School of Medicine, National Yang-Ming University, Peitou, Taipei 112, Taiwan.
Brain. 2011 Aug;134(Pt 8):2387-95. doi: 10.1093/brain/awr157. Epub 2011 Jul 4.
Persistent aura without infarction, a rare migraine disorder, is defined by aura symptoms that persist for >1 week without radiological evidence of cerebral infarction. To unveil its pathophysiological mechanisms, this study used magnetoencephalography to characterize the visual cortex excitability in persistent aura by comparison with episodic and chronic migraine. We recruited six patients with persistent visual aura, 39 patients with episodic migraine [12 in ictal phase; 27 in interictal phase (with aura, n = 9; without aura, n = 18)], 18 patients with chronic migraine and 24 healthy controls. Five sequential blocks of 50 neuromagnetic prominent 100 ms responses were obtained, and the dynamic change in visual cortex excitability was evaluated by the percentage changes of individual mean prominent 100 ms amplitudes at blocks 2-5 compared with block 1, with a significant increase indicating potentiation. We found that in patients with persistent aura, there was significant potentiation during ictal periods (P = 0.009 and 0.006 at blocks 2 and 5, respectively), and the excitability change was inversely correlated with the duration of aura persistence (correlation coefficient -0.812, P = 0.050, block 2). The interictal recordings (n = 3) also showed potentiation. In terms of the other migraine spectrum disorders, persistent aura differed from episodic migraine in the presence of ictal potentiation. Persistent aura further differed from chronic migraine in the absence of interictal potentiation in chronic migraine. There was a higher percentage change of response amplitude at the end of stimulation (block 5) in persistent aura (43.3 ± 11.7) than in chronic migraine (-7.6 ± 5.5, P = 0.006) and ictal recordings of episodic migraine (-4.9 ± 9.6, P = 0.020). Normal control subjects had no significant response changes. This magnetoencephalographic study showed that the visual cortex in patients with persistent visual aura maintains a steady-state hyperexcitability without significant dynamic modulation. The excitability characteristic supports persistent visual aura as a nosological entity in migraine spectrum disorders and suggests a pathophysiological link to sustained excitatory effects possibly related to reverberating cortical spreading depression.
持久先兆而无梗死，一种罕见的偏头痛疾病，其定义为先兆症状持续>1 周，而无脑梗死的影像学证据。为了揭示其病理生理机制，本研究使用脑磁图比较发作性偏头痛和慢性偏头痛来描述持久先兆的视觉皮层兴奋性。我们招募了 6 名持续性视觉先兆患者、39 名发作性偏头痛患者[发作期 12 名；间歇期（有先兆，n=9；无先兆，n=18）27 名]、18 名慢性偏头痛患者和 24 名健康对照者。获得了 5 个 50 个突出的 100ms 神经磁响应的连续块，通过与第 1 块相比，第 2-5 块中个体平均突出的 100ms 幅度的百分比变化来评估视觉皮层兴奋性的动态变化，显著增加表示增强。我们发现，在持续性先兆患者中，在发作期存在显著增强（第 2 块和第 5 块分别为 P=0.009 和 0.006），且兴奋度变化与先兆持续时间呈负相关（相关系数-0.812，P=0.050，第 2 块）。间歇期记录（n=3）也显示出增强。在其他偏头痛谱障碍方面，持续性先兆与发作性偏头痛的区别在于存在发作期增强。与慢性偏头痛相比，持续性先兆进一步的区别在于慢性偏头痛中没有间歇期增强。在持续性先兆（43.3±11.7）中，刺激结束时的反应幅度变化百分比更高（第 5 块），而在慢性偏头痛（-7.6±5.5，P=0.006）和发作性偏头痛的发作记录中则更低（-4.9±9.6，P=0.020）。正常对照组没有明显的反应变化。这项脑磁图研究表明，持续性视觉先兆患者的视觉皮层保持稳定的超兴奋性，没有明显的动态调节。兴奋性特征支持持续性视觉先兆作为偏头痛谱障碍中的一个病种实体，并提示与持续兴奋效应有关的病理生理联系，可能与皮层扩散性抑制的回荡有关。
