Benign myoclonus of early infancy

Benign myoclonus of early infancy, first described by Fejerman and Lombroso , is a paroxysmal phenomenon of the first 2 years of life which occurs in n eurologically healthy infants during wakefulness, and is usually triggered by excitement or frustration. We studied the neurophysiological features of the phenomenon in five children, aged 7 to 11 months, who were monitored b y video-EEG recording, and by polygraphic recording in 3 of the 5 cases. Th e phenomenon is characterized by a shudder-type, paroxysmal motor manifesta tion involving mainly the trunk and sometimes the head, associated with ton ic limb contractions of variable intensity, from hardly noticeable to more sustained. The EEC counterpart never showed modifications, the polygraphic study demonstrated a brief tonic limb contraction. The clinical manifestati on should not be confused with the spasms of epileptic infantile spasms syn drome, or with tonic reflex seizures of early infancy. Although the phenome non is already widely known, its polygraphic recording is rarely reported i n literature. The polygraphic data of our patients contributes to the diagn osis and understanding of the pathophysiology of this paroxysmal manifestat ion.