Common Problems of the Ear

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[edit] Common Problems of the Ear

Michael D. Seidman

George T. SimpsonII

Mumtaz J. Khan

Primary care physicians encounter many disorders that affect the ear, and thus they must understand common otologic problems and know basic anatomy and physiology of the ear (Fig. 178-1). Physicians also must be able to examine and evaluate disorders of the ear. They should know routine management for common otologic diseases and when to refer to an otolaryngologist.

Figure 178-1 Anatomy of the external, middle, and internal ear.

[edit] FOREIGN BODIES

Foreign bodies in the external auditory canal are a common problem, particularly in children. The foreign bodies include peanuts, plastic beads, pins, paper, and pencil erasers, virtually anything that can be placed in the canal. Insects may become trapped in the canal and produce irritating symptoms. Unless the ear canal is traumatized, these foreign bodies may be asymptomatic. When retained for some time, however, infection may develop and produce edema and inflammation of the canal wall itself, as well as purulent and foul-smelling discharge. The true etiology of the problem may be obscured.

The first step in evaluation and treatment of a foreign body in the ear is a complete examination of the head and neck, including the opposite ear and the nose to rule out the presence of multiple foreign bodies. In the absence of a clear history of foreign body placement, a foreign body may not be suspected or detected on the initial examination because of severe inflammation and swelling, which can sometimes mimic that of acute or chronic mastoiditis. This situation requires otolaryngology consultation.

Removal should never be attempted by the patient or the family, because it will usually be unsuccessful and may exacerbate the problem. Removal requires complete cooperation by the patient or immobilization to prevent movement of the patient's body and head. Sometimes, particularly in young children, immobilization will require brief general anesthesia. When a live insect is trapped in the ear canal, it may be killed by filling the canal with mineral oil or alcohol.

The basic principle of removal is to apply pressure behind the object so as to pull it from the canal. Instruments such as clamps or alligator forceps should not be used routinely, since they may push the foreign body further into the canal and may traumatize both the canal and the tympanic membrane. Small soft objects that are not occluding the canal may be removed using syringe irrigation, as in removing wax. The water should be at body temperature (lukewarm) to avoid inducing pain or caloric response with vertigo and nausea. Water irrigation should not be used with hygroscopic foreign bodies such as beans or other vegetable material, since they will swell with the absorption of water and make removal more difficult.

A small instrument such as a wax or wire-loop curet or a blunt hook can be passed through the canal until it is beside the foreign body, then used to pull the object from the canal. Because removal is most easily accomplished under direct vision through a binocular operating microscope, an otolaryngologist should be consulted if difficulty is encountered. If the foreign body is near the tympanic membrane, an audiogram may be obtained first to ensure hearing is not already compromised. If the foreign body has perforated the tympanic membrane, the patient should be seen by an otolaryngologist.

If no gross contamination has occurred, with no signs of inflammation or infection of the middle ear, medication is not usually necessary. An obvious infection should be treated as outlined later (see Otologic Infections). For lacerations of either the canal or the tympanic membrane, the ear canal should be kept dry to allow healing. This means preventing water from entering the ear canal while showering, bathing, and hair washing. Cotton balls coated with petroleum jelly may be placed in the external meatus to prevent the entry of water.

Any object in the ear canal that bleeds on manipulation should be suspected of being a mucosal polyp from the middle ear. These polyps occur in the presence of chronic middle ear infections. Their removal should not be attempted because they may be attached to the facial nerve or ossicles of the middle ear. An otolaryngologist must be consulted for this condition.

[edit] TRAUMA

[edit] External Ear Injuries

Trauma to the external ear may produce superficial abrasions, contusions, hematomas, lacerations, or partial or complete avulsion. Superficial abrasions are managed as elsewhere in the body. The ear must be inspected for other signs of injury.

Contusions may occur in the postauricular muscles and the muscles of mastication, such as the temporalis. Hematomas may occur when the perichondrium is torn. The accumulation of blood between the perichondrium and the cartilage will produce avascular necrosis and provide an excellent site for soft tissue infection and abscess formation. If untreated, these infections can result in a loss of portions of the cartilaginous skeleton of the ear, producing a severe cosmetic deformity: the classic "cauliflower ear" seen in wrestlers, boxers, and others with blunt ear trauma. Temporary treatment with petroleum jelly or collodion-soaked gauze may help to compress the swelling. Protective headgear is now available and should be worn to avert hematoma formation during athletic events. Large hematomas of the external ear must be treated immediately by incision and drainage, including saline irrigation to remove clots, placement of drains, compression dressings, and systemic antibiotics. An otolaryngologist should be contacted for urgent consultation and surgery if necessary.

