Language fMRI and Direct Cortical Stimulation in Epilepsy Preoperative Planning.

Ann Neurol. 2017 Feb 21;:

Authors: Austermuehle A, Cocjin J, Richard R, Agrawal S, Sepeta L, Gaillard WD, Zaghloul K, Inati S, Theodore WH

Abstract
OBJECTIVE: Presurgical language assessment can help minimize damage to eloquent cortex during resective epilepsy surgery. Two methods for presurgical language mapping are functional MRI (fMRI) and direct cortical stimulation (DCS) of implanted subdural electrodes. We compared fMRI results to DCS to help optimize non-invasive language localization and assess its validity.
METHODS: We studied 19 patients referred for presurgical evaluation of drug-resistant epilepsy. Patients completed 4 language tasks during preoperative fMRI. After subdural electrode implantation, we used DCS to localize language areas. For each stimulation site, we determined whether language positive electrode pairs intersected with significant fMRI activity clusters for language tasks.
RESULTS: Sensitivity and specificity depended on electrode ROI radii and statistical thresholding. For patients with at least one language positive stimulation site, an auditory description decision task provided the best tradeoff between sensitivity and specificity. For patients with no language positive stimulation sites, fMRI was a dependable method of excluding eloquent language processing.
INTERPRETATION: Language fMRI is an effective tool for determining language lateralization prior to electrode implantation, and is especially useful for excluding unexpected critical language areas. It can help guide subdural electrode implantation and narrow the search for eloquent cortical areas via DCS. This article is protected by copyright. All rights reserved.

PMID: 28220524 [PubMed - as supplied by publisher]