Benign paroxysmal positional vertigo.

Benign paroxysmal positional vertigo should be considered when a patient complains of attacks of dizziness of brief duration, that seem to occur under particular circumstances related to the position of the head. The true nature of the disorder may be missed unless examination is carried out in a certain way: the head must be positioned below the rest of the body and turned to one or other side. Diagnosis then depends on the occurrence of vertigo and on noting the transient nystagmus. There are a number of causes of benign paroxysmal positional vertigo-head injury is a relatively frequent one. It has been suggested that this disorder is due to deposits on the cupula of the precipitating posterior semicircular canal. Indeed, exercises designed to dislodge such deposits can be successful. If not, and the vertigo lasts for more than a few months, surgery can be considered.