基于分数低频振幅初步探索维生素D减少对 注意力缺陷多动障碍儿童脑功能影响的神经 机制

Preliminary Exploration of the Neurological Mechanism Underlying Vitamin D’s Mitigation of Brain Function Effects in Children with Attention Deficit Hyperactivity Disorder Based on Fractional Amplitude of Low-Frequency Fluctuation

摘要: 目的：应用分数低频振幅(fractional Amplitude of Low-Frequency Fluctuation, fALFF)技术，探索维生素D减少的注意力缺陷多动障碍(attention deficit hyperactivity disorder, ADHD)儿童静息态脑功能活动的影像学特征及其与临床症状的关联。材料与方法：本研究前瞻性纳入48例于我院初诊为ADHD的儿童，依据血清维生素D水平将其分为减少组(n = 29)与正常组(n = 19)。收集所有患儿的一般临床资料及行为量表评估结果，并行静息态功能磁共振成像扫描。采用fALFF方法评估局部脑活动强度，并进行组间比较；进一步提取差异脑区的平均fALFF信号，将其与整体维生素D水平及临床量表评分进行相关性分析。结果：组间比较发现，维生素D减少组ADHD患儿在一个以左侧背侧前扣带回/辅助运动区为中心，并主要涵盖左侧额上回及内侧前额叶的脑区(体素水平P < 0.005，团块水平P < 0.05，高斯随机场校正)，其fALFF值显著降低。相关性分析显示，该差异脑区的平均fALFF值与整体维生素D水平呈正相关(r = 0.523, P < 0.001)，与Achenbach儿童行为量表(Child Behavior Checklist, CBCL)量表中多动(r = −0.392, P = 0.035)、强迫行为(r = −0.390, P = 0.037)、总分(r = −0.421, P = 0.023)及康纳斯儿童行为量表(父母版) (Conners’ Parent Symptom Questionnaire, PSQ)中品行问题(r = −0.462, P = 0.012)与学习问题(r = −0.574, P = 0.001)评分均呈负相关。结论：本研究结果表明，维生素D减少的ADHD儿童在涉及认知控制与行为调节的关键脑区存在自发神经活动异常，且该异常与更严重的临床症状显著相关。这些发现提示，维生素D状态与ADHD儿童的脑功能及临床症状存在关联，为未来深入研究提供了新的影像学线索。

Abstract: Objective: To investigate the imaging characteristics of resting-state brain activity in children with attention deficit hyperactivity disorder (ADHD) who exhibit reduced vitamin D levels using fractional amplitude of low-frequency fluctuation (fALFF) technology, and to explore its association with clinical symptoms. Materials and Methods: This prospective study enrolled 48 children newly diagnosed with ADHD at our hospital. Participants were divided into a hypovitaminosis D group (n = 29) and a normal group (n = 19) based on serum vitamin D levels. General clinical data and behavioral assessment scores were collected for all children, who also underwent resting-state functional magnetic resonance imaging (fMRI) scans. The fALFF method was used to assess regional brain activity intensity, with intergroup comparisons conducted. Average fALFF signals from differentially active brain regions were extracted and correlated with overall vitamin D levels and clinical scale scores. Results Intergroup comparisons revealed significantly reduced fALFF values in ADHD children with vitamin D deficiency within a brain region centered on the left dorsal anterior cingulate cortex/supplementary motor area and primarily encompassing the left superior frontal gyrus and medial prefrontal cortex (voxel-level P < 0.005, cluster-level P < 0.05, Gaussian random field correction). Correlation analysis revealed that the mean fALFF value in this distinct brain region positively correlated with overall vitamin D levels (r = 0.523, P < 0.001) and negatively correlated with hyperactivity (r = −0.392, P = 0.035), compulsive behaviors (r = −0.390, P = 0.037), total scores (r = −0.421, P = 0.023), and negatively correlated with conduct problems (r = −0.462, P = 0.012) and learning problems (r = −0.574, P = 0.001) scores on the Conners’ Parent Symptom Questionnaire (PSQ). Conclusion: These findings indicate that children with ADHD and reduced vitamin D levels exhibit abnormal spontaneous neural activity in key brain regions involved in cognitive control and behavioral regulation. This abnormality correlates significantly with more severe clinical symptoms. These discoveries suggest an association between vitamin D status and both brain function and clinical symptoms in children with ADHD, providing novel imaging clues for future in-depth research.