title: Decreased thalamic blood flow in obsessive-compulsive disorder patients responding to fluvoxamine.
abstract: Functional imaging studies have pointed to a role of the orbitofrontal cortex (OFC), striatum and thalamus in the pathophysiology of obsessive-compulsive disorder (OCD). Effective treatment has been found to change brain activity within this circuitry. The aim of the present study was to explore possible differential effects of OCD responders and non-responders to drug treatment on the regional cerebral blood flow (rCBF). Measurements of rCBF were carried out in 15 out of 22 patients with OCD who completed an open-label trial with fluvoxamine. Patients were studied with 99mTc-HMPAO single photon emission computed tomography (SPECT) before and after 12 weeks of treatment. In addition, structural magnetic resonance imaging was obtained on all patients. Regions of interest comprised the OFC, caudate nucleus, putamen and thalamus. Seven patients responded to treatment. Levels of rCBF decreased significantly in the left caudate nucleus and the left and right putamen in both responders and non-responders to treatment. In responders, but not in non-responders, a significant decrease in rCBF was found in the right thalamus. Pre-treatment cerebellar and whole brain HMPAO uptake was significantly higher in responders to treatment compared with non-responders. We suggest that the thalamus plays a central role in the response to drug treatment.
authors.affiliation: Rudolf Magnus Institute of Neuroscience, Department of Psychiatry, Heidelberglaan 100, 3584 CX Utrecht, The Netherlands.
authors.forename: Kamini L
authors.initials: KL
authors.lastname: Ho Pian
authors.forename: Harold J G M
authors.initials: HJ
authors.lastname: van Megen
authors.forename: Nick F
authors.initials: NF
authors.lastname: Ramsey
authors.forename: René
authors.initials: R
authors.lastname: Mandl
authors.forename: Peter P
authors.initials: PP
authors.lastname: van Rijk
authors.forename: H J
authors.initials: HJ
authors.lastname: Wynne
authors.forename: Herman G M
authors.initials: HG
authors.lastname: Westenberg
mesh_terms: D000293:Adolescent; D000328:Adult; D002560:Cerebrovascular Circulation / Q000502:physiology; D005260:Female; D016666:Fluvoxamine / Q000627:therapeutic use*; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D009771:Obsessive-Compulsive Disorder / Q000188:drug therapy* / Q000503:physiopathology*; D012039:Regional Blood Flow / Q000502:physiology; D017367:Selective Serotonin Reuptake Inhibitors / Q000627:therapeutic use*; D013788:Thalamus / Q000033:anatomy & histology / Q000098:blood supply* / Q000503:physiopathology*; D015899:Tomography, Emission-Computed, Single-Photon
chemical_list: D016666:Fluvoxamine; D017367:Selective Serotonin Reuptake Inhibitors