Recurrent audiovestibular disturbance initially mimicking Ménière’s disease in a patient with anterior inferior cerebellar infarction

An anterior inferior cerebellar artery (AICA) stroke is characterized by vertigo, tinnitus, and deafness in addition to facial weakness, hemiataxia, and hypalgesia. Sometimes, it can present as sudden deafness with vertigo, without brainstem or cerebellar signs. We report a 55-year-old woman with hypertension and diabetes, showing recurrent audiovestibular disturbance before a typical pattern of AICA infarction, which was initially diagnosed as Ménière’s disease. In elderly patients with recurrent hearing loss and vertigo lasting several minutes, lack classic brainstem or cerebellar signs, if they have vascular risk factors, physicians may also consider the potential symptom of AICA infarction.     

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.     

Bilateral deafness as a prodromal symptom of basilar artery occlusion.

Bilateral deafness is a rare but possible symptom for ischemia of the vertebrobasilar system, primarily derived from occlusion of anterior inferior cerebellar arteries or their branches. Patients 1 and 2 developed sudden bilateral deafness, soon followed by coma. The proximal segment of the basilar artery was occluded due to atherothrombosis in Patient 1 and arterial dissection in Patient 2. Thrombolytic therapy failed to recanalize the basilar arterial flow. Both patients died of extensive infarction in the vertebrobasilar arterial territory. Sudden bilateral deafness can be a warning sign of imminent brainstem ischemia by occlusion of the basilar artery regardless of age. Prompt and intensive management for stroke is needed for patients with sudden bilateral deafness.     

Bilateral Cerebellar Infarctions Caused by a Stenosis of a Congenitally Unpaired Posterior Inferior Cerebellar Artery

Bilateral symmetrical cerebellar infarcts in the territory supplied by the medial posterior inferior cerebellar artery (PICA) branches are extremely rare. In the few cases published, it has not been possible to clearly pinpoint the cause of this infarct pattern. The authors present the case history of a 58-year-old man who had acute headaches accompanied by pronounced rotatory vertigo with nausea and vomiting. The neurological examination revealed bilateral cerebellar signs. Cranial magnetic resonance imaging showed bilateral, nearly symmetrical infarcts in the territory of the medial branches of both PICAs. These bilateral PICA infarctions were caused by a stenosis of an unpaired PICA originating from the left vertebral artery supplying both cerebellar hemispheres.     

以眩晕为首发症状的小脑梗死临床类型及供血区分布

目的:探讨以眩晕为首发症状的小脑梗死临床类型及病灶供血区分布特征。方法:对26例经MRI确诊、以眩晕为首发症状的小脑梗死患者的临床资料进行回顾性分析。结果:将眩晕为首发症状的小脑梗死分为2种临床类型:①稳定型:单纯自发性持续性眩晕伴平衡失调(19/26例,73.1%);②进展型:以持续性眩晕、平衡失调为首发症状,起病2d后伴有延迟神经功能受累症状(7/26例,26.9%)。梗死病灶以小脑后下动脉内侧支(16/26例,61.5%)受累最为常见;其次为小脑前下动脉区(6/26例,23.1%)及小脑上动脉区(2/26例,7.7%)。未见多发小脑供血动脉区梗死患者以单纯眩晕为首发症状。结论:以眩晕为首发症状的小脑梗死以小脑后下动脉内侧支受累最为常见,绝大多数患者呈良性病程,但需警惕可能出现的延迟神经功能受累症状和体征。     

Sudden deafness with vertigo as a sole manifestation of anterior inferior cerebellar artery infarction

Sudden deafness without associated neurological symptoms and signs is typically attributed to a viral inflammation of the labyrinth. Although sudden deafness occurs with anterior inferior cerebellar artery (AICA) infarction, the deafness is usually associated with other brainstem or cerebellum signs such as crossed sensory loss, lateral gaze palsy, facial palsy, Horner syndrome or cerebellar dysmetria. An 84-year-old woman suddenly developed right-sided tinnitus, hearing loss, vertigo and vomiting. Audiometry and electronystagmography documented absent auditory and vestibular function on the right side. T2-weighted and diffusion-weighted MRI showed a tiny infarct in the right lateral inferior pontine tegmentum. AICA occlusion can cause sudden deafness and vertigo without brainstem or cerebellar signs.     

