Department of Systems Neuroscience, University Medical Center Hamburg-Eppendorf, D-20246 Hamburg, Germany.
J Neurosci. 2011 Feb 9;31(6):1937-43. doi: 10.1523/JNEUROSCI.4496-10.2011.
Several lines of evidence suggest a major role of the trigeminovascular system in the pathogenesis of migraine. Using functional magnetic resonance imaging (fMRI), we compared brain responses during trigeminal pain processing in migraine patients with those of healthy control subjects. The main finding is that the activity of the spinal trigeminal nuclei in response to nociceptive stimulation showed a cycling behavior over the migraine interval. Although interictal (i.e., outside of attack) migraine patients revealed lower activations in the spinal trigeminal nuclei compared with controls, preictal (i.e., shortly before attack) patients showed activity similar to controls, which demonstrates that the trigeminal activation level increases over the pain-free migraine interval. Remarkably, the distance to the next headache attack was predictable by the height of the signal intensities in the spinal nuclei. Migraine patients scanned during the acute spontaneous migraine attack showed significantly lower signal intensities in the trigeminal nuclei compared with controls, demonstrating activity levels similar to interictal patients. Additionally we found-for the first time using fMRI-that migraineurs showed a significant increase in activation of dorsal parts of the pons, previously coined "migraine generator." Unlike the dorsal pons activation usually linked to migraine attacks, the gradient-like activity following nociceptive stimulation in the spinal trigeminal neurons likely reflects a raise in susceptibility of the brain to generate the next attack, as these areas increase their activity long before headache starts. This oscillating behavior may be a key player in the generation of migraine headache, whereas attack-specific pons activations are most likely a secondary event.
有几条证据表明三叉血管系统在偏头痛的发病机制中起着重要作用。我们使用功能磁共振成像（fMRI）比较了偏头痛患者和健康对照者在三叉神经疼痛处理过程中的大脑反应。主要发现是，对伤害性刺激的脊髓三叉神经核的活动表现出偏头痛间歇期的循环行为。虽然间歇期（即发作期之外）偏头痛患者的脊髓三叉神经核的活动比对照组低，但发作前期（即发作前）患者的活动与对照组相似，这表明三叉神经的激活水平在无疼痛的偏头痛间歇期内增加。值得注意的是，下一次头痛发作的距离可以通过脊髓核信号强度的高度来预测。在急性自发性偏头痛发作期间接受扫描的偏头痛患者的三叉神经核的信号强度明显低于对照组，表明其活动水平与间歇期患者相似。此外，我们首次使用 fMRI 发现，偏头痛患者的脑桥背侧部分的激活显著增加，此前被称为“偏头痛发生器”。与通常与偏头痛发作相关的脑桥背侧激活不同，伤害性刺激后脊髓三叉神经神经元的梯度样活动可能反映了大脑产生下一次发作的敏感性增加，因为这些区域在头痛开始之前很久就增加了它们的活动。这种振荡行为可能是偏头痛头痛产生的关键因素，而与发作相关的脑桥激活很可能是次要事件。
