title: Altered brain activation in ventral frontal-striatal regions following a 16-week pharmacotherapy in unmedicated obsessive-compulsive disorder.
abstract: Recent studies have reported that cognitive inflexibility associated with impairments in a frontal-striatal circuit and parietal region is a core cognitive deficit of obsessive-compulsive disorder (OCD). However, few studies have examined progressive changes in these regions following clinical improvement in obsessive-compulsive symptoms. To determine if treatment changes the aberrant activation pattern associated with task switching in OCD, we examined the activation patterns in brain areas after treatment. The study was conducted on 10 unmedicated OCD patients and 20 matched controls using event-related functional magnetic resonance imaging. Treatment improved the clinical symptoms measured by the Yale-Brown Obsessive Compulsive Scale and behavioral flexibility indicated by the switching cost. At baseline, OCD showed significantly less activation in the dorsal and ventral frontal-striatal circuit and parietal regions under the task-switch minus task-repeat condition compared with controls. After treatment, the neural responses in the ventral frontal-striatal circuit in OCD were partially normalized, whereas the activation deficit in dorsal frontoparietal regions that mediate shifting attention or behavioral flexibility persisted. It is suggested that altered brain activation in ventral frontal-striatal regions in OCD patients is associated with their cognitive flexibility and changes in these regions may underlie the pathophysiology of OCD.
authors.affiliation: Interdisciplinary Program in Neuroscience, Seoul National University, Seoul, Korea.
authors.forename: Ji Yeon
authors.initials: JY
authors.lastname: Han
authors.forename: Do-Hyung
authors.initials: DH
authors.lastname: Kang
authors.forename: Bon-Mi
authors.initials: BM
authors.lastname: Gu
authors.forename: Wi Hoon
authors.initials: WH
authors.lastname: Jung
authors.forename: Jung-Seok
authors.initials: JS
authors.lastname: Choi
authors.forename: Chi-Hoon
authors.initials: CH
authors.lastname: Choi
authors.forename: Joon Hwan
authors.initials: JH
authors.lastname: Jang
authors.forename: Jun Soo
authors.initials: JS
authors.lastname: Kwon
mesh_terms: D000328:Adult; D001479:Basal Ganglia / Q000378:metabolism*; D001526:Behavioral Symptoms / Q000188:drug therapy; D005260:Female; D005625:Frontal Lobe / Q000187:drug effects* / Q000503:physiopathology; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D009771:Obsessive-Compulsive Disorder / Q000188:drug therapy* / Q000503:physiopathology; D010296:Parietal Lobe / Q000187:drug effects* / Q000503:physiopathology