Inner ear infection (labyrinthitis)
Labyrinthitis and vestibular neuritis are disorders resulting from an infection that inflames the inner ear or the vestibulo-cochlear nerve (the eighth cranial nerve), which connects the inner ear to the brain. Vertigo, dizziness, and difficulties with balance, vision, or hearing may result.
Infections of the inner ear are usually viral; less commonly, the cause is bacterial. Although the symptoms of bacterial and viral infections may be similar, the treatments are very different, so proper diagnosis by a physician is essential. Such inner ear infections are not the same as middle ear infections, which are the type of bacterial infections common in childhood affecting the area around the eardrum.
Neuritis (inflammation of the nerve) affects the vestibular branch of the vestibulo-cochlear nerve, resulting in dizziness or vertigo but no change in hearing. The term neuronitis is also used. Labyrinthitis (inflammation of the labyrinth) occurs when an infection affects both branches of the nerve, resulting in hearing changes as well as dizziness or vertigo.
Symptoms of neuritis can be mild or severe, ranging from subtle dizziness to a violent spinning sensation (vertigo). They can also include nausea, vomiting, unsteadiness and imbalance, difficulty with vision, and impaired concentration. Sometimes the symptoms can be so severe that they affect the ability to sit up, stand, or walk. Labyrinthitis may produce the same symptoms, along with tinnitus (ringing or noises in the ear) and/or hearing loss.
The onset is usually very sudden, with severe dizziness developing abruptly during routine daily activities. In other cases, the symptoms are present upon awakening in the morning. After a period of gradual recovery that may last several weeks, some people are completely free of symptoms. Others have chronic dizziness, if the virus has damaged the vestibular nerve.
Diagnosis and Treatment
No specific tests exist to diagnose vestibular neuritis or labyrinthitis. When other illnesses have been ruled out, medications are often prescribed to control nausea and to suppress dizziness during the acute phase. Examples include Benadryl (diphenhydramine), Antivert (meclizine), Phenergen (promethazine hydrochloride), Ativan (lorazepam), and Valium (diazepam). Other medications that may be prescribed are steroids (e.g., prednisone), an antiviral drug (e.g., Acyclovir), or antibiotics (e.g., amoxicillin) if a middle ear infection is present.
If treated promptly, many inner ear infections cause no permanent damage. In some cases, however, permanent loss of hearing or damage to the vestibular system can occur. If symptoms of dizziness or imbalance persist for several months, vestibular rehabilitation exercises (a form of physical therapy) may be suggested in order to retrain the brain’s ability to adjust to the vestibular imbalance, in a process known as compensation. A key component of successful adaptation is a dedicated effort to keep moving, despite the symptoms of dizziness and imbalance.