title: Ocular motor disorders in mitochondrial encephalopathy with lactic acid and stroke-like episodes with the 3271 (T-C) point mutation in mitochondrial DNA.
abstract: BACKGROUND
  Ocular motor function can provide insights into areas of dysfunction within the nervous system. There are no published eye movement recordings in patients with mitochondrial encephalopathy with lactic acid and stroke-like episodes (MELAS). Our purpose in this study was to analyze the ocular motor features of a family with MELAS with a (T-C) mutation at nucleotide position 3271 in the mitochondrial tRNA-Leu gene.
  
  
  METHODS
  The search coil method was used to record visually-guided saccades, antisaccades, and triangular pursuit tasks in the horizontal and vertical planes in three patients in a Japanese family with MELAS.
  
  
  RESULTS
  The patients showed saccadic dysmetria and prolonged saccadic reaction times, deficits in the ability to suppress reflex eye movements, and increased reaction time during antisaccades, downbeat nystagmus, square wave jerks, and impairment in pursuit.
  
  
  CONCLUSIONS
  On the basis of eye movement recordings, patients with MELAS have frontal cortex as well as cerebellar dysfunction.
authors.affiliation: Department of Ophthalmology and Visual Sciences, Hokkaido University Graduate School of Medicine, Sapporo, Japan. yshinmei@med.hokudai.ac.jp
authors.forename: Yasuhiro
authors.initials: Y
authors.lastname: Shinmei
authors.forename: Manabu
authors.initials: M
authors.lastname: Kase
authors.forename: Yasuo
authors.initials: Y
authors.lastname: Suzuki
authors.forename: Takuya
authors.initials: T
authors.lastname: Nitta
authors.forename: Shinki
authors.initials: S
authors.lastname: Chin
authors.forename: Kazuhiko
authors.initials: K
authors.lastname: Yoshida
authors.forename: Yu-ichi
authors.initials: Y
authors.lastname: Goto
authors.forename: Toshiko
authors.initials: T
authors.lastname: Nagashima
authors.forename: Shigeaki
authors.initials: S
authors.lastname: Ohno
mesh_terms: D000328:Adult; D004272:DNA, Mitochondrial / Q000235:genetics*; D018450:Disease Progression; D005260:Female; D020022:Genetic Predisposition to Disease; D006801:Humans; D017241:MELAS Syndrome / Q000150:complications* / Q000235:genetics; D008297:Male; D008875:Middle Aged; D015835:Ocular Motility Disorders / Q000209:etiology* / Q000235:genetics / Q000503:physiopathology; D017354:Point Mutation; D011379:Prognosis; D011698:Pursuit, Smooth / Q000502:physiology; D012356:RNA, Transfer, Leu / Q000235:genetics*; D012438:Saccades / Q000502:physiology
chemical_list: D004272:DNA, Mitochondrial; D012356:RNA, Transfer, Leu