Abstracts

Rationale: OBJECTIVE: To evaluate post-operative mood changes following anterior temporal lobectomy (ATL) for treatment of drug-resistant epilepsy.BACKGROUND: Mood disorders are co-morbid with drug-resistant epilepsy. Surgery offers significant seizure reduction or potentially a cure. However ATL may carry a risk for cognitive and language deficits. We aim to study the effects of ATL on mood and whether the laterality of the lobectomy predicts risk for mood changes. Methods: In total 113 patients underwent surgical intervention for ATL at the University of California Irvine (UCI) between 2015 - 2018 in this single-center retrospective study. The presence of postoperative patient reported mood symptoms (depression, anxiety, suicidal ideation) or psychosis symptoms (hallucinations, delusions, aggressive behavior) was assessed based on clinic notes and available formal neuropsychological testing at 2, 6 and 12 months. Patients were evaluated for de novo or significant mood changes requiring psychotropic medication, and or any major psychiatric events defined as seeking emergent care or inpatient psychiatric admissions for mood related issues. Results: Fifty-two patients underwent temporal lobectomy. Of these patients, thirty-nine were included in the study. Eight were excluded due inadequate follow up at UCI, including those managed by outside neurologists. Four were excluded for other surgical co-morbidities including presence of CNS tumors. One patient expired suddenly from an unrelated car accident. Follow up time ranged from 12 to 66 months with the average follow up time of 28 months. Of the thirty-nine included patients, 19 underwent left ATL and 20 underwent right ATL. In the right ATL groups, mood changes were reported in 3 (15%), 6 (30%), and 5 (25%) at 2, 6, and 12 months respectively. In the left ATL groups, mood changes were reported in 1 (5.3%), 6 (32%), and 2 (11%) at 2, 6 and 12 months respectively. One (5%) had a major psychiatric event in the right ATL group and two (11%) had major psychiatric events in the left ATL group. There were 11 (55%) and 6 (32%) who developed de novo mood changes post-surgically in the right and left ATL groups respectively. Eighteen (90%) patients in the right ATL group and sixteen (84%) in the left ATL group achieved > 70% reduction of seizures at one year follow up. Conclusions: We have identified up to 55% and 32% incidence of de novo mood disorder following right and left ATL respectively up through one year. The right ATL group had more prevalent mood changes compared to the left with a tendency to worsen at 6 months post-surgery in both groups. There was higher instance of major psychiatric events in the left ATL group, however sample size was small (p=0.52). In summary, there was no statistically significant difference in the development of de novo mood disorders between either right or left ATL groups (p=0.32, 0.92 and 0.34 at 2, 6 and 12 months respectively). This study enforces known data that post-ATL mood related issues should be addressed and suggests that counseling and aggressive treatment may be indicated in temporal lobe epilepsy patients prior to surgery in anticipation of postoperative mood impairment. Funding: No funding