title: Multisystem disorder in late-onset chronic progressive external ophthalmoplegia.
abstract: BACKGROUND
  Chronic progressive external ophthalmoplegia (CPEO) is a mitochondrial syndrome on a disease spectrum with Kearns-Sayre syndrome (KSS). Clinical presentation is variable and our experience suggested that phenotypic differences exist in CPEO with onset after age 20.
  
  
  METHODS
  This descriptive study is a retrospective chart review of 40 patients with late-onset CPEO. Clinical features, laboratory and neurophysiology results were reviewed.
  
  
  RESULTS
  Multisystem dysfunction was very common in this series. Gastrointestinal dysfunction was more common than expected (60%) as was migraine headache (40%). Clinical characteristics on the KSS disease spectrum were uncommon in this series with only 2.5% having pigmentary retinopathy, 5% with cardiac conduction abnormality, and 22.5% having endocrinopathy (most often thyroid dysfunction rather than diabetes). Neurophysiology abnormalities included length-dependent axonal polyneuropathy in 44% (sometimes subclinical) and myopathic EMG changes in 26%. Exposure to sources of acquired mitochondrial toxicity including cigarette use and hepatitis C infection were more common than expected in this series.
  
  
  CONCLUSIONS
  Phenotype was different in this late-onset series compared with previous reports in CPEO patients. In this series of late-onset patients, multi-organ dysfunction was more common than previously reported in CPEO, and some classical mitochondrial manifestations, such as pigmentary retinopathy were rare. We suggest that acquired mitochondrial toxicity may have a role in the pathogenesis of adult-onset CPEO.
authors.affiliation: Division of Neurology, University of British Columbia, Vancouver.
authors.forename: Gerald
authors.initials: G
authors.lastname: Pfeffer
authors.forename: Sandra
authors.initials: S
authors.lastname: Sirrs
authors.forename: N Kevin
authors.initials: NK
authors.lastname: Wade
authors.forename: Michelle M
authors.initials: MM
authors.lastname: Mezei
mesh_terms: D000328:Adult; D000368:Aged; D004272:DNA, Mitochondrial / Q000235:genetics; D004576:Electromyography; D005260:Female; D005767:Gastrointestinal Diseases / Q000150:complications* / Q000175:diagnosis / Q000235:genetics; D017353:Gene Deletion; D034381:Hearing Loss / Q000209:etiology; D006801:Humans; D008297:Male; D008875:Middle Aged; D028361:Mitochondrial Diseases / Q000150:complications* / Q000453:epidemiology* / Q000235:genetics; D018763:Muscle Fatigue / Q000502:physiology; D017246:Ophthalmoplegia, Chronic Progressive External / Q000150:complications* / Q000453:epidemiology* / Q000235:genetics; D012189:Retrospective Studies
chemical_list: D004272:DNA, Mitochondrial