Stam C J, Visser S L, Op de Coul A A, De Sonneville L M, Schellens R L, Brunia C H, de Smet J S, Gielen G
Department of Clinical Neurophysiology, St Elisabeth Hospital, Amsterdam, The Netherlands.
Brain. 1993 Oct;116 ( Pt 5):1139-58. doi: 10.1093/brain/116.5.1139.
Parkinson's disease is characterized not only by tremor, akinesia and rigidity, but also by frontal cognitive dysfunction, that can be understood as a disturbance in the 'Supervisory Attentional System' (SAS). This concept refers to a system, located in the frontal cortex, that regulates attentional processes under novel, non-routine conditions. The hypothesis that cognitive dysfunction in Parkinson's disease results from a disturbance in the SAS was investigated by recording 'processing negativity' in 33 parkinsonian patients and 17 controls. Processing negativity is an event-related potential that reflects neuronal activity during selective attention. The contribution of the frontal cortex to selective attention can be studied directly using processing negativity. Parkinsonian patients were also scored for clinical symptoms and subjected to a neuropsychological test battery. Processing negativity was clearly disturbed in the parkinsonian patients. Moreover, parkinsonian patients with the lowest scores on 'frontal' neuropsychological tests such as Stroop, Trail Making and Word Fluency, also had the lowest processing negativity. Our results support the hypothesis that cognitive dysfunction in Parkinson's disease might be understood as a disturbance in the frontal regulation of attentional processes. Degeneration of the dopaminergic mesocortical innervation of the frontal cortex in Parkinson's disease is a possible neurochemical substrate of these frontal attentional disturbances.
帕金森病不仅以震颤、运动不能和强直为特征，还伴有额叶认知功能障碍，这可被理解为“监督注意系统”（SAS）的紊乱。这一概念指的是位于额叶皮质的一个系统，它在新奇、非常规条件下调节注意过程。通过记录33例帕金森病患者和17例对照者的“加工负波”，对帕金森病认知功能障碍源于SAS紊乱这一假说进行了研究。加工负波是一种与事件相关的电位，反映选择性注意期间的神经元活动。额叶皮质对选择性注意的贡献可直接用加工负波进行研究。还对帕金森病患者的临床症状进行评分，并让他们接受一套神经心理学测试。帕金森病患者的加工负波明显紊乱。此外，在诸如斯特鲁普、连线测验和词语流畅性等“额叶”神经心理学测试中得分最低的帕金森病患者，其加工负波也最低。我们的结果支持以下假说：帕金森病的认知功能障碍可能被理解为注意过程额叶调节的紊乱。帕金森病中额叶皮质多巴胺能中皮质神经支配的退化是这些额叶注意障碍可能的神经化学基础。
