Benign neonatal sleep myoclonus. A differential diagnosis of neonatal seizures
J. Daoust-Roy and S. S. Seshia
Clinical Neurophysiology Laboratory, Children's Hospital, Winnipeg, Manitoba, Canada.
OBJECTIVE--To describe 10 infants with benign neonatal sleep myoclonus.
DESIGN--Patient series, representing the experience of one pediatric
neurologist. SETTING--Referral-based Pediatric Neurology Service at a
Children's Hospital. PATIENTS--Sequential sample of 10 neonates referred
for assessment of seizures and found to have benign neonatal sleep
myoclonus. Neonates who did not have the events of concern during
electroencephalography or in whom electroencephalography was not done were
excluded even if the clinical features suggested the entity. RESULTS--Our
patients met the criteria for the diagnosis. The myoclonus often increased
with gentle restraint. The amplitude and duration of events mimicked
convulsive status epilepticus and serial seizures in four neonates. In two
of them the myoclonus worsened in spite of anticonvulsant therapy,
decreasing substantially when such treatment was stopped.
CONCLUSION--Benign neonatal sleep myoclonus, an entity characterized by (1)
neonatal onset, (2) myoclonic jerks only during sleep, (3) abrupt and
consistent cessation with arousal, (4) absence of concomitant
electrographic changes suggestive of seizures, and (5) good outcome must be
included in the differential diagnosis of neonatal seizures.
