Buchgreitz L, Egsgaard L L, Jensen R, Arendt-Nielsen L, Bendtsen L
Department of Neurology, Danish Headache Center, Glostrup Hospital, University of Copenhagen, Nordre Ringvej, Glostrup, Copenhagen, Denmark.
Brain. 2008 Dec;131(Pt 12):3232-8. doi: 10.1093/brain/awn199. Epub 2008 Aug 30.
Central sensitization caused by prolonged nociceptive input from muscles is considered to play an important role for chronification of tension-type headache. In the present study we used a new high-density EEG brain mapping technique to investigate spatiotemporal aspects of brain activity in response to muscle pain in 19 patients with chronic tension-type headache (CTTH) and 19 healthy, age- and sex-matched controls. Intramuscular electrical stimuli (single and train of five pulses delivered at 2 Hz) were applied to the trapezius muscle and somatosensory evoked potentials were recorded with 128-channel EEG both in- and outside a condition with induced tonic neck/shoulder muscle pain (glutamate injection into the trapezius muscle). Significant reduction in magnitude during and after induced tonic muscle pain was found in controls at the P200 dipole in response to both the first (baseline versus tonic muscle pain: P = 0.001; baseline versus post-tonic muscle pain: P = 0.002) and fifth (baseline versus tonic muscle pain: P = 0.04; baseline versus post-tonic muscle pain: P = 0.04) stimulus in the train. In contrast, there were no differences between the conditions in patients. No consistent difference was found in localization or peak latency of the dipoles. The reduction in magnitude during and after induced tonic muscle pain in controls but not in patients with CTTH may be explained by impaired inhibition of the nociceptive input in these patients. This may be the first evidence that the supraspinal response to muscle pain is abnormal in patients with CTTH.
肌肉长期伤害性输入引起的中枢敏化被认为在紧张型头痛的慢性化过程中起重要作用。在本研究中，我们使用一种新的高密度脑电图脑图谱技术，调查了19例慢性紧张型头痛（CTTH）患者和19名年龄及性别匹配的健康对照者对肌肉疼痛的脑活动时空特征。对斜方肌施加肌内电刺激（单个脉冲以及以2Hz频率发放的五个脉冲串），并在诱导的紧张性颈/肩肌肉疼痛（向斜方肌注射谷氨酸）状态下及之外，用128通道脑电图记录体感诱发电位。在对照组中，诱导的紧张性肌肉疼痛期间及之后，P200偶极子对脉冲串中第一个（基线与紧张性肌肉疼痛：P = 0.001；基线与紧张性肌肉疼痛后：P = 0.002）和第五个（基线与紧张性肌肉疼痛：P = 0.04；基线与紧张性肌肉疼痛后：P = 0.04）刺激的反应幅度显著降低。相比之下，患者组不同状态之间没有差异。偶极子的定位或峰值潜伏期没有发现一致的差异。对照组在诱导的紧张性肌肉疼痛期间及之后反应幅度降低，而CTTH患者没有，这可能是由于这些患者对伤害性输入的抑制受损所致。这可能是CTTH患者脊髓上对肌肉疼痛反应异常的首个证据。
