Nocturnal Myoclonus:
Involuntary shock-like contractions, irregular in rhythm and amplitude, followed by relaxation, of a muscle or a group of muscles. This condition may be a feature of some CENTRAL NERVOUS SYSTEMS DISEASES (e.g., EPILEPSY, MYOCLONIC). Nocturnal myoclonus may represent a normal physiologic event or occur as the principal feature of the NOCTURNAL MYOCLONUS SYNDROME. (From Adams et al., Principles of Neurology, 6th ed, pp102-3).Synonym: action myoclonus, upper extremity myoclonus, myoclonic jerks, myoclonic jerking, myoclonic jerk, lower extremity myoclonus, intention myoclonus, eyelid myoclonus, sleep myoclonus, segmental myoclonus, polymyoclonus, palatal myoclonus, oculopalatal myoclonus, myoclonus simplex, myoclonus.
