Vestibular Neuronitis
Vestibular neuronitis is also known as acute labyrinthitis (although this implies involvement of the auditory portion of the inner ear). It usually presents as sudden severe vertigo. The patient frequently experiences nausea and vomiting with the vertigo which can last for days or weeks. The etiology is thought to be of viral origin as many patients will relate an upper respiratory infection in the recent past. Attacks seem to occur more in the spring and summer months and clustering of cases has been described.
On examination, the patient may demonstrate spontaneous horizontal or rotational nystagmus. The nystagmus will increase in intensity when the patient is asked to gaze in the direction of the fast component of the nystagmus. The neurologic exam and specifically their cerebellar function should be normal.
Treatment for vestibular neuronitis consists of vestibular suppressant medications and anti-emetics if needed. Vestibular suppressants include antihistamines (meclizine, promethazine) and benzodiazepine (diazepam). Typically the symptoms of vertigo and nausea resolve after a few days to weeks, however feelings of instability may persist for months after a case of vestibular neuronitis.