Progressive hemispheric shrinking in hemimegalencephaly: a possible role for seizure-related neuronal loss.

Hemimegalencephaly (HME) is a developmental brain lesion consisting of a unilateral enlarged, dysplastic, and often highly epileptogenic cerebral hemisphere. Most patients exhibit early onset intractable seizures, status epilepticus, hemiplegia, hemianopsia, and developmental delay. Major surgical procedures are advocated for limiting the devastating consequences of epilepsy. We studied a female with HME, early onset intractable seizures and recurrent status epilepticus, in whom progressive hemiatrophy of the enlarged hemisphere and normal growth of the contralateral hemisphere, exceeding the size of the dysplastic hemisphere, was demonstrated by magnetic resonance imaging.