Abstracts

Resective surgery in patients with epilepsy associated with extensive bilateral cortical lesions is usually not considered, particularly when the lesion is a malformation of cortical development. Identification of exceptional situations depends upon precise diagnosis and careful analysis of individual cases. This work describes the surgical approach and the outcome of a selected series of patients operated for medically - refractory seizures associated with bilateral perisylvian ulegyria (BPU) . It is hoped that the findings reported below will highlight the relevance of a correct syndromic diagnosis in patients presenting since childhood with pseudobulbar palsy and epilepsy.
Six patients are reported who had surgery due to intractable partial and secondarily generalized seizures associated with MRI-defined BPU. Preoperative evaluation included the use of subdural electrodes in 5. Four patients had dual pathology, i.e., the association of BPU and hippocampal atrophy (sclerosis). All 4 had a temporal lobectomy, which in 2 of them was combined with ipsilateral resection of the epileptogenic ulegyric lesion and in the other with perirolandic multiple subpial transections (MSTs). The other 2 patients had only unilateral resection of the ulegyria. Histopathology was available to all.
In all 4 patients with dual pathology, intracranial electrodes lateralized the epileptogenic zone to the hemisphere harboring the atrophic hippocampus. Histopathological evaluation confirmed the abnormalities anticipated by the imaging findings in all patients. Three are seizure-free (class I, Engel), two have rare seizures (class II), and the patient who received perirolandic MSTs did not improve significantly (class IV). Mean follow up is 6.2 years. One patient had mild transient worsening of the dysarthria
BPU must be differentiated from the electroclinically similar but pathogenetically distinct bilateral perisylvian polymicrogyria. Medically-refractory epileptic patients with BPU may have associated hippocampal sclerosis ( dual pathology) and specific evaluation and resective surgical strategies can lead to successful surgical outcome. We thus conclude that, in contrast to bilateral perisylvian polimicrogyria, BPU should be regarded as a surgically remediable epilepsy syndrome.