Vertigo (medical)

Vertigo is a well-recognized medical condition that consists of "illusion of movement, either of the external world revolving around the individual or of the individual revolving in space". Most often, patients with vertigo "see" the room and world spinning around them, but sometimes that hallucination of movement is centered on the body, instead, and the patient feels as if he or she is spinning within the room or other setting. In severe vertigo, there is often nausea and even vomiting.

Causes/etiology

Benign paroxysmal positional vertigo (BPPV) is "the most common cause of recurrent vertigo".

Pathophysiology

Benign positional vertigo

The membranous labyrinth (lateral view of the right inner ear).
• The external semicircular canal is also called the horizontal or lateral canal.
• The superior semicircular canal is also called the anterior canal.

Most cases of benign positional vertigo are due to canaliths or otoliths (calcium carbonate crystals) in the posterior canal that stimulate the cupula. Disease of the horizontal canal accounts for 10-17% of cases.

Cardiac causes of dizziness can surprisingly manifest as vertigo.

Diagnosis

Skew deviation (vertical misalignment) suggests a central lesion.

Benign positional vertigo

The Dix–Hallpike maneuver can diagnose positional vertigo (BPPV):

• Posterior canal BPPV causes "upbeating and torsional nystagmus with the top pole of rotation beating toward the affected (downside) ear"
• Horizontal canal BPPV causes "horizontal geotropic (toward the ground) or apogeotropic (away from the ground) direction-changing paroxysmal positional nystagmus" Disease of the horizontal canal is better detected by the supine head roll test or (Pagnini–McClure maneuver).
• Anterior canal BPPV

Treatment

Benign positional vertigo

Clinical practice guidelines by the American Academy of Neurology address the treatment of benign positional vertigo. The guidelines state:

• For posterior semicircular canal disease, canalith repositioning procedure may be used.
• For horizontal semicircular canal disease, the roll maneuver (Lempert maneuver or barbecue roll maneuver) may be used.

Evidence within a systematic review by the Cochrane Collaboration support repositioning for vertigo due to the posterior canal.

More recently, head-shaking may be similarly effective for horizontal semicircular canal disease:

"patients were brought into a sitting position. After pitching the head forward by approximately 30°, we moved the head sideways in a sinusoidal fashion at an approximate rate of 3 Hz for 15 seconds"