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. Objective: Optimizing energy efficiency and minimizing adverse events would advance DBS for psychiatric applications. Methods: This double blind, randomized crossover trial compares 2 weeks of continuous versus cyclic DBS (0.1 seconds ON, 0.2 seconds 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), adverse events (AE), battery life, cognitive performance and quality of life. Results: Average Y-BOCS scores at baseline increased significantly with 5.5 points (p=0.006). 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 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.