title: Eye movement recordings to investigate a supranuclear component in chronic progressive external ophthalmoplegia: a cross-sectional study.
abstract: BACKGROUND
  It has been postulated that eye movement disorders in chronic progressive external ophthalmoplegia (CPEO) have a neurological as well as a myopathic component to them.
  
  
  OBJECTIVE
  To investigate whether there is a supranuclear component to eye movement disorders in CPEO using eye movement recordings.
  
  
  METHODS
  Saccade and smooth pursuit (SP) characteristics together with vestibulo-ocular reflex (VOR) gain and VOR suppression (VORS) gain in 18 patients with CPEO and 34 normal patients were measured using Eyelink II video-oculography.
  
  
  RESULTS
  The asymptotic values of the peak velocity main sequence curves were reduced in the CPEO group compared to those of normal patients, with a mean of 161 degrees/s (95% CI 126 degrees/s to 197 degrees/s) compared with 453 degrees/s (95% CI 430 to 475 degrees/s), respectively. Saccadic latency was longer in CPEO (263 ms; 95% CI 250 to 278), compared to controls (185 ms; 95% CI 181 to 189). Smooth pursuit and VOR gains were impaired in CPEO, although this could be explained by non-supranuclear causes. VORS gain was identical in the two groups.
  
  
  CONCLUSIONS
  This study does not support a supranuclear component to the ophthalmoplegia of CPEO, although the increased latencies observed may warrant further investigation.
authors.affiliation: Department of Ophthalmology, The Royal Free Hospital, London, UK.
authors.forename: A E
authors.initials: AE
authors.lastname: Ritchie
authors.forename: P G
authors.initials: PG
authors.lastname: Griffiths
authors.forename: P F
authors.initials: PF
authors.lastname: Chinnery
authors.forename: A W
authors.initials: AW
authors.lastname: Davidson
mesh_terms: D016022:Case-Control Studies; D003430:Cross-Sectional Studies; D006801:Humans; D008875:Middle Aged; D017246:Ophthalmoplegia, Chronic Progressive External / Q000209:etiology / Q000503:physiopathology*; D011698:Pursuit, Smooth / Q000502:physiology*; D012027:Reflex, Vestibulo-Ocular / Q000502:physiology*; D012438:Saccades / Q000502:physiology*