Cyclic versus continuous deep brain stimulation in patients with obsessive compulsive disorder: A randomized controlled trial

Background: Deep brain stimulation (DBS) of the ventral anterior limb of the internal capsule (vALIC) is effective for refractory obsessive-compulsive disorder (OCD), but patients typically require high stimulation voltages and DBS comes with a risk for adverse events (AE). Objective: The aim of the present study was to advance DBS for OCD by optimizing energy efficiency and minimize adverse events using a cyclic form of stimulation Methods: This double blind, randomized crossover trial compares 2 weeks of continuous versus cyclic DBS (0.1 s ON, 0.2 s OFF) in 16 patients with OCD. We compared OCD symptoms (Yale-Brown Obsessive-Compulsive Scale, Y-BOCS), Hamilton Depression Rating Scale (HAM-D), Hamilton Anxiety Scale (HAM-A), AEs, battery life, cognitive performance and quality of life. Results: Average Y-BOCS scores at baseline increased significantly with 5.5 points (p = 0.006) in the cyclic condition. Average HAM-D and HAM-A scores increased with 2.2 (p = 0.088) and 2.8 points (p = 0.018). The overall health scale of quality of life worsened during cyclic DBS (p = 0.044). Patients reported on average 3.3 AEs during continuous stimulation and 4.4 AEs during cyclic stimulation (p = 0.175), though stimulation-related AEs such as headache and concentration problems reduced during cyclic DBS. Battery usage during continuous DBS was 0.021 V per hour compared to 0.008 V per hour during cyclic DBS. Conclusion: Though specific stimulation-related AEs improved, cyclic stimulation (0.1 s ON, 0.2 s OFF) comes with a high relapse risk in patients with DBS for OCD. Cyclic DBS is no alternative for standard DBS treatment, but applicable in case of debilitating AEs.