Typically, the
movements occur in clusters of jerks at 1 to 5 Hz over a
period of several seconds. Benign neonatal sleep myoclonus
typically begins during the first week of life,
diminishes in the second month, and is usually gone
before 6 months of age, but has been reported to persist
as long as 3 years in one patient.3 Ictal and interictal
electroencephalograms (EEGs) are typically normal.4
The movements are most likely to occur during quiet
(non–rapid eye movement) sleep.5 They can also be
triggered by noise. Waking the baby causes the movements
to cease. Episodes of myoclonus can be exacerbated
by treatment with benzodiazepines.6 Treatment
is not required and neurologic outcome is normal