Value Of Resting-state Functional Magnetic Resonance Imaging In Repetitive Transcranial Magnetic Stimulation For Obsessive-compulsive Disorder

PurposeObsessive-compulsive disorder(OCD)is a mental disorder characterized by compulsive behavior and obsessive thinking.Its pathogenesis is not clear,and the existing drug therapies and cognitive behavioral therapy are not always effective.Repetitive transcranial magnetic stimulation(r TMS),a non-invasive neuroregulatory treatment,it has been shown to be safe and effective in the treatment of various neuropsychiatric disorders such as OCD.Resting-state functional magnetic resonance imaging(rs-f MRI)can reflect the spontaneous brain activity at rest,and has important research significance in exploring the neuropathogenesis of OCD.This study is based on rs-f MRI technology and r TMS technology,using the analytical method of functional connection(FC),to explore the neuropathogenesis of OCD and the mechanism of r TMS improving the neurological function in patients with OCD from the perspective of imaging.To understand the neural mechanism of successful treatment of r TMS,improve the understanding and treatment level of obsessive-compulsive disorder,and bring a new idea for the application of rs-f MRI and r TMS in the diagnosis and treatment of OCD.Materials and methodsIn this study,15 patients with obsessive-compulsive disorder were recruited as the OCD group and 20 healthy subjects as the healthy control group(HC),including 6 males and 9 females in the OCD group and8 males and 12 females in the HC group.Demographic information of all subjects was collected,and Yale-Brown Obsessive-Compulsive Scale(Y-BOCS)and Hamilton Anxiety Scale(Hamilton Anxiety Scale,HAMA)were applied to all patients with OCD.and the Hamilton Depression Scale(HAMD).Before treatment,all subjects in the OCD group and HC group were collected by rs-f MRI data.FC analysis was used to observe the difference of brain network connectivity in the OCD group at baseline,and Spearson correlation coefficient was used to analyze the correlation between FC intensity and clinical scale in the OCD group.Rs-f MRI data were collected again in the OCD group after r TMS treatment,and the FC changes before and after treatment were compared by paired sample t test.Spearson correlation coefficient was used to analyze the correlation between the FC changes before and after treatment and the clinical scale changes in the OCD group.ResultsThe age of the OCD group was 30.20±9.81 years old,and the education level was 16.20±2.96 years;the age of the HC group was 32.00±8.35 years old,and the education level was 15.10±4.31 years.There was no significant difference in age and education level between the two groups(P > 0.05).The Y-BOCS,HAMD and HAMA scores in the OCD group at baseline were 20.73±4.06,10.87±2.53 and 5.40±2.13,respectively,and the scores after r TMS were 10.67±1.80,3.60±1.40 and 2.67±1.45,respectively.Y-BOCS,HAMD and HAMA scores of OCD group before and after r TMS treatment were significantly different(P <0.05).Compared with HC group,FC abnormalities were found in several brain regions in the resting OCD group(corrected by GRF,P < 0.05).FC increased in the left dorsolateral prefrontal cortex(DLPFC)-left middle temporal gyrus and left inferior temporal gyrus.Reduced FC was seen between the left DLPFC-left middle frontal gyrus,left middle occipital gyrus,and right middle occipital gyrus.The FC value between left DLPFC-left middle temporal gyrus was significantly correlated with Y-BOCS score(r=0.667,P < 0.05),and the FC value between left DLPFC-left inferior temporal gyrus was significantly correlated with YBOCS score(r=0.591,P < 0.05).After 21 days of r TMS treatment,patients in the OCD group had reduced FC between left DLPFC-right inferior temporal gyrus and increased FC between left DLPFC-left middle frontal gyrus and left DLPFC-right middle occipitalic gyrus(all the above were corrected by GRF,P <0.05).The change degree of FC between left DLPFC-left middle frontal gyrus was significantly correlated with the change degree of Y-BOCS score(r=0.576,P < 0.05),and the change degree of FC between left DLPFC-right middle occipitalic gyrus was significantly correlated with the change degree of Y-BOCS score(r=0.624,P < 0.05).ConclusionCompared with the HC group,patients in the OCD group had a larger homeostasis of the brain network outside the cortex-striatum-thalamus-cortex(CSTC)circuit during resting state,such as the occipital and temporal lobes.These network imbalances may be the cause of different clinical symptoms in patients with OCD.In addition,the FC intensity between left DLPFC-left middle temporal gyrus and left inferior temporal gyrus at baseline was positively correlated with clinical scale scores,suggesting that the FC intensity between left DLPFC-left middle temporal gyrus and left inferior temporal gyrus at resting state may be a biomarker to predict the severity of clinical symptoms in patients with obsessive-compulsive disorder.After 21 days of r TMS treatment in the OCD group,the clinical symptoms were significantly improved,and the reduced FC in the left DLPFC-left middle frontal gyrus and left DLPFC-right middle occipital gyrus were significantly improved at baseline.The degree of improvement in the FC was significantly correlated with the degree of improvement in the clinical scale score.This suggests that the abnormal brain neural network in patients with obsessive-compulsive disorder has plasticity,and the altered FC before and after treatment may be the neuroregulatory mechanism of the effective treatment of OCD by rTMS.