摘要目的 运用功能磁共振(fMRI)静息态低频振幅(ALFF)方法 比较注意缺陷多动障碍(ADHD)儿童静息脑活动与正常儿童的差别；结合症状评分量表探讨ADHD症状严重程度与静息自发脑活动是否存在相关性.方法 学龄期ADHD32例,年龄及受教育程度匹配的正常儿童30名,分别采集两组儿童的静息状态fMRI脑血氧水平依赖(BOLD)信号,ALFF处理两组BOLD图像,进行双样本t检验获取显著性激活脑区图(P＜0.01).对ADHD组每个儿童症状评分量表(RS-Ⅳ)总分与提取的相应显著性脑区ALFF值进行相关分析获得相关显著脑区.结果 ADHD与正常组比较,ALFF值减低脑区:右额上回(BA9,t=-4.61),左额上回内侧(BA10,t=-3.63),左额中回(BA46,t=-4.09)及左前扣带回(BA24,t =-4.02).ALFF值增加脑区:左眶额叶内侧(BA11,t=3.52),右楔叶(t=3.93),右枕中回(BA19,t=3.82),右侧小脑(BA37,t=3.77),右颞中回(BA37,t=3.76),左旁中央小叶(BA6,t=3.77).ADHD组ALFF与RS-Ⅳ总分相关显著脑区:左额上回内侧(P=0.009,r=0.492),右楔叶(P=0.024,r=0.433).结论 静息状态下ADHD的前额叶自发活动水平低下,某些功能相关脑区活动增强可作为补偿机制；左额叶及右楔叶的静息自发活动水平与ADHD症状严重程度呈正相关.

abstractsObjective To investigate the difference of the spontaneous neuronal activity between attention-deficit hyperactivity disorder (ADHD) and normal children with amplitude of low-frequency fluctuation (ALFF) of the resting-state fMRI,and to discuss the correlation between the activity level of brain and symptom severity.Methods Thirty-two children with ADHD of school age and thirty age-and gender-matched controls were experienced with resting-state fMRI scans while blood oxygenation level dependent (BOLD) signal was acquired to calculate the amplitude of low-frequency fluctuation (ALFF).Linear correlations were performed between the aggregate score of RS-Ⅳ and ALFF voxels in ADHD patients.Results Compared to the controls,the ADHD group exhibited decreased ALFF in right superior frontal gyrus ( BA9,t =- 4.61 ),left superior medial frontal gyrus ( BA10,t =- 3.63 ),left mediate frontal ( BA46,t =- 4.09 ),and left anterior cingulate cortex ( BA24,t =- 4.02).Meanwhile,it showed increased ALFF in the medial orbitofrontal cortex( BA11,t =3.52 ),right cuneus gyrus ( t =3.93 ),right mediate occipital gyrus ( BA 19,t =3.82),right cerebellum ( BA37,t =3.77),right mediate temporal gyrus( BA37,t =3.76),and left paracentral lobe ( BA6,t =3.77 ).Altered ALFF in left superior medial frontal gyrus(P=0.009,r=0.492)and the right cuneus gyrus(P=0.024,r=0.433) showed correlation with the aggregate score of RS-Ⅳ.Conclusion The spontaneous neuronal activity decreases in prefrontal cortex and increases in default mode network of ADHD group,the activity level of left prefrontal and right cuneus gyrus is positively correlated with symptom severity.