Reduced vagal reserve in benign paroxysmal positional vertigo: preliminary results of a case-control HRV study

Benign Paroxysmal Positional Vertigo (BPPV) is traditionally viewed through a mechanical lens involving otoconial displacement. However, growing evidence suggests a link between BPPV and psychological stress. This study aims to evaluate autonomic nervous system balance in BPPV patients using Heart Rate Variability (HRV) as a non-invasive proxy for stress-related physiological regulation.

This prospective, observational, case-control study included a preliminary analysis of 50 participants, comprising 25 patients with clinically confirmed BPPV and demographically matched healthy controls. Perceived stress was assessed using the Perceived Stress Scale-10 (PSS-10). Time-domain HRV parameters including root mean square of successive differences (RMSSD), coefficient of variation of RR intervals (COV RR), and their dynamic changes (ΔRMSSD and ΔCOV RR) were analyzed.

Patients with BPPV demonstrated significantly higher perceived stress scores compared to controls (PSS-10: 32.24 ± 7.27 vs. 27.68 ± 6.24, p = 0.021). Despite comparable resting HRV parameters, significant reductions were observed in the BPPV group during controlled breathing conditions. Six-breath RMSSD values were significantly lower in BPPV patients compared with controls (37.14 ± 20.87 ms vs. 72.06 ± 60.28 ms, p = 0.009). Similarly, ΔRMSSD and ΔCOV RR values were significantly reduced in the BPPV group (p = 0.012 and p = 0.008, respectively). These findings remained significant after adjustment for covariates.

These preliminary findings suggest that BPPV is associated with increased perceived stress and impaired autonomic responsiveness. This autonomic inflexibility may play a role in BPPV pathophysiology, highlighting the need to integrate neuroendocrine and autonomic perspectives into vestibular research.