No Impact of Deep Brain Stimulation on Fear-Potentiated Startle in Obsessiveâ€“Compulsive Disorder

Johanna M P Baas,Damiaan Denys,Mariska H Mantione,Nienke C Vulink,P Richard Schuurman,Ali Mazaheri,Floris Klumpers,Martijn Figee

doi:10.3389/fnbeh.2014.00305

Abstract

Deep brain stimulation (DBS) of the ventral internal capsule is effective in treating therapy refractory obsessive–compulsive disorder (OCD). Given the close proximity of the stimulation site to the stria terminalis (BNST), we hypothesized that the striking decrease in anxiety symptoms following DBS could be the result of the modulation of contextual anxiety. However, the effect of DBS in this region on contextual anxiety is as of yet unknown. Thus, the current study investigated the effect of DBS on contextual anxiety in an experimental threat of shock paradigm. Eight patients with DBS treatment for severe OCD were tested in a double-blind crossover design with randomly assigned 2-week periods of active and sham stimulation. DBS resulted in significant decrease of obsessive–compulsive symptoms, anxiety, and depression. However, even though the threat manipulation resulted in a clear context-potentiated startle effect, none of the parameters derived from the startle recordings was modulated by the DBS. This suggests that DBS in the ventral internal capsule is effective in treating anxiety symptoms of OCD without modulating the startle circuitry. We hypothesize that the anxiety symptoms present in OCD are likely distinct from the pathological brain circuits in defensive states of other anxiety disorders.

Highlights

Obsessive–Compulsive Disorder (OCD) is an anxiety disorder characterized by persistent thoughts and repetitive ritualistic behaviors
Deep brain stimulation (DBS) is effective in patients with treatment-refractory obsessive–compulsive disorder (OCD) when aimed at the anterior limb of the internal capsule, the ventral striatum, the nucleus accumbens (NAcc), or the subthalamic nucleus (Nuttin et al, 1999, 2003; Sturm et al, 2003; Abelson et al, 2005; Greenberg et al, 2006, 2010; Mallet et al, 2008)
The current study investigated if the reduction in anxiety experienced by DBS treatment in OCD patients is dependent on changes in the basic defense systems in the brain indexed by fearpotentiated startle (FPS)

Summary

Introduction

Obsessive–Compulsive Disorder (OCD) is an anxiety disorder characterized by persistent thoughts (obsessions) and repetitive ritualistic behaviors (compulsions). DBS is effective in patients with treatment-refractory OCD when aimed at the anterior limb of the internal capsule, the ventral striatum, the nucleus accumbens (NAcc), or the subthalamic nucleus (Nuttin et al, 1999, 2003; Sturm et al, 2003; Abelson et al, 2005; Greenberg et al, 2006, 2010; Mallet et al, 2008). In a controlled trial (Denys et al, 2010), it was shown that bilateral stimulation targeted at the NAcc, with the active points of stimulation in the ventral part of the anterior internal capsule just adjacent to the accumbens (van den Munckhof et al, 2013) can be an effective treatment in highly refractory OCD patients

Methods

Results

Conclusion