Semicircular canals are long in patients with benign paroxysmal positional vertigo.

Objective: To search for any morphological variation contributing to aetiopathogenesis and the diagnosis of benign paroxysmal positional vertigo, we measured the sizes of the semicircular canals in patients with and without benign paroxysmal positional vertigo using multidetector computed tomography.

Methods: Cranial bone computed tomography images of 30 benign paroxysmal positional vertigo patients and 30 control patients were acquired with a 128-slice computed tomography scanner and a transverse plane with a thickness of 0.67 mm. The inner diameter, height and width of the canals were measured.

Results: The width of the anterior semicircular canals, and the width and height of the posterior semicircular canals of the affected ears in benign paroxysmal positional vertigo patients ( = 30) were significantly greater than in the control patients ( = 90; = 0.001, = 0.023, = 0.003, respectively).

Conclusion: In benign paroxysmal positional vertigo patients, the posterior and anterior semicircular canals are longer than those in people without benign paroxysmal positional vertigo. These morphological changes may contribute to elucidating the aetiopathogenesis and be used as a radiological sign for diagnosis of benign paroxysmal positional vertigo disease.