Department of Biomedicine, Neuroscience and Advanced Diagnostics (BIND), University of Palermo, Palermo, Italy.
Department of Psychology, Milan Center for Neuroscience - NeuroMi, University of Milano-Bicocca, Milano, Italy; Laboratory of Neuropsychology, IRCSS Istituto Auxologico, Milano, Italy.
J Pain. 2020 Jul-Aug;21(7-8):919-929. doi: 10.1016/j.jpain.2019.12.005. Epub 2020 Jan 3.
Multisensory processing can be assessed by measuring susceptibility to crossmodal illusions such as the Sound-Induced Flash Illusion (SIFI). When a single flash is accompanied by 2 or more beeps, it is perceived as multiple flashes (fission illusion); conversely, a fusion illusion is experienced when more flashes are matched with a single beep, leading to the perception of a single flash. Such illusory perceptions are associated to crossmodal changes in visual cortical excitability. Indeed, increasing occipital cortical excitability, by means of transcranial electrical currents, disrupts the SIFI (ie, fission illusion). Similarly, a reduced fission illusion was shown in patients with episodic migraine, especially during the attack, in agreement with the pathophysiological model of cortical hyperexcitability of this disease. If episodic migraine patients present with reduced SIFI especially during the attack, we hypothesize that chronic migraine (CM) patients should consistently report less illusory effects than healthy controls; drugs intake could also affect SIFI. On such a basis, we studied the proneness to SIFI in CM patients (n = 63), including 52 patients with Medication Overuse Headache (MOH), compared to 24 healthy controls. All migraine patients showed reduced fission phenomena than controls (P < .0001). Triptan MOH patients (n = 23) presented significantly less fission effects than other CM groups (P = .008). This exploratory study suggests that CM - both with and without medication overuse - is associated to a higher visual cortical responsiveness which causes deficit of multisensorial processing, as assessed by the SIFI. PERSPECTIVE: This observational study shows reduced susceptibility to the SIFI in CM, confirming and extending previous results in episodic migraine. MOH contributes to this phenomenon, especially in case of triptans.
多感觉处理可以通过测量对跨感觉错觉的敏感性来评估，例如声音诱导闪光错觉（SIFI）。当单个闪光伴随着 2 个或更多的哔哔声时，它被感知为多个闪光（裂变错觉）；相反，当更多的闪光与单个哔哔声匹配时，会产生融合错觉，导致单个闪光的感知。这种幻觉与视觉皮层兴奋性的跨感觉变化有关。事实上，通过经颅电流增加枕叶皮层兴奋性会破坏 SIFI（即裂变错觉）。同样，在发作期间，发作性偏头痛患者（尤其是在发作期间）的裂变错觉减少，与这种疾病的皮层过度兴奋性的病理生理模型一致。如果发作性偏头痛患者在发作期间 SIFI 减少，我们假设慢性偏头痛（CM）患者应该比健康对照组报告的幻觉效应更少；药物摄入也可能影响 SIFI。基于此，我们研究了 63 例 CM 患者（包括 52 例药物过度使用性头痛（MOH）患者）对 SIFI 的易感性，与 24 例健康对照组进行比较。与对照组相比，所有偏头痛患者的裂变现象均减少（P <.0001）。曲坦类 MOH 患者（n=23）的裂变效应明显低于其他 CM 组（P=.008）。这项探索性研究表明，CM - 无论是伴有还是不伴有药物过度使用 - 与更高的视觉皮层反应性相关，这会导致多感觉处理缺陷，如 SIFI 评估所示。观点：这项观察性研究表明 CM 对 SIFI 的敏感性降低，证实并扩展了先前在发作性偏头痛中的结果。MOH 导致了这种现象，尤其是在曲坦类药物的情况下。
