Relationship between autonomic nervous system function and endolymphatic space ratio in Ménière disease

Area of Science:

• Neurology
• Otolaryngology
• Cardiology

Background:

• Autonomic dysfunction is linked to Ménière disease (MD) and benign paroxysmal positional vertigo (BPPV).
• Positional blood pressure (BP) and heart rate (HR) changes can assess autonomic nervous system (ANS) function.
• Inner ear structure, specifically the endolymphatic space (ELS), may be influenced by ANS function.

Purpose of the Study:

• To investigate the relationship between MD/BPPV and ANS function.
• To analyze BP, HR, and ELS ratios in MD and BPPV patients.
• To identify differences in ANS function and inner ear structure between MD and BPPV.

Main Methods:

• Retrospective analysis of 168 patients diagnosed with MD (n=103) or BPPV (n=65).
• Inner ear MRI for ELS ratio calculation (overall, cochlea, vestibule, semicircular canals).
• Schellong test (S-test) and HR measurements to assess autonomic function during positional changes.

Main Results:

• A significantly higher proportion of MD patients (38.8%) had a positive S-test compared to BPPV patients (23.1%) (P=0.0427).
• In MD patients with a positive S-test, a trend showed increased cochlear ELS ratio correlated with decreased systolic BP (r=-0.346, P=0.0287).
• No significant differences were found in other combined groups.

Conclusions:

• ANS function appears to influence MD onset more than BPPV.
• A weak correlation exists between increased cochlear ELS ratio and decreased systolic BP in MD patients with a positive S-test.
• These findings suggest a potential link between autonomic regulation and inner ear changes in MD.