New England Medical Center Posterior Circulation Stroke Registry II. Vascular Lesions

Among 407 New England Medical Center Posterior Circulation Registry (NEMC-PCR) patients, the extracranial (ECVA) and intracranial vertebral arteries (ICVA) were the commonest sites of severe occlusive disease followed by the basilar artery (BA). Severe occlusive lesions were found in >1 large artery in 148 patients; 134 had unilateral or bilateral severe disease at one arterial location. Single arterial site occlusive disease occurred most often in the ECVA (52 patients, 15 bilateral) followed by the ICVA (40 patients, 12 bilateral) and the BA (46 patients). Involvement of the ICVAs and the BA was very common and some patients also had ECVA lesions. Hypertension, smoking, and coronary and peripheral vascular disease were most prevalent in patients with extracranial disease while diabetes and hyperlipidemia were more common when occlusive lesions were only intracranial. Intra-arterial embolism was the most common mechanism of brain infarction in patients with ECVA and ICVA occlusive disease. ICVA occlusive lesions infrequently caused infarction limited to the proximal territory (medulla and posterior inferior cerebellum). BA lesions most often caused infarcts limited to the middle posterior circulation territory (pons and anterior inferior cerebellum). Posterior cerebral artery occlusive lesions were predominantly embolic. Penetrating artery disease caused mostly pontine and thalamic infarcts. Prognosis was poorest in patients with BA disease. The best prognosis surprisingly was in patients who had multiple arterial occlusive lesions; they often had position-sensitive transient ischemic attacks during months or years.     

Bilateral intracranial vertebral artery disease in the New England Medical Center, Posterior Circulation Registry.

BACKGROUND: Previous studies of patients with bilateral intracranial vertebral artery (ICVA) disease were selective and retrospective. METHODS: We studied risk factors, vascular lesions, symptoms, signs, and outcomes in patients with bilateral ICVA disease among 430 patients in the New England Medical Center Posterior Circulation Registry. RESULTS: Forty-two patients had bilateral ICVA occlusive disease (18 had bilateral stenosis; 16, unilateral occlusion and contralateral stenosis; and 8, bilateral occlusion). The most common risk factors were hypertension (32/42 [76%]) and hyperlipidemia (22/42 [52%]). Sixteen patients (38%) had transient ischemic attacks (TIAs) only; 18 (43%), TIAs before stroke. Occlusive vascular disease also involved the basilar artery in 29 patients (69%), the extracranial vertebral arteries in 18 (43%), and the internal carotid arteries in 11 (26%). Only 6 patients had no other major vascular lesion. Cerebellar symptoms were common. Among 30 patients with infarction, 21 (70%) had proximal intracranial territory involvement, and 15 (50%) had distal territory involvement. The location of occlusive lesions in relation to posterior inferior cerebellar artery origins did not significantly influence prognosis. During follow-up, 31 patients had no symptoms or slight disability, 2 had progression, and 7 died. Among 7 patients with poor outcome, 6 also had basilar artery stenosis or occlusion and 5 had proximal and distal intracranial territory infarcts. CONCLUSIONS: Most patients with bilateral ICVA occlusive disease have hypertension, other major occlusive lesions, and TIAs before stroke. Short- and long-term outcomes are usually favorable, but patients with bilateral ICVA and basilar artery-occlusive lesions often have poor outcomes.     

New England Medical Center Posterior Circulation registry

Among 407 New England Medical Center Posterior Circulation registry patients, 59% had strokes without transient ischemic attacks (TIAs), 24% had TIAs then strokes, and 16% had only TIAs. Embolism was the commonest stroke mechanism (40% of patients including 24% cardiac origin, 14% intraarterial, 2% cardiac and arterial sources). In 32% large artery occlusive lesions caused hemodynamic brain ischemia. Infarcts most often included the distal posterior circulation territory (rostral brainstem, superior cerebellum and occipital and temporal lobes); the proximal (medulla and posterior inferior cerebellum) and middle (pons and anterior inferior cerebellum) territories were equally involved. Severe occlusive lesions (>50% stenosis) involved more than one large artery in 148 patients; 134 had one artery site involved unilaterally or bilaterally. The commonest occlusive sites were: extracranial vertebral artery (52 patients, 15 bilateral) intracranial vertebral artery (40 patients, 12 bilateral), basilar artery (46 patients). Intraarterial embolism was the commonest mechanism of brain infarction in patients with vertebral artery occlusive disease. Thirty-day mortality was 3.6%. Embolic mechanism, distal territory location, and basilar artery occlusive disease carried the poorest prognosis. The best outcome was in patients who had multiple arterial occlusive sites; they had position-sensitive TIAs during months to years.     

