History
A thorough medical history, including symptoms, past medical history, and medications, is essential to diagnosing labyrinthitis as the cause of the patient's vertigo or hearing loss. Symptoms to consider in the patient’s medical history include the following:
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Vertigo - Timing and duration, association with movement, head position, and other characteristics
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Hearing loss - Unilateral or bilateral, mild or profound, duration, and other characteristics
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Aural fullness
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Tinnitus
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Otorrhea
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Otalgia
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Nausea or vomiting
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Fever
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Facial weakness or asymmetry
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Neck pain/stiffness
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Upper respiratory tract infection symptoms - Preceding or concurrent
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Visual changes
The patient’s past medical history should be examined for the following:
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Episodes of dizziness or hearing loss
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Infections
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Sick contacts
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Ear surgery
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Hypertension/hypotension
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Diabetes
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Stroke
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Migraine
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Trauma (head or cervical spine)
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Family history of hearing loss or ear disease
The patient’s medication history should also be taken into account. Check for use of the following drugs:
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Aminoglycosides and other ototoxic medications
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Beta-blockers and other antihypertensives
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Tranquilizers, including benzodiazepines
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Antiepileptics
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Alcohol
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Illicit drugs
Viral labyrinthitis
Viral labyrinthitis is characterized by a sudden, unilateral loss of vestibular function and hearing. The acute onset of severe, often incapacitating, vertigo, frequently associated with nausea and vomiting, is characteristic of this disorder. The patient is often bedridden while the symptoms gradually subside. Vertigo eventually resolves after several days to weeks; however, unsteadiness and positional vertigo may persist for several months. Hearing loss is common and may be the primary presenting symptom in many patients.
An upper respiratory tract infection precedes the onset of cochleovestibular symptoms in up to 50% of cases. Recurrent attacks are reported but are rare and may be confused with Ménière disease. Resolution of vertigo and dysequilibrium is common and is due to partial recovery of vestibular function, with concurrent central compensation of the remaining unilateral vestibular deficit. Return of hearing usually mirrors the return of vestibular function.
A unique form of viral labyrinthitis is the aforementioned herpes zoster oticus, or Ramsay-Hunt syndrome. The cause of this disorder is reactivation of a latent varicella-zoster virus infection occurring years after the primary infection. Evidence suggests that the virus may attack the spiral and vestibular ganglion in addition to the cochlear and vestibular nerves. [2]
The initial symptoms of herpes zoster oticus are deep, burning, auricular pain followed a few days later by the eruption of a vesicular rash in the external auditory canal and concha. Vertigo, hearing loss, and facial weakness may follow singly or collectively. Symptoms typically improve over a few weeks; however, patients often suffer permanent hearing loss and persistent reduction of caloric responses. [3]
Autoimmune labyrinthitis
Autoimmune labyrinthitis is an uncommon cause of sensorineural hearing loss and may occur as a local, inner ear process or as part of a systemic autoimmune disease such as Wegener granulomatosis or polyarteritis nodosa. Hearing loss in autoimmune inner ear disease is typically bilateral and progressive over weeks to months. Vestibular complaints may occur in up to 80% of patients with autoimmune inner ear disease. [11, 12]
Physical
The physical examination includes a complete head and neck examination, with emphasis on the otologic, ocular, and cranial nerve portions of the examination. A brief neurologic examination is also necessary. Seek the presence of meningeal signs if meningitis is a consideration.
The otologic examination should be carried out as follows:
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Perform an external inspection for signs of mastoiditis, cellulitis, or prior ear surgery
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Inspect the ear canal for otitis externa, otorrhea, or vesicles
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Inspect the tympanic membrane and middle ear for the presence of perforation, cholesteatoma, middle ear effusion, or acute otitis media
The ocular examination should be performed as follows:
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Inspect the ocular range of motion and pupillary response
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Perform a funduscopic examination to assess for papilledema
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Observe for nystagmus (spontaneous, gaze-evoked, and positional); perform a Dix-Hallpike test if the patient can tolerate it
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If visual changes are suggested, consult an ophthalmologist
The neurologic examination should be performed as follows:
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Perform a complete cranial nerve examination
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Assess for balance using the Romberg test and tandem gait
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Assess cerebellar function by performing finger-to-nose and heel-to-shin tests
Viral labyrinthitis
Physical examination findings include spontaneous nystagmus towards the unaffected side, with diminished or absent caloric responses in the affected ear. The hearing loss is usually mild to moderate and is typically evident in the higher frequencies (>2000 Hz), although any degree or type of hearing loss may be present.
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Anatomy of the labyrinth.
