Alterations in Resting‐State Functional Brain Connectivity and Correlations with Vestibular/Ocular‐Motor Screening Measures in Postconcussion Vestibular Dysfunction

Abstract

BACKGROUND AND PURPOSE: Vestibular symptoms after concussion are common and associated with protracted recovery. The purpose of this study is to define resting‐state functional MRI (rs‐fMRI) brain connectivity alterations in patients with postconcussion vestibular dysfunction (PCVD) and correlations between rs‐fMRI connectivity and symptoms provoked during Vestibular/Ocular‐Motor Screening (VOMS) assessment. METHODS: Prospective IRB approved study. Study group: 12 subjects with subacute PCVD (2‐10 weeks); control group: 10 age‐matched subjects without history of concussion or vestibular impairment. Both groups underwent clinical vestibular assessment. rs‐fMRI was acquired on 3.0T Siemens Trio with a 12‐channel head coil. rs‐fMRI data analysis included independent component analysis‐based functional connectivity group differences, graph theory analysis, and ROI‐to‐ROI connectivity correlation analysis with VOMS clinical derivatives. Group difference maps between resting‐state networks were calculated using dual regression method and corrected for multiple comparisons. Correlation analysis between ROI‐to‐ROI rs‐fMRI brain activation and VOMS assessment ratings was performed using Pearson correlation coefficient, with a significance threshold of P≤ .05. RESULTS: Compared to controls, PCVD group demonstrated significantly increased rs‐fMRI connectivity between the default‐mode network and right middle frontal gyrus and right postcentral gyrus; and between a vestibular‐sensorimotor network and right prefrontal cortex. Significant positive correlations were found between clinical derivative VOMS scores and components of the vestibular, visual networks, and multisensory processing cortical representations. CONCLUSION: Altered rs‐fMRI brain connectivity with increased connectivity of visual input, multisensory processing, and spatial memory in PCVD is correlative with clinical derivative VOMS scores, suggesting maladaptive brain plasticity underlying vestibular symptomatology.