Myokymic discharges in amyotrophic lateral sclerosis (ALS): a rare electrophysiologic finding?
Myokymic discharges (MDs) are uncommonly recognized in amyotrophic lateral sclerosis (ALS). The electrophysiologic findings in 96 ALS patients were retrospectively reviewed. MDs were found in 5.2% of patients, in 0.81% of total muscles examined (8.2% cranial muscles vs. 0.15% limb muscles). The higher frequency of MDs in cranial muscles suggests a difference in the metabolic environment or other mechanism of instability of the anterior horn cells in the brainstem compared to the spinal cord.
Whaley
Nathaniel R
NR
Department of Neurology, Mayo Clinic, 4500 San Pablo Road, Jacksonville, FL 32224, USA.
Rubin
Devon I
DI
D000368:Aged; D000690:Amyotrophic Lateral Sclerosis / Q000150:complications* / Q000175:diagnosis / Q000503:physiopathology; D003937:Diagnosis, Differential; D004576:Electromyography / Q000379:methods*; D005500:Follow-Up Studies; D006801:Humans; D008875:Middle Aged; D009119:Muscle Contraction / Q000502:physiology*; D018482:Muscle, Skeletal / Q000503:physiopathology*; D020385:Myokymia / Q000175:diagnosis* / Q000209:etiology / Q000503:physiopathology; D012189:Retrospective Studies