Vestibular neuronitis, or vestibular neuritis, is a disorder that occurs as the result of a viral infection of the inner ear. The disorder is characterized by sudden severe dizziness or vertigo, but it does not affect the hearing. Most cases of vestibular neuronitis resolve within several weeks.
This disorder occurs when the vestibular nerve, a nerve that specializes in sending balance signals from the ear to the brain, becomes inflamed. This often occurs after a cold and usually affects only one ear at a time. The average age of onset is 41 years old. It affects men and women at equal rates.
People who develop vestibular neuronitis experience vertigo, often accompanied by upset stomach, vomiting, vision problems and an inability to concentrate. Patients also experience an involuntary flickering of the eyes called nystagmus. The first attack of vertigo is usually the worst and can last for several days. Many people also experience less-severe bouts of dizziness for several more days after the initial onset, particularly when the head is in a certain position.
Doctors diagnose vestibular neuronitis by performing a general but thorough physical examination. Most cases are fairly easy to diagnose and do not require extensive testing. The physician might recommend extra tests such as magnetic resonance imaging (MRI) for patients whose symptoms last longer than a month.
Doctors often perform a physical test called the Nylen-Barany or Dix-Hallpike examination to diagnose vestibular neuronitis. This test determines whether the dizziness occurs because of certain positions or movements of the head. The doctor tilts the patient's head to a 30- or 45-degree angle and positions the patient so that his or her head hangs over the edge of the table, then watches the patient for evidence of nystagmus. The process is then repeated with the head tilted in the other direction.
Vestibular neuronitis usually clears up on its own, so doctors usually prescribe drugs that will make the patient more comfortable until the symptoms stop occurring. Several medications include promethazine to control nausea, scopolamine for motion sickness and prednisone to reduce inflammation. The medications do not cure the disorder, but they make the symptoms easier to tolerate.
Most affected patients will be unable to work for several weeks. They might have difficulty thinking or concentrating and often develop a sensitivity to certain head motions. Most people who suffer from vestibular neuronitis will experience only one bout of in a lifetime, but approximately 5 percent of patients develop recurring symptoms.