Department of Neurology, IRCCS C. Mondino Institute of Neurology Foundation, University of Pavia, Pavia, Italy.
Mov Disord. 2011 Feb 15;26(3):442-8. doi: 10.1002/mds.23458. Epub 2010 Dec 15.
Pain is one of the major nonmotor symptoms of Parkinson's disease. We hypothesized that Parkinson's disease patients could show an early diffuse abnormal processing of the nociceptive inputs also in the absence of clinical pain syndrome and that this could represent the physiopathological substrate to explain the high incidence of diffuse pain symptoms.
We used the temporal summation threshold of the nociceptive withdrawal reflex and the related pain sensation to evaluate the facilitation in pain processing at spinal level. Fifteen (7 Women; 8 Men; mean age 63.0 ± 9.1) Parkinson's disease patients without clinical pain and 12 (6 Women, 6 Men; mean age 61.2 ± 4.2) healthy subjects were recruited. Parkinson's disease group has been subdivided into two subgroups, 7 early-stage Parkinson's disease patients with unilateral signs (Hoehn and Yahr stage 1) and 8 patients in a more advanced stage of the disease showing bilateral parkinsonian signs (Hoehn and Yahr stages 2 and 2.5), both "on" and "off" treatments with levodopa.
A significant facilitation in temporal summation of pain (reduced temporal summation threshold and increased painful sensation) was found in Parkinson's disease patients when compared with controls. This facilitation is more evident in Parkinson's disease with bilateral signs and on the side more affected in Parkinson's disease with unilateral signs. Levodopa administration failed to significantly modify the neurophysiological abnormalities; however, a slight improvement has been detected.
The increased gain in pain processing at spinal level in Parkinson's disease patients could be a consequence of the degenerative phenomena involving supraspinal projections implicated in the modulation of pain processing and could make Parkinson's disease patients more predisposed to develop a pain condition.
疼痛是帕金森病的主要非运动症状之一。我们假设帕金森病患者即使在没有临床疼痛综合征的情况下，也可能表现出伤害性传入的早期弥漫性异常处理，这可能代表了解释高发生率弥漫性疼痛症状的病理生理学基础。
我们使用伤害性撤回反射的时间总和阈值和相关的疼痛感觉来评估脊髓水平疼痛处理的易化。招募了 15 名（7 名女性；8 名男性；平均年龄 63.0 ± 9.1）没有临床疼痛的帕金森病患者和 12 名（6 名女性，6 名男性；平均年龄 61.2 ± 4.2）健康受试者。帕金森病组进一步分为两个亚组，7 名单侧表现（Hoehn 和 Yahr 1 期）的早期帕金森病患者和 8 名双侧帕金森病表现（Hoehn 和 Yahr 2 期和 2.5 期）的更晚期疾病患者，均接受左旋多巴的“开”和“关”治疗。
与对照组相比，帕金森病患者的疼痛时间总和易化（降低时间总和阈值和增加疼痛感觉）明显增加。这种易化在双侧表现的帕金森病患者中更为明显，在单侧表现的帕金森病患者中，受累侧更为明显。左旋多巴给药未能显著改变神经生理异常；然而，已经检测到轻微的改善。
帕金森病患者脊髓水平疼痛处理增益增加可能是涉及参与疼痛处理调制的皮质下投射退行性现象的结果，并且可能使帕金森病患者更容易发展为疼痛状况。