Neuro-Otological Aspects of Cerebellar Stroke Syndrome

Cerebellar stroke is a common cause of a vascular vestibular syndrome. Although vertigo ascribed to cerebellar stroke is usually associated with other neurological symptoms or signs, it may mimic acute peripheral vestibulopathy (APV), so called pseudo-APV. The most common pseudo-APV is a cerebellar infarction in the territory of the medial branch of the posterior inferior cerebellar artery (PICA). Recent studies have shown that a normal head impulse result can differentiate acute medial PICA infarction from APV. Therefore, physicians who evaluate stroke patients should be trained to perform and interpret the results of the head impulse test. Cerebellar infarction in the territory of the anterior inferior cerebellar artery (AICA) can produce a unique stroke syndrome in that it is typically accompanied by unilateral hearing loss, which could easily go unnoticed by patients. The low incidence of vertigo associated with infarction involving the superior cerebellar artery distribution may be a useful way of distinguishing it clinically from PICA or AICA cerebellar infarction in patients with acute vertigo and limb ataxia. For the purpose of prompt diagnosis and adequate treatment, it is imperative to recognize the characteristic patterns of the clinical presentation of each cerebellar stroke syndrome. This paper provides a concise review of the key features of cerebellar stroke syndromes from the neuro-otology viewpoint.     

Recent Advances in Cerebellar Ischemic Stroke Syndromes Causing Vertigo and Hearing Loss

Cerebellar ischemic stroke is one of the common causes of vascular vertigo. It usually accompanies other neurological symptoms or signs, but a small infarct in the cerebellum can present with vertigo without other localizing symptoms. Approximately 11 % of the patients with isolated cerebellar infarction simulated acute peripheral vestibulopathy, and most patients had an infarct in the territory of the medial branch of the posterior inferior cerebellar artery (PICA). A head impulse test can differentiate acute isolated vertigo associated with PICA territory cerebellar infarction from more benign disorders involving the inner ear. Acute hearing loss (AHL) of a vascular cause is mostly associated with cerebellar infarction in the territory of the anterior inferior cerebellar artery (AICA), but PICA territory cerebellar infarction rarely causes AHL. To date, at least eight subgroups of AICA territory infarction have been identified according to the pattern of neurotological presentations, among which the most common pattern of audiovestibular dysfunction is the combined loss of auditory and vestibular functions. Sometimes acute isolated audiovestibular loss can be the initial symptom of impending posterior circulation ischemic stroke (particularly within the territory of the AICA). Audiovestibular loss from cerebellar infarction has a good long-term outcome than previously thought. Approximately half of patients with superior cerebellar artery territory (SCA) cerebellar infarction experienced true vertigo, suggesting that the vertigo and nystagmus in the SCA territory cerebellar infarctions are more common than previously thought. In this article, recent findings on clinical features of vertigo and hearing loss from cerebellar ischemic stroke syndrome are summarized.     

小脑后下动脉解剖变异致双侧小脑梗死2例报道并文献复习

目的 探讨小脑后下动脉(posterior inferior cerebellar artery, PICA)解剖变异致双侧小脑梗死的临床特征及发病机制。方法 对2例经颅脑MRI确诊的双侧小脑梗死患者采用CT血管造影(CTA)、磁共振血管成像(MRA)或数字减影血管造影(DSA)显示其头颈部血管,从而了解后循环血管的形态特征并复习相关文献。结果 病例1经DSA证实左侧椎动脉较细,远端管腔闭塞,通过右椎动脉代偿供血原左侧PICA供血区但欠充分,双侧PICA共同起源于右侧椎动脉。病例2经CTA证实右侧椎动脉较左侧明显细且远端显示欠清,MRA示双侧PICA共同起源于左侧椎动脉。结论 2例双侧小脑梗死患者均存在一侧椎动脉优势供血,且双侧PICA共同起源于该侧椎动脉。在该解剖变异基础上一侧椎动脉发生病变时可出现双侧小脑梗死。因此,在临床中出现双侧小脑梗死时临床医师不能忽略这一解剖变异基础。     

