Background: In recent years, a large number of neuroimaging studies found that the Cortico-Striato- Thalamo-Cortical circuit (CSTC), including the prefrontal lobe, a significant part of CSTC, has disturbance metabolically in patients with Obsessive-Compulsive Disorder (OCD).
Aim: Explore the correlation between the neuro-metabolic features and clinical characteristics of OCD patients using magnetic resonance spectroscopy technology.
Methods: 88 patients with OCD who were not received medication and outpatient treatment for 8 weeks and 76 health controls were enrolled, there was no significant difference in gender, age or education level between the two groups. SIEMENS 3.0T MRI scanner was used to measure the spectral wave of Orbito Frontal Cortex (OFC) and Anterior Cingulate Cortex (ACC) of participants, setting mega-press sequences. Meanwhile, the concentrations of gamma-aminobutyric acid (GABA), glutamine/glutamate complex (Glx) and N-Acetyl Aspartate (NAA) were measured relative to concentration of water, on the ACC and OFC of participants, for statistical analysis via LC model version 6.3 software. The concentration of metabolic substances of the OCD group compared to the healthy control group was analyzed using two sample t-test. The correlation between substance concentration and scores on the scales, including Yale-Brown Obsessive Compulsive Scale (Y-BOCS), Hamilton Anxiety scale (HAMA) and Hamilton Depression scale (HAMD) was carried out using the Pearson correlation method.
Results: Compared with healthy controls, the GABA/W and NAA/W concentration in individuals with OCD are significantly decreased (p=0.031, t=2.193, p=0.002, t=3.223). Also, the concentration of GABA/W had a trend of decrease in the ACC. The GABA/W of the OFC had a negative correlation with Y-BOCS-O, Y-BOCS-C and Y-BOCS-T scores (p=0.037, r=0.221; p=0.007, r=0.283; p=0.014, r=0.259).
Conclusions: These results support that GABA concentration in the OFC area of patients with OCD is significantly decreased and the concentration in the ACC has a trend of decreasing. All of these indicate that there is a relationship between the GABA concentration and the psychopathology of OCD.
背景: 近年来, 大量的神经影像学研究发现强迫症（obsessive-compulsive disorder，OCD）在皮层- 纹状体-丘脑- 皮层（cortico-striato-thalamo-cortical，CSTC）环路存在代谢方面的异常，前额叶是CSTC 环路的重要脑区。.
目的: 本研究采用磁共振波谱技术研究OCD 患者前额叶神经代谢的特点及其与临床特征之间的关系。.
方法: 研究入组未用药（8 周及以上）的OCD 患者 78 例以及76 例健康对，性别、年龄及受教育年限无统计学差异。采用3.0 T 西门子磁共振扫描仪分别收集眶额回（orbito frontal cortex，OFC） 及前扣带回（anterior cingulate cortex，ACC）部位的磁共振波谱数据， 采集序列为mega-press 序列， 基于LCmodel 6.3 的分析方法得到OFC 及ACC 部位的γ- 氨基丁酸（gamma-aminobutyric acid，GABA）、谷氨酸复合物（glutamine/glutamate，Glx） 及N- 乙酰天门冬氨酸（NAA）比水的相对浓度进行统计分析；采用两样本t检验分析OCD 组与健康对照组代谢物质浓度的差异，基于Pearson 相关分析的方法，分析相关的代谢物质浓度与耶鲁- 布朗强迫量表（Y-BOCS），汉密尔顿焦虑、抑郁量表（HAMA、HAMD）得分的相关性。.
结果: 与健康对照组相比，OCD 患者OFC 部位的 GABA/W、NAA/W 显著减少（p=0.031，t=-2.193； p=0.002，t=-3.223）；ACC 部位的GABA/W 有减少趋势（p=0.059，t=-1.921）。 OFC 部位的GABA/W 与耶鲁-布朗强迫思维、行为及强迫总分（Y-BOCS-O、Y-BOCS-C、 Y-BOCS-T） 负相关（p=0.037，r=-0.221；p=0.007， r=-0.283；p=0.014，r=-0.259）。.
结论: OCD 患者OFC 部位的GABA 相对水平存在显著减少，ACC 存在减少趋势，且与临床症状相关，提示 GABA 与OCD 精神病理相关。.
Keywords: China; anterior cingulate cortex; gamma-aminobutyric acid; magnetic resonance spectroscopy; obsessive-compulsive disorder; orbitofrontal cortex.