Vestibular neuronitis causes a self-limited episode of vertigo, presumably due to inflammation of the vestibular division of the 8th cranial nerve; some vestibular dysfunction may persist.
Sometimes vestibular neuronitis is used synonymously with viral labyrinthitis. However vestibular neuronitis only presents with vertigo, while viral labyrinthitis is also accompanied by tinnitus, hearing loss, or both.
Although etiology is unclear, a viral cause is suspected.
Symptoms of vestibular neuronitis include a single attack of severe vertigo, with nausea and vomiting and persistent nystagmus toward the affected side, which lasts 7 to 10 days. The nystagmus is unidirectional, horizontal, and spontaneous, with fast-beat oscillations in the direction of the unaffected ear. The absence of concomitant tinnitus or hearing loss is a hallmark of vestibular neuronitis and helps distinguish it from Meniere disease as well as labyrinthitis. The condition slowly subsides over days to weeks after the initial episode. Some patients have residual dysequilibrium, especially with rapid head movements, probably due to permanent vestibular injury.
Patients suspected of having vestibular neuronitis undergo an audiologic assessment, electronystagmography with caloric testing, and gadolinium-enhanced MRI of the head, with attention to the internal auditory canals to exclude other diagnoses, such as cerebellopontine angle tumor, brain stem hemorrhage, or infarction. MRI may show enhancement of the vestibular nerves, consistent with inflammatory neuritis.
Symptoms of vestibular neuronitis are symptomatically addressed over the short term as in Meniere disease, ie, with anticholinergics, antiemetics (eg, prochlorperazine or promethazine 25 mg rectally or 10 mg po q 6 to 8 h), antihistamines or benzodiazepines, and a corticosteroid burst with rapid taper. If vomiting is prolonged, IV fluids and electrolytes may be required. Long-term use (ie, for more than several weeks) of vestibular suppressants is highly discouraged because these drugs delay vestibular compensation, particularly in the elderly. Vestibular rehabilitation (usually given by a physical therapist) helps compensate for any residual vestibular deficit.
Patients have severe, constant vertigo with nausea and vomiting and nystagmus towards the affected side lasting days to weeks.
There is no hearing loss or tinnitus.
Testing is done to exclude other disorders.
Treatment is directed at symptoms and includes antiemetics and antihistamines or benzodiazepines; corticosteroids may also be helpful.