Benign positional vertigo is condition in which a person develops a sudden sensation of spinning, usually when moving the head. It is the most common cause of vertigo.

Benign positional vertigo is due to a disturbance within the inner ear. The inner ear has fluid-filled tubes called semicircular canals. The canals are very sensitive to movement of the fluid, which occurs as you change position. The fluid movement allows your brain to interpret your body's position and maintain your balance.

Benign positional vertigo develops when a small piece of bone-like calcium breaks free and floats within the tube of the inner ear. This sends the brain confusing messages about your body's position.

There are no major risk factors. However, the condition may partly run in families. A prior head injury (even a slight bump to the head) or an inner ear infection called labyrinthitis may make some people more likely to develop the condition.

The main symptom is a spinning sensation, which:

• Is usually triggered by head movement
• Often starts suddenly

Most often, patients say they cannot roll in bed or tilt their head up to look at something.

Other symptoms can include:

• Vision complaints, such as a perception that things are jumping or moving
• Vomiting (in severe cases)

To diagnose benign positional vertigo, the health care provider will often perform a test called the Dix-Hallpike maneuver. The doctor holds your head in a certain position and asks you to lie quickly backward over a table. As you do this, the doctor will look for abnormal eye movements and ask if you feel a spinning sensation. The doctor may use various methods to help evaluate your eye movements.

A physical exam is otherwise normal. A complete medical history and careful neurological exam should be done to rule out other reasons for your symptoms. Tests that may be done include:

• EEG
• Electronystagmography
• Evoked auditory potential studies
• Head CT
• Head MRI
• Magnetic resonance angiography of the head
• Warming and cooling the inner ear with water (caloric stimulation) to test eye movements

The most effective treatment is a procedure called "Epley's maneuver," which can move the small piece of bone-like calcium that is floating inside your inner ear. Other exercises that can readjust your response to head movements are less effective.

Occasionally, medications may be prescribed to relieve the spinning sensations. Such drugs may include:

• Antihistamines
• Anticholinergics
• Sedative-hypnotics

However, such medicines often are not very effective for treating vertigo.

Benign positional vertigo is uncomfortable, but usually improves with time. This condition may occur again without warning.

Patients with severe vertigo may get dehydrated due to frequent vomiting.

Call your health care provider if vertigo develops that has not been evaluated or if treatment is ineffective. Also call if you develop any associated symptoms (such as weakness, slurred speech, visual problems) that may indicate a more serious condition.

Avoid head positions that trigger positional vertigo.

Cummings CW, Flint PW, Haughey BH, et al. Otolaryngology: Head & Neck Surgery. 4th ed. St Louis, Mo: Mosby; 2005:3226.

Hain TC. Cranial nerve VIII: vestibulocochlear system. In: Goetz, CG, eds. Textbook of Clinical Neurology. 3rd ed. Philadelphia, Pa: Saunders Elsevier; 2007:chap 12.