Nelson Eric E, Vinton Deborah T, Berghorst Lisa, Towbin Kenneth E, Hommer Rebecca E, Dickstein Daniel P, Rich Brendan A, Brotman Melissa A, Pine Daniel S, Leibenluft Ellen
Mood and Anxiety Disorders Program, National Institute of Mental Health, Building 106-C, 5413 W Cedar Lane, Bethesda, MD 20892, USA.
Bipolar Disord. 2007 Dec;9(8):810-9. doi: 10.1111/j.1399-5618.2007.00419.x.
Previous studies have indicated abnormalities in response flexibility in pediatric bipolar disorder (BD). Dysfunction in response flexibility may contribute to the pattern of behavioral and emotional dysregulation that is characteristic of BD, since depressed and manic patients respond inflexibly to emotional stimuli (i.e., anhedonia in the case of depression or inappropriate positive affect in the case of mania). The present study was undertaken to determine if neuronal responses differed between BD and control subjects on a simple motor response flexibility task.
To elucidate the neural substrates mediating response flexibility in pediatric BD, we studied 25 youth with BD and 17 age-, gender- and IQ-matched controls (CON) as they performed the change task while undergoing event-related functional magnetic resonance imaging (fMRI). The change task is a new fMRI task that requires subjects to both inhibit and replace a prepotent motor response with another motor response after the initial response has been cued.
On correctly performed change trials relative to correctly performed go trials, BD patients generated significantly more activity in the left dorsolateral prefrontal cortex (DLPFC) and in the primary motor cortex than did healthy controls, even though performance levels did not differ across groups.
These results indicate that functional deficits within the left DLPFC may mediate deficits in response flexibility in pediatric BD. This deficit may extend beyond the realm of motor control and also affect emotion regulation.
先前的研究表明，小儿双相情感障碍（BD）患者在反应灵活性方面存在异常。反应灵活性的功能障碍可能导致BD患者典型的行为和情绪调节失调模式，因为抑郁和躁狂患者对情绪刺激的反应缺乏灵活性（即抑郁时快感缺失，躁狂时出现不适当的积极情绪）。本研究旨在确定在简单的运动反应灵活性任务中，BD患者与对照组在神经元反应上是否存在差异。
为了阐明介导小儿BD反应灵活性的神经基质，我们研究了25名BD青少年和17名年龄、性别及智商匹配的对照组（CON），他们在执行变化任务时接受了事件相关功能磁共振成像（fMRI）检查。变化任务是一种新的fMRI任务，要求受试者在初始反应被提示后，抑制并以另一种运动反应替代优势运动反应。
相对于正确执行的“执行”试验，在正确执行的变化试验中，BD患者在左侧背外侧前额叶皮质（DLPFC）和初级运动皮质中产生的活动明显多于健康对照组，尽管两组的表现水平没有差异。
这些结果表明，左侧DLPFC内的功能缺陷可能介导小儿BD反应灵活性的缺陷。这种缺陷可能超出运动控制领域，还会影响情绪调节。