Lacerations of the external ear may be minor and require only a few simple sutures for closure. Fine sutures produce excellent results but should be removed in several days. The earlobe may be lacerated when earrings are torn away; repair uses simple sutures with an excellent result. If not closed primarily, these lacerations require more complex plastic repair later. When small lacerations extending through skin and cartilage are closed, care is taken to avoid penetration of the cartilage by sutures passing through the skin. This complication may lead to infection of the cartilage. More extensive lacerations and avulsions require an otolaryngologist.

The external ear canal is occasionally lacerated by a fingernail, cotton-tipped swab, hairpin, or other instrument. These lacerations usually do not cause problems and do not require repair. Antibiotic drops may be indicated if a laceration involves more than half the external canal, and larger lacerations, the risk for stenosis significantly increase. Placement of an otowick and application of antibiotic drops may be necessary. Water must be kept out of the ear. The physician must determine that the tympanic membrane is intact and that hearing function is normal. Laceration of the external canal skin may be associated with a fracture of the temporal bone; if the patient has been struck on the ear, such a fracture becomes more likely.

Trauma may produce injury to the tympanic membranes, including perforations or tears. Blows to the outer ear and explosive barotrauma may produce a tear in the tympanic membrane. Foreign bodies in the external canal also can cause membrane injury. Most tympanic membrane perforations or tears heal spontaneously without intervention. Unless the tympanic membrane is grossly contaminated by dirty water, antibiotics are not usually necessary, although they may be used prophylactically. Occasionally the otolaryngologist places a small paper patch over the perforation or laceration to speed the rate of healing. The examiner must assess and document the hearing status and other functions of the middle and inner ear at the initial examination. An audiogram should be obtained. If any question remains regarding healing of the injury, an otolaryngology consult must be sought.

[edit] Middle Ear Injuries

Middle ear injuries result when physical forces are transmitted to structures within the tympanic space. Such injuries may result from loud noises, pressure injuries, and the introduction of foreign objects through the tympanic membrane. Head trauma with basilar skull fracture may include facial paralysis, fracture, and dislocation of the ossicles with discontinuity of the ossicular chain and conductive hearing loss. The stapes may be subluxated out of position in the oval window. Forces may be transmitted from the stapes through the cochlea and may rupture the round window membrane. Ossicular injury and blood in the middle ear space result in conductive hearing loss. A leak of perilymph may produce symptoms of vertigo and sensorineural hearing loss, which may result from a displaced stapes or ruptured round window membrane. Such ruptures usually close spontaneously, and they may not be diagnosed as often as they occur. If they persist, a fistula may result with gradual deterioration of hearing. Perilymph fistulas are considered an otolaryngologic emergency.

[edit] Inner Ear Injuries

Structures of the inner ear may be injured by sudden forces associated with acceleration, deceleration, or blows to the head. Hydraulic forces transmitted by the ossicles may cause ruptures between the fluid cavities within the labyrinth, disruption or tearing of labyrinthine structures, and bleeding within the labyrinth. Symptoms may vary from hearing loss to dizziness, vertigo, and disequilibrium. These symptoms may be profound, immediate, and incapacitating. They may be irreversible. Significant inner ear injuries usually involve both the vestibular and the cochlear systems and may be associated with fractures of the temporal bone in the base of the skull.

Vertigo, hearing loss, and tinnitus constitute the syndrome of the labyrinthine concussion. The most common symptom is positional vertigo, with a brief attack of vertigo and nystagmus caused by a change in head position. The syndrome is similar to benign paroxysmal positional vertigo. The prognosis for this type of vertigo is good, with spontaneous remission usually occurring in 6 months but occasionally not until more than 2 years after the injury.

In evaluating ear trauma, computed tomography (CT) scanning for bony detail is helpful. Ear function after trauma must be evaluated by audiologic testing. With significant likelihood of major injury or significant sequelae, consultation with an otolaryngologist is mandatory on an urgent basis.

