Is vestibular function related to human hippocampal volume?

Area of Science:

• Neuroscience
• Otolaryngology
• Radiology

Background:

• Vestibular dysfunction is increasingly linked to cognitive decline and hippocampal atrophy.
• Hippocampal atrophy is a key biomarker for Alzheimer's disease.
• Investigating vestibular dysfunction as a dementia risk factor is crucial.

Purpose of the Study:

• To replicate findings on brain and hippocampal volume in individuals with bilateral vestibulopathy (BV).
• To explore the relationship between otolith function and hippocampal volume.
• To assess the impact of semicircular canal dysfunction on brain structure.

Main Methods:

• Compared whole-brain and hippocampal MRI volumes in adults aged 55-83.
• Matched 16 participants with BV to 16 healthy controls based on age, sex, and hearing.
• Evaluated otolith influence on hippocampal volume in 34 participants with preserved semicircular canal function.

Main Results:

• No significant differences in whole-brain or hippocampal volume were observed between BV patients and controls.
• Machine learning models could not classify inner ear health status above chance.
• Otolith parameters showed no association with hippocampal volume in participants with healthy semicircular canals.

Conclusions:

• Bilateral vestibulopathy does not lead to significant whole-brain or hippocampal volume loss.
• Saccular function is not associated with hippocampal volume changes in individuals with healthy semicircular canals.
• Current findings do not support vestibular dysfunction as a direct cause of hippocampal atrophy.