Department of Physical Therapy, School of Health Professions, Sackler Faculty of Medicine Tel Aviv University, Israel.
Sagol School of Neuroscience, Tel-Aviv University, Israel.
Pain Med. 2021 Oct 8;22(10):2311-2323. doi: 10.1093/pm/pnab103.
About one-third of patients with multiple sclerosis (MS) suffers from chronic and excruciating central neuropathic pain (CNP). The mechanism underlying CNP in MS is not clear, since previous studies are scarce and their results are inconsistent. Our aim was to determine whether CNP in MS is associated with impairment of the spinothalamic-thalamocortical pathways (STTCs) and/or increased excitability of the pain system.
The study was cross-sectional.
The study was conducted at a general hospital.
Participants were 47 MS patients with CNP, 42 MS patients without CNP and 32 healthy controls.
Sensory testing included the measurement of temperature, pain, and touch thresholds and the thermal grill illusion for evaluating STTCs function and hyperpathia and allodynia as indicators of hyperexcitability. CNP was characterized using interviews and questionnaires.
The CNP group had higher cold and warm thresholds (P < 0.01), as well as higher thermal grill illusion perception thresholds (P < 0.05), especially in painful body regions compared with controls, whereas touch and pain thresholds values were normal. The CNP group also had a significantly greater prevalence of hyperpathia and allodynia. Regression analysis revealed that whereas presence of CNP was associated with a higher cold threshold, CNP intensity and the number of painful body regions were associated with allodynia and hyperpathia, respectively.
CNP in MS is characterized by a specific impairment of STTC function, the innocuous thermal pathways, and by pain hyperexcitability. Whereas CNP presence is associated with STTC impairment, its severity and extent are associated with pain hyperexcitability. Interventions that reduce excitability level may therefore mitigate CNP severity.
约三分之一的多发性硬化症（MS）患者患有慢性剧烈中枢性神经痛（CNP）。MS 中 CNP 的发病机制尚不清楚，因为先前的研究很少且结果不一致。我们的目的是确定 MS 中的 CNP 是否与脊髓丘脑-丘脑皮质通路（STTCs）的损伤以及/或疼痛系统兴奋性的增加有关。
本研究为横断面研究。
本研究在一家综合医院进行。
参与者为 47 名有 CNP 的 MS 患者、42 名无 CNP 的 MS 患者和 32 名健康对照者。
感觉测试包括测量温度、疼痛和触觉阈值以及热格栅错觉，以评估 STTCs 功能和超敏反应及感觉异常作为兴奋性增加的指标。CNP 采用访谈和问卷调查进行评估。
CNP 组的冷觉和温觉阈值较高（P<0.01），热格栅错觉感知阈值也较高（P<0.05），尤其是在疼痛身体部位，而触觉和疼痛阈值正常。CNP 组超敏反应和感觉异常的发生率也显著更高。回归分析显示，存在 CNP 与冷觉阈值升高有关，而 CNP 强度和疼痛身体部位数量分别与感觉异常和超敏反应有关。
MS 中的 CNP 表现为 STTC 功能、无害热通路的特定损伤以及疼痛兴奋性增加。尽管 CNP 的存在与 STTC 损伤有关，但 CNP 的严重程度和范围与疼痛兴奋性增加有关。因此，降低兴奋性水平的干预措施可能会减轻 CNP 的严重程度。