Clinical findings of intracranial vertebral artery disease using magnetic resonance angiography

The vertebral artery lesion has a variety of clinical characteristics. We sought to clarify the clinical patterns and the location of the intracranial vertebral artery (ICVA) diseases according to analyses of images obtained using magnetic resonance angiography (MRA). We studied vascular lesions, risk factors, symptoms, signs, and outcomes in 35 patients with ICVA disease (3 had bilateral occlusion; 9, unilateral occlusion; 6, bilateral stenosis; and 17, unilateral stenosis). The most common site of unilateral and bilateral lesions was the distal ICVA after the origin of posterior inferior cerebellar artery (PICA). We found accompanying basilar artery disease in 28.6% of patients with unilateral and bilateral ICVA disease. The majority of the ICVA lesions were associated with internal carotid arteries disease (48.8%). The common vascular risk factors were hypertension (71%), diabetes mellitus (34%), hyperlipidemia (31%), smoking (29%), and coronary artery disease (23%). Eighteen patients (51.4%) had transient ischemic attacks (TIAs) only, 10 patients (28.6%) had TIAs before stroke, and 5 patients (14.3%) had strokes without TIAs. Most patients (80%) with TIAs, with or without stroke, had multiple episodes. Vertigo or dizziness, ataxia, limbs weakness and abnormal gait were the common symptoms and signs. At 6 months follow-up, 66.7% patients had no symptoms or only slight symptoms that caused no disability. Our data showed (1) the usual location of ICVA disease (occlusion or severe stenosis) was distal to PICA, especially near the vertebrobasilar junction; (2) the risk factors were hypertension, diabetes mellitus, hyperlipidemia, smoking, and coronary artery disease; (3) patients with ICVA disease had a high frequency of accompanying internal carotid, middle cerebral, or basilar artery disease; (4) vertigo or dizziness, and ataxia were the common symptoms and signs; (5) TIA was the most common clinical pattern; (6) the outcome was favorable, except in cases with bilateral ICVA occlusion.     

New England Medical Center Posterior Circulation Stroke Registry: I. Methods, Data Base, Distribution of Brain Lesions, Stroke Mechanisms, and Outcomes

Among 407 New England Medical Center Posterior Circulation Registry (NEMC-PCR) patients, 59% had strokes without transient ischemic attacks (TIAs), 24% had TIAs before strokes, and 16% had only posterior circulation TIAs. Embolism was the commonest stroke mechanism accounting for 40% of cases (24% cardiac origin, 14% arterial origin, 2% had potential cardiac and arterial sources). In 32%, large artery occlusive lesions caused hemodynamic brain infarction. Stroke mechanisms in the posterior and anterior circulation are very similar. Infarcts most often included the distal posterior circulation territory (rostral brainstem, superior cerebellum and occipital and temporal lobes), while the proximal (medulla and posterior inferior cerebellum) and middle (pons and anterior inferior cerebellum) territories were equally involved. Infarcts that included the distal territory were twice as common as those that included the proximal or middle territories. Most distal territory infarcts were attributable to embolism. Thirty day mortality was low (3.6%). Embolic stroke mechanism, distal territory location, and basilar artery occlusive disease conveyed the worst prognosis.     

