Dizziness handicap and clinical characteristics of posterior and lateral canal BPPV.

Purpose: Benign paroxysmal positional vertigo (BPPV) is diagnosed and divided into subtypes based on positioning vertigo and nystagmus. Whether these subtypes entail any significant differences in patient-reported symptoms; is yet not known. Such differences may have clinical and therapeutic consequences. Our aim was to assess dizziness handicap and clinical characteristics of posterior and lateral canal BPPV.

Methods: This prospective observational multicentre study analysed consecutive patients with BPPV, confirmed by standardized procedures including videonystagmography under diagnostic manoeuvres in a biaxial rotational chair. Patients were screened for other neurological and otological disorders.

Outcomes: Dizziness handicap inventory (DHI), posterior vs. lateral canal involvement.

Factors: age, gender, positional nystagmus intensity (maximum slow-phase velocity), symptom duration, 25-hydroxyvitamin D-level and traumatic aetiology.

Results: 132 patients aged 27-90 (mean 57, SD 13) years were included. Higher DHI scores were associated with lateral canal BPPV [95% CI (1.59-13.95), p = 0.01] and female gender [95% CI (0.74-15.52), p = 0.03]. Lateral canal BPPV was associated with longer symptom duration [OR 1.10, CI (1.03-1.17), p = 0.01] and lower 25-hydroxyvitamin D-levels [OR 0.80, CI (0.67-0.95), p = 0.03]. There was no correlation between DHI scores and nystagmus intensity.

Conclusions: This study suggests that patients with lateral canal BPPV have increased patient-perceived disability, lower vitamin D-levels and longer duration of symptoms. This subtype might therefore require closer follow-up. Patient-perceived disability is not related to positional nystagmus intensity.