Inflammatory Diseases of the Middle Ear Follow-up

Treatment of an ear with chronic discharge requires close otologic supervision, preferably by the same clinician. Regular microscopic aural toilet using an operating microscope and a suction apparatus is needed until resolution of discharge.

Patients who have undergone mastoidectomy, particularly those with an open mastoid cavity, need regular follow-up visits. Debris, desquamated epithelium, and wax tend to collect in the cavity. Without regular cleaning of the mastoid, this debris becomes infected with persistent and recurrent aural discharge.

Many studies show that breastfeeding influences the occurrence of acute suppurative otitis media (SOM), with a lower incidence of infection in breastfed children. Many hypotheses have been suggested for this effect: the presence of immunologic (immunoglobulin A [IgA]) and nonimmunologic antiviral and antibacterial factors in breast milk; a difference in the development of facial musculature between children who are breastfed and those who are bottle-fed; an allergy to cow milk, formula milk, or both, with resultant changes in the upper respiratory tract mucous membrane; and a difference in the positioning of children during breastfeeding and bottle feeding.

Complications of SOM occur when infection spreads outside the bony walls of the middle ear and the mastoid spaces. Infection can spread to the intracranial structures or involve structures within the temporal bone. The following are intracranial complications:

• Extradural abscesses are the most common intracranial complication and occur after bone demineralization or erosion to the middle or posterior fossa dura. Spread of infection from the petrous apex can cause a middle fossa extradural abscess with resultant irritation of the trigeminal ganglion and the abducens nerve. The triad of otorrhea, facial pain, and diplopia is known as Gradenigo syndrome.

• A subdural abscess forms when infection spreads into the subdural space with the formation of granulation tissue. Neurologic deterioration rapidly occurs, with headache and drowsiness being followed (within hours) by coma and death. The treatment of an otogenic subdural abscess involves high doses of antibiotics and neurosurgical drainage. Postoperative anticonvulsants may be required. Surgical exploration of the middle ear is delayed until the patient's general condition has improved.

• Before antibiotics were developed, sigmoid and transverse sinuses, together forming the lateral sinus, could thrombose, and this condition was a common complication of acute ear infections. Today, this is much less common with acute disease and is more common following chronic suppurative otitis media (CSOM).

  • Thrombophlebitis of the lateral sinus is often associated with perisinus extradural abscess. Infected clots can cause bacteremia, septicemia, and septic embolization. Cranial extension of the thrombus may lead to thrombosis in other sinuses.

  • Untreated, the clinical picture constitutes a wasting illness, with a fluctuating picket-fence fever pattern, rigors, and headache that develops over several weeks, as well as signs of papilledema in a patient with CSOM. These clinical signs are often masked when a patient is partially treated with antibiotics.

• Meningitis remains the most common complication of SOM and is potentially lethal. Infection to the meninges usually spreads directly through necrotic bone from the middle ear. Early symptoms and signs include headache, neck stiffness, and photophobia; monitor for progression to neck stiffness and a positive Kernig sign with vomiting and high pyrexia.

• Otogenic brain abscess is a complication of CSOM, although its incidence has fallen. Even with modern diagnostic imaging and expert neurosurgical management, the mortality rates are 10-20%. Temporal lobe abscesses follow direct spread of infection through the tegmen tympani, whereas cerebellar abscesses are usually found in association with lateral sinus thrombosis. Treatment involves high doses of antibiotics and neurosurgical intervention.

• Otitic hydrocephalus is a rare complication of otitis media and refers to the finding of increased intracranial pressure in association with a middle ear infection. The cause of this condition remains obscure, but it may be due to impaired CSF resorption after lateral sinus thrombosis. Common symptoms include headache, decreased visual acuity, drowsiness, nausea, and vomiting. CT scans of the brain show normal ventricular size. Treatment to reduce intracranial pressure includes steroids and mannitol.

