Introduction: Pediatric epilepsy has profound developmental and social implications. Cavernoma-related epilepsy is highly treatable with surgery (1). We describe a patient with a right infrasylvian cavernoma and a multimodal evaluation falsely lateralizing to the contralateral hemisphere.
Methods: Patient TM first had an episode of confusion at age 12 where he noted things “sounded funny.” Magnetic Resonance Imaging (MRI) identified a right temporal cavernoma. Video EEG captured partial seizures in the left temporal head region. His first type consisted of an auditory aura in both ears and headache. The second was described as staring off with automatic motor behaviors. Seizures were refractory to anti-epileptic medication treatment.
Results: Repeat MRI showed no change in the cavernoma, although there was increased intensity in the left anterior temporal lobe. F-18 fluorodeoxyglucose - Positron Emission Tomography (FDG-PET) identified focal hypometabolism corresponding to the right cavernoma, as well as left temporal hypometabolism. Ictal and interictal Single-Photon Emission Computed Tomography (SPECT) demonstrated focal hypoperfusion corresponding to the cavernoma, as well as hyperperfusion of the left temporal lobe on the ictal images. Subtraction ictal SPECT co-registered to MRI (SISCOM) confirmed a prominent perfusion abnormality in the left temporal lobe with more subtle abnormal perfusion in the cavernoma. Magnetoencephalography (MEG) showed spike sources around the cavernoma, but also in the left anterior temporal region. Multidisciplinary surgical conference was held and recommended a right intra-sylvian cavernoma lesionectomy. Surgical resection was performed, rendering TM seizure free on phenytoin and rufinamide.
Conclusions: Given the location of the cavernoma in the temporal operculum, the discordance in the Phase I results was especially unique. TM likely had bilateral independent epileptogenic foci, but the cavernoma triggered his habitual seizures. Given the high epileptogenicity surrounding cavernomas, the recommendation of resection with intraoperative electrocorticography can be safely undertaken, with an alternate option being well-placed depth electrodes and/or subdural grids (2).
Patient Care: This case report emphasizes a multidisciplinary approach to better characterize falsely lateralizing lesions and helps to guide treatment either for immediate lesionectomy or intradural grid and/or depth electrode placement.
Learning Objectives: By the conclusion of this session, participants should be able to: 1) Describe the importance of a comprehensive multidisciplinary approach to epilepsy, 2) Discuss, in small groups, the risks and benefits of proceeding directly to lesion resection versus surgically placed grids/depth electrodes, 3) Identify an effective treatment for falsely lateralizing epileptogenic cavernomas.
References: 1. Rosenow F, Alonso-Vanegas MA, Baumgartner C, Blümcke I, Carreño M, Gizewski ER et al.; Surgical Task Force, Commission on Therapeutic Strategies of the ILAE. Cavernoma-related epilepsy: review and recommendations for management--report of the Surgical Task Force of the ILAE Commission on Therapeutic Strategies. Epilepsia. 2013 Dec;54(12):2025-35.
2. Eisenschenk S, Gilmore RL, Cibula JE, Roper SN. Lateralization of temporal lobe foci: depth versus subdural electrodes. Clin Neurophysiol. 2001 May;112(5):836-44.