Abstract: Objective To analyze the prefrontal cortex (PFC) activation patterns during visuospatial working memory tasks in children with developmental dyslexia (DD) and their correlation with dyslexic symptoms, so as to provide neuroimaging evidence for the differential diagnosis of DD. Methods From May to June 2024, a screening for DD was conducted among all third- to fifth-grade students at a primary school in Xinjiang.Based on parental consent and handedness, 33 children with DD were enrolled and matched 1∶1 with typically developed (TD) controls by grade, age, and sex.Functional near-infrared spectroscopy (fNIRS) was employed to measure concentration changes of oxygenated hemoglobin (HbO₂) in the PFC during visuospatial working memory tasks to reflect cortical activation.Dyslexic symptoms were assessed using the Diagnostic Checklist for Chinese Children (DCCC).Group differences in HbO₂ β-values were analyzed using independent samples t-tests or Mann-Whitney U tests, while Spearman correlation examined relationships between prefrontal cortex activation and dyslexic symptoms in DD children. Results The fNIRS results revealed significantly lower HbO₂ β-values in the DD group compared to controls in the dorsolateral prefrontal cortex (channel 8: t=2.134), orbitofrontal cortex (channel 13: Z=2.860), and frontopolar cortex (channel 14: t=2.212) (P<0.05).Additionally, the total score of the DCCC scale and the scores of its 8 factors were significantly higher in the DD group than those in the normal control group (Z=6.983, 6.626, 6.986, 6.941, 6.358, 6.915, 6.710, 6.864, 6.876, P<0.001).Negative correlations were observed between HbO₂ β-values in the frontopolar cortex (channel 14) and scores on visual perception (r=-0.430) and writing impairment (r=-0.438) subscales (P<0.05). Conclusions Children with DD have deficits in visuospatial working memory, mainly manifested in insufficient activation of the dorsolateral prefrontal cortex, orbito frontal cortex and fronto polar cortex.The frontopolar cortex may serve as a potential biomarker for auxiliary DD diagnosis.

Key words: developmental dyslexia, visuospatial working memory, functional near-infrared spectroscopy, children

摘要： 目的 分析发展性阅读障碍(DD)儿童执行视空间工作记忆任务时大脑前额叶皮层脑激活特征及其与阅读障碍症状的相关性,为DD儿童的鉴别诊断提供神经影像学依据。 方法 2024年5—6月对新疆某地区1所小学3~5年级全体学生进行DD筛查,根据家长意愿及儿童利手情况,最终纳入33名DD儿童,按年级、年龄、性别进行1∶1匹配正常对照组儿童33名,利用功能性近红外成像(fNIRS)技术采集两组儿童视空间工作记忆任务下大脑前额叶皮层氧合血红蛋白(HbO₂)浓度变化,以反映其大脑前额叶皮层的激活情况,采用儿童汉语阅读障碍量表(DCCC)评估儿童的阅读障碍症状。采用两独立样本t检验或Mann-Whitney U检验比较两组儿童视空间工作记忆任务下大脑前额叶皮层HbO₂浓度变化的差异,并使用Spearman相关分析DD儿童大脑前额叶皮层HbO₂浓度变化与其阅读障碍症状的相关性。 结果 fNIRS结果显示DD组儿童在背外侧前额叶通道8(t=2.134)、眶额叶皮层通道13(Z=2.860)和额极皮层通道14(t=2.212)中HbO₂浓度变化的β值显著低于正常对照组儿童(P<0.05)。DD组儿童的DCCC总分及8个因子得分显著高于正常对照组儿童(Z=6.983、6.626、6.986、6.941、6.358、6.915、6.710、6.864、6.876,P＜0.001)。Spearman相关分析结果发现,DD儿童额极皮层通道14的HbO₂浓度变化的β值与视知觉障碍因子(r=-0.430,P<0.05)和书写障碍因子(r=-0.438,P<0.05)呈显著负相关。 结论 DD儿童存在视空间工作记忆缺陷,主要表现在背外侧前额叶、眶额叶皮层及额极皮层激活不足;额极皮层可能是辅助诊断DD儿童的生物学标记物。

关键词: 发展性阅读障碍, 视空间工作记忆, 功能性近红外成像技术, 儿童