Malignant migrating partial seizures in infancy.

Malignant migrating partial seizures in infancy is a rare, age-specific epileptic encephalopathy. It is characterized by onset before age 6 months, virtually continuous multifocal seizures with ictal electrical encephalographic activity shifting from one hemisphere to the other, no identifiable immediate or remote causes, intractability to antiepileptic drugs, and developmental arrest. This report adds two patients to the 21 previously described in the literature. One infant, microcephalic at birth, developed at age 4 months clusters of nearly continuous multifocal seizures with secondary generalization, refractory to antiepileptic drugs. By age 4.5 years she was seizure-free but remains without any cognitive or motor function. Patient 2, born with a normal head circumference, began seizures at age 3 months, never became seizure-free, and died at age 18 months. Electroencephalograms of both children were characteristic, and the neuroimaging finding was one of progressive cortical and subcortical atrophy. It has been hypothesized that neurotransmitter dysfunction with persistent, pronounced excitatory or cytotoxic mechanisms may explain the continuous, erratic epileptic activity. Awareness of malignant migrating partial seizures in infancy and research focused on its pathophysiologic mechanisms may reveal innovative treatments of this devastating, age-specific disorder.