Mostofsky S H, Lasker A G, Cutting L E, Denckla M B, Zee D S
Kennedy Krieger Institute, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA.
Neurology. 2001 Aug 14;57(3):423-30. doi: 10.1212/wnl.57.3.423.
Prevailing hypotheses suggest that attention deficit hyperactivity disorder (ADHD) is secondary to dysfunction of motor intentional systems mediated by prefrontal circuitry. Oculomotor paradigms provide a mechanism for examining and localizing dysfunction at the interface between movement and cognition.
Three different saccade tasks (reflexive or prosaccades, antisaccades, and memory-guided saccades) were used to examine functions necessary for the planning and the execution of eye movements, including motor response preparation, response inhibition, and working memory.
The study included 19 children with ADHD, divided into two groups: a group of 8 children on methylphenidate at the time of testing and a group of 11 children not taking any psychoactive medication. Results from the two groups were compared with those from 25 age- and gender-matched normal control children.
Both groups of children with ADHD made significantly more directional errors than did controls on the antisaccade task and significantly more anticipatory errors than did controls on the memory-guided saccade task, findings that are consistent with deficits in response inhibition. There were no significant differences in prosaccade latency, although unmedicated children with ADHD showed significantly greater variability in latency on the prosaccade task than did controls. On the memory-guided saccade task there were no significant differences in saccade accuracy; however, unmedicated children with ADHD showed longer saccade latency than did either controls or medicated children with ADHD.
Oculomotor findings suggest that deficits in prefrontal functions, in particular response inhibition, contribute to behavioral abnormalities observed in ADHD. Findings also suggest that the administration of methylphenidate is associated with improvements in the consistency of motor response. Although there were no observed improvements in response inhibition with methylphenidate, conclusions await a design in which subjects complete testing both on and off medication.
流行的假说认为，注意力缺陷多动障碍（ADHD）继发于由前额叶回路介导的运动意向系统功能障碍。眼动范式为检查和定位运动与认知之间界面的功能障碍提供了一种机制。
使用三种不同的扫视任务（反射性或顺向扫视、反扫视和记忆导向扫视）来检查眼球运动计划和执行所需的功能，包括运动反应准备、反应抑制和工作记忆。
该研究纳入了19名患有ADHD的儿童，分为两组：一组8名儿童在测试时服用哌甲酯，另一组11名儿童未服用任何精神活性药物。将两组的结果与25名年龄和性别匹配的正常对照儿童的结果进行比较。
两组患有ADHD的儿童在反扫视任务中比对照组犯的方向错误显著更多，在记忆导向扫视任务中比对照组犯的预期错误显著更多，这些结果与反应抑制缺陷一致。顺向扫视潜伏期没有显著差异，尽管未服药的ADHD儿童在顺向扫视任务中的潜伏期变异性比对照组显著更大。在记忆导向扫视任务中，扫视准确性没有显著差异；然而，未服药的ADHD儿童的扫视潜伏期比对照组或服药的ADHD儿童更长。
眼动研究结果表明，前额叶功能缺陷，特别是反应抑制缺陷，导致了ADHD中观察到的行为异常。研究结果还表明，哌甲酯的使用与运动反应一致性的改善有关。尽管未观察到哌甲酯对反应抑制有改善作用，但结论有待于设计一种受试者在服药和停药时都完成测试的研究。
