Treatment of seizures in subcortical laminar heterotopia with corpus callosotomy and lamotrigine.

Focal and generalized cortical dysgeneses are sometimes seen on the magnetic resonance images (MRI) of patients with epilepsy. Subcortical laminar heterotopia are bilateral collections of gray matter in the centrum semiovale that resemble a band or "double cortex" on MRI. We studied one male and two female patients with subcortical laminar heterotopia who had moderate to severe developmental delay, early-onset epilepsy, and medically refractory seizures. Atonic, atypical absence, tonic, myoclonic, complex partial, and generalized tonic-clonic seizures were recorded. Interictal and ictal electroencephalographic patterns were generalized and, less commonly, multifocal. Two years after corpus callosotomy, one patient was free of generalized tonic-clonic and atonic seizures, but the other patient who had undergone callosotomy had no significant reduction in seizure frequency. With lamotrigine treatment, the patient who had not had surgery had complete cessation of monthly episodes of status epilepticus and a dramatic reduction of generalized tonic-clonic seizures, and the other patient who received lamotrigine had a 50% reduction of her atonic seizures. In patients with subcortical laminar heterotopia, atonic and generalized tonic-clonic seizures can be substantially reduced or eliminated by corpus callosotomy or treatment with lamotrigine.