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Background: There has been no systematic study that carefully investigates the characteristic features of abnormal cervical vestibular-evoked myogenic potential (cVEMP) response associated with the AICA territory infarction., Objectives: To investigate the frequency, the characteristic patterns of abnormal cVEMP associated with AICA territory infarction, and the crucial site for producing abnormal cVEMP response in the AICA territory infarction., Methods: We studied 16 consecutive cases of unilateral AICA territory infarction diagnosed by brain MRI. VEMP was induced by a short click sound and was recorded in contracting sternocleidomastoid muscle. Each patient underwent a quantitative audiovestibular evaluation, including bithermal caloric test and pure tone audiogram., Results: Eight patients (50%) exhibited abnormal cVEMP response on the side of the AICA territory infarction. All patients with abnormal cVEMP showed an absent or decreased response in amplitude but no difference in latency. Patients with abnormal VEMP were significantly more likely to have canal paresis (CP), sensorineural hearing loss, or both compared with patients who had normal cVEMP. Conversely, abnormal cVEMP was more frequently observed among patients with CP than among those without CP. There was no difference in lesion sites according to brain MRI among patients with or without abnormal cVEMP response., Conclusions: Our findings suggest that the peripheral vestibular structure with the inner ear probably plays a crucial role in producing abnormal cVEMP response associated with AICA territory infarction., (Copyright © 2011 Elsevier B.V. All rights reserved.)

Backgrounds and Purpose: The aim of this study was to document the clinical presentation, vascular topographic patterns, stroke mechanism, and outcome of bilateral infarcts in the territory of the superior cerebellar artery (SCA) based on data collected from a prospective acute stroke registry., Methods: We studied the clinical and radiological features of 11 patients with bilateral infarctions in the territory of the SCA diagnosed by brain MRI., Results: Bilateral SCA infarcts represented 23.4% (11/47) of all SCA territory infarction. Bilateral SCA infarcts mostly associated with brainstem (n = 5), cerebral (n = 5), or non-SCA cerebellar lesions (n = 4). The most common clinical presentation at onset was sudden fall with axial lateropulsion and dysarthria (n = 6). In five patients with a coexisting infarct(s) in the brainstem, limb weakness and/or mental change were prominent and often masked the signs of cerebellar dysfunction. Six patients showed no stenosis or occlusion in the vertebrobasilar system on brain MRA. Five had an obvious cardiac source of emboli. Eight patients showed favorable outcomes with complete recovery or minimal disability, but three patients with additional extensive brainstem infarcts died within 1 week., Conclusions: Bilateral SCA territory infarcts show variable clinical, vascular topographic, and prognostic features. They usually result from cardiac emboli.

Abstract: Objectives: To document otolith dysfunction in patients with posterior inferior cerebellar artery (PICA) territory cerebellar infarction. Methods: From March to October 2006, 14 consecutive patients with PICA territory cerebellar infarctions (brainstem spared) diagnosed by brain MRI from the acute stroke registry at the Keimyung University Dongsan Medical Center were enrolled within 12 days of onset (mean 4.0 days). Otolith function tests included ocular torsion (OT), skew deviation, and subjective visual vertical (SVV) were performed. The extent of the cerebellar infarction was determined by previously validated MR anatomical templates. Results: All patients had an abnormal posture as a result of otolithic dysfunction. Eleven patients (79%) had at least one otolith-related test abnormality: abnormal tilt of SVV (79%), abnormal OT (29%), or skew deviation (21%). Two common patterns of otolith dysfunction were identified based on whether or not the nodulus was infarcted: 1) ipsilesional SVV tilt (mean 5.0° at binocular viewing) without accompanying abnormal OT or skew deviation (nodulus spared); 2) contralesional SVV tilt (mean 11.3° at binocular viewing) with concomitant abnormal OT and skew deviation (nodulus infarcted). Patients with type 1 infarcts (i.e., nodulus spared) fell toward the side of lesion while patients with type 2 infarcts (i.e., nodulus infracted) fell toward the opposite side. Conclusion: Isolated PICA territory cerebellar infarction usually produces two distinct patterns of otolith dysfunction — Ipsilesional SVV tilt and falling without accompanying OT or skew deviation if the nodulus is spared and contralesional SVV tilt and falling with OT and skew deviation if nodulus is infarcted. [Copyright &y& Elsevier]