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Hearing loss
OVERVIEW: Complete or partial hearing loss that may involve the middle ear (mechanical, conductive) or the inner ear (nerve, sensorineural)
System(s) affected: Nervous
Genetics: Both types may be on a genetic basis
Incidence/Prevalence in USA:
• 140/100,000/year (134 adults, 6 school age children)
• 3,494 (cases/100,000), with 3,333 for adults and 161 for school age children
Predominant age: All ages, but more common in elderly
Predominant sex: Male = Female
SIGNS AND SYMPTOMS: Obvious difficulty hearing, with possible association of other symptoms such as tinnitus, dizziness, pain, and fullness
CAUSES: • Conductive
• Cerumen impaction
• Perforation of tympanica membrane
• Middle ear fluid (serous otitis media)
• Acute otitis media
• Adhesive otitis media
• Damage to ossicles (trauma, infection, etc.)
• Tympanosclerosis (thickening of drum that may produce fixation)
• Otosclerosis (new bone growth that produces stapes fixation)
• Cholesteatoma (growth of skin into middle ear)
• Middle ear tumor (glomus, etc.)
• Congenital problems (atresia, ossicular fixation, etc.)
• Temporal bone fracture, injuries
• Sensorineural
• Acoustic tumor
• Meniere's disease
• Noise induced (industrial, recreational, occupational)
• Hereditary
• Congenital
• Viral (relatively common, esp. mumps)
• Ototoxicity (ASA, quinine, gentamicin, kanamycin, etc.)
• Syphilis - hearing loss, tinnitus, dizzy
• Presbycusis (hearing loss related to aging)
• Temporal bone injury, fracture
• Metabolic (hypothyroid, etc.)
• Perilymphatic (inner ear) fistula (usually secondary to pressure changes or trauma)
• Autoimmune disease
RISK FACTORS: Nasal allergy and other causes of eustachian tube obstruction; exposure to loud noise levels; use of ototoxic antibiotics; prematurity; heredity (otosclerosis)
DIAGNOSIS DIFFERENTIAL DIAGNOSIS: • In conductive loss, must rule out cholesteatoma
• In sensorineural loss, must rule out acoustic tumor
LABORATORY: N/A
Drugs that may alter lab results: N/A
Disorders that may alter lab results: N/A
PATHOLOGICAL FINDINGS: N/A
SPECIAL TESTS: • Audiometry including pure tone and speech testing, and impedance (middle ear pressure) testing. Both types of hearing loss may fluctuate, making audiometric results variable from test to test. Marked conductive loss in one ear may be difficult to exclude (mask) when testing opposite ear.
• Otoscopy with operating microscope (sometimes necessary to see small superior, attic perforation, indicating a cholesteatoma)
IMAGING: • CT scan (not routinely needed) is useful to demonstrate tumors and cholesteatoma of the temporal bone
• MRI scan is more useful to show acoustic and other cerebellopontine angle tumors (usually produce a sensorineural hearing loss)
DIAGNOSTIC PROCEDURES: • Exploratory tympanotomy sometimes necessary to confirm presence of middle ear fluid, tumor, etc.
• Underlying conditions are identified primarily on basis of history of hearing loss, otoscopy, and hearing test (audiometry)
• FTA or equivalent
• Sed rate for autoimmune disease
TREATMENT APPROPRIATE HEALTH CARE: Outpatient
GENERAL MEASURES: • Conductive (mechanical)
• Cerumen: Remove with suction and irrigation (not if perforation is present). Don't direct water against drum but against canal wall. Manipulation with wire curette may help.
• Tympanic membrane perforation: Surgical correction
• Serous otitis (primarily in children). Treat underlying conditions. Use decongestants, antibiotics. Urge inflation of eustachian tube (hold nose and blow).
• Adhesive otitis: Looks like perforation. Treat eustachian tube problem. May need surgery.
• Damage to ossicles: Don't manipulate. Refer to otolaryngologist.
• Tympanosclerosis: Drum has white plaques. Treat only if hearing loss is present.
• Otosclerosis: Suspect on basis of history of onset, early in life, that is progressive, with positive family history of hearing loss. Consider surgery. Refer to otolaryngologist.
• Cholesteatoma: Identify by perforation that is located near margin of drum. Refer to otolaryngologist.
• Middle ear tumor: May see through drum. Most commonly will be glomus tumor, which has red color and may cause pulsation. Significant problem, needs prompt referral to otolaryngologist.
• Congenital deformity: Don't attribute all hearing loss in children to infections and middle ear fluid. Refer to otolaryngologist.
• Temporal bone injury: If limited, may only involve middle ear. Drum likely to appear blue. Refer to otolaryngologist.
• Sensorineural (nerve)
• Acoustic tumor: Most significant type of hearing loss. Very important to diagnose promptly. Suspect when unilateral hearing loss and tinnitus (with or without dizziness) are present. Needs much higher degree of suspicion on part of primary care physician. Refer to otolaryngologist.
• See topic on Meniere's disease
• Noise damage: The most common cause of hearing loss in this country. Very frequent on occupational basis, and has the attention of federal government (OSHA regulations). Also occurs secondary to sports and recreation (hunting, use of guns, loud music, chain saws, shop tools). Needs much greater level of recognition at primary care level. Refer to otolaryngologist.
• Hereditary/congenital: Needs immediate recognition early in life, so that if significant, hearing aids can be placed. Rarely, surgery may be effective.
• Viral: A relatively common cause of permanent hearing loss, frequently unilateral, e.g., mumps
• Ototoxic (medication): Needs much more recognition at primary care level. Suspect when hearing loss, and perhaps dizziness and tinnitus come on during course of treatment with certain antibiotics (and many other medications). See Medications.
