Cerebral Electromagnetic Research On Neuropathologic Mechanisms Of Obssesive-Compulsive Disorder

To study the neuropathologic mechanisms of ObssesiveCompulsive Disorder(OCD),this research adopted the Electroencephalogram(EEG)event related potential(ERP)technology combining Magneto-encephalography(MEG)source imaging and connectivity analysis,compared the OCD patients and healthy controls in the amplitude and latency of ERP N270 and P300,as well as the related brain magnetic source localization.13 at least 4 weeks medication-free OCD patients with a DSM-IV diagnosis of OCD and 13 well-matched healthy controls,performed a classic N270 dual-feature delayed matching task while event-related potentials and MEG signals were simultaneously recorded.From the behavioral data,we found that OCD patients had longer reaction times and lower correct response rate.The ERP results showed that the N270 latency of the OCD patients was shortened while the amplitude increased.The most significant difference between the tow groups is the increased amplitude in the task-irrelavent mismatch states of the OCD patients.The OCD patient’s amplitude of P300 was also significantly higher.From the related MEG source localization we found that,the OCD patients showed greater activation in the right dorsolateral prefrontal,right inferior frontal gyrus,anterior cingulate cortex(ACC)and bilateral posterior temporal lobe.And the right prefrontal cortex’s activation time was longer than the health controls.The above results indicated that patients with OCD had a decline in the selective attention and executive founction,the over activated prefrontal cortex and ACC may contribute to the pathogenic mechanisms underlying OCD.