___ Neurological Disorders: Obsessive-compulsive disorder ___

Obsessive-compulsive disorder - Brain Regions and their Dysfunctions

Obsessive-compulsive disorder "It can be assumed that several malfunctioning processes are altered within the OCD: 1) error recognition; and, 2) emotion and motivation. (...) Functional imaging research in humans has shown an increased functional activity in the OFC, ACC, head of the caudate nucleus and thalamus in OCD patients. (...) Observations are suggestive of the responsibility of 5HT neurotransmission in the dysfunction of the frontal-subcortical loops that emanate from the OFC and ACC. However, several lines of research suggest that the dopamine system, with which 5HT interacts, may play a major role in the expression of OC symptoms." S "During a 'stop' task, (adolescent boys) with OCD showed reduced activation in right orbitofrontal cortex, thalamus and basal ganglia; inhibition failure elicited mesial frontal underactivation. Task switching and interference inhibition were associated with attenuated activation in frontal, temporoparietal and cerebellar regions." S "We detected significant reduction of GM (gray matter) in the inferior frontal gyrus, the medial frontal gyrus, the insula, the cingulate gyrus, and the superior temporal gyrus of OCD patients. A significant increase in GM density was observed in the postcentral gyrus, the thalamus, and the putamen." S "In patients with OCD, structural and volumetric abnormalities have been identified (...) both in the prefrontal region and in the basal ganglia (striatum, thalamus, amygdala). The dysfunction of these regions (...) can be described as dopaminergic hyperfunction in the PFC and serotonergic hypofunction in the basal ganglia. The dysfunction of the so-called 'cortico-striato-thalamic' loops is strongly linked to the symptoms of OCD, where the dopamine is the most dominant neurotransmitter." S
Affected Region	Dysfunctions
Postcentral gyrus	"Patients with obsessions/checking rituals showed severer memory deficits and decreased activity in the postcentral gyrus than patients with cleanliness/washing rituals." S Significant increase in gray matter density in the postcentral gyrus S
Cuneus	Greater activation in the cuneus during a two-back task S
Insular lobe	Greater activation in the left insula during a two-back task S Significant reduction of gray matter in the insula S
Orbitofrontal Cortex	Increased functional activity in the OFC S Reduced activation in right orbitofrontal cortex during a 'stop' task in adolescent boys S "Right orbitofrontal cortex activity showed a significant positive correlation with Y-BOCS scores in OCD. S
Dorsolateral PFC	Greater activation in the right dorsolateral prefrontal cortex during a two-back task S
Temporal lobe	Greater activation in the left superior temporal gyrus during a two-back task S Significant reduction of gray matter in the superior temporal gyrus S
Hippocampus	The mean left and right hippocampal volumes of patients with refractory OCD were smaller. OCD severity was related to the left hippocampus. Duration of illness was correlated with the hippocampus. S
Amygdala	The mean amygdala volumes of patients with refractory OCD were smaller. OCD severity was not correlated with amygdala volumes. Duration of illness was correlated with the left amygdala. S
Anterior Cingulate Cortex	Increased functional activity in the ACC S Significant reduction of gray matter in the cingulate gyrus S Right-sided high-frequency stimulation via a lead placed in the anterior limb of the internal capsule was associated with activation of the ACC S
Basal ganglia	Reduced activation in the basal ganglia during a 'stop' task in adolescent boys S Serotonergic hypofunction in the basal ganglia S
Caudate nucleus	Increased functional activity in the head of the caudate nucleus S Right-sided high-frequency stimulation via a lead placed in the anterior limb of the internal capsule was associated with activation of the ipsilateral head of the caudate S
Putamen	Significant increase in gray matter density in the putamen S
Thalamus	Increased functional activity in the thalamus S Reduced activation in the thalamus during a 'stop' task in adolescent boys S Significant increase in gray matter density in the thalamus S Right-sided high-frequency stimulation via a lead placed in the anterior limb of the internal capsule was associated with activation of the medial thalamus S Hyperactive cortico-striato-thalamic loops S
Cerebellum	Right-sided high-frequency stimulation via a lead placed in the anterior limb of the internal capsule was associated with activation of the contralateral cerebellum S

External Link Disclaimer: We as the creators of Brain-Maps.com are not responsible for the contents or reliability of any linked websites and do not necessarily endorse the views expressed within them. The listing of a link shall not be taken as endorsement of any kind. We cannot guarantee that these links will work all of the time and we have no control over the availability of linked pages.

Please note: While we as the creators of Brain-Maps.com make every effort to post the most accurate and reliable information, we do not guarantee or warrant that the information on this web site is complete, accurate or up-to-date. We assume no responsibility for the use or application of any posted material. This web site is intended solely for the purpose of electronically providing both the public and scientists with brain-related information and convenient access to the data resources. We assume no responsibility for any error, omissions or other discrepancies between the electronic and printed versions of documents.

We do not provide individual advice or counseling, whether medical, legal, or otherwise. If you are seeking specific advice or counseling, you should contact a licensed medical practitioner or professional. For comments, corrections or suggestions please send us an e-mail »