Vestibular neuronitis or neuritis is characterized by the onset of intense true vertigo over several hours that is usually rotary (i.e., a feeling of spinning). It is usually accompanied by severe nausea and vomiting. Symptoms peak within 24 hours and gradually resolve over several weeks. It classically does not have associated hearing loss, although in some patients a high frequency hearing loss in the affected ear can be measured. Full recovery within 3 months is the norm, but occasional patients remain markedly impaired and never fully compensate. This is more common in the elderly. Recurrences occur in up to 20 - 30 percent. In rare cases, both ears may be affected sequentially, leading to loss of bilateral vestibular reflexes and oscillopsia (a sensation whereby the horizon appears to ''bounce up and down'')
Vestibular neuronitis is thought to be a viral reactivation syndrome and attacks seem to follow viral upper respiratory illnesses in some, but not all, patients. Patients with the condition are not considered 'infectious.'