Responses to the Dix-Hallpike test in primary care: A comparison between subjective and objective benign paroxysmal positional vertigo.

Patients who experience both vertigo and nystagmus in the Dix-Hallpike test (DHT) are diagnosed with objective benign paroxysmal positional vertigo (BPPV). This test provokes only vertigo in between 11% and 48% of patients, who are diagnosed with subjective BPPV. Detection of nystagmus has important diagnostic and prognostic implications. To compare the characteristics of patients diagnosed with objective and subjective BPPV in primary care. Cross-sectional descriptive study. Two urban primary care centers. Adults (≥18 years) diagnosed with objective or subjective BPPV between November 2012 and January 2015. DHT results (vertigo or vertigo plus nystagmus; dependent variable: nistagmus as response to DHT), age, sex, time since onset, previous vertigo episodes, self-reported vertigo severity (Likert scale, 0-10), comorbidities (recent viral infection, traumatic brain injury, headache, anxiety/depression, hypertension, diabetes mellitus, dyslipidemia, cardiovascular disease, altered thyroid function, osteoporosis, cervical spondylosis, neck pain). In total, 134 patients (76.1% women) with a mean age of 52 years were included; 59.71% had subjective BPPV. Objective BPPV was significantly associated with hypertension, antihypertensive therapy, and cervical spondylosis in the bivariate analysis and with cervical spondylosis (OR=3.94, p=0.021) and antihypertensive therapy (OR 3.02, p=0.028) in the multivariate analysis. Patients with subjective BPPV were more likely to be taking benzodiazepines [OR 0.24, p=0.023]. The prevalence of subjective BPPV was higher than expected. Cervical spondylosis and hypertensive therapy were associated with objective BPPV, while benzodiazepines were associated with subjective BPPV.