Benign Paroxysmal Positional Vertigo (BPPV)

A disorder of the inner EAR in which certain positions of the head cause sudden and severe, though brief, episodes of VERTIGO (sensations of spinning or motion). Many people experience symptoms upon awakening from sleep, as they roll from one position to another or tilt their heads. Though the vertigo episode typically lasts only a few minutes, it can result in feelings of NAUSEA and dizziness as well as balance disturbances, that continue for several hours.

Doctors believe calcifications called otoconia, small “stones” of calcium carbonate, cause BPPV. Otoconia occur naturally in the utricle and saccule, two of the structures within the inner ear that are part of the vestibular system, the body’s balance mechanisms. When otoconia escape from the utricle they can enter the semicircular canals, where they collide with NERVE endings that send positional messages to the BRAIN. These collisions overwhelm the messaging network. The otoconia tend to dissolve in the inner ear fluid over time. About half the people who develop BPPV experience head trauma or serious INFECTION, such as OTITIS (ear infection) or SINUSITIS (sinus infection), before BPPV symptoms begin, leading doctors to believe that such assaults on the integrity of the inner ear jars the otoconia out of the utricle.

Symptoms and Diagnostic Path

The key symptom of BPPV is sudden, severe, and limited episodes of vertigo without TINNITUS (ringing or rushing sound in the ears) or hearing impairment. The presence of either or both of the latter suggests another disorder. Symptoms tend to occur with certain positions, though symptoms can occur even when avoiding trigger positions. Between episodes, there are no symptoms. The pattern of symptoms is fairly conclusive, though doctors typically conduct a comprehensive AUDIOLOGIC ASSESSMENT to determine whether there is any HEARING LOSS with the expectation that results will be normal.

Other diagnostic procedures for BPPV may include

 

• Dix-Hallpike test, positional test performed during physical examination; positive for BPPV when it causes NYSTAGMUS (rapid and involuntary darting movements of the eyes) or brings on an episode of vertigo
• caloric test, in which the doctor gently instills warm and then cold water into each ear; normal response evokes vertigo and abnormal response, diagnostic of BBPV, evokes little or no vertigo
• electronystagmography, in which tiny electrodes placed around the eyes detect the abnormal darting eye movements characteristic of vertigo
• imaging procedures such as COMPUTED TOMOGRAPHY (CT) SCAN or MAGNETIC RESONANCE IMAGING (MRI) to rule out other possible causes for the symptoms

The combination of test results and history of symptoms helps the doctor distinguish BPPV from other disorders that affect the vestibular system.

Treatment Options and Outlook

For many people who have BPPV, the symptoms simply go away over time, generally within several months, as the inner ear fluid dissolves the otoconia. Some people benefit from ANTIHISTAMINE MEDICATIONS or scopolamine, drugs that suppress vestibular function, or antinausea medications. There are several positional treatments (among the most commonly used are the Epley maneuver and the Semont maneuver) that some doctors perform to attempt to jolt the otoconia out of the semicircular canals and at least into the vestibule if not back into the utricle. These maneuvers succeed 70 to 90 percent of the time.

Rarely the otolaryngologist may recommend one of two operations for BPPV if it continues for longer than a year without response to other treatment:

 

• Posterior ampullar neurectomy severs a branch of the nerve that conveys motion signals from the utricle, ending its ability to send messages of motion to the brain.
• Posterior canal plugging seals the involved semicircular canal so the otoconia can no longer float in its fluid.

Surgery nearly always ends BPPV; when it does not, further examination typically reveals complicating factors or conditions that contribute to the symptoms. Nearly everyone who develops BPPV eventually recovers fully from the condition, with balance restored to normal. During the course of the condition and while undergoing treatment with one of the maneuvers, doctors recommend avoiding positions that may trigger symptoms, especially tilting the head back, until BPPV symptoms no longer occur. Once BPPV is resolved, it generally does not recur.

Risk Factors and Preventive Measures

Otoconia seem to naturally occur in many people, causing problems only when they become lodged in vestibular structures such that they interfere with the movement of fluid that is essential for balance. It also appears that the body’s natural processes dissolve and absorb the otoconia over time, so most of these calcifications do not become large enough to obstruct the vestibular channels. Because doctors do not know what causes otoconia to form, there are no known methods for preventing them. Prompt treatment for ear and sinus infections to reduce further trauma to the inner ear may help keep otoconia from causing symptoms.