Abstracts

Rationale: For medically intractable focal epilepsy, resection of the epileptogenic lesion is the standard of care for many patients due to its superior efficacy. In most institutions, an epilepsy surgery conference is held prior to surgical intervention with repeated review (re-review) of the semiology, neuroimaging and electrophysiological data. The goal of this study was to assess how often radiologic re-review at surgical epilepsy conference resulted in a change in the interpretation of the head MRI.Methods: Charts were reviewed for 239 patients (all ages) who had been presented at presurgical epilepsy conference between 2010 and 2012. Surgical epilepsy conference notes, operative notes and radiology reports were reviewed. In preparation for the epilepsy surgery conference, a team of neuroradiologists with special interest in epilepsy reviewed all the radiology exams of the patients presented at the conference. The conference notes were read to determine whether the radiologist re-review found a previously unreported potentially epileptogenic lesion in the head MRI, the nature of the hypothesized lesion and its location. The findings discussed at surgical epilepsy conference were then compared with the original MRI interpretation.Results: 6 patients were excluded due to not having had MRIs performed before surgical epilepsy conference. Of the remaining 233 patients, 114 were female (48.9%). Ninety four (40.3%) underwent resective surgery. Of the 233 patients whose MRIs were re-reviewed, 41 (17.6%) had a previously undiagnosed finding, of which 18 (43.9%) underwent resective surgery. In 4 of the 41 patients (9.8%) with previously undiagnosed findings, re-review detected abnormalities that were not amenable to surgical resection (autoimmunity or significant bilateral pathology where only unilateral was originally recognized). The most common abnormalities detected at re-review were cortical dysplasia/malformation (20/41; 48.8%) followed by findings suggestive of mesial temporal sclerosis (4/41; 9.8%).Conclusions: Re-review of the radiologic data at surgical epilepsy conference had a substantial effect on patient care, with new lesions identified 17.6% of the time. It is not surprising that that a subspecialty epilepsy conference would provide unique opportunities for improved image interpretation. In the context of the semiologic and electrographic localization, the radiologist is able to make new assessments of the radiologic data. Also, the surgical epilepsy conference allows “fresh eyes” to view the radiologic data, including not only the radiologist but also other providers. It is not surprising that the most commonly reported pathology suspected in re-review was cortical dysplasia, given the radiologic subtlety of these lesions. It is important to note that in nearly 10% of cases in which re-review detected pathology beyond that described in the original interpretation, the pathology was not amenable to surgery. Re-review of head MRI data at presurgical epilepsy conference provides valuable clinical information that can impact clinical decision-making.