Bilateral sudden deafness as a prodrome of anterior inferior cerebellar artery infarction

BACKGROUND: Acute ischemic stroke in the distribution of the anterior inferior cerebellar artery is known to be associated with hearing loss, facial weakness, ataxia, nystagmus, and hypalgesia. There have been few reports on bilateral deafness and vertebrobasilar occlusive disease. Furthermore, previous reports have not emphasized the inner ear as a localization of bilateral deafness. OBJECTIVE: To describe the presentation of acute ischemic stroke in the distribution of the anterior inferior cerebellar artery as sudden bilateral hearing loss with minimal associated signs. DESIGN AND SETTING: Case report and tertiary care hospital. PATIENT: A 66-year-old man with diabetes mellitus developed sudden bilateral deafness, unilateral tinnitus, and vertigo 7 days before the onset of dysarthria, facial weakness, and ataxia. T2-weighted magnetic resonance imaging scans showed hyperintensities in the right lateral pons and right middle cerebral peduncle and a possible abnormality of the left middle cerebellar peduncle. A magnetic resonance angiogram showed moderately severe stenosis of the distal vertebral artery and middle third of the basilar artery. The patient's right limb coordination and gait improved steadily over several weeks, but there was no improvement in hearing in his right ear. CONCLUSIONS: The relatively isolated onset of deafness as well as the severity and persistence of the hearing loss led us to conclude that the hearing loss in this case was likely due to prominent hypoperfusion of the internal auditory artery, with labyrinthine infarction as the earliest event. Vertebrobasilar occlusive disease should be considered in the differential diagnosis of sudden bilateral deafness.     

Sudden deafness in vertebrobasilar ischemia: clinical features, vascular topographical patterns and long-term outcome

BACKGROUND AND PURPOSE: The aim of this study is to document the clinical features and natural history of sudden deafness associated with vertebrobasilar ischemia (VBI) and to describe the vascular topographic patterns of ischemic lesions on brain MRI associated with sudden deafness based on data collected from a prospective acute stroke registry. METHODS: From 364 consecutive cases of VBI diagnosed by clinical features and brain MRI between January 2000 and September 2003, 29 patients were identified as having sudden deafness as a symptom of VBI. RESULTS: In our series, the incidence of sudden deafness following VBI is 8.0% (29/364). Hearing loss occurred unilaterally (n=27) or bilaterally (n=2). All but one had vertigo as an associated symptom. Nine patients (31%) presented with an isolated audiovestibular loss initially and subsequently had delayed neurological deficits. Nearly a half of patients (14/29: 48%) showed cochlear features of hearing loss. Seventeen (81%) of 21 patients who were followed for at least 1 year after onset of sudden deafness had a recovery of hearing partially (n=10) or completely (n=7). The improvement rate of hearing loss in patients with profound hearing loss was significantly lower than that in patients with less than profound hearing loss (40% vs. 89%, P<0.01). In addition to infarction in the territory of anterior inferior cerebellar artery (n=23), cerebellar infarction in the territory of the medial branch of posterior inferior cerebellar artery (n=4) or an isolated brainstem infarction (n=2) was also associated with sudden deafness. CONCLUSION: An isolated sudden deafness with cochlear audiometric features can be the initial presentation of VBI. Sudden deafness due to VBI often has a good outcome. There is topographic heterogeneity of ischemic lesions on brain MRI in patients with sudden deafness due to VBI.     

Repetitive Episodic Isolated Vertigo in a Patient with Cerebellar Infarction

Isolated vertigo is an important symptom of posterior circulation stroke. It has been reported that 11.3% of patients with isolated vertigo have a stroke and that most lesions are located in the cerebellum, particularly in the posterior inferior cerebellar artery. We report the case of a 63-year-old man with multiple atherosclerotic risk factors and atrial fibrillation who showed repeated episodes of isolated vertigo. His repeated vertigo was short-lasting and was often triggered by body position, mimicking benign paroxysmal positional vertigo. Cranial computed tomography on the third hospital day showed left cerebellar infarction within the territory of the posterior inferior cerebellar artery. The vertigo was ameliorated on the fifth hospital day and warfarin was prescribed for secondary prevention. Clinicians should pay special attention to cases in which a patient presents isolated vertigo, even if it shows transient recurrence or is triggered by a positional change, especially in patients with multiple cerebrovascular risk factors.     

