Department of Neurology, Inselspital, University Hospital Bern, University of Bern, Bern, Switzerland.
Department of Neurology, University of California, San Francisco, San Francisco, CA, USA.
Brain. 2020 Apr 1;143(4):1106-1113. doi: 10.1093/brain/awaa053.
Patients with visual snow syndrome suffer from a continuous pan-field visual disturbance, additional visual symptoms, tinnitus, and non-perceptional symptoms. The pathophysiology of visual symptoms might involve dysfunctional visual cortex. So far, the extra-visual system has not been investigated. We aimed at identifying structural and functional correlates for visual and non-visual symptoms in visual snow syndrome. Patients were compared to age- and sex-matched controls using 18F-2-fluoro-2-deoxy-d-glucose PET (n = 20 per group) and voxel-based morphometry (n = 17 per group). Guided by the PET results, region of interest analysis was done in voxel-based morphometry to identify structural-functional correspondence. Grey matter volume was assessed globally. Patients had corresponding hypermetabolism and cortical volume increase in the extrastriate visual cortex at the junction of the right lingual and fusiform gyrus. There was hypometabolism in the right superior temporal gyrus and the left inferior parietal lobule. Patients had grey matter volume increases in the temporal and limbic lobes and decrease in the superior temporal gyrus. The corresponding structural and functional alterations emphasize the relevance of the visual association cortex for visual snow syndrome. The broad structural and functional footprint, however, confirms the clinical impression that the disorder extends beyond the visual system.
视觉雪综合征患者患有持续的全视野视觉障碍、附加视觉症状、耳鸣和非知觉症状。视觉症状的病理生理学可能涉及功能失调的视觉皮层。到目前为止，尚未研究过视觉外系统。我们旨在确定视觉雪综合征的视觉和非视觉症状的结构和功能相关性。使用 18F-2-氟-2-脱氧-d-葡萄糖正电子发射断层扫描 (n = 20 组) 和基于体素的形态测量学 (n = 17 组)，将患者与年龄和性别匹配的对照组进行比较。根据 PET 结果，在基于体素的形态测量学中进行了感兴趣区分析，以确定结构-功能对应关系。全局评估灰质体积。患者在右侧舌回和梭状回交界处的视皮层外区域存在相应的代谢亢进和皮质体积增加。右侧颞上回和左侧顶下小叶代谢减少。患者的颞叶和边缘叶灰质体积增加，颞上回灰质体积减少。相应的结构和功能改变强调了视觉联合皮层对视觉雪综合征的重要性。然而，广泛的结构和功能足迹证实了临床印象，即该疾病不仅局限于视觉系统。
