Extraocular muscle contraction as a tool for benign paroxysmal positional vertigo diagnosis

When diagnosing benign paroxysmal positional vertigo, extraocular muscle contraction and the nystagmus it causes, though recognized as an important indicator, is less commonly seen as a principal method of diagnosis. However, through determining the direction of resulting nystagmus during diagnostic tests such as the supine roll test and the Dix-Hallpike test, which semicircular canals are involved in individual cases of benign paroxysmal positional vertigo can be ascertained, in both cases involving only one semicircular canal or cases of multi-canal benign paroxysmal positional vertigo.