Different brain areas involved in either idiopathic or acquired Obsessive Compulsive Disorder (OCD).

Abstract

Abstract Introduction: Knowledge about Obsessive Compulsive Disorder (OCD) is accumulating through neuro‐imaging research investigating involved brain circuits, most notably the CorticoStriatoThalamoCortical (CSTC) circuit. Somewhat hidden is the fact that over time many case reports have been published on acquired OCD due to neurological lesions. Although these cases may yield important insights into the neuro‐anatomy of OCD, to our knowledge they have never been reviewed. In this article, we will review all published cases of OCD due to acquired brain lesions for a bottom‐up understanding of OCD’s neuro‐anatomy. These findings may lead to a better understanding of brain areas that can be targeted with Deep Brain Stimulation (DBS). Methods: PubMed, PsychInfo, Scholar Google were used to find case reports about acquired OCD, either alone or in combination with other related basal ganglia disorders, like Huntington’s and Parkinson’s disease. This search yielded a total of 31 case reports, dated from 1988 until 2010, which contained 57 cases of acquired OCD. The age‐range was 7‐78 years. Results: In most case reports acquired OCD could be traced back to lesions of the basal ganglia and frontal lobes. Other associated areas were the temporal and parietal lobes. In addition, the occipital lobe, cerebellum and brainstem were involved in some of the cases. The described obsessive‐compulsive symptoms consisted mostly of obsessive doubts and checking, contamination fear and washing, and repetitive mental rituals. Other associated behavioral phenomena were apathy, depression and aggression. Also several OC‐spectrum disorder symptoms like tics and trichotillomania were observed. Conclusion: Lesion studies on a total of 57 patients with OCD following brain injuries confirm involvement of the cortico‐striatal circuit in OCD pathogenesis. However, additional areas seem to be involved, such as the cerebellum, parietal cortex and brainstem. These findings warrant further research into the role of these areas in OCD, particularly their potential role in DBS. Future research should also investigate the validity of the concept of ‘compulsivity’ as this more fully encompasses the obsessive compulsive symptoms found in these case reports.