Benign Neonatal Sleep Myoclonus

Abstract

Neonatal sleep myoclonus is a unique movement disorder because the myoclonic jerks occur only during sleep. Such jerks are common in adults1and represent a benign phenomenon that does not require medical intervention or treatment. We studied three infants with sleep myoclonus that began in the first month of life. All of the infants were neurologically normal, as were the EEGs both in waking and sleep. Although initially there was considerable concern about neurologic status because of confusion with neonatal seizures and other more serious CNS disorders, such as the sphingolipidoses, sleep myoclonus in these infants proved to be entirely benign on followup. REPORT OF CASES Case 1.—A 4,876-g male infant was born following a normal pregnancy and delivery; his Apgar scores were 8 (one minute) and 10 (five minutes). The results of examination of the infant and placenta were normal. The infant fed well on a standard formula