强迫症患者脑内环路磁共振波谱成像研究

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

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。

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.