Abstracts

Rationale:
Determining epilepsy surgery candidacy largely depends on the ability to lateralize and localize the epileptogenic focus. Aura semiology has been shown to have localizing value in determining the symptomatogenic zone, which often lies in close proximity to the epileptogenic zone. Given the association between aura semiology and localization, it has been assumed that multifocal auras would indicate multifocal ictal onset zones or a widespread network, making that patient a suboptimal candidate likely to experience poor post-operative outcomes. However, no study has examined the relationship between the presence of multifocal auras and surgical progression and post-operative outcome.
Method:
Charts were reviewed from patients presented at New York University Grossman School of Medicine Multidisciplinary Conference, where cases are evaluated for epilepsy surgery candidacy. Inclusion criteria included presence of focal epilepsy, age 13 or older, and presentation between 2011-2017. Exclusion criteria included prior resective epilepsy surgery, psychogenic nonepileptic seizures, nonverbal and unable to report aura, generalized epilepsy, neurodegenerative disorder, hemispherectomy, and callosotomy. Basic demographic and clinical data were collected for all patients ranging from age at presentation to lobe of resection. Aura semiologies were then classified as follows: temporal auras included olfactory, gustatory, affective, psychic, abdominal, autonomic, dysphasic, vestibular, or auditory semiologies, extratemporal auras included visual, somatosensory, and motor semiologies, and non-localizing auras included indescribable and other semiologies. Patients with aura semiologies in a single category were coded as a single, unifocal aura, and patients with aura semiologies in multiple categories were coded as having multifocal auras. The main outcome variables were progression to resection and post-operative freedom from impaired awareness seizures at one year. Chi-square, Fisher-exact, and Freeman-Halton extension were used for statistical comparisons with an alpha level of 0.05. Results757 charts were reviewed, with 394 meeting inclusion criteria. Of the patients in this study, 188 (47.7%) proceeded to a resection. Those with multifocal auras were not significantly less likely to proceed to resection than those with a single, unifocal aura or no aura (p=0.774). Among our 188 cases who underwent resection, 132 had complete follow-up data at one year. Of the 132 who proceeded to resection, 84 (63.6%) were seizure free at one year. Those with multifocal auras were not significantly less likely to be seizure free than those with a single, unifocal aura or no aura (p=0.358). Among those with multifocal auras, 26 (65%) were seizure free at one year, compared to 44 (67.7%) of those with a single, unifocal aura, and 14 (51.8%) of those with no aura. Interestingly, those with a single, unifocal aura and multifocal auras were significantly more likely to undergo temporal resection than those with no aura (p=0.030).
Conclusion:
Those with multifocal auras do not have worse outcomes compared to those with no aura or a single, unifocal aura. This may indicate that those with multifocal auras may not have multifocal ictal onsets, but rather localized ictal onset zones that are in fact amenable to resection.
Funding:
:No funding supported this abstract.