Labyrinthitis

What is Labyrinthitis?

Labyrinthitis is a condition in which the inner part of the ear known as the membranous labyrinth gets inflamed. This typically results in symptoms like dizziness, nausea, vomiting, tinnitus (ringing in the ears), and/or hearing loss. Not much information is available on the prevalence of labyrinthitis, but it appears to become more common as people age. It’s important to know that many other serious conditions, like a stroke, might present similar symptoms. This is why it’s essential to have a complete medical examination and tests before confirming a diagnosis of labyrinthitis.

This condition normally occurs due to a bacterial or viral infection, but it can also emerge as a symptom of a systemic autoimmune disease (where the body’s immune system attacks its own cells) or HIV – human immunodeficiency virus. Treatment strategies are customised depending upon the cause of the condition and controlling the symptoms. While most patients fully recover, some may experience ongoing balance or hearing issues.

Everybody’s inner ear is made up of two parts: the bony labyrinth and the membranous labyrinth. The bony labyrinth is a collection of bone cavities within the temporal bone (a bone in your skull). It is composed of three main parts: the vestibule, cochlea, and three semicircular canals. These structures contain a fluid known as perilymph.

The membranous labyrinth resides within the bony labyrinth and includes four structures: the saccule, utricle, semicircular ducts, and cochlear duct. These are all filled with a different kind of fluid known as endolymph. The inner ear connects with the middle ear via two points (the oval window connects to the vestibule, and the round window connects to the cochlear duct) and the central nervous system via two points (the internal auditory canal and cochlear aqueduct).

What Causes Labyrinthitis?

Labyrinthitis is a condition where the membranous labyrinth, a structure in the ear, becomes inflamed. This can be triggered by viruses, bacteria, or even certain diseases. In rare situations, it can lead to the formation of new bone within the membranous labyrinth, a condition known as labyrinthitis ossificans.

Sometimes, labyrinthitis is used interchangeably with vestibular neuritis as the symptoms are very similar. However, vestibular neuritis refers specifically to inflammation of the vestibular nerve, a nerve in the ear used for balance, without inflammation of the membranous labyrinth.

Viral Labyrinthitis

The most common cause of labyrinthitis is a viral infection of the upper respiratory tract, essentially a common cold. In newborns, labyrinthitis caused by rubella or cytomegalovirus (CMV) infections from the mother is one of the leading causes of hearing loss from birth. After birth, mumps and measles continue to be the top causes of hearing loss due to viruses.

There’s also Ramsay-Hunt syndrome which is a reactivation of the varicella-zoster virus, the same virus that causes chickenpox. This can create a rash, typically in the mouth or ear, and lead to facial nerve paralysis. It can also affect the nerves important for hearing and balance in about 25% of cases.

Sudden hearing loss, although its exact cause is uncertain, some suggest CMV inflammatory proteins as a possible cause.

Bacterial Labyrinthitis

Bacterial labyrinthitis typically arises from bacterial meningitis or a middle ear infection known as otitis media. This inflammation can happen in two ways. In serous labyrinthitis, the inflammation is caused by bacterial toxins or inflammation-promoting substances making their way into the membranous labyrinth. Suppurative labyrinthitis is caused more directly by a bacterial infection entering the inner ear.

Autoimmune Labyrinthitis

In rare cases, labyrinthitis can be linked to polyarteritis nodosa and granulomatosis with polyangiitis, which are inflammations of the blood vessels.

HIV/ Syphilis

Both syphilis and HIV have been linked to labyrinthitis. However, more research is needed to understand whether this inflammation is caused by infections due to lowered immunity from HIV or by the virus itself.

Risk Factors and Frequency for Labyrinthitis

Labyrinthitis, specifically its occurrence and prevalence, is not widely studied. Nevertheless, it has been observed in South Korea that the frequency of disorders related to the vestibular system, which includes labyrinthitis, varies between 3.1% and 35.4%. This frequency tends to increase with age. The most common form of labyrinthitis is viral labyrinthitis, which often follows an infection of the upper respiratory tract. This type typically occurs in adults aged 30 to 60 and is two times more likely to affect females.

When it comes to severe bacterial labyrinthitis, also known as suppurative bacterial labyrinthitis, it is a common cause of hearing loss in children under the age of 2. This is usually a complication of bacterial meningitis. Fortunately, such cases are very rare these days, thanks to antibiotics. This severe form of labyrinthitis can also result from longstanding or untreated middle ear infection, or from a cholesteatoma, a noncancerous skin growth that can develop in the middle ear. It can occur at any age.

Signs and Symptoms of Labyrinthitis

If you’re thinking that you might have labyrinthitis, a number of things could make you more likely to have it. For example, recent viral infections, especially those of the upper respiratory tract such as the common cold, can increase your risk. Past surgeries or injuries related to the ear, skull, or temporal bone (the bone that surrounds the ear) might also put you at higher risk. Likewise, if you’ve ever had meningitis or infections of the middle ear, both acute and chronic, these too could add to your risk.

