Abstracts

Rationale: Psychiatric disorders (PD) represent a significant comorbidity in epilepsy, affecting 1 in 3 patients with epilepsy (PWE). PD have long been considered a consequence of epilepsy, but recent studies posit that the bidirectional association could be due to a greater dysfunction of global neural networks in PWE or shared pathogenic mechanisms. PD may be overlooked in preliminary evaluations despite their ability to exacerbate epilepsy, impair quality of life (QOL), and worsen preexisting psychiatric diagnoses (PPDx). This study aims to clarify the effect of epilepsy surgery (ES) on incidences of psychiatric comorbidity and identify potential predictors of psychiatric outcome. Accurately forecasting post-operative (PO) psychopathology is crucial to achieving a better QOL in the long-term.

Methods: A total of 18 longitudinal patients who underwent ES at the National Institutes of Health in the past 5 years were identified from our surgical database. Reviewed factors include age of onset, presence of PPDx, laterality and location of epileptogenic zone, Weschler’s Full Scale IQ, and Engel Score (ES). The QOLIE-31 (QOL in Epilepsy), NDDI-E (Neurological Disorders Depression Inventory for Epilepsy), and GAD7 (Generalized Anxiety Disorder-7) questionnaires were administered at 3 distinct timepoints: Baseline (BL), 3 Months (3M) PO, 1 year (1Y) PO. Patients were organized into limbic (LB) vs non-limbic (NL) categories based on involvement of the amygdala and hippocampus—both vital for emotional regulation. Activities of daily living such as education, employment, and driving status were evaluated with demographics. Repeated measures analysis of covariance (RM-ANCOVA) were performed to evaluate change over time.

Results: NL patients saw significant improvement in QOLIE score (p=0.0012) over time as did PWE with PPDx (p< 0.0001) who were unemployed (p=0.0066). Tukey's test showed that the Least Square-Mean (LSM) was lower at BL (PPDx group: LSM=39.3) than at follow-up (LSM=62.0 at 3M, 61.3 at 1Y). Irrespective of PPDx, there was no change in NDDI-E score over time (p=0.4633). There was significant reduction in GAD7 scores among non-driving patients (p=0.0461) with a higher LSM at BL (10.0) than at follow-up (4.9 at 3M, 2.2 at 1Y). This indicates that non-driving PWE saw a greater improvement in their anxiety.