Ashina M, Bendtsen L, Jensen R, Lassen L H, Sakai F, Olesen J
Department of Neurology, Glostrup Hospital, University of Copenhagen, Denmark and Department of Medicine, Kitasato University, Sagamihara, Japan.
Brain. 1999 Sep;122 ( Pt 9):1629-35. doi: 10.1093/brain/122.9.1629.
It has been demonstrated recently that nitric oxide synthase (NOS) inhibition has an analgesic effect in patients with chronic tension-type headache. The aim of the present study was to investigate the influence of the NOS inhibitor, L-N(G) methyl arginine hydrochloride (L-NMMA), on two of the most prominent features of chronic tension-type headache, i.e. increased muscle hardness and increased myofascial tenderness. In a double blind, crossover designed trial, 16 patients with chronic tension-type headache were randomized to receive intravenous infusion of 6 mg/kg L-NMMA or placebo on 2 days separated by at least 1 week. Muscle hardness of the trapezius muscle was measured with a hardness meter. Myofascial tenderness in the pericranial region was evaluated by manual palpation with standardized and validated methodology. All parameters were recorded at baseline and at 60 and 120 min after start of infusion. Compared with baseline, muscle hardness, 107 +/- 17 kPa/cm and tenderness, 18 +/- 11 were significantly reduced at 60 and 120 min to: hardness, 101 +/- 17 kPa/cm and 101 +/- 17 kPa/cm, respectively; tenderness, 15 +/- 11 and 14 +/- 11, respectively, after treatment with L-NMMA (P < 0.05 and P < 0.01, respectively), while there was no significant reduction at any time after treatment with the placebo. Compared with the placebo, the summary score of muscle hardness was significantly reduced (P = 0.04), while tenderness showed a non-significant reduction (P = 0.11) following treatment with L-NMMA. Since increased muscle hardness in patients with chronic tension-type headache may reflect sensitization of second order neurons due to prolonged nociceptive input from myofascial tissues, we suggest that the decrease in muscle hardness following treatment with L-NMMA may be caused by reduction of central sensitization.
最近已证实，一氧化氮合酶（NOS）抑制对慢性紧张型头痛患者具有镇痛作用。本研究的目的是探讨NOS抑制剂L-N(G)甲基精氨酸盐酸盐（L-NMMA）对慢性紧张型头痛两个最突出特征的影响，即肌肉硬度增加和肌筋膜压痛增加。在一项双盲、交叉设计的试验中，16例慢性紧张型头痛患者被随机分为两组，在至少间隔1周的2天内分别接受静脉输注6mg/kg的L-NMMA或安慰剂。用硬度计测量斜方肌的肌肉硬度。采用标准化且经过验证的方法通过手动触诊评估颅周区域的肌筋膜压痛。在输注开始时、60分钟和120分钟记录所有参数。与基线相比，L-NMMA治疗后60分钟和120分钟时，肌肉硬度（107±17kPa/cm）和压痛（18±11）显著降低至：硬度分别为101±17kPa/cm和101±17kPa/cm；压痛分别为15±11和14±11（P分别<0.05和P<0.01），而安慰剂治疗后任何时间均无显著降低。与安慰剂相比，L-NMMA治疗后肌肉硬度的汇总评分显著降低（P=0.04），而压痛虽有降低但无统计学意义（P=0.11）。由于慢性紧张型头痛患者肌肉硬度增加可能反映了由于肌筋膜组织长期伤害性输入导致的二级神经元敏化，我们认为L-NMMA治疗后肌肉硬度降低可能是由于中枢敏化的减轻所致。
