title: Distinguishing spinocerebellar ataxia with pure cerebellar manifestation from multiple system atrophy (MSA-C) through saccade profiles.
abstract: OBJECTIVE
  Patients with spinocerebellar ataxia with pure cerebellar presentation (SCD) and multiple system atrophy (MSA-C) show similar symptoms at early stages, although cerebellofugal pathology predominates in SCD, and cerebellopetal pathology in MSA-C. We studied whether saccade velocity profiles, which reflect the accelerating and braking functions of the cerebellum, can differentiate these two disorders.
  
  
  METHODS
  We recorded visually guided (VGS) and memory guided saccades (MGS) in 29 MSA-C patients, 12 SCD patients, and 92 age-matched normal subjects, and compared their amplitude, peak velocity and duration (accelerating and decelerating phases).
  
  
  RESULTS
  Hypometria predominated in VGS and MGS of MSA-C, whereas hypometria was less marked in SCD, with hypermetria frequently noted in MGS. Peak velocity was reduced, and deteriorated with advancing disease both in SCD and MSA-C groups at smaller target eccentricities. The deceleration phase was prolonged in SCD compared to MSA-C and normal groups at larger target eccentricities, which deteriorated with advancing disease.
  
  
  CONCLUSIONS
  Saccades in MSA-C were characterized by a more prominent acceleration deficit and those in SCD by a more prominent braking defect, possibly caused by the cerebellopetal and cerebellofugal pathologies, respectively.
  
  
  CONCLUSIONS
  Saccade profiles provide important information regarding the accelerating and braking signals of the cerebellum in spinocerebellar ataxia.
authors.affiliation: Department of Neurology, Graduate School of Medicine, University of Tokyo, Tokyo, Japan; Department of Cell Physiology, School of Medicine, Kyorin University, Tokyo, Japan. Electronic address: yterao-tky@umin.ac.jp.
authors.forename: Yasuo
authors.initials: Y
authors.lastname: Terao
authors.affiliation: Neurological Clinic for Children, Tokyo, Japan.
authors.forename: Hideki
authors.initials: H
authors.lastname: Fukuda
authors.affiliation: Department of Neurology, Graduate School of Medicine, University of Tokyo, Tokyo, Japan.
authors.forename: Shin-Ichi
authors.initials: SI
authors.lastname: Tokushige
authors.affiliation: Department of Neurology, Graduate School of Medicine, University of Tokyo, Tokyo, Japan.
authors.forename: Satomi
authors.initials: S
authors.lastname: Inomata-Terada
authors.affiliation: Department of Neurology, Graduate School of Medicine, University of Tokyo, Tokyo, Japan.
authors.forename: Akihiro
authors.initials: A
authors.lastname: Yugeta
authors.affiliation: Department of Neurology, Graduate School of Medicine, University of Tokyo, Tokyo, Japan.
authors.forename: Masashi
authors.initials: M
authors.lastname: Hamada
authors.affiliation: Department of Neurology, School of Medicine, Fukushima Medical University, Fukushima, Japan.
authors.forename: Yoshikazu
authors.initials: Y
authors.lastname: Ugawa
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D002531:Cerebellum / Q000503:physiopathology*; D004585:Electrooculography / Q000379:methods*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D019578:Multiple System Atrophy / Q000175:diagnosis / Q000503:physiopathology*; D010775:Photic Stimulation / Q000379:methods*; D011930:Reaction Time / Q000502:physiology; D012438:Saccades / Q000502:physiology; D020754:Spinocerebellar Ataxias / Q000175:diagnosis / Q000503:physiopathology*
keywords: Cerebellum; Fastigial nucleus; Multiple system atrophy; Peak velocity; Saccade metrics; Spinocerebellar ataxia