MEG event-related desynchronization and synchronization deficits during basic somatosensory processing in individuals with ADHD
MEG event-related desynchronization and synchronization deficits during basic somatosensory processing in individuals with ADHD
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DOI：
10.1186/1744-9081-4-8
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发表时间：
2008-02-12
影响因子：
5.1
通讯作者：
Tannock, Rosemary
中科院分区：
文献类型：
--
作者：
Dockstader, Colleen;Gaetz, William;Tannock, Rosemary
背景资料：注意力缺陷/多动障碍（ADHD）是一种流行的复杂疾病，其特征在于注意力不集中、多动和冲动的症状。来自ADHD的神经生物学研究的会聚证据将额-纹状体-小脑回路的功能障碍确定为行为缺陷的来源。最近的研究表明，控制基本感觉处理的区域，如躯体感觉皮层，在ADHD患者中显示异常，这表明这些过程也可能受到损害。方法：我们使用事件相关脑磁图（MEG）来检查初级（SI）和次级（SII）躯体感觉皮层对正中神经刺激的反应，9名ADHD成年人和10名健康对照者。刺激是在两种平衡条件下向正中神经呈现的短暂（0.2 ms）无痛电脉冲：不可预测和可预测的刺激呈现。结果：健康对照组在SI和SII中表现出较强的事件相关性延迟和同步性。相比之下，ADHD患者在α（8-12 Hz）和β（15-30 Hz）频段的事件相关性延迟和事件相关性同步分别明显较弱。这在正中神经刺激的随机呈现期间是最显著的。成人ADHD表现出显着较短的持续时间的β反弹在SI和SII除了当刺激事件的发生可以预测。在这种情况下，在ADHD组的SI（但不是SII）的节奏没有不同的controls.Conclusion：我们的研究结果表明，躯体感觉处理与ADHD的个人改变。脑磁图是一种很有前途的方法来分析感觉输入过程中的神经活动模式（例如：例如，在一个实施例中，触觉刺激的检测、刺激的可预测性），并有助于我们理解基本感觉处理如何成为高阶处理中涉及的更复杂神经网络的基础和/或受其影响。
Background: Attention-Deficit/Hyperactivity Disorder (ADHD) is a prevalent, complex disorder which is characterized by symptoms of inattention, hyperactivity, and impulsivity. Convergent evidence from neurobiological studies of ADHD identifies dysfunction in fronto-striatal-cerebellar circuitry as the source of behavioural deficits. Recent studies have shown that regions governing basic sensory processing, such as the somatosensory cortex, show abnormalities in those with ADHD suggesting that these processes may also be compromised.Methods: We used event-related magnetoencephalography (MEG) to examine patterns of cortical rhythms in the primary (SI) and secondary (SII) somatosensory cortices in response to median nerve stimulation, in 9 adults with ADHD and 10 healthy controls. Stimuli were brief (0.2 ms) non-painful electrical pulses presented to the median nerve in two counterbalanced conditions: unpredictable and predictable stimulus presentation. We measured changes in strength, synchronicity, and frequency of cortical rhythms.Results: Healthy comparison group showed strong event-related desynchrony and synchrony in SI and SII. By contrast, those with ADHD showed significantly weaker event-related desynchrony and event-related synchrony in the alpha (8-12 Hz) and beta (15-30 Hz) bands, respectively. This was most striking during random presentation of median nerve stimulation. Adults with ADHD showed significantly shorter duration of beta rebound in both SI and SII except for when the onset of the stimulus event could be predicted. In this case, the rhythmicity of SI (but not SII) in the ADHD group did not differ from that of controls.Conclusion: Our findings suggest that somatosensory processing is altered in individuals with ADHD. MEG constitutes a promising approach to profiling patterns of neural activity during the processing of sensory input (e. g., detection of a tactile stimulus, stimulus predictability) and facilitating our understanding of how basic sensory processing may underlie and/or be influenced by more complex neural networks involved in higher order processing.