Pediatric Epilepsy Surgery: The Non-Invasive Pre-Surgical Evaluation.

Background Drug-resistant epilepsy (DRE) is a debilitating condition that afflicts individuals across all demographics, including children. The only recourse for many of these individuals is neurosurgery to reduce seizure burden, either by resecting or ablating the cerebral source or modulating it with a stimulator device. In either case, a thorough pre-surgical evaluation is required to identify brain regions of interest and construct an appropriate surgical plan. The scope of this evaluation has grown rapidly over the years as new and refined techniques have emerged. The aim of this article is to condense the most salient points regarding investigational tools used commonly in this process and provide a framework from which epilepsy management providers can tailor their own epilepsy surgery pathway. Summary This article will discuss criteria to identify appropriate candidates for epilepsy surgery, as well as various techniques that are used to localize seizure onset, interictally active areas, dysfunctional regions, and eloquent cortex. Topics reviewed include neuroimaging (MRI, PET, SPECT), electrophysiology (EEG and MEG), and functional mapping procedures (fMRI, TMS, neuropsychologic evaluation, intracarotid amobarbital test). Key Messages A comprehensive, multi-modal pre-surgical evaluation including imaging, electrophysiology, and functional mapping is essential to establish the bounds of the epileptogenic zone in relation to eloquent cortex. Abbreviations: electro-encephalogram (EEG), magneto-encephalogram (MEG), positron emission tomography scan (PET), single photon emission computed tomography (SPECT), functional magnetic resonance imaging (fMRI), transcranial magnetic stimulation (TMS).