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Background: Lateropulsion of the body--that is, falling to one side--is a well-known clinical feature of stroke in the posterior circulation. Body lateropulsion as an isolated or predominant manifestation of a pontine stroke has not been reported previously., Objective: To elucidate the possible mechanisms of patients presenting with body lateropulsion as an isolated or predominant symptom of an isolated pontine infarction., Methods: Between May 2004 and February 2006, out of 134 patients admitted with an isolated pontine stroke, we identified 8 (6%) consecutive patients in the Keimyung University Stroke Registry who had body lateropulsion as the main presenting symptom., Results: All lesions were localised to the paramedian tegmentum just ventral to the fourth ventricle. All except one showed a uniform pattern of body lateropulsion, in which the direction of falling was away from the side of an infarct. In two patients body lateropulsion was the sole clinical manifestation, whereas the other patients had other neurological signs. All but one patient had contraversive tilting of the subjective visual vertical (SVV). In all cases, the direction of SVV tilt corresponded to the direction of body lateropulsion. The mean net tilt angle was 6.1 degrees., Conclusions: Based on the known anatomy of ascending vestibular pathways, SVV tilting and MRI findings, it is concluded that body lateropulsion probably results from damage to the graviceptive pathway ascending through the paramedian pontine tegmentum.

The caloric test is probably the most widely used clinical test of vestibular function. A unilateral decrease in response to cold and warm water reliably indicates a unilateral peripheral vestibular lesion. Central signs on caloric testing are less common but important to recognize because they are often associated with lesions of the brainstem. We describe a patient with a tumor originating in the floor of the fourth ventricle who presented with premature reversal after cold stimulation on one side and perverted nystagmus after cold stimulation of the other side. [ABSTRACT FROM AUTHOR]

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]

Abstract: 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 1week. Conclusions: Bilateral SCA territory infarcts show variable clinical, vascular topographic, and prognostic features. They usually result from cardiac emboli. [Copyright &y& Elsevier]