Linear Vertigo in Benign Paroxysmal Positional Vertigo: Prevalence and Mechanism.

This study aimed to determine the prevalence and mechanism of linear vertigo reported by the patients during the attacks of benign paroxysmal positional vertigo (BPPV). We prospectively evaluated the characteristics (rotational vs. linear) of positional vertigo in 70 patients with posterior and horizontal canal BPPV using a questionnaire allowing multiple choices. In patients with linear vertigo, we further assessed the directionality of linear vertigo. We adopted the velocity-storage model to explain the occurrence and direction of linear vertigo in these patients with BPPV. Patients reported only rotational vertigo in 46 (46/70, 65.7%), only linear vertigo in 10 (14.3%), and both rotational and linear vertigo in 14 (20%). The patients experienced fear from rotational vertigo in 54 (54/70, 77.1%) and from linear vertigo in 20 (20/70, 28.6%). The direction of linear vertigo was concordant with the direction of inertial acceleration predicted by the velocity-storage model. Patients with BPPV may experience linear as well as rotational vertigo during the attacks. This linear vertigo may be ascribed to centrally estimated inertial acceleration.