title: Motion perception without Nystagmus--a novel manifestation of cerebellar stroke.
abstract: OBJECTIVE
  The motion perception and the vestibulo-ocular reflex (VOR) each serve distinct functions. The VOR keeps the gaze steady on the target of interest, whereas vestibular perception serves a number of tasks, including awareness of self-motion and orientation in space. VOR and motion perception might abide the same neurophysiological principles, but their distinct anatomical correlates were proposed. In patients with cerebellar stroke in distribution of medial division of posterior inferior cerebellar artery, we asked whether specific location of the focal lesion in vestibulocerebellum could cause impaired perception of motion but normal eye movements.
  
  
  RESULTS
  Thirteen patients were studied, 5 consistently perceived spinning of surrounding environment (vertigo), but the eye movements were normal. This group was called "disease model." Remaining 8 patients were also symptomatic for vertigo, but they had spontaneous nystagmus. The latter group was called "disease control." Magnetic resonance imaging in both groups consistently revealed focal cerebellar infarct affecting posterior cerebellar vermis (lobule IX). In the "disease model" group, only part of lobule IX was affected. In the disease control group, however, complete lobule IX was involved.
  
  
  CONCLUSIONS
  This study discovered a novel presentation of cerebellar stroke where only motion perception was affected, but there was an absence of objective neurologic signs.
authors.affiliation: Department of Neurology, Case Western Reserve University, Cleveland, Ohio. Electronic address: aasefshaikh@gmail.com.
authors.forename: Aasef G
authors.initials: AG
authors.lastname: Shaikh
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002526:Cerebellar Diseases / Q000150:complications* / Q000175:diagnosis / Q000503:physiopathology / Q000523:psychology; D002531:Cerebellum / Q000098:blood supply* / Q000473:pathology; D038524:Diffusion Magnetic Resonance Imaging; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009039:Motion Perception; D009759:Nystagmus, Pathologic / Q000209:etiology* / Q000503:physiopathology / Q000523:psychology; D012189:Retrospective Studies; D012720:Severity of Illness Index; D020521:Stroke / Q000150:complications* / Q000175:diagnosis / Q000503:physiopathology / Q000523:psychology; D014717:Vertigo / Q000209:etiology* / Q000503:physiopathology / Q000523:psychology
keywords: Perception; Purkinje neuron; posterior inferior cerebellar artery; velocity storage