Common Ear Conditions
Acute Otitis Media (middle ear infection)
Middle ear infections usually affect children although adults are not exempt. The usual source is an ascending infection from the nasopharynx up the Eustachian tube. The source of infection could be from an isolated upper respiratory tract or sinus infection or from recurrent tonsillitis and adenoiditis.
The main symptoms are pain and deafness. Constitutional symptoms such as fever, lethargy and poor appetite are also common. Examination reveals a red, bulging eardrum (Figure 1). If the infection is not adequately or promptly treated, the build up of pus in middle ear can rupture through the eardrum into the external ear canal. The patient will experience discharge with relief of pain. The perforation usually heals spontaneously when appropriate treatment is instituted.
Treatment consists of oral antibiotics and pain relief. If effective, symptoms subside within 48 to 72 hours. If symptoms do not subside or worsen, a myringotomy (cut in the eardrum) is performed to drain the infection.
Related Links – http://www.nidcd.nih.gov/health/hearing/otitismedia.asp
Chronic Suppurative Otitis Media (Chronic eardrum perforation)
There are two types of chronic middle ear infection; a chronic perforation eardrum (tubotympanic type) and entrapment of skin in the middle ear (cholesteatoma).
In some patients with acute middle ear infection, build up of pus and pressure cause rupture of the eardrum with ear discharge into the external ear canal. The ruptured or perforated eardrum will heal spontaneously if treatment is instituted adequately and promptly. However, if the perforated eardrum does not heal and close after 3 months, it is considered a chronic perforation (figure 2). These perforations will not heal and close without surgical intervention.
When there is persistent Eustachian tube dysfunction, the air in the middle ear becomes absorbed and not replaced. Over time, the relative negative pressure in the middle ear sucks the eardrum inwards. The more flaccid top part of the eardrum is first to retract and a pocket forms. Skin, dirt, wax gets trapped in this pocket forming a cholesteatoma (figure 3). Cholesteatomas enlarge as the trapped contents cannot discharge itself and erodes surrounding structures like the bone, ossicles, and facial nerve.
Patients present with deafness and recurrent discharge. This condition is usually painless. Discharge from the middle ear can develop as a result of an ascending infection up the Eustachian tube or water and dirt entering from the external ear.
Infections are treated with ear cleaning using suction under a microscope and instillation of antibiotic eardrops. Once the middle ear infection resolves, surgical closure (myringoplasty) is recommended for a chronic perforation. This procedure is done under general anaesthesia in day surgery. Success rates range from 95 to 98% in uncomplicated cases. In the case of cholesteatoma, it must be excised to prevent further damage from its expansion. This requires a mastoid operation which is done under general anaesthesia. Patients usually stay overnight after surgery. The main aim of mastoid surgery is to render the ear safe (from complications of cholesteatoma). Hearing improvement is a secondary goal.
Otitis Media with Effusion (serous otitis media, glue ear)
Otitis media with effusion (OME) affects mainly children. It is thought that Eustachian tube dysfunction results in negative pressure in the middle ear compartment. This in turn leads to fluid accumulation in the middle ear. Large adenoids and recurrent infection of the adenoids can also affect Eustachian tube function.
The main presenting symptom is deafness. Usually, there is not much pain and no discharge. Older children will be able to inform parents of the hearing loss. However, younger children may present with delayed or unclear speech. In Chinese, presentation with one-sided OME requires exclusion of nose cancer. Examination of the ear will reveal dull or yellow appearing eardrums which may also be retracted. Sometimes, bubbles (figure 4) or an air-fluid level may be seen. Examination of the nasopharynx using a flexible endoscope (or plain x-ray in uncooperative children) will usually show large obstructing adenoids in children.
The initial treatment of children with OME is conservative. Studies have shown that the use of a prolonged course of oral antibiotics increases the rate of spontaneous resolution of OME. If the fluid persists after medical therapy, drainage via a myringotomy (cut in eardrum) and a grommet tube insertion will reverse the deafness. Most grommet tubes inserted are short term, ie. they extrude after 6 to 9 months. Re-accumulation of OME occurs in a small percentage of children after extrusion of grommet tubes and re-insertion is necessary. Adenoidectomy is recommended at this time if the adenoids are large. If OME persists after multiple tube insertions, a long term T-tube (lasting 2 to 3 years) may be inserted.
Related links – http://www.nlm.nih.gov/medlineplus/ency/article/007010.htm
Otosclerosis is a condition in which the stapes ossicle is fixed at its connection to the inner ear (figure 5). This is the result of abnormal bone growth around that area. This condition is inherited with parents having a 50% chance of passing the condition to their children. However, only 40% of the affected children will actually show clinical or histopathological evidence of the disease. Of all patients with otosclerosis, only 60% have a family history.
Patients are generally young adults in their twenties and thirties and present with progressive hearing loss in both ears. Pregnancy has been reported to accelerate the disease in some women. Examination usually reveals normal appearing eardrums. However, when the disease is in the active phase, a pinkish color may be seen through the eardrum (flamingo flush). Tuning fork tests and audiometry will confirm a conductive hearing loss.
Treatments options include surgery and hearing amplication. Surgery should be performed by trained otologists (ear doctors) and is targeted at by-passing the diseased bone by replacing it with a prosthesis (usually made of titanium) that connects the healthy incus ossicle to the inner ear (figure 6). The risks and success of surgery should be discussed with your ENT surgeon. Patients averse to surgery can be helped with the prescription of hearing aids.
Related links –
Acoustic neuromas are slow-growing benign tumors that arise from the nerve of balance. Ninety-five percent of patients present with a unilateral (one-sided) sensorineural hearing loss. Associated symptoms include tinnitus (ringing in the ear) and a blockage sensation. The gold standard investigation for determining the presence of an acoustic neuroma is an MRI scan with contrast (figure 7).
Three treatment options are established; observation, stereotactic radiation and surgical excision. The factors that determine which option is best for a patient include age, size of tumor, presence of brainstem compression, hearing level and rate of tumor growth.
Related Links – http://anausa.org/
MBBS (S'pore), FRCS (Edin), FRCS (Glasg) Fellow, Otology / Neurotology (Can)
1st NUH-NUS Temporal Bone Dissection Course, Jan 2005