Benign paroxysmal positional vertigo

DALLAS -- Benign paroxysmal positional vertigo is easily diagnosed using a simple office procedure, the Dix-Hallpike test, Dr. Gregory W Schneider said at the annual meeting of the American Academy of Family Physicians.

There's no need for referral for costly electronystagmography. And a single 15 to 30-minute physical therapy session is curative in 80% of cases, said Dr. Schneider, a family physician at the University of Texas, Dallas.

Benign paroxysmal positional vertigo (BPPV) and the other peripheral vestibular disorders collectively constitute the most common cause of dizziness.

The history is invaluable in differentiating central from peripheral vestibular disorders. Suspect a central cause and order brain imaging if the vertigo is accompanied by neurologic symptoms, loss of consciousness, or vertical nystagmus. Constant vertigo suggests a central lesion. Nausea and vomiting are most often associated with peripheral vertigo, as are rotatory or horizontal nystagmus, he said.

The history also distingnishes BPPV from the other major peripheral vestibular disorders: Meniere's disease, vestibular neuronitis, and perilymphatic fistula. If the patient reports hearing loss, tinnitus, or aural fullness, it's probably not BPPV.

The classic history of BPPV involves rolling over in bed to hit the alarm clock and experiencing the sudden onset of vertigo for a couple of minutes. Another common trigger is the over-the-shoulder glance that precedes a change of lanes while driving, Dr. Schneider said.

BPPV occurs when the tiny motion-sensing fibers known as otoconia become dislodged from the otolith organs--the utricle and saccule--and are inappropriately deposited in one of the three semicircular canals within the vestibular labyrinth. The posterior semicircular canal is involved in 95% of cases.

The key finding in a positive DixHallpike test is nystagmus, usually in a rotatory pattern with fast eye movements toward the forehead.

For the test, the patient starts out seated on the examining table while the physician rotates the patient's head 45 degrees to one side. The physician then swiftly lowers the patient to a recumbent position with the head slightly below horizontal and still turned to 45 degrees. The physician observes closely for nystagmus, which in a positive Dix-Hallpike commences several seconds after the drop to recumbency and lasts no longer than about a minute. The test needs to be done on both sides. Usually one vestibular complex is involved.

For in-office physical therapy Dr. Schneider favors the modified Epley maneuver, which requires a 20-30-minute session.

The Epley maneuver jars the wayward otoconia from the semicircular canal and gets them to fall back into the otolith organs. The patient is seated on the examining table, with the head turned 45 degrees as in the Dix-Hallpike test, for 1-4 minutes. The patient is assisted in falling back to a recumbent position with the head slightly below horizontal for 1-4 minutes, or until any elicited symptoms wane. Then slowly over the course of about a minute the patient's head is turned 45 degrees to the opposite side for 1-4 minutes. The patient is then assisted back into the seated position, and waits once more.

After the session the patient maintains strict bed rest for 1-2 days with the head of the bed raised at a 30-degree angle to prevent the otoconia from moving back into the semicircular canal.

Three-quarters of those who respond to physical therapy remain symptom free for at least a year. If there is no response after three sessions of physical therapy patients are best referred to an otolaryngologist for possible surgery he said.

COPYRIGHT 2001 International Medical News Group
COPYRIGHT 2001 Gale Group