Diagnosis of the subtype and affected ear of benign paroxysmal positional vertigo using a questionnaire.

Conclusion: The prediction of subtype and the affected ear of benign paroxysmal positional vertigo (BPPV) derived from the answers to our questionnaire can support the definitive diagnosis of BPPV.
Objectives: We examined to what extent the diagnosis of subtype and the affected ear of BPPV judged from answers to a questionnaire agreed with the diagnosis decided by the results of the positional nystagmus test.
Methods: We asked the following questions: 'What kind of head movements induce vertigo?' and 'How long does the vertigo continue?'. As for the affected ear, we asked which ear was lower during stronger vertigo when induced in a supine position or during sleep.
Results: The percentages of correct diagnosis speculated by the combined answers were 69% in posterior canal-type BPPV, 48% in BPPV with geotropic nystagmus, and 39% in BPPV with apogeotropic nystagmus. The percentage of correct diagnoses of the affected ear was more than 80%.