多灶性后循环缺血患者的病灶分布与血管形态异常及近期预后分析

目的 观察多灶性后循环缺血患者的病灶分布和血管形态异常的特点,评估患者出院时的近期预后及其与病灶分布和血管形态的关系.方法 对34例经过MR/所证实的多灶性后循环缺血患者行主动脉弓及全脑血管DSA,全面分析病灶分布及血管形态异常的特点;同时对患者出院时的近期预后用改良Rankin分级(MRS)评分表进行评估,分析病灶分布及血管形态异常与近期预后的关系.结果 多灶性后循环缺血患者最常被累及的部位是脑桥(22例),最常被累及的区段是中段+远段(12例);34例患者中有26例(76.5%)DSA显示出血管形态异常,最常被累及的动脉是椎动脉起始段(14例)和颅内段(13例)及基底动脉(7例);出院时7例患者(20.6%)存在预后不良,其中6例(17.6%)为重度残疾,1例(2.9%)死亡.近中远段同时受累和基底动脉受累的患者表现出预后不良.结论 血管形态异常是多灶性后循环缺血的重要病理基础和致病因素,病灶区段的分布和数目及血管受累部位是决定预后的关键因素.     

Juvenile-onset multiple brain infarcts localized in the posterior circulation: a case report]

We report a 37-year-old male patient with multiple brain infarcts due to arterial lesions localized in the posterior circulation, who developed a paramedian pontine infarct on the left side. He had been treated as schizophrenia for 20 years. A cranial CT performed one year before showed old small infarcts in the territories of the bilateral thalamo-perforating and left thalamo-geniculate arteries and the right posterior inferior cerebellar artery. The vertebral and basilar arteries were small in diameter on MRI and MR angiography(MRA). Cerebral angiography revealed a narrow smooth basilar artery. In addition, the P2 segments of the bilateral posterior cerebral arteries were markedly narrow with irregular walls. Carotid arteriograms were normal and no atherosclerosis was found. The nature of these arterial lesions remains unknown in this case. Even if MRA shows vertebrobasilar artery hypoplasia, a known congenital risk factor of a posterior circulation infarct, we must rule out a possibility that some arterial pathology is going on.     

Atherothrombotic cerebellar infarction: vascular lesion-MRI correlation of 31 cases.

BACKGROUND AND PURPOSE: Correlation of MRI findings with atherosclerotic vascular lesions has rarely been attempted in patients with cerebellar infarction. The aim of this study was to correlate the MRI lesions with the vascular lesions seen on conventional cerebral angiography in cerebellar infarction. METHODS: The subjects included 31 patients with cerebellar infarcts who underwent both MRI and conventional cerebral angiography. We analyzed the risk factors, clinical findings, imaging study, and angiography results. We attempted to correlate MRI lesions with the vascular lesions shown in the angiograms. RESULTS: The vascular lesions seen on angiograms were subdivided into 3 groups: large-artery disease (n=22), in situ branch artery disease (n=6), and no angiographic disease with hypertension (n=3). The proximal segment (V1) lesions of vertebral artery were the most common angiographic features in patients with large-artery disease in which stroke most commonly involved the posterior inferior cerebellar artery (PICA) cerebellum. The V1 lesions with coexistent occlusive lesions of the intracranial vertebral and basilar arteries were correlated with cerebellar infarcts, which had no predilection for certain cerebellar territory. The intracranial occlusive disease without V1 lesion was usually correlated with small cerebellar lesions in PICA and superior cerebellar artery (SCA) cerebellum. The subclavian artery or brachiocephalic trunk lesion was associated with small cerebellar infarcts. The in situ branch artery disease was correlated with the PICA cerebellum lesions, which were territorial or nonterritorial infarct. No angiographic disease with hypertension was associated with small-sized cerebellar infarcts within the SCA, anterior inferior cerebellar artery, or SCA cerebellum. CONCLUSIONS: Our study indicates that the topographic heterogeneity of cerebellar infarcts are correlated with diverse angiographic findings. The result that large-artery disease, in which nonterritorial infarcts are more common than territorial infarcts, is more prevalent than in situ branch artery disease or small-artery disease, suggest that even a small cerebellar infarct can be a clue to the presence of large-artery disease.     

后循环进展性脑梗死42例临床分析

目的研究后循环进展性脑梗死的临床表现及MRI、MRA、DSA特征。方法对我院2003年1月～2004年12月住院的42例后循环进展性脑梗死的患进行回顾性分析。结果在急性后循环脑梗死中约25％为进展性，发病3～5天内进展多见。主要危险因素为高血压、糖尿病、冠状动脉疾病、高脂血症、吸烟。眩晕为最常见(85．7％)，以及构音障碍50．0％，意识障碍47．6％，共济失调42．9％，肢体瘫痪66．7％(偏瘫52．4％、四肢瘫14．3％)。多部位梗死多于单部位梗死，后循环近段、远段同时梗死或远段梗死，预后不良，基底动脉主干阻塞预后差。结论应提高对后循环进展性脑梗死的认识，及时识别，尽早治疗。     

Embolism from vertebral artery origin occlusive disease.

