Résumé
Objective To approach potential abnormalities of neuro-chemical compounds in cerebrum of obsessive-compulsive disorder and to analyze the relationship among the abnormalities with duration of illness and symptom severity. Methods 19 patients with obsessive-compulsive disorder and 22 comparison subjects were scanned by 1H magnetic resonance spectroscopy to exam bilateral prefrontal lobe, temporal lobe, parietal lobe, occipital lobe, anterior cingutate and caudate nucleus, hippocampus as well as splenium and genu of corpus callosum,thalamus. The ratios of N-acetylaspartate (NAA) and choline (Cho) to creatine (Cr) were respectively recorded.The severities of obsessive-compulsive symptoms were assessed by Yale-Brown Obsessive-Compulsive Scale. Results ( 1 ) The ratios of NAA/Cr in right caudate nucleus and left hippocampus were higher than those in normal controls (1.23 ±0.37 vs 1.0 ±0.33, t=2.14, P=0.039;1.34 ±0.25 vs 1. 10 ±0.45, t=2.41, P=0.021 ), but NAA/Cr ratios in genu of corpus callosum were lower(0. 97 ±0.30 vs 1.19 ± 0. 26, t = -2.47, P= 0.018 ).(2) The Cho/Cr ratios in right caudate nucleus and left temporal lobe were higher than those in control groups (1.09±0.51 vs0. 67±0.21,t=3.32, P=0.003;2.58±0.62vs0.84±0.17, t=2.21,P=0.03). (3) The duration of illness was negatively correlated with the Cho/Cr ratios of right prefrontal lobe ( r = - 0. 507, P =0. 027 ). (4) The NAA/Cr ratios of genu of corpus callosum as well as the Cho/Cr ratios of left temporal lobe were negatively correlated with YBOCS score ( r 1 = - 0.457, P = 0.049; r 2 = - 0. 585, P = 0.009 ). Conclusion Neuronal functions increase in right caudate nucleus and left hippocampus which are opposite in genu of corpus callosum. These abnormalities may play an important role in pathogenesis of OCD.