Neurology Unit, Parkinson Disease and Movement Disorders Division, DIMI Department of Engineering and Medicine of Innovation, University of Verona, Verona, Italy.
UOC Neurology A, Department of Neurosciences, AOUI, Verona, Italy.
Mov Disord. 2023 Sep;38(9):1688-1696. doi: 10.1002/mds.29509. Epub 2023 Jun 14.
Restless legs syndrome (RLS) is a complex sensorimotor disorder. Symptoms worsen toward evening and at rest and are temporarily relieved by movement. Symptoms are perceived as painful in up to 45% of cases, and nociception system may be involved.
To assess the descending diffuse noxious inhibitory control in RLS patients.
Twenty-one RLS patients and twenty age and sex-matched healthy controls (HC) underwent a conditioned pain modulation protocol. Cutaneous heat stimuli were delivered via laser evoked potentials (LEPs) on the dorsum of the right hand (UL) and foot (LL). N2 and P2 latencies, N2/P2 amplitude and pain ratings (NRS) were recorded before (baseline), during, and after a heterotopic noxious conditioning stimulation (HNCS) application. The baseline/HNCS ratio was calculated for both UL and LL.
N2 and P2 latencies did not vary between groups at each condition and limbs. Both groups showed a physiological N2/P2 amplitude and NRS reduction during the HNCS condition in UL and LL in comparison to baseline and post conditions (all, P < 0.003). Between-groups comparisons revealed a significant lower amplitude reduction in RLS at the N2/P2 amplitude during the HNCS condition only for LL (RLS, 13.6 μV; HC, 10.1 μV; P = 0.004). Such result was confirmed by the significant difference at the ratio (RLS, 69%, HC, 52.5%; P = 0.038).
The lower physiological reduction during the HNCS condition at LL in RLS patients suggests a defect in the endogenous inhibitory pain system. Further studies should clarify the causal link of this finding, also investigating the circadian modulation of this paradigm. © 2023 International Parkinson and Movement Disorder Society.
不宁腿综合征（RLS）是一种复杂的感觉运动障碍。症状在傍晚和休息时加重，运动可暂时缓解。多达 45%的病例中，症状被感知为疼痛，可能涉及伤害感受系统。
评估 RLS 患者的下行弥散性伤害性抑制控制。
21 名 RLS 患者和 21 名年龄和性别匹配的健康对照者（HC）接受了条件性疼痛调制方案。通过激光诱发的电位（LEPs）在右手（UL）和右脚（LL）的背部给予皮肤热刺激。记录 N2 和 P2 潜伏期、N2/P2 振幅和疼痛评分（NRS），分别在基线、期间和异源性伤害性条件刺激（HNCS）应用后。计算 UL 和 LL 的基线/HNCS 比值。
在每个条件和四肢下，组间 N2 和 P2 潜伏期均无差异。与基线和后条件相比，两组在 UL 和 LL 中均表现出 HNCS 条件下的 N2/P2 振幅和 NRS 生理性降低（均 P<0.003）。组间比较显示，仅在 LL 中，RLS 在 HNCS 条件下 N2/P2 振幅的振幅降低更为明显（RLS，13.6μV；HC，10.1μV；P=0.004）。这种结果在比值上也存在显著差异（RLS，69%；HC，52.5%；P=0.038）。
RLS 患者在 LL 中 HNCS 条件下生理降低减少，表明内源性抑制性疼痛系统存在缺陷。进一步的研究应阐明这一发现的因果关系，同时也应研究这一范式的昼夜节律调制。 © 2023 国际帕金森病和运动障碍学会。
