运用扩散张量成像技术初步探讨脑深部电极刺激治疗难治性强迫症的治疗机理

目的运用DTI技术比较7例难治性强迫症患者术前和术后脑白质的改变来探讨内囊前肢脑深部电极刺激的治疗机理。方法7例接受内囊前肢脑深部电极刺激手术的难治性强迫症患者术前和术后分别行3T MRI和DTI检查,进行以体素为基础的部分各向异性(FA)和平均扩散率(MD)值比较,并进行配对t检验。结果在双侧额叶前部、内囊前肢、桥脑前上部和扣带回前部发现了明显的FA值下降和MD值增高,除了扣带回的MD值外其余部位的数值改变均具有统计学意义。结论深部脑电极刺激可能是通过破坏扣带回和额部的白质纤维素来达到治疗目的的。

Investigation on the mechanism of deep brain stimulation in treatment-resistant obsessive-compulsive disorder by diffusion tensor imaging: a preliminary study

Objective To investigate the white matter abnormalities in patients with treatment-resistant obsessive-compulsive disorder (OCD) by comparing the diffusion tensor images before and after operation, and try to make further understanding of the mechanism of deep brain stimulation of the anterior limb of internal capsule. Methods Seven adult patients received the deep brain stimulation in the anterior limb of interal capsules and underwent MR examination pre- and post-operation respectively on a 3.0T MR scanner. A voxel-based region of interest based analysis was performed for the mean diffusion (MD) and fractional anisotropy (FA) value in various white matter locations in the brain. A paired-t test statistics was performed for these parameters comparing the pre and post images. Results There was significant reduction in FA and increasing in MD in the frontal lobe, anterior limb of internal capsular, cerebral peduncle, and anterior cingulate. Statistically significant changes were found in all the regions except the MD in the anterior cingulated. Conclusion These evidences suggest that the mechanism of deep brain stimulation in treating treatment-resistant OCD may be related to destroying the function of fibers in the frontal lobes and cingulates fasciculus.