Rommelse Nanda N J, Altink Marieke E, Oosterlaan Jaap, Buschgens Cathelijne J M, Buitelaar Jan, De Sonneville Leo M J, Sergeant Joseph A
Department of Clinical Neuropsychology, Vrije Universiteit Amsterdam, Amsterdam, The Netherlands.
J Child Psychol Psychiatry. 2007 Nov;48(11):1071-9. doi: 10.1111/j.1469-7610.2007.01781.x.
Attention-deficit/hyperactivity disorder (ADHD) is strongly influenced by heritability. Identifying heritable vulnerability traits (endophenotypes) that mark a relatively high risk of developing the disorder can contribute to the identification of risk genes. A fruitful area for the search for such endophenotypes may be motor control in children with ADHD, since the disorder is frequently accompanied by motor problems.
The current study used a large sample of 350 children with ADHD, 195 non-affected siblings and 271 normal controls aged 5-19 years. Children were administered two computerised motor control tasks in which they had to trace a path between two circles (Tracking task) and follow a randomly moving target (Pursuit task). Both tasks were performed with both the right and the left hand.
Children with ADHD were less precise and stable than controls. Non-affected siblings also deviated from controls, but only on the Tracking task. Group differences were modulated by the use of the right versus the left hand: no group differences emerged when the right hand was used, yet group differences did emerge when the left hand was used. Performance on both tasks was significantly familial.
Imprecision and instability of movements in children with ADHD and in their non-affected siblings as measured by the Tracking task might be suitable endophenotypic candidates: these deficits are familially present in children having ADHD as well as in their non-affected siblings. Motor performance might be best assessed in children using their left hand, because motor control deficits are most pronounced using the left hand. This might relate to right hemispheric brain pathology in children with ADHD (and possibly in their non-affected siblings) that is related to the control of the left hand and/or relate to differential effects of daily life practice on both hands, which may be smaller on the left hand.
注意力缺陷多动障碍（ADHD）受遗传因素的影响很大。识别那些标志着患该疾病风险相对较高的可遗传的易感性特征（内表型），有助于确定风险基因。对于此类内表型的研究，一个富有成效的领域可能是ADHD儿童的运动控制，因为该疾病常伴有运动问题。
本研究使用了一个包含350名ADHD儿童、195名未患病同胞以及271名5至19岁正常对照儿童的大样本。对儿童进行两项计算机化运动控制任务，即他们必须在两个圆圈之间追踪路径（追踪任务）以及跟踪一个随机移动的目标（追踪任务）。两项任务均用右手和左手完成。
ADHD儿童的动作不如对照组精确和稳定。未患病同胞与对照组也存在差异，但仅在追踪任务中。组间差异受使用右手还是左手的调节：使用右手时未出现组间差异，但使用左手时出现了组间差异。两项任务的表现都具有显著的家族性。
通过追踪任务测量，ADHD儿童及其未患病同胞动作的不精确和不稳定可能是合适的内表型候选特征：这些缺陷在患有ADHD的儿童及其未患病同胞中都有家族性表现。使用左手对儿童进行运动表现评估可能是最佳方式，因为使用左手时运动控制缺陷最为明显。这可能与ADHD儿童（可能还有其未患病同胞）的右半球脑病变有关，该病变与左手控制有关，和/或与日常生活中双手练习的差异效应有关，左手的差异效应可能较小。
