Benign positional vertigo, its diagnosis, treatment and mimics

The diagnosis of benign positional vertigo (BPV) relies on a history of episodic positional vertigo and a distinctive pattern of nystagmus during provocative positional testing. The direction of the induced nystagmus is specific to the affected canal and the velocity profile reflects the underlying mechanism of canalithiasis (free-floating otoconia within the canal duct) or cupulolithiasis (otoconia adherent to the cupula). We review current theories on the pathophysiology of BPV, the clinical history and examination underlying its diagnosis, and recommended repositioning manoeuvres for each of the BPV subtypes. Disorders other than BPV which may present with a similar history and/or positional nystagmus are discussed.