Tongue and limb myokymia in amyotrophic lateral sclerosis

Myokymic discharges are spontaneous repetitive motor unit action potential (MUAP) discharges, characterized by single or groups of discharges with intervening silent periods. The electrically recorded myokymic discharges may or may not be accompanied by clinically visible myokymia, which is defined as a continuous quivering or undulation of the skin or mucous membrane overlying a muscle. Myokymia has been reported only rarely in ALS patients,1,2 or in the tongue.3,4 We are unaware of any reports of tongue myokymia occurring in ALS. A 77-year-old man complained of progressive dysarthria and difficulty eating for 6 months. He denied difficulty swallowing; however, he had to eat slowly to prevent food from going into his nose. His speech was nasal. There were continuous quivering and undulating tongue movements. Motor examination showed diffuse fasciculations in all extremities, without atrophy or weakness. Jaw jerk and all tendon reflexes were hyperactive. Plantar responses were flexor. The remainder of the neurologic examination was normal. There …