We report 10 patients with severe occlusive disease of the vertebral artery (VA) origin in the neck with intra-arterial embolism to the posterior circulation. The VA lesions in seven patients were complete occlusions, and three patients had severe atherostenosis. All patients had strokes in the vertebrobasilar territory. The most frequent recipient sites of intra-arterial embolism were the intracranial VA-posterior inferior cerebellar artery region (8), and the distal basilar artery (BA) and its superior cerebellar and posterior cerebral artery branches (7). Two patients had pontine infarction due to BA embolism. The most common clinical signs were due to cerebellar infarction. Atherosclerotic disease of the VA origin has features in common with disease of the internal carotid artery origin. Both have similar risk factors and demography, and each can cause strokes by intracranial intra-arterial embolism.     

Racial differences in the distribution of posterior circulation occlusive disease

We compared clinical and arteriographic features in 27 white and 24 black patients with symptomatic posterior circulation occlusive disease. The degree of arterial stenosis was measured independently by two examiners at 12 sites within the vertebrobasilar territory. Racial comparisons were made based upon the distribution of extra- and intracranial occlusive lesions and symptomatic sites of the lesions. White patients had significantly more angina pectoris, more lesions of the origin of the left vertebral artery and more high grade lesions of the extracranial vertebral arteries. Black patients had significantly higher mean diastolic blood pressure, more diabetes mellitus, more lesions of the distal basilar artery, more high grade lesions of intracranial branch vessels and more symptomatic intracranial branch disease. Race was found to be the only factor increasing the risk of intracranial posterior circulation occlusive disease. Knowledge of the contribution of race to the distribution of posterior circulation lesions will help guide evaluation and treatment strategies for patients with vertebrobasilar occlusive disease.     

Clinical features of proven basilar artery occlusion

Our study describes the early symptoms and signs of 85 patients with either basilar artery occlusion or bilateral distal vertebral artery occlusion documented by selective angiography. The most common prodromal symptoms were vertigo, nausea, and headache, which occurred during the 2 weeks before the stroke. Angiographic findings of 49 patients were classified into proximal, middle, and distal basilar artery occlusions. Twenty-two of these patients had additional vertebral artery lesions. A fourth group was composed of 36 patients with bilateral distal vertebral artery occlusion without opacification of the basilar artery through a vertebral artery injection. Onset was sudden in 20 patients; sudden, but preceded by prodromal symptoms in 11 patients; and progressive in 54 patients. Patients with progressive strokes often had bilateral vertebral artery occlusions. Most patients with acute onset had occlusion of the middle and distal basilar artery. An embolic origin of basilar artery occlusion from an arteriosclerotic vertebral artery lesion was assumed to be an important mechanism. An embolus reaching the basilar artery may not necessarily reach the top of the artery, but may also become lodged more proximally.     

Cerebellar infarction in the territory of the superior cerebellar artery: a clinicopathologic study of 33 cases

We reviewed the clinical and pathologic findings in 33 patients with infarcts in the territory of the superior cerebellar artery (SCA). The clinical manifestations included the rostral basilar artery syndrome (8); coma at onset, often with tetraplegia (11); cerebellar and vestibular signs (9, with delayed coma due to cerebellar swelling in 6); and, in only 1 patient, the "classic" syndrome of the SCA. Clinical features were overshadowed by an infarct in the territory of the middle cerebral artery in 3 other patients, and the diagnosis was made only at autopsy in a fourth. Pathologically, SCA infarcts occurred in isolation in 7 patients. The most striking finding was the high frequency of associated infarcts in the territory of the rostral part of the basilar artery (73%). One-third of patients also had an infarct in the territory of the posterior inferior cerebellar artery, sometimes associated with infarction of the anterior inferior cerebellar artery. Tonsillar herniation was observed in 15 patients, 8 of whom had no infarcts in other cerebellar territories. Occlusions occurred mainly in the distal basilar artery and distal vertebral artery. The infarcts were mostly caused by cardiac and artery-to-artery emboli.     

