Disrupted connectivity within visual, attentional and salience networks in the visual snow syndrome

• Main Authors: Ffytche, D. (Author), Goadsby, P.J (Author), O'Daly, O. (Author), Puledda, F. (Author), Schankin, C. (Author), Williams, S.C.R (Author)
• Format: Article
• Language: English
• Published: John Wiley and Sons Inc 2021
• Subjects: adult; Adult; Article; attention; Attention; attention network; basal ganglion; brain; Brain; brain function; cerebellum; clinical article; clinical study; comorbidity; connectome; Connectome; controlled study; diagnostic imaging; female; Female; follow up; functional connectivity; functional magnetic resonance imaging; human; Humans; lingual gyrus; magnetic resonance imaging; Magnetic Resonance Imaging; male; Male; migraine; nerve cell network; Nerve Net; neurologic disease; nuclear magnetic resonance imaging; pathophysiology; photophobia; physiology; post hoc analysis; posterior cingulate; precuneus; priority journal; prolonged visual disturbance; pulvinar; salience network; sensory stimulation; thalamus; vision; Vision Disorders; visual disorder; visual motion network; visual network; Visual Perception; visual snow syndrome; visual stimulation; visual system; young adult; Young Adult
• Online Access: View Fulltext in Publisher

 Here we investigate brain functional connectivity in patients with visual snow syndrome (VSS). Our main objective was to understand more about the underlying pathophysiology of this neurological syndrome. Twenty-four patients with VSS and an equal number of gender and age-matched healthy volunteers attended MRI sessions in which whole-brain maps of functional connectivity were acquired under two conditions: at rest while watching a blank screen and during a visual paradigm consisting of a visual-snow like stimulus. Eight unilateral seed regions were selected a priori based on previous observations and hypotheses; four seeds were placed in key anatomical areas of the visual pathways and the remaining were derived from a pre-existing functional analysis. The between-group analysis showed that patients with VSS had hyper and hypoconnectivity between key visual areas and the rest of the brain, both in the resting state and during a visual stimulation, compared with controls. We found altered connectivity internally within the visual network; between the thalamus/basal ganglia and the lingual gyrus; between the visual motion network and both the default mode and attentional networks. Further, patients with VSS presented decreased connectivity during external sensory input within the salience network, and between V5 and precuneus. Our results suggest that VSS is characterised by a widespread disturbance in the functional connectivity of several brain systems. This dysfunction involves the pre-cortical and cortical visual pathways, the visual motion network, the attentional networks and finally the salience network; further, it represents evidence of ongoing alterations both at rest and during visual stimulus processing. © 2021 The Authors. Human Brain Mapping published by Wiley Periodicals LLC.