不同戒断期海洛因依赖者脑改变研究

Research of brain change in heroin-addicted subjects at different abstinence time

目的应用功能磁共振(function magnetic resonance imaging,f MRI)与扩散张量成像(diffusion tensor imaging,DTI)研究不同戒断期海洛因依赖者脑改变。方法将37名海洛因成瘾者分为长期戒断组(19)与短期戒断组(18),成瘾者与17名健康志愿者进行功能磁共振扫描与扩散张量成像,扫描过程中要求观看相关线索图与中性控制图片。分析脑激活情况及胼胝体膝部与压部、双侧额叶的部分各向异性(fractional anisotropy,FA)与表观扩散系数(apparent diffusion coefficient,ADC)值变化。结果短期组在海洛因相关线索诱导下(与中性线索相比)激活了枕叶(BA 19,37,39),颞叶(BA 19,21,39)、海马,楔叶、顶叶、后扣带回(BA 23,29,30)及小脑等广泛脑区。长期组激活了枕叶(BA 19),颞叶(BA 21)及海马等脑区,减弱激活的脑区包括额叶(BA 6,8,9),楔叶、舌回(BA 27)、后扣带回、背侧纹状体、岛叶及小脑等。长期组胼胝体压部FA值高于短期组(P<0.05);短期组左侧额叶FA值低于长期组(P<0.05);两组ADC值无明显统计学差异。结论长短期海洛因戒断人员脑功能及脑白质结构不同。

Objective To investigate and compare the brain change in heroin-addicted subjects at different abstinence time using function magnetic imaging（ f MRI） and diffusion tensor imaging（ DTI）. Methods We performed f MRI and DTI in 35 currently abstinent heroin abusers who were divided into long-term abstinent group（ n = 17） and short-term abstinent group（ n = 18）,and 17 healthy volunteers. Measurements of fractional anisotropy and ADC of the identified regions（ genu and splenium of corpus callosum,bilateral frontal lobe） were obtained from all subjects. Results（ 1） In the short-term group,greater activation was found in response to heroin cues compared to control cues in occipital（ BA 19 /37 /39）,temporal（ BA 21）,parietal（ BA 7 /31）,hippocampus,posterior cingulate（ BA 23 /29） and Cerebellum cortical regions.（ 2） In contrast,activations in occipital（ BA19）,temporal（ BA21）,hippocampus and deactivations in frontal（ BA 6 /8 /9）,posterior cingulate（ BA 23 /29）,dorsal striatum and insula were observed in the long-term group.（ 3） The fractional anisotropy at callosal splenium in the long-term group was higher than that in the short-term group（ P〈0. 05）. The fractional anisotropy at left prefrontal cortex in the short-term group was higher than that in the long-term group（ P〈0. 05）. No significant difference in ADC was found among the three groups. Conclusion Heroin abuse appears to alter brain function and white matter microstructure differentially in long-term and short-term abstinent heroin addicts.