Overview
Definition
A peripheral vestibular disorder that causes brief episodes of mild to intense dizziness (vertigo) triggered by specific changes in head position.
Epidemiology
The most common cause of peripheral vertigo. More common in women and older adults.
Etiology & Risk Factors
- Canalithiasis: Calcium carbonate crystals (otoconia) dislodge from the utricle and migrate into the semicircular canals (most commonly the posterior canal).
- When the head moves, the crystals shift, causing abnormal fluid movement and triggering a false sense of rotation.
Clinical Symptoms
- Brief (< 1 minute) episodes of severe spinning vertigo
- Triggered by rolling over in bed, looking up, or bending down
- Nausea and vomiting (due to vertigo)
- NO hearing loss, tinnitus, or focal neurologic deficits (which rules out Meniere's or central vertigo)
Clinical Approach
Diagnosis
- Dix-Hallpike Maneuver (Diagnostic): Rapidly moving the patient from a sitting to a supine position with the head turned 45 degrees. Elicits vertigo and upbeat, torsional nystagmus (if posterior canal is involved).
Management
- Epley Maneuver (Canalith Repositioning Procedure): A series of head movements designed to guide the crystals out of the semicircular canal back into the utricle. Highly effective (curative in ~80% of cases after one session).
- Vestibular suppressants (Meclizine, Promethazine) are generally NOT recommended as they inhibit central compensation and do not fix the underlying mechanical problem.
Complications
- High risk of falls in the elderly
- Significant distress/nausea