIHSS scores, more lentiform nucleus infarcts, ICA or M1-MCA occlusions, treatment with rt-PA, and fewer M3, M5, or M6 infarcts and M2-MCA occlusions than no-EVT patients. EVT patients had shorter onset-to-hospitalization times and more frequent favorable functional outcomes (p=0.007). Mortality, recurrent ischemic stroke, and hemorrhagic infarction were similar in both groups. EVT was associated with significantly better functional outcomes among patients with insular ribbon (p=0.043) and M3 (p=0.0008) infarcts. M3 patients had significantly fewer rt-PA and EVT, and longer onset-to-hospitalization times.ConclusionsAn occlusion in the insular ribbon or M3 region was associated with favorable functional outcomes in patients treated with EVT after cardioembolic stroke.     

Pathophysiological studies in moyamoya disease by rCBF and cortical artery pressure measurements in comparison to those in ICA or MCA occlusion

The authors measured preoperative rCBF and intraoperative cortical artery pressure (CAP) during STA-MCA anastomosis to investigate cerebral hemodynamics in moyamoya disease. Six of 13 patients including 3 children showed ischemic attack and the remaining presented hemorrhagic attack. rCBF was measured by single photon ECT with Xe-133 inhalation technique. CAP's and rCBF's in moyamoya disease were compared to those in the 22 internal carotid artery (ICA) and 8 middle cerebral artery (MCA) occlusion. Systemic arterial blood pressure (SABP) was obtained at the radial artery. Mean rCBF in the MCA territory in moyamoya disease, ICA occlusion, and MCA occlusion were 39, 37, and 33 ml/100 g/min respectively. Mean SABP and CAP in moyamoya disease were 103 and 28 mmHg, respectively. In ICA occlusion, mean SABP and CAP were 98 and 45 mmHg, respectively. In MCA occlusion, mean SABP and CAP were 89 and 36 mmHg, respectively. To clarify the hemodynamics, vascular resistance was obtained from the following equations: The proximal vascular resistance (Rp), which was produced from the cervical ICA to cortical artery, was obtained by (mean SABP - mean CAP)/(rCBF). And distal vascular resistance (Rd) which was produced from the cortical artery to jugular vein, was obtained by (mean CAP)/(rCBF). Mean Rp in moyamoya disease ICA occlusion and MCA occlusion were 2.01, 1.21 and 1.70, respectively. Rd in moyamoya disease, ICA occlusion and MCA occlusion were 0.79, 1.37 and 1.22, respectively. There were significant differences in Rp and Rd between moyamoya disease and ICA or MCA occlusion. In ischemic group in moyamoya disease, rCBF, SABP, CAP, Rp and Rd were 41 ml/100 g/min, 111 mmHg, 28 mmHg, 1.92 and 0.70, respectively.(ABSTRACT TRUNCATED AT 250 WORDS)     

Early superficial temporal artery to middle cerebral artery bypass in acute ischemic stroke

Objective

To evaluate the effects and safety of superficial temporal artery–middle cerebral artery (STA–MCA) anastomosis in the early stage after an acute ischemic event and the improvement of present symptoms in patients with intracranial atherosclerotic occlusive disease with stroke/stroke in progress.

Methods

From 2006 to 2010, 20 patients (15 males and five females) with atherosclerotic cerebrovascular disease were treated with an STA–MCA bypass. All of the patients presented with an acute ischemic stroke or stroke in progress despite maximal medical treatment. The patients underwent an STA–MCA bypass within 7 days from symptom onset. The clinical outcome and hemodynamic study of the 20 patients were preoperatively and postoperatively investigated. A pooled analysis was performed, and the results were compared with those obtained from other delayed STA–MCA bypass studies.

Results

Among the 20 patients who underwent an early STA–MCA bypass, fourteen (70%) patients achieved a good functional outcome (mRS 0, n = 3; mRS 1, n = 9; mRS 2, n = 2). Prior to surgery, the mean basal regional cerebral blood flow (rCBF) and cerebrovascular reserve capacity (CVR) in the symptomatic hemisphere were 37.3 ± 4.3 ml/100 g/min and −1.68 ± 2.9%. The mean basal rCBF and CVR had significantly increased postoperatively, and no reperfusion-induced hemorrhage had occurred. In the pooled analysis, no significant differences were observed in the clinical outcome (P = 0.328) or in the incidence of postoperative complications (P = 0.516) between patients who underwent an early STA–MCA bypass and in patients who underwent a delayed STA–MCA bypass in previous studies.

Conclusions

In this study, which consisted of 20 carefully selected patients with acute ischemic stroke, an early STA–MCA bypass was safely and effectively performed, and in some cases, an early STA–MCA bypass resulted in rapid neurological improvement. An early STA–MCA bypass was beneficial in select patients who had acute ischemic stroke with imaging evidence of a small infarction.     

Internal carotid artery agenesis: diagnosis,clinical spectrum,associated conditions and its importance in the era of stroke interventions

Abstract

Background: Internal carotid artery (ICA) agenesis has been usually reported as an asymptomatic condition in association with other congenital anomalies. However, it is less well described in the context of clinical neurological syndromes.

Method: Five cases of ICA agenesis are reviewed. The diagnosis of ICA agenesis was based on the absence of bony carotid canal on computed tomography. Brain CT and magnetic resonance image (MRI) scans were done in all the patients and four vessels digital angiograms were obtained in two. Clinical presentation, coexistent radiological findings and associated abnormalities are reviewed.

Findings: The initial presentations were pulsatile tinnitus, ischemic stroke, migraine, Horner's syndrome, and subarachnoid hemorrhage. Collateral circulation was supplied via the posterior communicating artery and the anterior communicating artery. Ophthalmic artery was supplied by meningeal arteries. On CT, all cases demonstrated agenesis of the bony carotid canal. Smaller cavernous sinus were detected in all cases, enlargement of the foramen spinosum was found in three patients and hyper-pneumatization of the petrous apex was detected in two cases. In one patient a cerebral aneurysms was detected and treated with an endovascular approach. Other associated vascular abnormalities were aortic origin of the vertebral artery in two patients, ICA coiling in two cases and fenestration of basilar artery in one case.

Conclusion: ICA agenesis is usually asymptomatic but occasionally may be associated with ischemic stroke. Collateral supply is usually effective in preventing stroke but may become inefficient leading to ischemia. Associated anomalies such as cerebral aneurysms are commonly depicted on the same side as the ICA agenesis and may represent a potential life-threatening condition.