Hicks Stephen L, Robert Matthieu P A, Golding Charlotte V P, Tabrizi Sarah J, Kennard Christopher
Department of Clinical Neuroscience, Imperial College, London, UK.
Prog Brain Res. 2008;171:555-8. doi: 10.1016/S0079-6123(08)00678-X.
The oculomotor deficits associated with Huntington's Disease (HD) are one of the earliest signs of disease onset. They include a marked delay in executing voluntary saccades and a difficulty inhibiting saccades to task-irrelevant stimuli. In addition, HD patients develop a deficit in task-switching, which can be demonstrated by the continued adherence to a rule after it has been recently changed. These deficits are likely to be the result of a progressive neural degeneration of the fronto-striatal system, which is a distinguishing feature of HD neuropathology. It is predicted that as the disease progresses the magnitude of these specific deficits should increase. We tested a cohort of early HD patients and presymptomatic HD gene carriers on a series of oculomotor tasks designed to measure saccade initiation, inhibition and rule switch cost. Saccadic latencies and error rates in early HD patients were found to be systematically higher than controls. Presymptomatic HD subjects showed small increases in saccadic latencies and error rates that were in proportion to the predicted age of disease onset. These results suggest that saccadometry and a cognitively demanding oculomotor task may be useful as an indicator of function in HD.
与亨廷顿舞蹈症（HD）相关的动眼神经缺陷是疾病发作的最早迹象之一。这些缺陷包括执行自主扫视动作时明显延迟，以及难以抑制对与任务无关刺激的扫视。此外，HD患者在任务切换方面出现缺陷，这可通过在规则最近改变后仍持续遵循该规则来证明。这些缺陷可能是额纹状体系统进行性神经退化的结果，这是HD神经病理学的一个显著特征。据预测，随着疾病进展，这些特定缺陷的程度应会增加。我们对一组早期HD患者和症状前HD基因携带者进行了一系列旨在测量扫视启动、抑制和规则切换成本的动眼神经任务测试。结果发现，早期HD患者的扫视潜伏期和错误率系统性地高于对照组。症状前HD受试者的扫视潜伏期和错误率有小幅增加，且与预测的疾病发作年龄成比例。这些结果表明，眼跳测量法和一项需要认知能力的动眼神经任务可能有助于作为HD功能的一个指标。
