title: An adult-onset myopathy characterized by a double ring appearance of muscle fibers.
abstract: We report a 33-yr-old man with an unusual neuromuscular disorder characterized by progressive generalized weakness of 3 yr duration whose muscle biopsy showed a double ring appearance in most muscle fibers. This double ring appearance was due to a peripheral outer sarcoplasmic mass and an inner ring of annular myofibrils surrounding a core of normal longitudinally oriented myofibrils. Nerve conduction studies were normal. Electromyography showed fibrillations, positive waves, and increased brief duration, low amplitude, polyphasic potentials.
authors.affiliation: Department of Neurology, Creighton University Medical Center, Omaha, NE 68135.
authors.forename: C L
authors.initials: CL
authors.lastname: Coulter
authors.forename: W A
authors.initials: WA
authors.lastname: Marks
authors.forename: J B
authors.initials: JB
authors.lastname: Bodensteiner
authors.forename: R W
authors.initials: RW
authors.lastname: Leech
authors.forename: P
authors.initials: P
authors.lastname: Tonin
authors.forename: S
authors.initials: S
authors.lastname: DiMauro
authors.forename: R A
authors.initials: RA
authors.lastname: Brumback
mesh_terms: D000328:Adult; D004576:Electromyography; D015444:Exercise / Q000502:physiology; D005260:Female; D006003:Glycogen / Q000378:metabolism; D006801:Humans; D008854:Microscopy, Electron; D009132:Muscles / Q000378:metabolism / Q000473:pathology*; D009210:Myofibrils / Q000648:ultrastructure; D009468:Neuromuscular Diseases / Q000473:pathology*; D012519:Sarcoplasmic Reticulum / Q000648:ultrastructure
chemical_list: D006003:Glycogen