Labyrinthitis, also known as vestibular neuritis, neurolabirinitis or acute peripheral vestibulopathy, is a benign, self-limiting disease that causes intense vertigo.
Labyrinthitis is caused by an inflammation of the inner ear, a region in which is located a structure called labyrinth, responsible for our balance. Among all the causes of dizziness, labyrinthitis is one of the most common.
To understand what labyrinthitis is, it is first necessary to know what the labyrinth is and how the inner ear works.
The labyrinth is an organ that is part of the vestibular apparatus, responsible for maintaining balance. The maze is a set of semicircular arches that have liquids inside. The movement of these fluids is interpreted by the brain helping to identify movements and keep us in balance.
The information passed through the labyrinth through the movement of these liquids helps the brain to interpret angular movements, linear accelerations and gravitational forces. Whoever "feels" and takes these fluid movements to be interpreted by the brain is the vestibulocochlear nerve, also called the auditory nerve. The auditory nerve has two branches, each responsible for one of the basic functions of the ear: the cochlear branch informs the brain about sounds picked up by the ear while the vestibular branch informs about movements of our body captured by the vestibular apparatus.
Just as curiosity: do you know why we get dizzy after we've done it several times? Because when we stop, even though we are still, the liquids inside our inner ear are still in rotational motion for a few seconds, causing the brain to interpret that we are still running. If we close our eyes, the dizziness increases even more, because with open eyes the vision tells the brain that we are standing, thus attenuating the wrong message that the auditory nerve is sending.
The term labyrinthitis has been misused to designate any disease of the labyrinth. In fact, labyrinthitis is the inflammation of the labyrinth and/or the vestibular portion of the auditory nerve, responsible for the innervation of the labyrinth. This inflammation is most often caused by a viral infection. In at least 50% of cases of labyrinthitis, the patient reports having had a recent respiratory virus, such as influenza, sinusitis or pharyngitis.
Labyrinthitis can also be caused by other types of viruses, such as varicella zoster, the virus responsible for chicken pox (chickenpox) and shingles. Reactivation of chicken pox, called herpes zoster, can affect the inner ear in a frame called Ramsay-Hunt syndrome, which includes vertigo, hearing loss, dermatological lesions and facial paralysis.
More rarely, labyrinthitis can be caused by a bacterial infection, usually occurring after a history of bacterial otitis or bacterial meningitis. The labyrinthitis of bacterial origin is a case more serious than the viral labyrinthitis, being able to evolve with permanent deafness and sepsis.
The main symptom of labyrinthitis is a sudden and intense vertigo*, commonly associated with nausea, vomiting and imbalance when walking. The picture of vertigo is usually so strong that the patient tries to stay in bed.
* We call dizziness the dizziness that has a rotational characteristic, that is, one in which we have the impression that we or the surrounding environment is spinning.
An important sign of vertigo is the presence of nystagmus: involuntary, rapid and short eye movement, usually in the lateral direction, as in the video below. It occurs in labyrinthitis and all other diseases that occur with vertigo.
Vertigo dizziness also has the characteristic of having periods of improvement and worsening over the days. Vertigo tends to get worse whenever there are jerky head movements.
When labyrinthitis is caused by inflammation of the labyrinth, hearing loss of the affected ear is also present. When labyrinthitis attacks only the vestibular branch of the auditory nerve, characterized by pure vestibular neuritis, there is only dizziness without hearing loss because the cochlear branch is intact. The picture of hearing loss is usually mild to moderate intensity, being more evident for high frequency sounds. The presence of tinnitus is also common.
Some doctors distinguish between labyrinthitis and vestibular neuritis, calling only labyrinthitis cases where there is hearing loss, indicating inflammation of the labyrinth and not the vestibular branch of the auditory nerve. Therefore, summarizing the symptoms of labyrinthitis: dizziness, nausea, vomiting, imbalance, hearing loss and tinnitus.
Labyrinthitis is a self-limiting disease that improves spontaneously, but in some cases the symptoms may last for a few weeks. As a rule, the first 2 or 3 days are the worst, with the picture showing progressive improvement over the next few days. A residual dizziness, especially after sudden head movements, may persist for several months. Only 1% or 2% of patients who had labyrinthitis had recurrence of the disease, usually in the ear that had not been affected.
As already mentioned, labyrinthitis is a self-limiting condition that improves with time alone. However, the symptoms are often very intense, uncomfortable, and sometimes prolonged. Rest and hydration are indicated for all cases. The use of corticosteroids seems to accelerate the cure of labyrinthitis of viral origin. The most commonly used regimen is high dose prednisone (60 mg) for 5 days with progressive reduction to 5 mg on the 10th day.
The use of medications to control symptoms is also indicated, the most commonly used are antiemetics (against nausea) such as metoclopramide (Plasil or Primperan) and antihistamines. In some cases anxiolytics such as alprazolam and diazepam may also be used.
Bacterial labyrinthitis is treated with antibiotics.