Common symptoms of labyrinthitis include feeling extremely dizzy, as if the room is spinning, along with nausea and vomiting. These extreme dizzy spells usually last no more than three days. However, issues with balance and brief, sporadic dizzy spells can continue for several weeks. You might also experience hearing loss or a ringing noise in your ear. These symptoms can help tell labyrinthitis apart from vestibular neuritis, which doesn’t usually cause any hearing-related symptoms. If you’re experiencing neurological symptoms like numbness, muscle weakness, difficulty swallowing or speaking, and facial pain, you should report these to your doctor as they might indicate a stroke affecting the brainstem. If you’ve had more than one episode of room-spinning vertigo, Ménière’s disease might also be considered as a potential diagnosis.

Your doctor will conduct a physical exam to check for signs of labyrinthitis. They will look for a rapid, involuntary movement of your eyes in a particular direction, which is a symptom known as nystagmus. You might also be asked to walk in a straight line or stand with your feet together and eyes closed to assess your balance and coordination. This, along with checks for reflexes and sensitivity, will form part of a comprehensive neurological examination. Hearing tests might show loss of hearing in the affected ear. If you report any hearing abnormalities, a full hearing test may be necessary. A look into your ear might reveal signs that could explain the origin of your symptoms, such as a middle ear infection or a noncancerous skin cyst known as cholesteatoma. If bacterial meningitis is a concern, the doctor will check for a specific type of rash that doesn’t fade under pressure.

Testing for Labyrinthitis

Hearing tests, or audiometry, are helpful in determining the degree of hearing loss that may be caused by damage to the nerves involved in hearing. For the beginning stages of the disease, complex tests related to the balance system in our ears, such as evoked myogenic potentials, electronystagmography, and rotary chair tests aren’t needed. However, these tests can be beneficial in evaluating long-term impacts and remaining impairments.

The type of lab tests the doctor orders will depend on the patient’s symptoms and what the doctor thinks is causing the problem. For example, if severe vomiting is a symptom, a urea and electrolytes panel might be performed to see if there is a need for an electrolyte supplement. If bacterial meningitis, a severe brain infection, is suspected, the doctor might want to test the patient’s cerebrospinal fluid, which surrounds the brain and spinal cord. If the patient is at high risk of HIV or syphilis, or if the symptoms are unusual, the doctor might test for these diseases. Lastly, if the patient is showing body-wide symptoms or unusual symptoms even with negative test results for diseases, the doctor might consider screening for autoimmune diseases, where the body mistakenly attacks its own cells.

Scans like MRI (Magnetic resonance imaging) and CT (computed tomography) can also be useful in ruling out other potential diseases or problems. About 13% of acoustic neuromas, which are slow-growing tumors of the nerve that connects the ear to the brain, show signs of sudden hearing loss, which can be found out using an MRI. Also, scanning with a contrast material called Gadolinium using MRI is highly precise in predicting if a patient with bacterial meningitis will subsequently develop hearing loss, which happens in about 14% of cases.

Treatment Options for Labyrinthitis

Treatment for labyrinthitis, an inflammation of the inner ear, needs to be personalized for each patient. It depends on the cause and symptoms they are having.

If it’s caused by a virus, the best course of action is generally to rest and stay hydrated at home. It’s important, however, that if your symptoms get worse or you start experiencing any neurological problems (like weakness, double vision, slurred speech, or difficulty walking), you should go back to the hospital or doctor right away.

When it comes to bacterial labyrinthitis, antibiotics can help. The kind of antibiotic and how you take it (orally or intravenously) depends on where the infection comes from. For example, oral antibiotics might be the first course of action if the infection is related to an acute ear infection with an intact eardrum. In other cases, when an ear infection just doesn’t improve, you may need antibiotics delivered intravenously. If there’s a possibility that you have bacterial meningitis, doctors will start antibiotics right away while they confirm the diagnosis with imaging or Fluid sampling.

For labyrinthitis caused by the body’s immune system (autoimmune labyrinthitis), corticosteroids are usually the first treatment. If these don’t help, doctors might consider using other immunomodulators like azathioprine, etanercept, or cyclophosphamide. Because these medications have fewer side effects than corticosteroids, they’re often used for long-term treatment. They should, however, be overseen by a specialist. If tests show that you have syphilis or HIV, you’ll need to start appropriate treatment and consult a specialist.

During the initial onset of vertigo (dizziness and loss of balance), you’ll probably want to lie still with your eyes closed. However, you should try to move around as much as possible once you can, even if it makes you dizzy, as it’s thought to be beneficial for recovery.

Certain medications like benzodiazepines and antihistamines can help with the initial vertigo, while anti-nausea medications like prochlorperazine can help control nausea and vomiting. Steroids can help patients with sudden hearing loss, who should also see a specialist. Tinnitus (ringing in the ears) can occur and can sometimes lead to reactive depression. Early interventions with various treatments like tinnitus retraining, maskers, hearing aids and biofeedback can help manage it.

Surgery is only required in a small number of cases, such as if you have a cholesteatoma (a noncancerous skin growth) in your ear or severe mastoiditis (an infection of the bones behind the ear), or perhaps to drain fluid or create a hole in the eardrum if the labyrinthitis is due to an ear infection.

