title: [A case of distal myopathy with rimmed vacuole formation, progresses into proximal-dominant muscle involvement].
abstract: A case of 55-year-old male with distal myopathy with rimmed vacuole formation is reported. He first noticed dragging of his legs at the age of forty-three. Two years later, he was evaluated to have muscle wasting and weakness in lower legs. In another ten years, he became unable to stand or walk unaided. On physical examination, proximal limb muscles were more severely affected than distal limb muscles. Notably, muscle strength of the quadriceps femoris muscles were weak (MRC Scale 3/5), compared to hamstrings, tibialis anterior muscle and gastrocnemius muscle (4/5). Serum creatine kinase, electromyography, nerve conduction velocities were all compatible with this diagnosis. A computed tomography of the musculoskeletal system was consistent with physical findings. Muscle biopsy revealed many fibers with typical rimmed vacuoles (approximately 6% of fibers). Additionally, small amount of ragged-red fibers (0.5%) was noted. Histochemical reaction showed a focal deficiency of cytochrome c oxidase. This case suggests that during the longstanding course of the illness, proximal limb muscles may be more severely affected, and quadriceps femoris muscle may be predominantly involved.
authors.affiliation: Department of Neurology, University of Tsukuba.
authors.forename: K
authors.initials: K
authors.lastname: Ishikawa
authors.forename: N
authors.initials: N
authors.lastname: Ohkoshi
authors.forename: K
authors.initials: K
authors.lastname: Arasaki
authors.forename: H
authors.initials: H
authors.lastname: Mizusawa
authors.forename: I
authors.initials: I
authors.lastname: Kanazawa
mesh_terms: D030401:Cytochrome-c Oxidase Deficiency; D005121:Extremities; D006801:Humans; D008297:Male; D008875:Middle Aged; D009132:Muscles / Q000166:cytology* / Q000201:enzymology; D009135:Muscular Diseases / Q000473:pathology*; D013997:Time Factors; D014617:Vacuoles / Q000473:pathology*