Abstracts

Rationale: The effect of the responsive neurostimulator (RNS) on mood has only been investigated with regards to depression. No concrete data exists on its effect on anxiety. Thus, the objective of this study was to evaluate the impact of RNS implantation on anxiety. Methods: Retrospective review of patients implanted at Emory University with RNS from November 2004 to May 2018 was performed. Patient demographics, disease and implantation characteristics, as well as longitudinal anxiety scores (Beck's anxiety inventory: BAI) were collected. Results: Thirty-five patients (63% female, mean age 39 years) were included in the study. They suffered from medication refractory epilepsy (preoperative mean AED burden of 2.7) for an average of 18 years with a mean baseline seizure frequency of 6.4 seizures/month. 1/5 underwent prior VNS implantation and 1/4 had prior surgery. 48% had preexisting anxiety and 83% preexisting depression. RNS was implanted for an average of 23 months in bilateral mesial temporal regions in 40% of patients, unilateral mesial temporal region in 29% of patients and in a combination of mesial temporal plus thalamic and neocortical locations in the remainder. The cumulative median seizure frequency reduction and responder rate was -54%. The mean preoperative BAI score was 13. At 6 months, 7/13 (54%) patients with available data had worse BAI scores, but the mean BAI score was 12 and the mean change from baseline was -1. At 12 months, 6/14 (43%) patients with available data had worse BAI scores, but the mean BAI score was 8 and the mean change from baseline was -2. There was no de novo diagnosis of psychopathology post implantation and only 1 patient was started on psychiatric medications postoperatively. Male patients were most likely to exhibit worsening of their BAI scores, both at 6 and at 12 months (Fischer’s exact test, p=0.005 and p=0.03 respectively). Otherwise, post implantation worsening of anxiety was not associated with any additional parameter, including other demographic or epilepsy related variables, preexisting psychopathology or neurostimulation location and response. Conclusions: Responsive neurostimulation (RNS) does not appear to have an overall negative impact on anxiety. Yet, male gender may be a risk factor for worsening anxiety. Further longitudinal studies are required to better elucidate the effect of RNS on anxiety. Funding: No funding