Perisylvian, including insular, childhood epilepsy: Presurgical workup and surgical outcome

Objective: To report the presurgical workup, surgical procedures, and outcomes in a series of pediatric patients with drug-resistant epilepsy involving the perisylvian/insular regions.Methods: We retrospectively assessed 16 pediatric patients affected by drug-resistant focal epilepsy involving perisylvian/insular regions, who consecutively underwent tailored resective surgery. All patients underwent a detailed presurgical workup, which included the analysis of the anatomoelectroclinical correlations with scalp electroencephalography (EEG) and/or with stereo-electroencephalography (SEEG), brain magnetic resonance imaging (MRI), and comprehensive cognitive and neuropsychological evaluations. After surgery, all patients underwent serial clinical and laboratory evaluations.Results: Focal motor seizures restricted to perioral area, associated with symptoms related to the surrounding areas (as auditory hallucinations, unpleasant paresthesia, fear, and epigastric sensation), characterized the ictal semiology in 75% of patients. In 50%, autonomic manifestations were present and in 56% subjective manifestations were reported. The 50% of the patients underwent SEEG with insular sampling to better define the epileptogenic zone. In all patients, the insular cortex was always part of the epileptogenic zone, and tailored resections also involved, with variable degree, the frontal, parietal, and temporal opercula. Preoperatively, the neuropsychological assessment revealed impairments in specific cognitive functions and mild or moderate cognitive compromise in 88% of the patients. Postoperatively, one patient had permanent slight hemiparesis. At the most recent follow-up (median 39 months), seizure outcome was satisfactory in 69% of patients: seven patients were completely seizurefree (Engel class Ia), two were free of disabling seizure (class Ic), and two had rare disabling seizures (class II). The cognitive functioning remained unchanged in 62%, and improved in 38%.Significance: The assessment of perisylvian/insular epilepsy in children is particularly challenging. However, tailored resections based on a careful presurgical evaluation, including SEEG recording, may lead to a good seizure control and to a better overall outcome.