Bilateral distal vertebral artery occlusion

Nine patients with bilateral occlusions of the distal vertebral arteries had clinical profiles that differed from patients with other vertebrobasilar lesions and formed a recognizable subunit. Bilateral distal vertebral artery occlusion is uncommon; it occurs primarily in hypertensive patients, and neurologic deficits develop progressively or stepwise over a longer time period than in basilar artery or branch occlusion. It causes mostly cerebellar and lower brainstem signs as a result of chronic low flow in the posterior circulation; it may cause sudden respiratory death. The prognosis is grave. Anticoagulant therapy alone is probably ineffective.     

Limb ataxia and proximal intracranial territory brain infarcts: clinical and topographical correlations

Background

Limb ataxia is classically attributed to cerebellar hemispheric lesions, although isolated lesions of the inferior cerebellar peduncle (ICP) in the medulla may also cause this sign. It is still unclear why only some patients with acute cerebellar infarcts in the posterior inferior cerebellar artery (PICA) territory present with limb ataxia. The proximal intracranial posterior circulation (P‐PC) territory includes structures fed by the intracranial vertebral arteries (ICVAs): the medulla, supplied by small ICVAs branches, and posterior inferior portion of the cerebellum, fed by PICA. ICP and PICA territory cerebellar infarcts most often occur independently but occasionally occur together.

Objective

To identify structures responsible for limb ataxia in acute P‐PC brain infarcts, correlating clinical and topographical findings.

Methods

Sixteen patients (8 women) were included, aged 30–82 years (mean 62 years), with isolated acute strokes in the P‐PC territory.

Results

The cases reported here indicate that limb ataxia in acute P‐PC territory infarcts may be associated with damage to the ICP in the dorsolateral medulla, regardless of a hemispheric cerebellar lesion. In fact, among the nine patients with PICA stroke, limb ataxia was observed only in the two patients who also presented damage to the dorsolateral medulla involving the ICP. Of the seven patients with isolated dorsolateral medullary infarct, only five patients with ICP damage had limb ataxia.

Conclusions

When correlating limb ataxia and acute P‐PC infarcts, it is important to take into account the entire ICVA territory.Limb ataxia is characterised by dysmetria, dyssynergia and intention tremor, and is clinically assessed by the finger‐to‐nose and heel‐to‐knee tests.¹ It is classically associated with hemispheric cerebellar lesions² and rarely with brainstem lesions.³ Previous reports on cerebellar strokes focused on the frequency of neurological signs in patients with different cerebellar arterial territory infarcts.^4,5 Limb ataxia was reported in only approximately 50% of cases of posterior inferior cerebellar artery (PICA) infarcts but it was not related to the histological or neuroradiological findings.^4,5 A very recent clinical and MRI study⁶ reported limb ataxia in only 4 of 13 patients with acute PICA stroke. The authors correlated this finding with impairment of the intermediate and lateral cerebellar cortex or of the cerebellar nuclei, which are involved in the control of limb coordination. However, it is well known that lesions of the inferior cerebellar peduncle (ICP) without involvement of the cerebellar hemisphere may also cause limb ataxia.⁷The proximal intracranial posterior circulation (P‐PC) territory includes structures fed by the intracranial vertebral arteries (ICVAs), the medulla and the posterior inferior portion of the cerebellum. The blood supply of the posterior inferior cerebellum and the ICP derive from different branches of the ICVAs. The lateral medulla is supplied by small branches that originate from the ICVA and course through the lateral medullary fossa to supply the ICP and the dorsolateral medulla. The ICVA also gives rise to the PICA. The medial branch of the PICA supplies a small portion of the dorsal medulla but not the ICP. ICP and PICA territory cerebellar infarcts most often occur independently but occasionally occur together. Only 1 in 5 proximal territory infarcts include both the lateral medulla and the PICA territory cerebellum.⁸ When both occur together it is usually caused by a long occlusion of the ICVA which blocks flow in both the PICA and lateral medullary penetrators.Here we describe 16 patients with acute infarcts in the ICVA territory in order to understand the role of the cerebellum and of the ICP in the occurrence of limb ataxia.     

