Labyrinthitis (otitis interna)

Labyrinthitis (otitis interna)

Labyrinthitis is inflammation of the inner ear. It is also called otitis interna. The inner ear consists of an outer bony labyrinth filled with fluid called perilymph. It has three parts namely the cochlea, the vestibule and the three semicircular canals. Suspended in the perilymph is an inner membranous labyrinth filled with fluid called endolymph. Perilymph and endolymph is different. The membranous labyrinth consists of the cochlear duct, the saccule, the utricle, the endolymphatic duct and sac and the duct of the semicircular canals.

The inflammation in labyrinthitis can be due to infection, toxins, allergens, medication and injury. Infections are usually caused by viruses and bacteria. It is often seen following a cold, flu or middle ear infection (otitis media). The causative agent enters the labyrinth from the middle ear via the oval and round window. It can also enter the labyrinth via the bloodstream and bony canals leading into the labyrinth. The cochlear aqueduct is such a canal and a common route for bacteria to enter in meningitis.

Patients present with hearing loss, tinnitus and vertigo. Pain and a high fever can be seen in infections. They are often nauseous and may have a headache. Labyrinthitis is usually an acute rapid progressive disorder but may in some cases develop over months. This can happen in autoimmune inner ear disease.

Labyrinthitis should be treated early and aggressively. Antibiotics and steroids are usually prescribed. Dizziness, fever, nausea and headache are treated symptomatically. Fluid in the middle ear may need draining and a grommet.

Hearing should be monitored meticulously in the following period as labyrinthitis may lead to permanent hearing loss. Whereas some patients may need a hearing aid others may only benefit from cochlear implantation. The problem is that the inflammation in the labyrinth may lead to permanent scar tissue and even new bone formation which will make it very difficult to perform a cochlear implantation at a later stage.

The damage to the inner ear balance mechanism may lead to permanent balance problems. The prognosis for this is good and patients will usually benefit a lot from a vestibular rehabilitation program.