Surgical treatment of polymicrogyria with advanced radiologic and neurophysiologic techniques

Coexistence of multiple seizure types, inclusion of the motor cortex in the epileptogenic zone, and poor delimitation of the abnormal cortex make most patients with polymicrogyria (PMG) unlikely candidates for epilepsy surgery (Guerrini R et al., Epilepsy and malformations of the cerebral cortex in Epileptic syndromes in infancy, childhood and adolescence, 2005).

We present here a child with frontal PMG and intractable epilepsy evaluated with advanced magnetic resonance imaging (MRI) and neurophysiologic techniques. Diffusion tensor imaging and fiber tractography showed severe involvement of neighboring white matter tracts besides the cortex. The evaluation also included functional MRI, chronic subdural electroencephalogram monitoring, and intra-operative motor mapping. The patient had a decrease in seizure frequency and an increase in his developmental skills after the surgery.

Advanced neuroradiologic and neurophysiologic techniques are required to provide an effective and safe resection of the epileptogenic cortex in cortical dysplasias.