强迫症患者脑内环路磁共振波谱成像研究

目的 应用磁共振波谱成像（MRS）研究首发强迫症患者脑内环路物质代谢,探讨其发病机制.方法 对20例首发强迫症患者及20例健康志愿者行常规磁共振及三维磁共振氢质子波谱（1H-MRS）检查,测量双侧前额叶、眶额叶、尾状核头部、前扣带回、丘脑的N-乙酰天门冬氨酸（NAA）、胆碱复合物（Cho）与肌酸（Cr）的比值,对两组之间各部位的比值分别进行两独立样本t检验.结果 首发强迫症组患者丘脑的Cho/Cr比值（1.37-0.11）明显高于对照组（1.17±0.09）,差异有统计学意义（P＜0.01）;而前额叶、眶额叶、尾状核头部、前扣带回的Cho/Cr比值与对照组间差异无统计学意义（P＞0.05）.首发强迫症患者尾状核头部、丘脑的NAA/Cr分别为（1.22±0.15）、（1.22±0.11）,明显低于对照组[分别为（1.47±0.17）、（1.35±0.11）],差异有统计学意义（P＜0.01）;前扣带回、眶额叶的NAA/Cr分别为（2.92±0.15）、（2.78±0.23）,均高于对照组[分别为（2.76±0.21）、（2.57±0.18）],差异有统计学意义（P＜0.01）;而前额叶未见明显变化（P＞0.05）.结论 首发强迫症患者皮质-纹状体-丘脑-皮质环路的功能存在障碍,该神经环路在强迫症发病机制中可能起着一定的作用.

Study of neuroanatomical circuit in first-episode obsessive-compulsive disorder by magnetic resonance spectroscopy

Objective To find the characteristics of metabolic changes in neuroanatomical circuit in patients with first-episode obsessive-compulsive disorder through 1 H-MRS. Methods Twenty patients with first-episode ob- sessive-compulsive disorder （the study group） and twenty gender- and age-matched normal controls （the control group） were involved in the study. The neurochemical abnormalities including the levels of choline （Cho）/creatine （Cr）, N-acetylaspartate （NAA）/Cr were measured respectively in prefrontal lobe, anterior cingutate, orbital frontal lobe, caudate nucleus and thalamus with three-dimension 1H-proton magnetic resonance spectroscopy （3D 1H-MRS）. Results The values of Cho/Cr ratios in thalamus were significant higher in the study group than the control group （P〈0.01）, and the values of NAA/Cr in caudate nucleus, thalamus were significantly lower in the study group （P〈 0.01）, but the values of NAA/Cr in anterior cingutate, orbital frontal lobe were higher （P〈0.01）. Conclusion There are some special neurochemical and histological structure changes （cortico-striatal-thalamic-cortical cycle） in first-epi- sode obsessive-compulsive disorder. IH-MRS can find these changes through assessing the metabolic abnormalities.