Motor loop dysfunction causes impaired cognitive sequencing in patients suffering from Parkinson's disease
Motor loop dysfunction causes impaired cognitive sequencing in patients suffering from Parkinson's disease
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DOI：
10.1016/j.neuropsychologia.2015.09.017
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发表时间：
2015-10-01
期刊：
影响因子：
2.6
通讯作者：
Schubotz, Ricarda I.
中科院分区：
文献类型：
--
作者：
Schoenberger, Anna R.;Hagelweide, Klara;Schubotz, Ricarda I.
帕金森病（PD）的认知功能障碍通常归因于前额叶-基底节丘脑-皮质环多巴胺缺乏。虽然最近的研究指出，在PD的运动和认知能力之间的密切相互作用，所谓的“运动回路”连接补充运动区（SMA）和壳核已被认为是唯一的关于患者的运动障碍。我们的研究通过测试患者的串行预测任务（SPT）来挑战这一观点，这是一项认知任务，要求参与者预测刺激序列，特别是参与运动环路的前运动部位。我们假设运动回路的影响会导致SPT表现受损，特别是当内部序列表征受到外部刺激暂停的挑战时。如所示的运动任务，我们进一步预计这种损害将补偿的外侧运动前皮质（PM）的过度活跃，我们测试了16名男性PD患者和16名男性年龄匹配的健康对照组的多巴胺能药物的功能磁共振成像研究。所有受试者进行了两个版本的SPT：一个与正在进行的序列（SPTO），和一个序列包含非信息通配符（SPT+）增加记忆序列表示的要求。ON组患者（与对照组相比）表现为沿着SMA和壳核活动减退。与开启药物治疗相比，关闭药物治疗的患者表现较差，但SPT+与SPTO相比，PM活性显著增加。此外，患者的表现正协变与PM活动，证实了补偿帐户。我们的数据揭示了运动回路对PD认知功能障碍的贡献，并表明SMA和PM在运动控制之外存在密切的相互作用。(C)2015爱思唯尔有限公司版权所有。
Cognitive impairment in Parkinson's disease (PD) is often attributed to dopamine deficiency in the prefrontal-basal ganglia thalamo-cortical loops. Although recent studies point to a close interplay between motor and cognitive abilities in PD, the so-called "motor loop" connecting supplementary motor area (SMA) and putamen has been considered solely with regard to the patients' motor impairment. Our study challenges this view by testing patients with the serial prediction task (SPT), a cognitive task that requires participants to predict stimulus sequences and particularly engages premotor sites of the motor loop. We hypothesised that affection of the motor loop causes impaired SPT performance, especially when the internal sequence representation is challenged by suspension of external stimuli. As shown for motor tasks, we further expected this impairment to be compensated by hyperactivity of the lateral premotor cortex (PM).We tested 16 male PD patients ON and OFF dopaminergic medication and 16 male age-matched healthy controls in an functional Magnetic Resonance Imaging study. All subjects performed two versions of the SPT: one with on-going sequences (SPTO), and one with sequences containing non-informative wildcards (SPT+) increasing the demands on mnemonic sequence representation. Patients ON (compared to controls) revealed an impaired performance coming along with hypoactivity of SMA and putamen. Patients OFF compared to ON medication, while showing poorer performance, exhibited a significantly increased PM activity for SPT+ vs. SPTO. Furthermore, patients' performance positively covaried with PM activity, corroborating a compensatory account. Our data reveal a contribution of the motor loop to cognitive impairment in PD, and suggest a close interplay of SMA and PM beyond motor control. (C) 2015 Elsevier Ltd. All rights reserved.