• Syphilis: Treat with high dose penicillin given intravenously, as well as steroids
• Presbycusis: No specific treatment available, but important to provide hearing rehabilitation. This includes counseling patient to avoid factors that may cause further loss (noise exposure, ototoxic drugs). Emphasize development of lip reading skills, and counseling family to pronounce words clearly, face patient when speaking, etc. Offer hearing aid trial when patient is a suitable candidate.
• Temporal bone injury: No treatment available specifically for hearing loss unless middle ear is involved
• Metabolic: Treatment of specific problem (e.g. hyperlipidemia, hypothyroid)
• Perilymphatic fistula: Diagnosis based on history of injury to ear including barotrauma during diving. Treatment is early exploration to confirm fistula in round or oval window of middle ear, with repair of fistula. Refer to otolaryngologist.
• Total or near total sensorineural hearing loss: Cochlear implant (electronic device inserted into mastoid and inner ear)
• Autoimmune sensorineural hearing loss: Steroids and chemotherapy. Refer to otolaryngologist.
SURGICAL MEASURES: See General Measures
ACTIVITY: • Patients having perforation of the ear drum or ventilation tube in place should be advised not to swim or allow water to enter the ear
• Patients having hearing loss secondary to noise exposure should be advised to avoid loud noise, or to use suitable protection (ear plugs or ear muffs)
DIET: Patients whose hearing loss is due to Meniere's disease should avoid excessive use of salt
PATIENT EDUCATION: See information under other headings
MEDICATIONS DRUG(S) OF CHOICE: • Cerumen impaction - it is frequently helpful to soften the wax prior to removing it. triethanolamine polypeptide oleate-condensate (Cerumenex) is popular, but should not be used in the presence of a perforation, and may produce a skin reaction. A good alternative is simply to place, or have the patient place mineral oil in the ear canal overnight prior to wax removal. Hexachlorophene (pHisoHex) and topical docusate sodium (Colace) are also useful to soften very hard wax.
• Acute otitis media - erythromycin or amoxicillin
• Chronic otitis media with purulent drainage - neomycin-polymyxin B-hydrocortisone (Cortisporin) otic drops (or an equivalent) placed into the ear canal (3-6 drops bid)
• Serous otitis media - decongestant, e.g., phenylephrine - phenylpropanolamine - guaifenesin (Entex) and erythromycin
• Sudden sensorineural hearing loss with no apparent cause - steroid therapy in high dosage form (80 mg/day of prednisone, or equivalent steroid) may be helpful
Contraindications: History of sensitivity to any of the antibiotics referred to above
Precautions: Avoid the temptation of over-diagnosing red ear and using antibiotics without a well thought out diagnosis
Significant possible interactions: Refer to manufacturer's literature
ALTERNATIVE DRUGS: • Acute otitis media - cefaclor
• Chronic ear infection with drainage - ear drops and powder containing ciprofloxacin. Gentamicin drops is another alternative.
FOLLOW UP PATIENT MONITORING: Hearing testing (audiometry) is the primary means of monitoring patient progress
PREVENTION/AVOIDANCE: • Impaired eustachian tube function (serous otitis media, acute otitis media) - improve tubal function with treatment of allergic and sinus disease. Treat upper respiratory infections (URI) promptly and aggressively if ear problems are frequent.
• Sensorineural hearing loss due to noise exposure (or any type of nerve deafness) - advise against excessive noise exposure; recommend ear plugs/ear muffs
• Nerve deafness due to ototoxic medications may be prevented by the avoidance, or careful use of drugs known to be ototoxic (consider audiometric monitoring if used). The most frequently implicated antibiotics are gentamicin, kanamycin, neomycin, vancomycin, and streptomycin. Other implicated drugs include lidocaine, morphine, digitalis, quinidine, and furosemide. Use of these drugs cannot always be avoided. Be more suspicious of the possibility that a given medication might be ototoxic, and when hearing loss is a problem, to prescribe with care.
• Serious nerve deafness resulting from CNS disease (meningitis, lues) may be prevented by thorough treatment of the primary problem
• If URI present, avoid flying or diving
POSSIBLE COMPLICATIONS: • Middle ear problems may progress to chronic ear problems (perforations, cholesteatoma)
• Cholesteatoma is capable of producing major complications including permanent loss of hearing, balance problems, facial nerve paralysis, meningitis, lateral sinus thrombosis, and brain abscess. Glomus tumors and acoustic tumors must be identified, or major CNS complications may result.
• Meniere's disease may proceed to total and permanent hearing loss if not treated, and may occur in spite of treatment
• Severe nerve deafness, particularly associated with tinnitus may produce such an emotional impact on the patient that suicide may occur. Treat the patient with empathy and understanding, offer help even if it seems limited. Encouragement and followup care are extremely helpful in managing these patients.
EXPECTED COURSE AND PROGNOSIS: Sensorineural hearing loss is usually permanent, but in a few instances, may be stabilized, improved, or even cured
MISCELLANEOUS ASSOCIATED CONDITIONS: Noise, allergy, sinus disease, trauma, heredity, ototoxicity, CNS infections (meningitis, lues), age, hyperlipidemia, hypothyroid, barotrauma and autoimmune disease
AGE-RELATED FACTORS:
Pediatric: Eustachian tube problems and secondary middle ear problems are more common in infants and small children, usually becoming less frequent by approximately age 10
Geriatric: Presbycusis is common and is made worse by noise exposure and other factors
Others: N/A
PREGNANCY: Otosclerosis may become active during pregnancy
SYNONYMS: N/A
ICD-9-CM: 380.4 Impacted cerumen
385.00 Tympanosclerosis, unspecified
387.9 Otosclerosis, unspecified
382.0 Acute suppurative otitis media
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