Journal Article

Brain network dynamics in people with visual snow syndrome

Strik, Myrte, Clough, Meaghan, Glarin, Rebecca, Kolbe, Scott C., White, Owen B., Solly, Emma J., Fielding, Joanne

2023

Overview

Visual snow syndrome (VSS) is a neurological disorder characterized by a range of continuous visual disturbances. Little is known about the functional pathological mechanisms underlying VSS and their effect on brain network topology, studied using high‐resolution resting‐state (RS) 7 T MRI. Forty VSS patients and 60 healthy controls underwent RS MRI. Functional connectivity matrices were calculated, and global efficiency (network integration), modularity (network segregation), local efficiency (LE, connectedness neighbors) and eigenvector centrality (significance node in network) were derived using a dynamic approach (temporal fluctuations during acquisition). Network measures were compared between groups, with regions of significant difference correlated with known aberrant ocular motor VSS metrics (shortened latencies and higher number of inhibitory errors) in VSS patients. Lastly, nodal co‐modularity, a binary measure of node pairs belonging to the same module, was studied. VSS patients had lower modularity, supramarginal centrality and LE dynamics of multiple (sub)cortical regions, centered around occipital and parietal lobules. In VSS patients, lateral occipital cortex LE dynamics correlated positively with shortened prosaccade latencies (p = .041, r = .353). In VSS patients, occipital, parietal, and motor nodes belonged more often to the same module and demonstrated lower nodal co‐modularity with temporal and frontal regions. This study revealed reduced dynamic variation in modularity and local efficiency strength in the VSS brain, suggesting that brain network dynamics are less variable in terms of segregation and local clustering. Further investigation of these changes could inform our understanding of the pathogenesis of the disorder and potentially lead to treatment strategies. Visual snow syndrome (VSS) is a neurological disorder characterized by a range of continuous visual disturbances. Little is known about the functional pathological mechanisms underlying VSS and their effect on brain network topology, which was studied using high‐resolution resting‐state 7 T MRI. VSS patients demonstrated reduced dynamic variation in modularity and local efficiency strength, suggesting that brain network dynamics are less variable in terms of segregation and local clustering. Network dynamic alterations were centered around occipital cortices and related to ocular motor processing changes.

• Publisher: John Wiley & Sons, Inc
• Subject: 7 T MRI / Anxiety / Brain / Brain - diagnostic imaging / Clustering / Comparative analysis / Drug use / Dynamics / Eigenvectors / Eye movements / Functional magnetic resonance imaging / Humans / Magnetic Resonance Imaging / Mathematical analysis / Medical research / Medicine, Experimental / Migraine / Modularity / Modules / Nervous system diseases / Network switching / Network topologies / network topology / Neural networks / Neurological diseases / Neurological disorders / Occipital Lobe / ocular motor behavior / Parietal Lobe / Pathogenesis / Patients / Post traumatic stress disorder / resting‐state functional MRI / Saccadic eye movements / Snow / Temporal cortex / Topology / ultra‐high field MRI / Vision Disorders / visual snow / visual snow syndrome