[edit] HEARING IMPAIRMENT

Hearing is one of the primary special senses. Hearing impairment not only compromises communication but also may result in inappropriate responses to environmental dangers and induce a sense of isolation with profound emotional effects. An estimated 10% to 15% of the population has some degree of hearing impairment, which means about 30 million persons in the United States have hearing difficulty. Hearing loss is frequently overlooked as a major problem despite its common occurrence. Primary care physicians must understand hearing impairment and its socioeconomic ramifications. They have an important responsibility for identifying hearing difficulties and obtaining appropriate consultation and treatment (Fig. 178-2).

Figure 178-2 Normal audiogram. Pure tone audiograms are graphic representations of the thresholds of perception for tones of various frequencies. Loudness of the tone is measured in decibels (dB), and frequency or pitch of the tone is measured in hertz (Hz) or cycles per second.

[edit] Causes of Hearing Loss

Hearing impairment implies a defect in the appropriate identification of acoustic information in the external environment. It may involve any portion of the transducer mechanism of the ear. That is, hearing impairment may result from a defect in the mechanical conduction of sound from the external environment, in sensorineural coding, in transmission of signals to the central nervous system (CNS), or from a mixture of these defects.

[edit] Conductive Hearing Loss.

Conductive hearing losses are characterized by mechanical defects or a relative inefficiency in the mechanical portion of the auditory system (Fig. 178-3). Any or all anatomic portions of the external or middle ear may be involved.

Figure 178-3 Audiogram illustrating moderate conductive hearing loss characterized by air-bone gap in the right ear.

[edit] External Ear.

In the external ear, any problem or condition that prevents sound energy from reaching the middle ear will result in a hearing loss. The most common condition that produces a hearing loss is occlusion of the external ear canal by cerumen. A buildup of cerumen gradually occludes the canal. Most frequently, cerumen becomes impacted in the ear canal through misguided attempts to clean the ear canal using a fingertip or a cotton-tipped applicator. Rather than migrating externally, the cerumen is pushed more medially in the canal, eventually occluding it. Hearing may be restored by removing the cerumen from the canal.

Infection of the soft tissues of the external ear canal produces a conductive hearing loss by closing the canal with edema and retained secretions. Effective management requires removal of all secretions and use of medical therapy.

Overgrowth of the bony wall of the external ear canal may result from contact with cold water while swimming, as in long-distance swimmers, surfers, and scuba divers. The bony knobs may close the ear canal and contribute to retention of the cerumen, fluid, and local inflammation. Occlusion may produce a conductive hearing loss. This condition is called external canal bony exostosis. Exostoses do not require treatment when they are small. When they become large and symptomatic, however, they must be removed surgically by an otolaryngologist.

Rare conditions that produce a conductive hearing loss through occlusion in the external ear canal include tumors and congenital atresias of the canal. Occasionally, multiple recurrent external canal infections can produce a fibrotic or cicatricial stenosis of the canal that requires surgical treatment.

[edit] Tympanic Membrane.

When movement of the tympanic membrane is impaired, a mild to moderate mechanical or conductive hearing loss results. Impaired mobility may result from middle ear infection with a buildup of fluid or effusion. A perforation after infection or trauma impairs mobility of the tympanic membrane. The membrane's mechanical efficiency may be compromised by scar tissue formation and deposition of calcium, a condition called tympanosclerosis, or by a healed perforation with hypermobility of the tympanic membrane at the site of healing. Eustachian tube dysfunction, barotrauma, or barotitis (middle ear inflammation associated with diving injuries or flying) results in negative middle ear pressure and impairs mobility of the tympanic membrane.

[edit] Middle Ear.

Besides those involving the tympanic membrane (e.g., middle ear effusion, otitis media, barotitis, tympanosclerosis), other conditions affect structures of the middle ear and result in a conductive hearing loss. Otosclerosis, a bony fusion of the stapes, reduces the motion of the ossicle, resulting in hearing loss. It is inherited in an autosomal dominant pattern with variable penetrance. Otosclerosis occurs (but frequently is not detected) in 10% of the population and is treatable with surgery. Ossicular discontinuity, fracture, or subluxation may result from trauma and interfere with the middle ear sound conduction mechanism. Congenital malformations also may produce conductive hearing loss. Cholesteatoma (keratoma), a collection of normal squamous epithelium occurring within a sac or forming a ball, also affects sound conduction in the middle ear. Cholesteatomas usually follow a perforation or retraction pocket in the tympanic membrane. The ball of squamous epithelium gradually enlarges over time and, through direct pressure and enzymatic resorption, can cause the destruction of the ossicles and erosion of structures within the inner ear or cranial cavity. If communication with the outside exists, chronic infection and drainage may occur and induce otitis media or disseminated infection, with serious sequelae. The degree of destruction may not be appreciated initially, since the collection of squamous cells may become a mechanical transmission device to the inner ear, even when extensive destruction has already occurred.

