This article presents an approach to differentiation of migrainous positional vertigo (MPV) from horizontal canal benign paroxysmal positional vertigo (HC-BPPV). Such an approach is essential because of the difference in intervention between the two disorders in question. Results from evaluation of the case study presented here revealed a persistent ageotropic positional nystagmus consistent with MPV or a cupulolithiasis variant of HC-BPPV. The patient was treated with liberatory maneuvers to remove possible otoconial debris from the horizontal canal in an attempt, in turn, to provide further diagnostic information. There was no change in symptoms following treatment for HC-BPPV. This case was diagnosed subsequently as MPV, and the patient was referred for medical intervention. Treatment has been successful for 22 months. Incorporation of HC-BPPV treatment, therefore, may provide useful information in the differential diagnosis of MPV and the cupulolithiasis variant of HC-BPPV.

The purpose of this study was to determine the prevalence of reduced or absent labyrinthine reactivity (vestibulopathy) in two groups of participants with posterior canal BPPV. One group had prior diagnosis of otologic disease (positive history group). No one in the second group had ever been diagnosed with otologic disease (negative history group). Caloric responses were retrospectively analyzed for the two groups. Patients with a positive history exhibited a greater prevalence of vestibulopathy than patients with a negative history. The positive history group, on average, also exhibited a larger unilateral weakness than those patients in the negative history group. We conclude that patients with BPPV and a history of otologic disease are more likely to present with vestibulopathy, than patients with BPPV and no history of otologic disease. This finding supports the benefit of complete vestibular evaluation in patients with BPPV to ensure comprehensive and successful treatment outcome.