功能磁共振对注意缺陷多动障碍儿童两半球功能连接强度的分析

Intensity of functional connection between bilateral hemispheres of children with attention-deficit hyperactivity disorder by functional magnetic resonance imaging

目的应用静息态功能磁共振成像（rs-fMRI）技术对注意缺陷多动障碍（ADHD）儿童两半球问的功能连接强度进行研究，探讨ADHD的神经机制。方法2012年10月至2014年4月对学龄期ADHD与正常儿童各31名分别进行功能磁共振成像（fMRI）扫描，采用半球间同伦（VMHC）的方法进行分析研究。结果ADHD组与正常对照组比较均显示出正激活脑区，提示其VMHC值高于正常儿童的脑区主要位于双侧前额叶（t=5．81），双侧枕叶（t=5．82），双侧小脑后叶（t=6．17），组间差异有统计学意义（FDR校正Q〈0．01）。结论ADHD儿童双侧前额叶间的功能连接强度增加表现为注意力及工作记忆障碍；两侧枕叶间增强使启动记忆过程变缓；而小脑间的高连接强度使神经环路受损，加重ADHD症状。

Objective To explore the neural mechanisms of attention-deficit hyperactivity disorder （ADHD） through analyzing the intensity of functional connection between bilateral hemispheres of children with ADHD by resting-state functional magnetic resonance imaging （rs-fMRI）. Methods The approach of voxel-mirrored homotopic connectivity （VMHC） was employed to analyze 31 school-age and 31 ADHD children by rs-fMRI scans. Results Positively activated brain regions were visualized when comparing ADHD and normal children, suggesting that ADHD children＇s VMHC scores were higher in bilateral frontal lobe （t = 5.81 ）, bilateral occipital lobe （ t = 5.82） and bilateral eerebellar posterior lobe （ t = 6. 17 ）. Statistically significant differences existed between two groups （ FDR correction, Q 〈 O. 01 ）. Conclusions The increased intensity of functional connection between bilateral prefrontal lobes in children with ADHD reflects attention disorder and leads to a decline of working memory. The strengthening of bilateral occipital lobes slows down memory process. And the increased intensity of eerebellar connections may damage neural circuits and aggravate ADHD symptoms.