Maccora Simona, Giglia Giuseppe, Bolognini Nadia, Cosentino Giuseppe, Gangitano Massimo, Salemi Giuseppe, Brighina Filippo
Department of Biomedicine, Neuroscience and Advanced Diagnostics (BIND), University of Palermo, Palermo, Italy.
Department of Psychology & NeuroMi Milan Center for Neuroscience, University of Milan Bicocca, Milan, Italy.
Front Hum Neurosci. 2019 Jul 17;13:247. doi: 10.3389/fnhum.2019.00247. eCollection 2019.
Migraine is a highly disabling disease characterized by recurrent pain. Despite an intensive effort, mechanisms of migraine pathophysiology still represent an unsolved issue. Evidence from both animal and human studies suggests that migraine is characterized by hyperresponsivity or hyperexcitability of sensory cortices, especially the visual cortex. This phenomenon, in turn, may affect multisensory processing. Indeed, migraineurs present with an abnormal, reduced, perception of the Sound-induced Flash Illusion (SiFI), a crossmodal illusion that relies on optimal integration of visual and auditory stimuli by the occipital visual cortex. Decreasing visual cortical excitability with transcranial direct current stimulation (tDCS) can increase the SiFI in healthy subjects. Moving away from these issues, we applied cathodal tDCS over the visual cortex of migraineurs, with and without aura, in order to decrease cortical excitability and thus physiologically restoring the perception of a reliable SiFI. Differently from our expectations, tDCS was unable to reliably modulate SiFI in migraine. The chronic, relatively excessive, visual cortex hyperexcitability, featuring the migraineur brain, may render tDCS ineffective for restoring multisensory processing in this disease.
偏头痛是一种以反复发作为特征的高度致残性疾病。尽管人们付出了巨大努力，但偏头痛病理生理学的机制仍然是一个未解之谜。来自动物和人体研究的证据表明，偏头痛的特征是感觉皮层，尤其是视觉皮层的反应过度或过度兴奋。反过来，这种现象可能会影响多感官处理。事实上，偏头痛患者对声音诱发闪光错觉（SiFI）的感知异常、降低，SiFI是一种跨模态错觉，依赖于枕叶视觉皮层对视觉和听觉刺激的最佳整合。通过经颅直流电刺激（tDCS）降低视觉皮层兴奋性可以增加健康受试者的SiFI。撇开这些问题不谈，我们对有或无先兆的偏头痛患者的视觉皮层施加阴极tDCS，以降低皮层兴奋性，从而在生理上恢复对可靠SiFI的感知。与我们的预期不同，tDCS无法可靠地调节偏头痛患者的SiFI。以偏头痛患者大脑为特征的慢性、相对过度的视觉皮层过度兴奋，可能使tDCS在恢复该疾病的多感官处理方面无效。
