背景:视觉雪综合征是一种以典型的感知障碍为特征的疾病。临床表现表明视觉过滤机制受损,可能涉及原发性和继发性视觉大脑区域,以及高阶注意力网络。在皮层振荡的层面上,alpha节律是一种突出的EEG模式,涉及视觉信息的优先级。可以将其视为视觉网络内的抑制性调制的关联。
方法:将21名视觉雪花综合征患者与21名年龄相匹配的对照组进行比较,性别,还有偏头痛.我们通过使用快速傅里叶变换识别个体α峰频率,然后计算个体α峰周围的功率谱密度(+/-1Hz)来分析静息状态α节律。我们预计视觉雪综合症参与者的主要视觉皮层的α波段功率谱密度会降低。
结果:枕骨电极(O1和O2)上的α波段功率谱密度没有显着差异,导致我们的主要假设被拒绝。然而,在颞叶和顶叶电极上,α波段的功率谱密度显着降低。在没有共病偏头痛的参与者亚组中,个体α峰频率也有增加的趋势。
结论:我们的主要发现是顶叶和颞叶大脑区域对应于次级视觉皮层区域的α谱带的功率谱密度降低。这些发现在电生理水平上补充了先前的功能和结构成像数据。他们强调了高阶视觉大脑区域的参与,并可能反映抑制性自上而下调制的干扰。α节律改变可能代表特定神经调节的新目标。
背景:我们在osf.org平台(DOI:https://doi.org/10.17605/OSF进行预处理和数据分析之前预先注册了研究。IO/XPQHF,注册日期:2022年11月19日)。
BACKGROUND: Visual snow syndrome is a disorder characterized by the combination of typical perceptual disturbances. The clinical picture suggests an impairment of visual filtering mechanisms and might involve primary and secondary visual brain areas, as well as higher-order attentional networks. On the level of cortical oscillations, the alpha rhythm is a prominent EEG pattern that is involved in the prioritisation of visual information. It can be regarded as a correlate of inhibitory modulation within the visual network.
METHODS: Twenty-one patients with visual snow syndrome were compared to 21 controls matched for age, sex, and migraine. We analysed the resting-state alpha rhythm by identifying the individual alpha peak frequency using a Fast Fourier Transform and then calculating the power spectral density around the individual alpha peak (+/- 1 Hz). We anticipated a reduced power spectral density in the alpha band over the primary visual cortex in participants with visual snow syndrome.
RESULTS: There were no significant differences in the power spectral density in the alpha band over the occipital electrodes (O1 and O2), leading to the rejection of our primary hypothesis. However, the power spectral density in the alpha band was significantly reduced over temporal and parietal electrodes. There was also a trend towards increased individual alpha peak frequency in the subgroup of participants without comorbid migraine.
CONCLUSIONS: Our main finding was a decreased power spectral density in the alpha band over parietal and temporal brain regions corresponding to areas of the secondary visual cortex. These findings complement previous functional and structural imaging data at a electrophysiological level. They underscore the involvement of higher-order visual brain areas, and potentially reflect a disturbance in inhibitory top-down modulation. The alpha rhythm alterations might represent a novel target for specific neuromodulation.
BACKGROUND: we preregistered the study before preprocessing and data analysis on the platform osf.org (DOI: https://doi.org/10.17605/OSF.IO/XPQHF , date of registration: November 19th 2022).