Okada Akinori, Nakamura Tomohiko, Suzuki Junichiro, Suzuki Masashi, Hirayama Masaaki, Katsuno Masahisa, Sobue Gen
Department of Neurology, Nagoya University Graduate School of Medicine, Japan.
Intern Med. 2016;55(21):3113-3118. doi: 10.2169/internalmedicine.55.7067. Epub 2016 Nov 1.
Objective Pain and cognitive impairment are important clinical features in patients with Parkinson's disease (PD). Although pain processing is associated with the limbic system, which is also closely linked to the cognitive function, the association between pain and cognitive impairment in PD is still not well understood. The aim of the study was to investigate the association between pain processing and cognitive impairment in patients with PD. Methods Forty-three patients with PD and 22 healthy subjects were studied. Pain-related somatosensory evoked potentials (SEPs) were generated using a thin needle electrode to stimulate epidermal Aδ fibers. Cognitive impairment was evaluated using the Mini-Mental State Examination (MMSE), the Frontal Assessment Battery, and Japanese version of the Montreal Cognitive Assessment (MoCA-J), and their correlation with pain-related SEPs was investigated. Results The N1/P1 amplitude was significantly lower in PD patients than the controls. N1/P1 peak-to-peak amplitudes correlated with the MMSE (r=0.66, p<0.001) and MoCA-J scores (r=0.38, p<0.01) in patients with PD. These amplitudes also strongly correlated with the domains of attention and memory in the MMSE (attention, r=0.52, p<0.001; memory, r=0.40, p<0.01) and MoCA-J (attention, r=0.45, p<0.005; memory, r=0.48, p<0.001), but not in control subjects. Conclusion A good correlation was observed between the decreased amplitudes of pain-related SEPs and an impairment of attention and memory in patients with PD. Our results suggest that pathological abnormalities of the pain pathway are significantly linked to cognitive impairment in PD.
目的 疼痛和认知障碍是帕金森病（PD）患者的重要临床特征。尽管疼痛处理与边缘系统相关，而边缘系统也与认知功能密切相关，但PD中疼痛与认知障碍之间的关联仍未得到充分理解。本研究的目的是调查PD患者疼痛处理与认知障碍之间的关联。方法 对43例PD患者和22名健康受试者进行研究。使用细针电极刺激表皮Aδ纤维产生与疼痛相关的体感诱发电位（SEP）。使用简易精神状态检查表（MMSE）、额叶评估量表和日语版蒙特利尔认知评估量表（MoCA-J）评估认知障碍，并研究它们与疼痛相关SEP的相关性。结果 PD患者的N1/P1波幅明显低于对照组。PD患者中N1/P1峰峰值波幅与MMSE评分（r = 0.66，p < 0.001）和MoCA-J评分（r = 0.38，p < 0.01）相关。这些波幅也与MMSE（注意力，r = 0.52，p < 0.001；记忆力，r = 0.40，p < 0.01）和MoCA-J（注意力，r = 0.45，p < 0.005；记忆力，r = 0.48，p < 0.001）中的注意力和记忆领域密切相关，但在对照组中并非如此。结论 在PD患者中，观察到与疼痛相关SEP波幅降低与注意力和记忆障碍之间存在良好的相关性。我们的结果表明，疼痛通路的病理异常与PD中的认知障碍显著相关。
