Heightened degree connectivity of the striatum in obsessive-compulsive disorder induced by symptom provocation

• Published in: Journal of affective disorders Vol. 276; pp. 1069 - 1076
• Main Authors: Beucke, Jan C., Simon, Daniela, Sepulcre, Jorge, Talukdar, Tanveer, Feusner, Jamie D., Kaufmann, Christian, Kathmann, Norbert
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier B.V 01-11-2020
• Subjects: Brain Mapping; Corpus Striatum - diagnostic imaging; Degree connectivity; Functional magnetic resonance imaging; Humans; Magnetic Resonance Imaging; Medicin och hälsovetenskap; Neural Pathways; Nucleus accumbens; Obsessive-compulsive disorder; Obsessive-Compulsive Disorder - diagnostic imaging; Striatum; Symptom provocation; Nucleus accumbens; Functional magnetic resonance imaging; Striatum; Degree connectivity; Obsessive-compulsive disorder; Symptom provocation
• ISSN: 0165-0327; 1573-2517; 1573-2517
• DOI: 10.1016/j.jad.2020.07.062

•Results provide the first implication of an abnormality of the nucleus accumbens (NAc, that is, the target of deep brain stimulation in OCD) during symptom provocation in OCD, using degree connectivity methods.•Previous symptom provocation studies using neuroimaging had found no abnormalities or alterations in dorsal striatum, but no NAc abnormality in OCD, despite strong deep brain stimulation evidence in OCD implicating the NAc.•Results are observed under control of medication, which respresents a major confounder in neuroimaging studies, as all participants are unmedicated.•The two patient samples are independent.
Neurosurgical intervention studies have provided direct evidence that the ventral striatum/nucleus accumbens (NAc) mediates symptoms of obsessive-compulsive disorder (OCD), yet meta-analysis of functional neuroimaging studies using symptom provocation revealed no striatal activation differences, and the existing studies reporting hyperactivity found abnormalities in dorsal but not ventral striatal subdivisions. Resting-state neuroimaging evidence holds that corticostriatal areas are more connected both locally and to distant regions, but the functional inferences to be drawn from these altered network characteristics regarding the present experience of OCD symptoms remain limited.
The present study tested whether symptom provocation induces abnormally high striatal network connectivity using two independent datasets of unmedicated patients with OCD. One study (14 patients, 14 matched controls) required passive viewing of OC-related, emotionally aversive and neutral pictures, the other (21 patients, 21 controls) involved self-referential evaluation of the same picture types, as well as distraction from these stimuli (engagement in a simple task).
Heightened local connectivity of the dorsal striatum occurred during passive viewing of briefly presented OC-related pictures in patients, however group differences were also observed in a neutral control condition. In contrast, distracted symptom provocation selectively yielded local connectivity differences of the ventral striatum, as heightened NAc connectivity to its immediate neighborhood was exclusively observed when OC-related pictures were accompanied by concurrent task demands.
Small samples sizes.
In moderately affected patients with OCD, symptom provocation induces a discrete, condition-specific network abnormality anchored in NAc, the location targeted by deep brain stimulation for refractory patients with OCD.