The following are intratemporal complications:

• Facial nerve paralysis may occur as a complication of acute or chronic suppuration within the temporal bone. In acute disease, infection spreads from the middle ear into the fallopian canal, presumably via congenital dehiscences in the canal. Prognosis of nerve recovery with antibiotics is excellent. In chronic disease, facial nerve involvement is more common with cholesteatomatous disease and is thought to be due to osteitis, bony erosion, and compression due to edema and direct infection of the nerve. In cases that do not involve cholesteatoma, a dehiscent fallopian canal is common.

• Suppurative labyrinthitis and labyrinthine fistula are due to an acute infection from the middle ear into the labyrinth via the round window. Symptoms associated with labyrinthine fistula include vertigo, otorrhea, hearing loss, headache and facial palsy. In chronic infection, these complications are due to bony erosion of the otic capsule. The bone that covers the lateral semicircular canal is the most common site affected.

• Because of the close proximity of the mastoid system, most cases of SOM have a degree of mastoid air cell inflammation. Today, clinical mastoid involvement is uncommon because of antibiotics.

• Subperiosteal abscess and postauricular fistula are complications of both acute SOM and CSOM. They are due to the spread of infection through the mastoid air cells into the soft tissue around the ear. Although these complications are now rare in the postantibiotic era, they still remain common in areas where access to health care is poor. Swelling and erythema develop behind the ear with protrusion of the pinna and loss of the postauricular crease. In chronic disease, if left untreated, a subperiosteal abscess may spontaneously rupture and lead to a postauricular fistula between the mastoid and the exterior. Treatment involves surgical excision of the fistulous tract with mastoidectomy for the underlying CSOM.

• Petrositis due to the spread of infection to the petrous apex can occur as a complication of both acute SOM and CSOM. Because of the close proximity of the petrous apex to the trigeminal ganglion and the abducent nerve, corresponding nerve palsies can occur.

• A cholesterol granuloma, an uncommon inflammatory lesion of the temporal bone associated with a giant cell reaction, can be a complication of otitis media. Bony erosion is rare.

The following are developmental complications:

• Impaired hearing and delayed speech development are the most common long-term effects of recurrent episodes of otitis.

• One study showed that children aged 8-10 years who underwent myringotomy and ventilation tube insertion to treat SOM had performance results (articulation of words, discrimination of sounds, auditory attention) that were significantly worse than those of healthy controls. Another study suggested that children with otitis media during the first 3 years of life continued to have difficulties with the comprehension of visual language, the articulation of words, attention, and reading capacity until they were aged 11 years. ^[26]

Surgical management of chronic inflammatory conditions of the middle ear and the associated complications pose risks to the patient. Preoperative counseling of the patient is imperative. The patient must understand the nature of these risks.

In obtaining consent, the surgeon must explain to the patient, in layman's terms, the nature, the purpose, and the material risk of the proposed procedure. Such risks include hearing loss, facial nerve paralysis, bleeding, infection, vertigo, and disease recurrence.

If necessary, the surgeon should supplement a verbal explanation with drawings or diagrams to ensure that the patient has sufficient knowledge of the proposed procedure to make an informed decision.

Preventive measures for otitis media are integral in reducing its incidence and complications. This can be accomplished by educating parents about reducing known risk factors for otitis media, including exposure to passive smoke, bottle propping, and pacifier use.

Because S pneumoniae is the most commonly reported bacterial cause of AOM, accounting for 28-55% of cases, counseling parents to the use of pneumococcal vaccines in their children can significantly reduce the incidence of AOM. Multiple studies demonstrate significant population reductions in AOM rates and antibiotic usage after universal introduction of pneumococcal vaccination.

Viral vaccines have also been associated with reducing the incidence of AOM related to viral etiologies. Encouraging children to receive the influenza vaccine can protect against episodes of otitis media during influenza outbreaks. Their exact role in reducing rates of AOM, however, remains to be epidemiologically demonstrated.