Abstracts

Rationale: Epilepsy developing from a genetic basis has been hypothesized for decades. Despite abundant data showing an increased risk of seizures with epilepsy family history and a known difference of response to antiepileptic medications in genetic syndromes, the relationship between genetic basis and post-epilepsy surgery outcomes remains unknown (Lennox WG, The genetics of epilepsy Am J Psychiatry 1947;103:457-62). Postoperative seizure recurrence in some cases may be related to a newly matured epileptogenic focus driven by a genetic etiology. We aim to analyze the influence of a positive epilepsy family history as a genetic factor on the surgical outcomes. Methods: We retrospectively collected clinical characteristics of post-epilepsy surgery patients at the Cleveland Clinic between January 2009 and December 2012. Family history in a first degree relative was taken as a surrogate marker for a genetic etiology of epilepsy. Details regarding family history of febrile seizures, specifics of surgery and seizure recurrence at follow-up were gathered. Using jmp statistical software, Kaplan Meier survival curves comparing post-operative seizure recurrence between patients with positive and negative family history, followed by a subgroup analysis dichotomizing for temporal versus extra-temporal resection. Results: 226 patients were included. The baseline characteristics showed no significant differences between the two groups (table 1). The survival analysis could not show a significant difference in the rate of seizure recurrence in patients with and without a positive family history (p=0.15; figure 1). Also there was no significant difference regarding age of onset and pre-operative seizure frequency between the two groups (table 1). A subgroup analysis of temporal resections survival curves showed a slightly higher seizure recurrence in patients with a positive family history (p= 0.09; figure 1). In patients who had undergone extra-temporal epilepsy surgery a one-way ANOVA showed that a positive family history of epilepsy correlated with a higher number of preoperative ictal patterns on EEG (p=0.02). In the subgroup of frontal lobe resections, epilepsy duration showed some correlation with a positive family history (p=0.09). There was no significant difference between lesional and non-lesional MRI in patients who had a positive family history of epilepsy (p=0.9). Conclusions: There was a tendency for worse epilepsy surgery outcomes in patients with a positive family history, more so in the temporal resections group, however the results did not reach statistical significance, possibly due to the low number of patients with a positive family history. In the extra-temporal resection group, patients with a positive family history had a higher number of ictal patterns of presentation suggesting a difficult to localize and control epileptogenic focus. The observed correlations warrant further exploration of potential genetic mechanisms of post operative seizure outcomes particularly in the era of "personalized medicine" with increasing stress on the correlation of genetics with treatment options. Future larger scale studies are needed to confirm these finding and explore their significance. Funding: No funding disclosures