Benign paroxysmal positional vertigo

What it is

Vertigo is the illusion of rotational, linear or tilting movement of the self or the environment, and it is produced either peripherally, in the inner ear, or centrally, in the brainstem and cerebellum. Benign paroxysmal positional vertigo is the peripheral form in which episodic sudden vertigo lasting seconds is triggered by changes in head position, so it is a positional vertigo. Two forms are described: canalithiasis, the migration of free floating otoliths within the endolymph of the semicircular canal, and cupulolithiasis, an otolith attached to the cupula of the semicircular canal. It originates in the posterior semicircular canal in more than 90% of cases, with a range of 85% to 95% reported.

Causes and risk

Head injury and head trauma, viral infection such as URTI, ear infection, and degenerative disease are the named causes, and idiopathic is the most common of them.

How it presents

The vertigo is acute, transient and rotatory, lasting seconds to minutes and under a minute. It is initiated by changes in head position, such as rolling to one side, extending the head to look up, lying down, turn over or sit up in bed, and it starts a few seconds after the head movement, which is the latency. The patient is asymptomatic at rest, and the vertigo is relieved by visual fixation. The nystagmus is rotatory and geotropic, its fast phase towards the floor. There is no hearing loss and there are no neurologic symptoms. Nausea and vomiting may be severe.

Peripheral and central vertigo part company on these points. In the peripheral form the latency is 2 to 20 seconds, the duration is less than 1 minute, the nystagmus is direction fixed, horizontal or rotatory, and fatiguable, and compensation is rapid. In the central form there is no latency, the duration is more than 1 minute, the nystagmus is direction changing, horizontal or vertical, and nonfatiguable, imbalance is mild to moderate, and neurologic symptoms are common.