Several patients may continue to have problems with their balance after labyrinthitis has apparently resolved. This can have a major impact on someone’s life, and these patients should be referred for rehabilitation which focusses on balance.

What else can Labyrinthitis be?

There are several conditions that can have symptoms similar to labyrinthitis. These include:

• Vestibular neuritis: Much like labyrinthitis, but doesn’t cause hearing loss.
• Meniere disease: This condition also causes hearing loss and dizziness; however, the symptoms come and go.
• Benign positional vertigo: This condition can cause a feeling of spinning but not hearing loss. You can tell it’s this condition if the Dix-Hallpike test result comes back positive.
• Posterior fossa CVA: If patients show any signs of ataxia, hoarseness, dysarthria, or trouble swallowing, a CT or MRI scan of the head should be done immediately to rule out this condition.
• Acoustic neuromas/vestibular schwannomas: These can be seen on a specific type of MRI scan.
• Ear malformations: These types of abnormalities, such as missing or abnormal parts, usually cause progressive hearing loss and can be identified using CT or MRI scans.
• Temporal bone fracture: This should be considered if the patient recently suffered a head injury. It can be confirmed with a CT scan.
• Inner ear hemorrhage: This is often related to injury and can be easily seen on an MRI scan.
• Temporal bone neoplasm: This usually comes with cranial nerve deficits or facial paralysis and should be investigated with an MRI and/or CT scan.
• Multiple Sclerosis: This condition is more likely to occur along with other systemic symptoms such as muscle stiffness or signs of optic neuritis.

What to expect with Labyrinthitis

The intense dizziness (vertigo) that comes with labyrinthitis, an inflammation of the inner ear, usually goes away within a few days. However, milder symptoms may continue for several weeks. Generally, the outlook is good if the patient does not have any serious brain-related side effects.

Neurological complications such as problems with the brain or nerves may need more treatments, and this can make the prognosis (the likely course of a medical condition) uncertain. For instance, some patients might need a ventriculoperitoneal shunt, a device that drains excess cerebrospinal fluid from the brain to the abdomen, if they have hydrocephalus (a build-up of fluid in the brain) due to bacterial meningitis (an infection that causes inflammation of the membranes surrounding the brain and spinal cord).

Patients who take benzodiazepines (a type of medicine used to treat anxiety and insomnia) or antihistamines (a type of medicine used to treat allergies) for a long period to manage their vertigo may experience delayed recovery of their balance system. Furthermore, suppurative labyrinthitis, a type of labyrinthitis with pus-filled swelling, is more likely to result in permanent hearing loss.

Possible Complications When Diagnosed with Labyrinthitis

Bilateral vestibular hypofunction is a severe issue that tends to follow a condition called bilateral labyrinthitis, often triggered by bacterial meningitis. The condition can lead to vision problems and hinder one’s sense of space, sometimes making people dependent on walking aids. After severe bouts of labyrinthitis, patients might suffer from hearing loss or a ringing in the ears—issues that can be managed with hearing aids or particular therapies for the ringing sound.

Severe Cases Consequences:

• Visual problems
• Difficulties in understanding space
• Reliance on walking aids
• Tinnitus or hearing loss manageable with aids or therapies

A complete loss of hearing is a rare—and quite severe—outcome of bilateral labyrinthitis, most often caused by bacterial meningitis. There’s also a condition called labyrinthitis ossificans that’s known to follow severe labyrinthitis. If bacterial labyrinthitis isn’t treated appropriately, it can worsen into an ailment known as mastoiditis, usually remedied effectively using IV antibiotics. However, in incredibly severe instances, it might require procedures like mastoidectomy with tympanoplasty. There exist infrequent events where labyrinthectomy might become necessary to stop the disease, particularly within cases of labyrinthitis brought on by cholesteatoma.

Severe Cases Complications:

• Total hearing loss
• Labyrinthitis ossificans
• Mastoiditis, treatable with IV antibiotics
• Potential need for operations like mastoidectomy with tympanoplasty
• In rare cases, a labyrinthectomy may be required

Preventing Labyrinthitis

Labyrinthitis, a condition that affects your inner ear and causes feelings of spinning (vertigo), can often develop as a result of another infection, such as an ear infection (otitis media) or a brain infection (meningitis). Hence, it’s crucial to diagnose and treat these conditions early to avoid or reduce the chance of getting labyrinthitis, or at least to lessen the chances of long-term issues related to it. It’s also important for everyone to stay updated with their vaccinations to decrease their chances of getting illnesses like measles, mumps, or rubella that can lead to labyrinthitis.

In case you experience vertigo, it’s recommended that you try to move around as soon as you can, as research suggests this helps the balance system in your inner ear (vestibular system) adapt better to the condition and improves your long-term outlook. Generally, if people with vertigo undergo extensive treatment with certain types of drugs like benzodiazepines (sedatives) and/or antihistamines (used to treat allergies), it seems to delay the recovery of their balance system.