Mechanical (conductive) hearing loss frequently can be improved or eliminated safely by surgery. Underlying disease must be treated. If surgery is not possible or desired, hearing aids may significantly improve hearing.

[edit] Sensorineural Hearing Loss.

Disorders within the cochlea, including the auditory nerve and its connections in the brainstem, produce hearing loss that is classified as sensorineural. Sensorineural hearing losses are divided into those involving the cochlea and those involving the retrocochlear region (the eighth cranial nerve and central pathways).

Several disorders within the cochlea produce hearing loss. A common and increasingly recognized form of hearing loss is that induced by noise trauma (Fig. 178-4). This trauma can be explosive noise, but most often it is prolonged exposure to excessive levels of noise above 85 dB. Mechanical stress on structures of the inner ear may produce temporary injury and, if prolonged, result in permanent injury and increasing hearing loss. The most easily damaged structures are the hair cells in the organ of Corti, which is attached to the basilar membrane in the basal turn of the cochlea. Since hair cells in this region of the cochlea are involved in the perception of high-frequency sounds, the initial hearing loss is about 4000 Htz but gradually progresses to involve higher and lower frequencies. Temporary hearing loss from loud noise exposure is called a temporary threshold shift. Such a hearing loss typically improves over 24 to 72 hours. Repeated or persistent noise exposures produce an irreversible hearing loss.

Figure 178-4 Audiogram of bilateral noise-induced sensorineural hearing loss. Typically, it is a high-frequency hearing loss, with normal audition at lower frequencies.

The most common form of sensorineural hearing loss after traumatic noise exposure is presbycusis. This hearing loss of aging represents gradual, progressive degeneration of cochlear structures and central neural connections. Some degeneration of the mechanical portion of hearing may also occur. Typically, hearing loss is most severe in the highest frequencies and is less in lower frequencies (Fig. 178-5). Presbycusis may have a hereditary component involving sensitivity to a variety of factors that produce degeneration. The ability to attenuate presbycusis using dietary restriction and antioxidant therapy shows promise.^[1][2]

Figure 178-5 Audiogram of mid-to high-frequency sensorineural hearing loss consistent with presbycusis. Hearing loss is most severe at the highest frequencies and is less at lower frequencies.

Sensorineural hearing loss may result from viral or bacterial infections of cochlear structures. Such hearing loss is usually rapidly progressive and frequently total. Similar hearing loss results from labyrinthitis of any etiology but is usually associated with vestibular symptoms (vertigo and disequilibrium). Syphilitic (luetic) involvement of the labyrinth produces a fluctuating hearing loss and disequilibrium. Symptoms gradually progress, and hearing deteriorates without treatment.

Ménière's disease may be present in patients who experience fluctuating hearing loss. It comprises the syndrome of fluctuating sensorineural hearing loss, tinnitus, pressure symptoms in the ear, and vertigo. The ultimate etiology is unknown, but the pathology involves the buildup of intralabyrinthine pressure, called endolymphatic hydrops. The increased pressure distends structures of the labyrinth in episodes associated with a sudden onset of cochlear and vestibular symptoms. Therapies have had varying success, including salt-restricted diet and vasodilator agents, including nicotinic acid, histamine, 5% carbon dioxide inhalations, diuretic, and diazepam. The symptoms may be associated with periods of increased stress. Symptoms wax and wane and may be absent for months to years and then return. Occasionally, profound hearing loss and loss of vestibular function may result. The majority of patients benefit from diuretics and salt restriction. Approximately 15% to 20% fail medical management, and several surgical options are available (see Vertigo).

Although usually associated with conductive hearing losses, otosclerosis also may produce intralabyrinthine symptoms, particularly tinnitus and sensorineural hearing loss. Surgery in otosclerosis, while improving hearing, may not affect the other symptoms. Medical treatment with sodium fluoride occasionally leads to stabilization of hearing.

Fistulas involving leakage of perilymphatic fluid from the middle ear or mixing of perilymphatic fluid with endolymphatic fluid may be associated with sudden hearing loss. The symptoms do not usually persist but may be variably present and may occur episodically. Fistulas are usually associated with physical activity or sudden barotrauma; they may follow external trauma to the ear and head. Bed rest with the head elevated must be begun immediately, with otolaryngologic consultation. Surgical correction is occasionally required.

