Impaired pain processing in Parkinson's disease and its relative association with the non-motor symptom

背景和目的：帕金森病（PD）与许多非运动症状有关。其中，疼痛和嗅觉障碍往往是常见的运动前症状。PD已被证明表现出异常的中枢疼痛处理，尽管其潜在机制尚未完全了解。方法：对42例PD患者（男18例，女24例）和11例健康对照者（男8例，女3例）进行了嗅觉功能检测。用细针电极刺激表皮Aδ纤维，在头顶记录体感诱发电位（SEP）。结果：两组患者的N1潜伏期和P1潜伏期无显著性差异，但N1/P1峰-峰波幅显著降低（p<0. 05）。05)在PD患者中，在PD患者中，N1/P1振幅与疾病持续时间之间存在显著相关性（r=-0. 35，p<0. Hoehn-Yahr分期（r=-0. 05）。38，p<0. 05)和《生物多样性公约》第三部分（r=-0. 42，p<0. 01）。此外，OSIT-J评分与SEP波幅相关（r=0. 999，P < 0. 05）。41，p<0. 01).结论：PD患者在Aδ纤维的特异性伤害性刺激下疼痛加工受损，并与嗅觉功能障碍显著相关。我们认为，这种机制可能涉及边缘系统在PD病理。

Background and purpose : Many non-motor symptoms are associated with Parkinson's disease(PD). Of these, pain and olfactory disturbance tend to be common premotor symptoms. PD has been shown to exhibit abnormal central pain processing, although underlying mechanisms are not yet fully understood. In order to investigate this further, we assessed PD patients by specific Aδstimulation with intra-epidermal needle electrode and determined olfactory function.Methods : Forty-two patients(18 males and 24 females) with PD and 11 healthy control subjects(8 males and 3 females) were studied. A thin needle electrode was used to stimulate epidermal Aδfibers, and somatosensory evoked potentials(SEPs) recorded at the vertex. Olfactory function was evaluated using the Odor Stick Identification Test for Japanese(OSIT-J) and its relationship with pain-related SEPs was investigated.Results : There were no significant differences in N1 latencies or P1 latencies although N1/P1 peak-to-peak amplitudes were significantly lower(p<0. 05) in PD patients than in control subjects. In PD patients, there were significant correlations between N1/P1 amplitudes and disease duration(r=-0. 35, p<0. 05), Hoehn-Yahr stage(r=-0. 38, p<0. 05) and UPDRS part III(r=-0. 42, p<0. 01). Furthermore, the OSIT-J scores correlated with SEP amplitude(r=0. 41, p<0. 01).Conclusion : Pain processing in PD patients was impaired under specific nociceptive stimulation of Aδfibers and significant correlation with smell dysfunction was detected. We suggest that this mechanism may involve the limbic system during PD pathology.