title: Nerve and muscle involvement in mitochondrial disorders: an electrophysiological study.
abstract: Involvement of the peripheral nervous system in mitochondrial disorders (MD) has been previously reported. However, the exact prevalence of peripheral neuropathy and/or myopathy in MD is still unclear. In order to evaluate the prevalence of neuropathy and myopathy in MD, we performed sensory and motor nerve conduction studies (NCS) and concentric needle electromyography (EMG) in 44 unselected MD patients. NCS were abnormal in 36.4% of cases, and were consistent with a sensori-motor axonal multineuropathy (multifocal neuropathy), mainly affecting the lower limbs. EMG evidence of myopathy was present in 54.5% of patients, again mainly affecting the lower limbs. Nerve and muscle involvement was frequently subclinical. Peripheral nerve and muscle involvement is common in MD patients. Our study supports the variability of the clinical expression of MD. Further studies are needed to better understand the molecular basis underlying the phenotypic variability among MD patients.
authors.affiliation: Department of Neuroscience, Neurological Clinic, University of Pisa, Via Roma 67, 56126 Pisa, Italy. mancusomichelangelo@gmail.com
authors.forename: Michelangelo
authors.initials: M
authors.lastname: Mancuso
authors.forename: Selina
authors.initials: S
authors.lastname: Piazza
authors.forename: Leda
authors.initials: L
authors.lastname: Volpi
authors.forename: Daniele
authors.initials: D
authors.lastname: Orsucci
authors.forename: Valeria
authors.initials: V
authors.lastname: Calsolaro
authors.forename: Elena
authors.initials: E
authors.lastname: Caldarazzo Ienco
authors.forename: Cecilia
authors.initials: C
authors.lastname: Carlesi
authors.forename: Anna
authors.initials: A
authors.lastname: Rocchi
authors.forename: Lucia
authors.initials: L
authors.lastname: Petrozzi
authors.forename: Rosanna
authors.initials: R
authors.lastname: Calabrese
authors.forename: Gabriele
authors.initials: G
authors.lastname: Siciliano
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D004576:Electromyography / Q000379:methods; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D028361:Mitochondrial Diseases / Q000150:complications* / Q000473:pathology*; D018482:Muscle, Skeletal / Q000473:pathology / Q000503:physiopathology; D009135:Muscular Diseases / Q000209:etiology*; D009431:Neural Conduction / Q000502:physiology; D010523:Peripheral Nervous System Diseases / Q000209:etiology*; D055815:Young Adult