~100 cases have been reported; this may increase with improved awareness of the condition.
Age at onset
3 to 20 months; peak at 5 to 6 months.
Males = females in the non-familial form but more females are reported in the familial cases.
Neurological and mental status
The familial form is most likely autosomal dominant disorder with genetic heterogeneity (chromosomes 19q, 16, or 2).
Diurnal focal seizures of motion arrest, decreased responsiveness, staring, eye and head deviation, simple automatisms, and mild clonic movements. They may or may not progress to generalized convulsions. Alternating from one side to the other side is common. Duration is usually short, from 30 sec to 3 min. They occur in clusters of a maximum of 8 to 10 per day for 1 to 3 days and may recur after 1 to 3 months.
All relevant tests are normal.
Excellent, with normal development and complete seizure remission.
Difficult in sporadic form that requires long follow-up.
In the active seizure period, empirical drug treatment is usually effective. This is usually withdrawn after 1 to 3 years.
Reviewed and revised June 2008 by Steven C. Schachter, MD
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