Mylius V, Engau I, Teepker M, Stiasny-Kolster K, Schepelmann K, Oertel W H, Lautenbacher S, Möller J C
Department of Neurology, Philipps University of Marburg, Rudolf-Bultmann-Str 8, 35033 Marburg, Germany.
J Neurol Neurosurg Psychiatry. 2009 Jan;80(1):24-8. doi: 10.1136/jnnp.2008.145995. Epub 2008 Jul 24.
Patients suffering from Parkinson's disease (PD) often complain about painful sensations. Recent studies detected increased subjective pain sensitivity and increased spinal nociception, which appeared to be reversible by dopaminergic treatment. Possibly, reduced descending pain inhibition contributes to this finding.
Subjective pain thresholds as well as nociceptive reflex thresholds were investigated to isolate potential loci of the pathophysiological changes within the pain pathway. In addition, the diffuse noxious inhibitory control (DNIC) system as one form of descending control was assessed.
15 patients with PD and 18 controls participated in the study. Electrical and heat pain thresholds as well as the nociceptive flexion reflex (NFR) thresholds were determined. Thereafter, the electrical pain thresholds were measured once during painful heat stimulation (conditioning stimulation) and twice during innocuous stimulation (control stimulation).
Patients with PD exhibited lower electrical and heat pain thresholds as well as lower NFR thresholds. Suppression of the electrical pain thresholds during painful heat stimulation (conditioning stimulation) compared with control stimulation did not differ significantly between the groups. No differences in the thresholds between patients with PD with and without clinical pain were seen.
Finding the NFR threshold to be decreased in addition to the decreased electrical and heat pain thresholds indicates that the pathophysiological changes either already reside at or reach down to the spinal level. Reduced activation of the DNIC system was apparently not associated with increased pain sensitivity, suggesting that DNIC-like mechanisms do not significantly contribute to clinical pain in PD.
帕金森病（PD）患者常诉说有疼痛感。最近的研究发现主观疼痛敏感性增加以及脊髓伤害感受增加，而多巴胺能治疗似乎可使其逆转。可能是下行性疼痛抑制减弱导致了这一发现。
研究主观疼痛阈值以及伤害性反射阈值，以确定疼痛通路中病理生理变化的潜在位点。此外，评估作为下行性控制形式之一的弥漫性伤害性抑制控制（DNIC）系统。
15例PD患者和18名对照者参与了本研究。测定电刺激和热刺激疼痛阈值以及伤害性屈曲反射（NFR）阈值。此后，在热痛刺激（条件刺激）期间测量一次电刺激疼痛阈值，在无害刺激（对照刺激）期间测量两次。
PD患者的电刺激和热刺激疼痛阈值以及NFR阈值较低。与对照刺激相比，热痛刺激（条件刺激）期间电刺激疼痛阈值的抑制在两组之间无显著差异。有临床疼痛和无临床疼痛的PD患者之间阈值无差异。
除电刺激和热刺激疼痛阈值降低外，NFR阈值也降低，这表明病理生理变化要么已经存在于脊髓水平，要么已延伸至脊髓水平。DNIC系统激活减弱显然与疼痛敏感性增加无关，这表明类似DNIC的机制对PD临床疼痛的影响不大。
