title: Ocular motor characteristics of different subtypes of spinocerebellar ataxia: distinguishing features.
abstract: Because of frequent involvement of the cerebellum and brainstem, ocular motor abnormalities are key features of spinocerebellar ataxias and may aid in differential diagnosis. Our objective for this study was to distinguish the subtypes by ophthalmologic features after head-shaking and positional maneuvers, which are not yet recognized as differential diagnostic tools in most common forms of spinocerebellar ataxias. Of the 302 patients with a diagnosis of cerebellar ataxia in 3 Korean University Hospitals from June 2011 to June 2012, 48 patients with spinocerebellar ataxia types 1, 2, 3, 6, 7, or 8 or with undetermined spinocerebellar ataxias were enrolled. All patients underwent a video-oculographic recording of fixation abnormalities, gaze-evoked nystagmus, positional and head-shaking nystagmus, and dysmetric saccades. Logistic regression analysis controlling for disease duration revealed that spontaneous and positional downbeat nystagmus and perverted head-shaking nystagmus were strong predictors for spinocerebellar ataxia 6, whereas saccadic intrusions and oscillations were identified as positive indicators of spinocerebellar ataxia 3. In contrast, the presence of gaze-evoked nystagmus and dysmetric saccades was a negative predictor of spinocerebellar ataxia 2. Positional maneuvers and horizontal head shaking occasionally induced or augmented saccadic intrusions/oscillations in patients with spinocerebellar ataxia types 1, 2, and 3 and undetermined spinocerebellar ataxia. The results indicated that perverted head-shaking nystagmus may be the most sensitive parameter for SCA6, whereas saccadic intrusions/oscillations are the most sensitive for spinocerebellar ataxia 3. In contrast, a paucity of gaze-evoked nystagmus and dysmetric saccades is more indicative of spinocerebellar ataxia 2. Head-shaking and positional maneuvers aid in defining ocular motor characteristics in spinocerebellar ataxias. © 2013 Movement Disorder Society.
authors.affiliation: Department of Neurology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea.
authors.forename: Ji Sun
authors.initials: JS
authors.lastname: Kim
authors.forename: Ji Soo
authors.initials: JS
authors.lastname: Kim
authors.forename: Jinyoung
authors.initials: J
authors.lastname: Youn
authors.forename: Dae-Won
authors.initials: DW
authors.lastname: Seo
authors.forename: Yuri
authors.initials: Y
authors.lastname: Jeong
authors.forename: Ji-Hoon
authors.initials: JH
authors.lastname: Kang
authors.forename: Jeong Ho
authors.initials: JH
authors.lastname: Park
authors.forename: Jin Whan
authors.initials: JW
authors.lastname: Cho
mesh_terms: D000328:Adult; D000368:Aged; D000704:Analysis of Variance; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009759:Nystagmus, Pathologic / Q000175:diagnosis / Q000209:etiology; D015835:Ocular Motility Disorders / Q000175:diagnosis* / Q000209:etiology*; D012044:Regression Analysis; D012189:Retrospective Studies; D012438:Saccades; D020754:Spinocerebellar Ataxias / Q000145:classification* / Q000150:complications*; D014741:Video Recording
keywords: cerebellum; electro-oculography; eye movements; nystagmus; spinocerebellar ataxia