Multiple acute infarcts in the posterior circulation.

OBJECTIVE--to evaluate clinical, radiological, and prognostic features of patients with multiple acute infarcts in remote arterial territories of the posterior circulation. DESIGN--Data analysis from a prospective acute stroke registry in a community based primary care centre using a standard protocol including MRI and MRA. RESULTS--In three and a half years, 27 of the 236 patients (11%) with posterior circulation stroke had multiple acute infarcts in the posterior circulation as shown by gadolinium enhancement on MRI. Eighteen patients had multiple infratentorial and supratentorial infarcts including the cerebellum and posterior cerebral artery territory, with coexisting brainstem involvement in seven patients. Fourteen patients had a rostral basilar artery syndrome and cerebellar signs; four patients had a visual field defect with cerebellar signs. Causes were vertebral (six) or basilar (four) artery atheromatosis, and cardioembolism (four). Seven patients had multiple acute infarcts in the posterior circulation of the cerebellum and lower brainstem. Brainstem and cerebellar signs were found in most patients (five); aetiologies were small vessel disease (four), cardioembolism (one), and vertebral artery dissection (one). Two patients with large artery atheromatosis had multiple acute infarcts in the posterior circulation in the brainstem and posterior cerebral artery territory. One month after stroke more than 25% of the patients were dependent or had died. There was no difference in the outcome between the three groups, and recovery was linked to the size of infarcts rather than to a high number of infarcts. CONCLUSIONS--multiple acute infarcts in the posterior circulation usually involve the cerebellum. Simultaneous brainstem and posterior cerebral artery territory infarcts sparing the cerebellum are uncommon. They can be suspected clinically before neuroimaging, mainly when supratentorial and infratentorial infarcts coexist. This may be important, because different patterns of infarction are associated with different causes of stroke.     

小脑梗死的分型与后循环血管病变

目的 研究有无大血管病变患者小脑梗死灶的特征,探讨小脑梗死分型与后循环血管病变的关系。 方法 收集我科自2006年1月～2008年3月期间住院的小脑梗死患者共35例,所有患者均同时具备颅脑磁共振成像（magnetic resonance imaging,MRI）和血管造影检查,包括计算机断层摄影血管造影（computed tomographic angiography,CTA）、磁共振血管造影（magnetic resonance angiography,MRA）和数字减影血管造影（digital subtraction angiography,DSA）检查。根据血管造影检查的结果将入组患者分为两组：大血管病变组20例,小血管病变组15例,分析两组小脑梗死的分型和后循环血管病变（包括狭窄或闭塞）的关系。 结果 ⑴大血管病变组20例中,颅内血管（椎动脉颅内段或基底动脉）病变最多见（10例,50%）,梗死类型多为分水岭梗死（7例,70%）;其次为颅外血管合并颅内血管（椎动脉颅外段合并颅内段或基底动脉）病变（8例,40%）,梗死灶多为小脑后下动脉（PICA）供血区的区域性梗死（7例,87.5%）;单独颅外血管（椎动脉颅外段）病变最少见（2例,10%）,梗死分布无明显倾向性。⑵小血管病变组15例中,梗死灶亦多位于分水岭区（9例,60%）。 结论 由于小脑血液供应特点,小脑梗死中分水岭梗死和腔隙性梗死较区域性梗死更为常见。小梗死灶（直径≤2cm）可能存在后循环大血管的狭窄或闭塞,应予积极的治疗和干预,以防病情加重。     

Intraluminal clot in the vertebrobasilar circulation: clinical and radiologic features

We studied 15 patients with angiographically documented intraluminal clot in the vertebrobasilar (VB) circulation and ischemic stroke. Progressive brainstem signs were the most common presentation; the neurologic deficit was maximum at stroke onset in 4. Seven experienced their first symptoms during sedentary activities. Thirteen of the initial 15 CTs revealed infarcts in the VB territory, 7 with multiple foci. Intraluminal clot was present in the vertebral artery in 7 patients (2 bilateral), basilar artery in 7, posterior cerebral artery in 5, and superior cerebellar artery in 1. Multiple clots were seen in 5 patients. Stroke risk factors were present in the majority of cases. Although cardiac source embolism was the most common single etiology (4 patients), most patients had other causes including migraine, coagulopathy associated with malignancy and nephrotic syndrome in systemic lupus erythematosus, vertebral artery dissection with local embolism, delayed irradiation arteriopathy, and a fusiform, ectatic basilar artery. Six (40%) died within 5 months of follow-up. Intraluminal clot in the posterior circulation is a marker for multiple stroke mechanisms, not all of which are embolic. Intraluminal clot should prompt investigations into occult risk factors when no cause appears obvious.     