The clinical and topographic spectrum of cerebellar infarcts: A clinical—magnetic resonance imaging correlation study

We studied 34 consecutive patients with non–mass-producing cerebellar infarcts using a standard protocol of investigations including magnetic resonance imaging (MRI). We analyzed the topography of infarcts to determine the involved arterial territories and we correlated the findings with neurological dysfunction and potential causes of stroke. Sixteen patients had an infarct in the territory of the posterior inferior cerebellar artery (PICA); 2, in the territory of the anterior inferior cerebellar artery (AICA); 13, in the territory of the superior cerebellar artery (SCA); and 8 had junctional infarcts between the territories of the medial and lateral branches of the PICA or PICA/SCA territories. PICA or medial PICA territory infarcts were manifested by acute vertigo and truncal ataxia, while the patients with lateral PICA territory infarcts presented with unsteadiness, limb ataxia and dysmetria without dysarthria. Patients with infarcts in the AICA territory were characterized by limb and trunk ataxia associated with signs of lateropontine involvement. Patients with SCA territory infarcts presented with dysarthria, unsteadiness and/or vertigo, limb ataxia, and dysmetria. Cardiac embolism was the main cause of large infarcts in the territories of the PICA (8/16) or SCA (4/7). Multiple small infarcts were associated with vertebrobasilar atherosclerosis (8/12). These clinical–MRI correlations allow better definition of the topographic and etiological spectrum of cerebellar infarction, which was previously based on pathological studies in subjects with severe infarction.     

119例小脑梗死的临床分析

目的探讨小脑梗死的中国缺血性脑卒中分型诊断(CISS)、受累血管区域、合并小脑外梗死病灶以及临床表现。方法回顾性分析自2012年1月至2015年12月119例急性小脑梗死住院患者的头颅MRI影像、病因学检查以及临床表现等资料。结果 119例小脑梗死患者中,单侧小脑梗死78例(UCI组),双侧小脑梗死41例(BCI组)。两组的CISS分型无明显差异。UCI组以小脑后下动脉区梗死发生率最高(35.9%),与BCI组比较,差异有显著统计学意义(P0.01);BCI组中小脑后下动脉+小脑上动脉区梗死发生率最高(39.0%),但两组间比较差异无显著性;其余区域的梗死发生率在两组中差异无显著性。63/119例(52.9%)同时合并小脑外梗死灶。BCI组合并小脑外后循环梗死的发生率(53.7%)较单侧UCI组高(P0.05),而UCI组合并前循环梗死较BCI组更多(P0.05)。主要症状、体征包括:头晕/眩晕、眼球震颤、眼倾斜反应、听觉减退、小脑性构音障碍、共济失调,浅感觉障碍、锥体束征以及意识障碍等。意识障碍在BCI组的发生率高于UCI组(P0.01),其余各项两组间比较差异无显著性。结论小脑梗死的主要病因为大动脉粥样硬化;小脑后下动脉区梗死在UCI中最常见,BCI常合并小脑外的后循环供血区梗死;UCI和BCI的受累小脑动脉以及合并小脑外梗死的区域有一定差异,提示两者病因机制存在不同;意识障碍等严重神经功能缺损表现在BCI更为常见。     

Unilateral sudden deafness as a primary symptom of brainstem and cerebellar infarction]

We report a case with a unilateral sudden sensorineural hearing loss caused by an infarction of brainstem and cerebellum. The patient was a 74-year-old male presented with a sudden onset of hearing loss and tinnitus in the right ear and dizziness. Steroid was administered on suspicion of idiopathic sudden deafness. However, the initial symptoms were deteriorated approximately 2 weeks later. He newly complained of the numbness of the right face and double vision, and he was transferred to our hospital for further evaluation. Neurological examination demonstrated horizontal nystagmus, diminution in the right facial sensation, right peripheral facial palsy, right hearing loss and cerebellar ataxia. Urgent MRI disclosed fresh infarctions of the right middle cerebellar peduncle and cerebellum localized in the territory of anterior inferior cerebellar artery. In general, idiopathic sudden deafness and Meniere's disease are frequent diagnosis in cases of sudden hearing loss with vertigo, but these symptoms may rarely be caused by cerebrovascular disorder. In patients with risk factors for arteriosclerosis, cerebrovascular disorder should be taken into consideration even if idiopathic sudden deafness may be suspected clinically. We emphasize the diagnostic importance of careful observation on neurological findings and early detection of radiological abnormalities on MRI.     

