ALTERED CORTICO-STRIATAL FUNCTIONAL CONNECTIVITY DURING RESTING STATE IN OBSESSIVE-COMPULSIVE DISORDER

Hintergrund: Neuroimaging studies show that obsessive-compulsive disorder (OCD) is characterized by an alteration of the cortico-striato-thalamo-cortical (CSTC) system [1]. As resting-state functional connectivity (FC) studies investigated only specific parts of the CSTC in patients with OCD up to now, the present study aimed at exploring FC in the CSTC as a whole. Methoden: We investigated potential alterations in resting-state FC within the CSTC system in 44 OCD patients and 40 healthy controls by taking into consideration all relevant nodes of the direct and indirect CSTC loop. Ergebnisse: Compared to healthy controls, OCD patients showed an increased FC between the left subthalamic nucleus (STN) and the left external globus pallidus (GPe), as well as an increased FC between the left GPe and the left internal globus pallidus (GPi). Diskussion: The results further support CSTC involvement in OCD pathology. However, our findings showing increased FC between relevant structures of the indirect pathway contradict the current hypothesis. The results highlight the role of the STN which is a relevant target region of deep brain stimulation (DBS) in patients with treatment-refractory OCD [2]. Hence, our findings could contribute a neurobiological framework to a better comprehension of the fundamental processes underlying DBS. Fazit: Our findings highlight the importance of the indirect pathway, especially of the STN, in OCD pathology and could introduce an altered interpretation of the classical model of the CSTC. Furthermore, the results may improve insight on DBS as a treatment for severe OCD. They could provide a basis for future investigations improving the accurate choice of DBS targets and thus increasing clinical outcome for patients as well as reducing the probability of adverse events.