后循环动脉瘤显微外科手术治疗

目的 探讨后循环动脉瘤手术适应证和治疗效果.方法 纳入42例共44个后循环动脉瘤,包括基底动脉动脉瘤26例(27个)、椎动脉动脉瘤16例(17个).其中15例分别行颈外动脉-大脑后动脉P2段(4例)、颈内动脉-大脑后动脉P2段(2例)、颌内动脉-大脑后动脉P2段(2例)、椎动脉颅内外段(2例)、枕动脉.小脑后下小动脉(5例)搭桥联合动脉瘤孤立术;余27例行单纯动脉瘤夹闭术.结果 经随访共37例(基底动脉顶端动脉瘤14例、基底动脉主干动脉瘤3例、椎动脉动脉瘤9例、小脑后下动脉动脉瘤5例、大脑后动脉P1～P2段交界处动脉瘤4例、小脑上动脉动脉瘤l例和小脑前下动脉动脉瘤1例)患者恢复正常生活活动能力,无一例发生手术相关性神经功能障碍,恢复良好率达88.09%.其余5例患者,1例(基底动脉顶端动脉瘤)术后出现严重神经功能缺损症状与体征,生活不能自理;2例(1例基底动脉顶端动脉瘤、1例基底动脉主干动脉瘤)因术后发生脑干缺血,围手术期死亡;2例(椎动脉动脉瘤)复发患者经再次治疗康复.结论 对于不宜直接行手术夹闭的后循环动脉瘤,为了避免因夹闭动脉瘤和延长临时阻断载瘤动脉时间而发生术后脑缺血事件.可选择颅内外血管搭桥联合动脉瘤孤立术,以避免动脉瘤夹闭术带来的危险.     

Lesion patterns and etiology of ischemia in the anterior inferior cerebellar artery territory involvement: a clinical – diffusion weighted – MRI study

The topography and mechanism of stroke in the anterior inferior cerebellar artery (AICA) territory are delineated before, but the detailed clinical spectrum of lesions involving AICA territory was not studied by diffusion weighted imaging (DWI). We reviewed 1350 patients with posterior circulation ischemic stroke in our registry. We included patients if the diagnosis of AICA territory involvement was confirmed, and DWI, and magnetic resonance angiography were obtained in the 3 days of symptoms onset. The potential feeding arteries of the AICA territory were evaluated on magnetic resonance imaging (MRI) using a three-dimensional rotating cineoangiographic method. There were 23 consecutive patients with lesion involving AICA territory, six with isolated lesion in the AICA territory, six with posterior inferior cerebellar artery, 11 with multiple posterior circulation infarcts (MPCIs). The clinical feature of isolated AICA infarct was vertigo, tinnitus, dysmetria, ataxia, facial weakness, facial sensory deficits, lateral gaze palsy, and sensory-motor deficits in patients with pontine involvement. Patients with largest lesion extending to the anterior and inferolateral cerebellum showed mixed symptomatology of the lateral medullary (Wallenberg's syndrome) and AICA territory involvement. Patients with MPCIs presented various clinical pictures with consciousness disturbances and diverse clinical signs because of involvement of different anatomical structures. Large-artery atherosclerotic disease in the vertebrobasilar system was the main cause of stroke in 12 (52%) patients, cardioembolism (CE) in one (4%), and coexisting large-artery disease and a source of CE in four (17%). The main cause of stroke was atheromatous vertebrobasilar artery disease either in the distal vertebral or proximal basilar artery. The outcome was usually good except those with multiple lesions. The new MRI techniques and clinical correlations allow better definition of the diverse topographical and etiological spectrum of AICA territory involvement and associated infarcts which was previously based on pathological and conventional MRI studies.