Ototoxic effects of medication are of increasing importance. Most often, Salicylates produce ototoxic drug effects, including tinnitus, hearing loss, dizziness, and disequilibrium. The hearing loss involves all frequencies. Symptoms rapidly disappear after cessation of medication. Other drugs producing ototoxic effects include ethacrynic acid and furosemide. Quinine-related antimalarial compounds cause a progressive irreversible hearing loss, sometimes of delayed onset. Malarial infections, however, may produce permanent sensorineural hearing loss if the labyrinth has been infected. Quinine and its analogs may cause fetal injury and congenital deafness. Nitrogen mustard and cisplatin, as used in chemotherapy, also can produce significant hearing loss.

Clinically, the most significant agents producing ototoxicity are the aminoglycosides, all of which produce varying degrees of auditory and vestibular damage. Streptomycin and gentamicin have their greatest effects on the vestibular end organ; kanamycin, tobramycin, and neomycin cause more damage to the cochlear end organ. Patients receiving aminoglycosides rarely complain of vertigo but experience unsteadiness of gait, particularly in darkness. A sensorineural hearing loss is produced, beginning in the high frequencies and progressing to a flat, moderately severe loss across all frequencies. Serial audiograms must be obtained for any patient receiving a prolonged course of these agents. Aminoglycosides produce their effects by damaging the hair cells of the inner ear. Unlike other common antibiotics, aminoglycosides are concentrated in both the perilymph and endolymph so that the hair cells are exposed to high concentrations. The ototoxicity of aminoglycosides does not correlate well with serum drug levels. If the total dose is limited to less than 2 gm, however, and the duration of therapy is less than 10 days, the incidence of ototoxicity is low. Because these drugs are eliminated almost exclusively by the kidneys, they must be used with caution in renal failure.

Several congenital disorders may produce a sensorineural hearing loss. When they are not identified at an early age, the acquisition of language skills is severely impaired. Many individuals have been misdiagnosed with mental impairment when their only problem was impaired hearing. Such events have profound and devastating lifelong consequences for education and quality of life. For this reason, hearing screening should begin at a young age, and full audiologic testing should be used when any child appears to have a significant problem in interacting appropriately with the environment.

Currently, the only effective treatment for sensorineural hearing loss is the use of amplification devices. Research studies have been designed to regenerate cochlear hair cells, and avian models have had some success. All cases of suspected hearing loss should be evaluated by an otolaryngologist.

[edit] Retrocochlear Hearing Loss.

When the site of the hearing disorder involves the auditory nerve, brainstem, or CNS, it is defined as a retrocochlear hearing loss. Common causes include CNS sequelae of infection or cerebrovascular injuries such as a stroke, intracranial bleed, or concussion. Other CNS disorders include demyelinating and other degenerative diseases or neoplasms. A common site of retrocochlear pathology involves the eighth cranial nerve, either within the internal auditory canal or within the posterior fossa in the cerebellar pontine angle near the brainstem. Tumors here are rare but must not be overlooked. Within the auditory canal or near its opening, the most common neoplasm is the vestibular schwannoma, a benign tumor arising in the perineurium of the cochleovestibular nerve. Occasionally, congenital keratomas may occur in this area. Other benign tumors are meningiomas. Primary intracranial malignancies or metastases may produce similar symptoms. Vestibular schwannoma and the cerebellar pontine angle tumors have an insidious onset and thus may be encountered in a primary care practice. Early symptoms may include tinnitus, hearing loss, and disequilibrium.

[edit] Mixed Hearing Loss.

A mixed hearing loss is present when a conductive hearing impairment occurs simultaneously with sensorineural hearing loss. A mixed or combined hearing loss may follow injury involving structures of the external, middle, and inner ears. Infection may produce acute and chronic changes in the structure of the ear, including acute inflammation and nerve injury, as well as tympanosclerosis. Congenital disorders may involve structures in any or all parts of the ear. A mixed hearing loss may produce variable and confusing signs on physical examination and requires more specialized testing for proper identification.

