Cognitive impairment in patients with chronic unilateral vestibulopathy: A resting-state functional MRI study

The association between cognitive impairment and chronic unilateral vestibulopathy (CUVP) remains unclear. Vestibular dysfunction is linked to increased risk of Alzheimer's disease (AD), suggesting that cognitive deficits in CUVP may provide insight into early AD-related processes.

To assess cognition in CUVP patients, and investigate its correlation with brain functional and structural changes.

37 patients with left CUVP (LCUVP), 30 patients with right CUVP (RCUVP), and 38 healthy control (HC) were recruited. Patients underwent vestibular evaluations, neuropsychological scales, functional MRI (fMRI), and structural MRI (sMRI). The fractional amplitude of low frequency fluctuations (fALFF), regional homogeneity (ReHo), functional connectivity (FC) and voxel-based morphometry (VBM) were analyzed.

Compared with HC, CUVP patients showed extensive cognitive impairment. The fALFF of right precuneus, the ReHo of right lingual gyrus and precuneus were decreased in CUVP patients, and the FC between right precuneus and bilateral angular gyrus, between right lingual gyrus and middle occipital gyrus were changed (voxel p < 0.001 and cluster p < 0.01, corrected by GRF). Exploratory correlation analyses suggested trends between brain function and cognitive/vestibular measures. Sensitivity analyses controlling for mood symptoms confirmed the robustness of most imaging findings. VBM revealed no significant gray matter differences between CUVP patients and HC.

In CUVP patients, abnormal functional activities mainly involved occipital and parietal lobes related to cognitive performance, while brain structure did not change, suggesting that functional brain alterations may be more sensitive than structural changes. These findings suggest potential neural correlates of vestibular-related cognitive decline that may be relevant to early stages of AD.