Abstracts

Rationale: We investigated the prevalence of post-epilepsy surgery de novo psychogenic nonepileptic seizures (PNES) in patients with drug-resistant epilepsy and possible influence of risk factors on these seizures. Methods: In this retrospective study, we examined data from all patients with a clinical diagnosis of drug-resistant epilepsy who underwent epilepsy surgery at Jefferson Comprehensive Epilepsy Center between 1986 and 2014 and had a minimum of 2-year postoperative follow-up. Postsurgical outcome was identified. Diagnosis of PNES was verified in the epilepsy monitoring unit with ictal recording. Potential associated factors were assessed comparing patients with or without postoperative PNES. Results: Nine-hundred twenty-two patients were studied. Sixteen patients (1.7%) had PNES. A full scale IQ below 80 was significantly associated with post-epilepsy surgery de novo PNES (odds ratio: 5.2; p = 0.002; 95% confidence interval: 1.86-14.48). A history of preoperative psychiatric problems was also significantly associated with post-epilepsy surgery de novo PNES (odds ratio: 4.2; p =0.02; 95% confidence interval: 1.16-15.17). Other factors were not significantly associated with post-epilepsy surgery de novo PNES in our study. Conclusions: Post-epilepsy surgery de novo PNES are not common, but they exist and should be taken into consideration. Potential risk factors associated with the development of such seizures include a full scale IQ below 80, a history of psychiatric problems preoperatively, and probably a female gender (not supported in our study). The nature of any potential neuro-psycho-biological link between brain lesion, surgery and PNES is not clear and deserves further investigation. Funding: None.