Granot M, Buskila D, Granovsky Y, Sprecher E, Neumann L, Yarnitsky D
Department of Neurology, Rambam Medical Center, and Technion Faculty of Medicine, Haifa, Israel.
Clin Neurophysiol. 2001 Oct;112(10):1881-7. doi: 10.1016/s1388-2457(01)00646-0.
To characterize laser evoked potentials (LEP), pain psychophysics and local tissue response in fibromyalgia patients.
LEP were recorded in 14 women with fibromyalgia in response to bilateral stimulation of tender and control points in upper limbs by 4 blocks of 20 stimuli at each point. Subsequently, heat pain thresholds were measured and supra-threshold magnitude estimations of heat pain stimuli were obtained on a visual analogue scale. Finally, the extent of the local tissue response induced by the previous stimuli was evaluated.
Laser stimuli elicited two long latency waves: A late wave (mean latency 368.9+/-66.9 ms) in most patients (13/14) from stimuli at all points, and an ultra-late wave (mean latency 917.3+/-91.8 ms) in 78.5% of the patients at the control points and in 71.4% at the tender points. Amplitude of ultra-late waves was higher at the tender points (20.67+/-11.1 microV) than at the control points (10.47+/-4.1 microV) (P=0.016). Pain thresholds were lower in the tender (41.2+/-2.7 degrees C) than the control points (43.9+/-3.2 degrees C) (P=0.008). Local tissue response was significantly more intense at tender than control points (P=0.004).
Ultra-late laser evoked potentials can be recorded simultaneously with late potentials. Our findings are compatible with presence of peripheral C-fiber sensitization, mostly at tender points, probably combined with generalized central sensitization of pain pathways in fibromyalgia.
对纤维肌痛患者的激光诱发电位（LEP）、疼痛心理物理学及局部组织反应进行特征描述。
对14名纤维肌痛女性患者进行LEP记录，通过对上肢的压痛点和对照点进行双侧刺激，每个点进行4组，每组20次刺激。随后，测量热痛阈值，并在视觉模拟量表上获得热痛刺激的阈上强度估计值。最后，评估先前刺激引起的局部组织反应程度。
激光刺激引发两个长潜伏期波：大多数患者（13/14）在所有点的刺激下均出现一个晚期波（平均潜伏期368.9±66.9毫秒），78.5%的患者在对照点和71.4%的患者在压痛点出现一个超晚期波（平均潜伏期917.3±91.8毫秒）。超晚期波在压痛点的振幅（20.67±11.1微伏）高于对照点（10.47±4.1微伏）（P = 0.016）。压痛点的疼痛阈值（41.2±2.7℃）低于对照点（43.9±3.2℃）（P = 0.008）。压痛点的局部组织反应明显比对照点强烈（P = 0.004）。
超晚期激光诱发电位可与晚期电位同时记录。我们的研究结果与外周C纤维致敏的存在相符，主要在压痛点，可能与纤维肌痛中疼痛通路的全身性中枢致敏相结合。
