Encephalopathy and SCN1A mutations.

We describe three children with genetically different sodium channel alpha 1 subunit (SCN1A) mutation associated epilepsy who experienced a sudden and sustained neurologic regression following status epilepticus in two and acute sepsis in one. Neuroimaging showed evidence of cerebral ischemia in one, but the other two cases showed cerebellar signal abnormalities. The selectivity of cerebellar white matter change suggests a different mechanism of injury or increased susceptibility of this brain region to injury in at least some patients with SCN1A mutations. This report adds to the spectrum and mechanism of acute neurologic deterioration and functional deficit associated with SCN1A mutations, which remains to be fully understood.