title: Mitochondrial pseudomyasthenia.
abstract: The classic ocular motor presentation of mitochondrial disorders is chronic, symmetric, and diffuse weakness. We describe a man with 25 years of asymmetric ptosis, ophthalmoparesis, and facial weakness that partially responded to steroid therapy. Serologic and electrophysiological investigations for myasthenia gravis were negative, but muscle biopsy confirmed a mitochondrial myopathy. This case illustrates the potential of mitochondrial ophthalmoparesis to mimic the features of ocular myasthenia.
authors.affiliation: Departments of Medicine (Neurology), University of British Columbia, Vancouver, British Columbia, Canada. jasonbarton@shaw.ca
authors.forename: Jason J S
authors.initials: JJ
authors.lastname: Barton
authors.forename: John
authors.initials: J
authors.lastname: Maguire
authors.forename: Michelle
authors.initials: M
authors.lastname: Mezei
authors.forename: Trevor
authors.initials: T
authors.lastname: Hurwitz
authors.forename: Hannah R
authors.initials: HR
authors.lastname: Briemberg
mesh_terms: D006801:Humans; D008297:Male; D008875:Middle Aged; D017240:Mitochondrial Myopathies / Q000150:complications / Q000175:diagnosis*; D018482:Muscle, Skeletal / Q000473:pathology / Q000648:ultrastructure; D009157:Myasthenia Gravis / Q000150:complications / Q000175:diagnosis*