Abstracts

Rationale: We sought to extend our previous study of vagus nerve stimulation (VNS) effects on mood and anxiety in patients with epilepsy. Methods: Mood and anxiety was assessed before (Time 1) and 3 months after initiating a vagus nerve stimulation (Time 2) in forty intractable epilepsy patients. A matched control group of twenty adult seizure patients on stable antiepileptic drugs was employed. In thirty VNS patients and all controls the mood and anxiety scales used were the Cornell Dysthymia Rating Scale (CDRS), the Hamilton Depression and Anxiety Scales (Ham-D and Ham-A), the Beck Depression Index (BDI), the Profile of Mood States (POMS) and the State-Trait Anxiety Index (STAI-TRAI). Ten additional VNS patients were tested only with the BDI. Statistics used were two-factor repeated measures ANOVA for between group analysis, paired-samples t-test for within group analysis and Pearson Bivariate Test for correlation. Results: Between groups: There were no significant differences in mood and anxiety scales between the groups at Time 1. Significant differences in seizure frequency were present in the VNS group (improved) compared to the control group at Time 2. Within groups: In the VNS group, significant changes in scales across time (improvement) were seen in CDRS (p=.001), Ham-D (p=.025), BDI (p=.024), TRAI (p=.011) and tension-anxiety category of the POMS (p=.005). There were no correlations between improved scale scores and changes in seizures rates. There were no changes in the control groups. Discussion: These results continue to support the beneficial effect on VNS on mood and anxiety in epilepsy patients, independent on its antiepileptic effect.