Introduction:
Labyrinthitis ossificans results commonly due to an infection or an inflammatory process in the inner ear or cochlea associated with trauma to the temporal bone, tumor, or hemorrhage. This inflammatory process disturbs the communication of sensory information between the ear and the brain. In some instances, it may present as a symptom of systemic autoimmune disease or human immunodeficiency virus (HIV) infection. The symptoms are similar to other ear conditions and need thorough examination for diagnosis and treatment.
What Are the Causes of Labyrinthitis Ossificans?
Labyrinthitis ossificans is caused due to inflammation of the membranous labyrinth due to a bacterial, viral, or systemic disease. Labyrinthitis ossificans results when there is a bony growth within the labyrinth membrane. Due to its symptoms and clinical presentation, it is confused with other conditions like vestibular neuritis.
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Viral Labyrinthitis: It is the most common cause of labyrinthitis as a secondary infection to viral upper respiratory tract infection. It is generally associated with maternal rubella or cytomegalovirus infections, a common cause of congenital deafness. During the post-natal period, measles and mumps are the significant causes of hearing loss. Other viral infections include Ramsay-Hunt syndrome, which produces a vesicular rash in the ear or oral mucosa, and facial nerve paralysis. It also involves cochlear and vestibular nerves resulting in sensorineural hearing loss.
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Bacterial Labyrinthitis: It arises with bacterial meningitis or otitis media. Bacterial labyrinthitis occurs through two mechanisms- inflammation secondary to bacterial cytokines or host toxins and inflammatory mediators traversing into a membranous labyrinth through an oval window called the serous labyrinth. And direct inflammation due to bacterial infection called suppurative labyrinthitis. The oval window is the common point and may access bony labyrinth growths arising from congenital or acquired defects.
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Systemic or Autoimmune Labyrinthitis: It results due to a rare complication of polyarteritis nodosa and granulomatosis with polyangiitis. Labyrinthitis is also associated with HIV or syphilis due to immunosuppression as an opportunistic infection.
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Injury or Trauma: Injury to the labyrinth as a sequel to infection or trauma to the otic capsule can result in ossification leading to hearing loss which can be unilateral or bilateral and can occur after bacterial meningitis infection.
What Are the Symptoms of Labyrinthitis Ossificans?
The symptoms of labyrinthitis ossificans can vary depending on the extent of bone growth and the affected structures. The condition is often gradual, and symptoms may develop over time as the bone growth progresses. Common symptoms of labyrinthitis ossificans can include
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Hearing loss is often the first symptom of labyrinthitis ossificans. It may begin as mild hearing loss, but over time, it can progress to severe or complete deafness in the affected ear. The hearing loss may be unilateral, affecting only one ear, or bilateral, affecting both ears.
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Tinnitus, an auditory symptom distinguished by a ringing or buzzing sensation within the ear, is a common indication of labyrinthitis ossificans. It may persistently or periodically occur, with internal sounds unrelated to external stimuli. Labyrinthitis ossificans can cause vertigo, a sensation of room spinning, or dizziness. It can be sudden and severe and occur only when moved head in a certain way.
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Balance problems can be a significant symptom of labyrinthitis ossificans because of the inner ear infection, which disrupts ear function. It is associated with instability, feeling off-balance, and difficulty walking.
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Nausea and vomiting are common labyrinthitis ossificans symptoms due to severe vertigo and balance problems.
What Is the Diagnosis of Labyrinthitis Ossificans?
The diagnosis of labyrinthitis ossificans commonly involves a comprehensive approach, combining medical history review, physical examination, and various diagnostic tests.
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Medical History: To gather a comprehensive medical background, the healthcare provider conducts an inquiry into the symptoms, their onset, any prior viral or bacterial infections, history of trauma, exposure to loud noises, and any underlying medical conditions of the patient.
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Physical Examination: During a physical examination, the healthcare provider may conduct assessments to identify indications of inflammation or injury within the inner ear. The doctor may also perform a hearing test to assess the extent of hearing loss, such as Rinne and Weber's healing tests. The patient may present with Romberg's and tandem gait representing neural or balance problems. An otoscopy can be done to investigate the etiology.
Diagnostic Tests: Tests for labyrinthitis ossificans include:
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CT (computed tomography) scan and MRI (magnetic resonance imaging) scan are imaging tests that provide detailed images of the inner ear structures. They are used to visualize bone growth and assess the extent of the damage.
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Audiometry: A hearing test helps evaluate the extent of hearing loss and assesses how well a person can hear various sound frequencies.
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Electronystagmography (ENG): ENG is a test that evaluates vestibular systems useful for assessing long-term compensations and residual deficits.
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Laboratory tests: If bacterial meningitis is suspected, CSF (cerebrospinal fluid) cultures. HIV and syphilis serology in high-risk patients with systemic symptoms. In patients with severe nausea and vomiting, electrolyte panels are performed to assess electrolyte replacements.
What Is the Treatment of Labyrinthitis Ossificans?
Treatment focuses on managing symptoms and preventing further damage, while in other cases, surgery may be necessary to remove the affected bone and restore hearing and balance function. Some standard treatment options:
Medications:
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Medications are prescribed to manage symptoms such as vertigo, nausea, vomiting, and tinnitus.
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Vestibular suppressants are used to relieve vertigo and nystagmus, while antiemetics are given to alleviate nausea and vomiting.
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Corticosteroids are prescribed to reduce inflammation in the inner ear and improve the symptoms.
Rehabilitation Therapy: It is suggested for severe balance and vertigo problems to reduce the risk of falls. A physiotherapist prescribes exercises to improve balance and coordination.
Hearing Aids: Hearing aids can be used to manage hearing loss resulting from labyrinthitis ossificans. These help in sound amplification and communication.
Surgery: Surgical intervention is required in severe cases where bone growth is significant. The surgical procedure employed will be determined based on the bone growth level and the individual's specific requirements. It can also be done in cases with cholesteatoma or severe mastoiditis. Some effusion drainage or myringotomy can be required in labyrinthitis secondary to otitis media.
Monitoring: Regular monitoring is necessary to track the progression of the condition and assess vertigo and balance problems that impact an individual's life.
Conclusion:
Labyrinthitis ossificans is a rare but severe condition that can cause significant hearing loss and balance problems. If an individual encounters symptoms such as hearing loss, tinnitus, or vertigo after a bacterial or viral infection, it is crucial to seek medical attention promptly. Diagnosing the condition early and administering appropriate treatment makes it feasible to effectively manage the symptoms and mitigate the risk of potential complications.
