Department of Systems Neuroscience, University Medical Center Hamburg-Eppendorf, Germany.
Pain. 2010 Oct;151(1):97-103. doi: 10.1016/j.pain.2010.06.024. Epub 2010 Jul 16.
Habituation deficits in various sensory modalities have been observed in migraine patients in several experimental designs. The underlying neuronal mechanisms are, however, still unknown. Past studies have used electrophysiological measures and focussed on habituation behaviour during one single session. We were interested in how repeated painful stimulation over several days is processed, perceived and modulated in migraineurs. Fifteen migraine patients and 15 healthy controls were stimulated daily with a 20 min trigeminal pain paradigm for eight consecutive days, using functional MRI performed on days one and eight and one follow-up measurement three months later. The results demonstrate that migraine patients did not differ in behavioural pain ratings compared to the controls at any time. However, functional imaging data revealed a significant difference in several brain areas over time. The activity level in the prefrontal cortex (PFC) and the rostral anterior cingulate cortex (rACC) increased in healthy control subjects from day one to day eight, whereas it decreased in migraine patients. These data suggest that several brain areas known to be involved in endogenous pain control show a completely opposite behaviour in migraine patients compared to healthy controls. These brain networks seem not to be disrupted per se in migraine patients but changed activity over time responding to repetitive nociceptive input. The alteration of pain inhibitory circuits may be the underlying mechanism responsible for the dys-functional neuronal filters of sensory input.
在各种感觉模态中观察到偏头痛患者在几种实验设计中的习惯化缺陷。然而，潜在的神经元机制仍然未知。过去的研究使用了电生理测量方法，并集中在单次会话期间的习惯化行为上。我们感兴趣的是，在偏头痛患者中，经过几天的重复疼痛刺激是如何被处理、感知和调节的。15 名偏头痛患者和 15 名健康对照者在连续 8 天内每天接受 20 分钟三叉神经疼痛范式的刺激，在第 1 天和第 8 天进行功能磁共振成像，并在 3 个月后进行一次随访测量。结果表明，偏头痛患者在任何时候的行为疼痛评分与对照组均无差异。然而，功能成像数据显示，随着时间的推移，几个大脑区域存在显著差异。健康对照组的前额叶皮层（PFC）和前扣带回皮质的活动水平从第 1 天到第 8 天增加，而偏头痛患者则减少。这些数据表明，已知参与内源性疼痛控制的几个大脑区域在偏头痛患者中表现出与健康对照组完全相反的行为。这些大脑网络本身在偏头痛患者中似乎没有受到干扰，但随着时间的推移，它们对重复伤害性输入的反应发生了变化。疼痛抑制回路的改变可能是感觉输入功能障碍神经元滤波器的潜在机制。
