title: Clinical evaluation of eye movements in spinocerebellar ataxias: a prospective multicenter study.
abstract: BACKGROUND
  Ocular motor abnormalities reflect the varied neuropathology of spinocerebellar ataxias (SCAs) and may serve to clinically distinguish the different SCAs. We analyzed the various eye movement abnormalities detected prospectively at the baseline visit during a large multicenter natural history study of SCAs 1, 2, 3, and 6.
  
  
  METHODS
  The data were prospectively collected from 12 centers in the United States in patients with SCAs 1, 2, 3, and 6, as part of the Clinical Research Consortium for Spinocerebellar Ataxias (NIH-CRC-SCA). Patient characteristics, ataxia rating scales, the Unified Huntington Disease Rating Scale functional examination, and clinical staging were used. Eye movement abnormalities including nystagmus, disorders of saccades and pursuit, and ophthalmoparesis were recorded, and factors influencing their occurrence were examined.
  
  
  RESULTS
  A total of 301 patients participated in this study, including 52 patients with SCA 1, 64 with SCA 2, 117 with SCA 3, and 68 with SCA 6. Although no specific ocular motor abnormality was pathognomonic to any SCA, significant differences were noted in their occurrence among different disorders. SCA 6 was characterized by frequent occurrence of nystagmus and abnormal pursuit and rarity of slow saccades and ophthalmoparesis and SCA 2 by the frequent occurrence of slow saccades and infrequent nystagmus and dysmetric saccades. SCA 1 and SCA 3 subjects had a more even distribution of eye movement abnormalities.
  
  
  CONCLUSIONS
  Prospective data from a large cohort of patients with SCAs 1, 2, 3, and 6 provide statistical validation that the SCAs exhibit distinct eye movement abnormalities that are useful in identifying the genotypes. Many of the abnormalities correlate with greater disease severity measures.
authors.affiliation: Department of Neurology (MM, MSO, CF, GX, TA, SHS), McKnight Brain Institute, University of Florida, Gainesville, Florida; Department of Neurology (KPF, SMP), University of Utah, Salt Lake City, Utah; Department of Neurology (SP), University of California, Los Angeles, Los Angeles, California; Department of Neurology (GW), Emory University, Atlanta, Georgia; Department of Neurology (CG), University of Chicago, Chicago, Illinois; Department of Neurology (JS), Massachusetts General Hospital, Harvard Medical School; Department of Neurology (HP, VS), University of Michigan, Ann Arbor, Michigan; Department of Neurology (SY), Johns Hopkins University, Baltimore, Maryland; Department of Neurology (TZ), University of South Florida, Tampa, Florida; Department of Neurology (SHK, PM), Columbia University, New York, New York; and Department of Neurology (KB), University of Minnesota, Minneapolis, Minnesota.
authors.forename: M
authors.initials: M
authors.lastname: Moscovich
authors.forename: Michael S
authors.initials: MS
authors.lastname: Okun
authors.forename: Chris
authors.initials: C
authors.lastname: Favilla
authors.forename: Karla P
authors.initials: KP
authors.lastname: Figueroa
authors.forename: Stefan M
authors.initials: SM
authors.lastname: Pulst
authors.forename: Susan
authors.initials: S
authors.lastname: Perlman
authors.forename: George
authors.initials: G
authors.lastname: Wilmot
authors.forename: Christopher
authors.initials: C
authors.lastname: Gomez
authors.forename: Jeremy
authors.initials: J
authors.lastname: Schmahmann
authors.forename: Henry
authors.initials: H
authors.lastname: Paulson
authors.forename: Vikram
authors.initials: V
authors.lastname: Shakkottai
authors.forename: Sarah
authors.initials: S
authors.lastname: Ying
authors.forename: Theresa
authors.initials: T
authors.lastname: Zesiewicz
authors.forename: S H
authors.initials: SH
authors.lastname: Kuo
authors.forename: P
authors.initials: P
authors.lastname: Mazzoni
authors.forename: Khalaf
authors.initials: K
authors.lastname: Bushara
authors.forename: Guangbin
authors.initials: G
authors.lastname: Xia
authors.forename: Tetsuo
authors.initials: T
authors.lastname: Ashizawa
authors.forename: S H
authors.initials: SH
authors.lastname: Subramony
mesh_terms: D000328:Adult; D005260:Female; D005820:Genetic Testing; D006801:Humans; D008297:Male; D008875:Middle Aged; D015835:Ocular Motility Disorders / Q000175:diagnosis* / Q000209:etiology*; D011446:Prospective Studies; D012720:Severity of Illness Index; D020754:Spinocerebellar Ataxias / Q000145:classification / Q000150:complications* / Q000235:genetics; D014481:United States