Seasonality of benign paroxysmal positional vertigo : A retrospective study from Central Europe.

BACKGROUND: Although benign paroxysmal positional vertigo (BPPV) is the most common cause of vertigo in clinical practice, factors influencing the pathophysiology remain not fully understood. OBJECTIVE: Here we aim to investigate possible seasonal influences on the occurrence of BPPV in Vienna, a city located in a Central European country with pronounced seasonal fluctuations. METHODS: We retrospectively investigated data from 503 patients presenting with BPPV to the outpatient clinics of the Medical University of Vienna between 2007 and 2012. Analyses included age, gender, type of BPPV, seasonal assignment, as well as daylight hours and the temperature in Vienna at symptom onset. RESULTS: Out of 503 patients (159 male, 344 female, ratio 1:2.2; mean age 60 ± 15.80 years), most patients presented with posterior (89.7%) and left-sided (43.1%) BPPV. There was a significant seasonal difference (χ2 p = 0.036) with the majority of symptoms occurring in winter seasons (n = 142), followed by springtime (n = 139). Symptom onset did not correlate with the average temperature (p = 0.24) but on the other hand very well with daylight hours (p < 0.05), which ranged from 8.4 h per day in December, to an average of 15.6 h in July. CONCLUSION: Our results show a seasonal accumulation of BPPV during winter and springtime, which is in line with previous studies from other climatic zones, suggesting an association of this seasonality with varying vitamin D levels.