Seasonal and monthly variation in benign paroxysmal positional vertigo: a systematic review and meta‑analysis

The relationship between seasonal variations and the incidence of benign paroxysmal positional vertigo (BPPV) has been widely studied, but the findings remain inconsistent. This systematic review and meta-analysis aimed to evaluate whether BPPV demonstrates seasonal variation.

A comprehensive search was conducted across PubMed, Embase, Cochrane Library, Web of Science, and CNKI databases for studies on the monthly or seasonal incidence of BPPV from their inception up to August 2024. Pooled monthly or seasonal incidence rates, risk ratios (RRs) for one season versus another and 95% confidence intervals (CIs) were combined using the random-effects model. This meta-analysis has been registered at International Prospective Register of Systematic Reviews (PROSPERO) (NO. CRD42024583513).

Ten eligible studies were included, comprising 5,063 subjects. Pooled BPPV incidence was highest in winter (28%) and lowest in summer (21%). Additionally, the pooled monthly incidence was highest in December (12.6%) and lowest in July (7.4%). The overall RRs and 95% CIs are as follows: winter versus summer (1.30 [1.07,1.59]); winter versus spring (1.01 [0.88,1.17]); winter versus autumn (1.11[0.95,1.30]); spring versus autumn (1.09 [0.91,1.31]); spring versus summer (1.29 [1.00,1.66]); autumn versus summer (1.17 [0.97,1.42]).

Our meta-analysis suggests that there may be seasonal variation in the incidence of BPPV. The finding of seasonal patterns provides a new perspective to our understanding of BPPV, suggesting environmental factors may play a potential role in its pathophysiology. However, larger cohort studies and multicenter datasets are warranted to validate these findings in future research.