Lateral inferior pontine infarction: 2 clinical aspects

Cases of lateral inferior pontine infarction are rare in the literature. We report two cases with MRI correlations. One involved the whole territory, the other the tegmental area only. Both also involved the middle cerebellar peduncle and one of them the adjacent lobules of the cerebellum. The first case emphasizes the classical alternate syndrome. The second case shows that acute vertigo mimicking a labyrinthine lesion can occur when involving the territory of the anterior inferior cerebellar artery.     

Bilateral cerebellar infarction in the medial branches of posterior inferior cerebellar arterial territory--using endoscopic third ventriculostomy to relieve acute hydrocephalus

Simultaneous bilateral cerebellar infarctions in posterior inferior cerebellar arterial (PICA) territory, without brain stem involvement are rare. We herein report a 51-year-old man developed sudden dizziness, nausea and vomiting. CT revealed hypodense bilateral lesions over the cerebellum corresponding to the medial PICA (mPICA) branch territory. His mental state deteriorated 2 days after onset; repeated CT showed severe third and lateral ventricular dilation. Endoscopic third ventriculostomy (ETV) was done to relieve the acute obstructive hydrocephalus. The patient was later discharged with only mild residual ataxia. Compared with conventional surgical treatments (external ventricular drainage, craniectomy and cerebellectomy), ETV has several advantages, including less risk and minimal invasiveness. However, further study is needed on its safety and efficacy under such circumstances.     

Ocular torsion associated with infarction in the territory of the anterior inferior cerebellar artery: frequency, pattern, and a major determinant

BACKGROUND: Acute ischemic stroke in the distribution of the anterior inferior cerebellar artery (AICA) can cause the vestibular dysfunction in the roll plane of the vestibuloocular reflex with abnormal ocular torsion (OT). There has been no systemic study that carefully investigates the nature of OT that occurs with AICA infarction. OBJECTIVES: To investigate the frequency, the characteristic patterns of OT associated with AICA territory infarction, and the crucial site for determining the direction of OT in AICA territory infarction. METHODS: We studied 12 consecutive cases of infarction in the territory of the AICA diagnosed by brain MRI. Fundus photography, prism cover test, and subjective visual vertical tilting test were performed to evaluate the function of the otolith system. Pure tone audiogram was also performed to evaluate the function of the auditory system. RESULTS: Nine (75%) of 12 patients exhibited pathological ocular torsion (OT). Two types of pathological OT were found: ipsiversive OT accompanying skew deviation (n=6), and contraversive OT only (n=3). Six patients with ipsiversive OT with skew deviation showed an audiovestibular loss with canal paresis and hearing loss ipsilaterally whereas three patients with contraversive OT without skew deviation had a normal audiovestibular response. In all cases with pathological OT, the direction of the subjective visual vertical tilt corresponded to the direction of the OT. CONCLUSIONS: Our findings emphasize that the peripheral vestibular structure with inner ear probably plays a crucial role in determining the direction of OT associated with AICA territory infarction.     

Anomalous Origin of the Middle Meningeal Artery from the Basilar Artery: A Case Report

Anomalous courses, anastomoses, and origins of the middle meningeal artery have often been described in the literature; however origin from the basilar artery or its branches is exceedingly rare with only five previous reports. We describe a middle meningeal artery originating from a large lateral pontine branch of the basilar artery. The lateral pontine branch also supplied most of the cerebellar hemispheric territory normally vascularized by both the anterior inferior cerebellar artery and posterior inferior cerebellar artery. We discuss the anatomy and possible embryological development of middle meningeal origin from the basilar artery.