[edit] DIAGNOSIS OF HEARING LOSS

The diagnosis of hearing loss requires a suspicion of its presence, either by the patient or the examining physician. In moderate to severe hearing loss, communication clearly is impaired, and a hearing loss is likely. In mild degrees of hearing loss, however, a high index of suspicion is necessary. The patient may not be aware of the gradual onset of the loss and may use the psychologic defense of denial to avoid facing the realities of aging and altered body image. Because of the socially isolating effects of impaired communication, what may initially appear to be depression or even irrational behavior may actually be the result of hearing loss. Severe or profound hearing loss of long duration prevents proper self-assessment of accurate pronunciation and may result in slurred speech, which can be misinterpreted as resulting from other pathology (Table 178-1). Family members may become frustrated and angry with the person who has the hearing impairment if the nature of the problem is not recognized. Communication problems may be attributed to antisocial tendencies or impaired mental status. For all these reasons, awareness of possible hearing impairment and suspicion of its presence are essential.

Table 178-1 Hearing Threshold Levels and Associated Handicaps

✢Assumes all medical or surgical treatment has been applied. If the hearing loss is detected in childhood, special education may be required.

Sudden sensorineural hearing loss is a relatively rare entity that accounts for varying degrees of hearing impairment. The etiology is elusive, but vascular, viral, or autoimmune causes may be most common. Treatment is controversial, and medications have included vasodilators, anticoagulants, steroids, and Hypaque. Treatment is much more likely to be efficacious if instituted early in the course (i.e., within 24 hours and preferably earlier).

With a thorough examination of the ear, the primary care physician usually can recognize the presence of a hearing loss even if the problem cannot be diagnosed more accurately. The physician may have the patient undergo an audiologic evaluation. In most cases of hearing loss, a consultation from an otolaryngologist is essential. During this consultation a complete audiogram may be obtained and appropriate therapy arranged. The physician must understand the process involved in audiologic testing to interpret a report directly from the audiologist or an otolaryngologic consultation.

[edit] TINNITUS

Tinnitus is noise heard by the patient in the absence of any external stimulation. Recent estimates suggest that approximately 40 million Americans are affected by tinnitus. Rarely, the sound can be heard by the examiner.

[edit] Objective Tinnitus

Objective tinnitus can be heard when the examiner places a stethoscope (with the bell removed) in the patient's external auditory canal or places the bell around the ear on the neck. A blowing sound that coincides with inspiration and expiration can result from an abnormally patent (patulous) eustachian tube. The history may indicate this type of tinnitus because of the association with respiration. Objective tinnitus most frequently follows rapid weight loss or may occur during a debilitating illness.

Sharp clicking sounds that occur in bursts and last for several seconds or minutes may be produced by tetanic contractions of the muscles of the soft palate or the tensor tympani muscle. This phenomenon is known as palatal myoclonus. Occasionally the palatal contractions can be observed by the examiner when the tinnitus is audible. Disturbances in the vascular blood flow produce a pulsatile sound that is synchronous with the heartbeat. Aneurysms, vascular neoplasms, and arteriovenous malformations may produce this tinnitus. A venous hum produced by turbulence within the internal jugular vein can produce a "whooshing" or continuous machinelike sound synchronized with the pulse. The examiner may eliminate the sound by occluding the distal jugular vein while avoiding obstructing arterial flow. Carotid bruits may also manifest as pulsatile tinnitus. Radiologic studies with contrast may reveal an enlarged jugular bulb or carotid vascular disease. Ligation of the internal jugular vein may be curative in some patients.

Recent studies have shown that highly sensitive recording techniques can detect the sound produced by the normal motion of cochlear hair cells. This sound represents mechanical effects produced by the stiffening of the basilar membrane within the cochlea and are called otoacoustic emissions. Although these sounds are found in patients with normal hearing without any symptoms, they may produce subjective tinnitus.

[edit] Subjective Tinnitus

Subjective tinnitus is a sound in the ears or head heard only by the patient. Tinnitus may be produced by lesions or conditions within the external ear canal, tympanic membrane, middle ear structures, cochlea, auditory nerve, brainstem, and cerebral cortex. Patients may describe the noise as an ill-defined buzzing, ringing, whistling, or hissing or may identify a specific noise associated with insect or motor sounds. This description can be diagnostically valuable. Ménière's syndrome produces a low-pitched, continuous tinnitus similar to an ocean roar and frequently becomes very loud immediately preceding an acute attack of vertigo. It may then disappear after the attack. In otosclerosis, tinnitus is usually low pitched and continuous but can be intermittent. Cerumen, foreign bodies, or loose hairs in the external ear canal may rub against the tympanic membrane and produce a variety of sounds. Noise or physical trauma, including acoustic trauma from an explosion, produces a high-pitched tinnitus that usually subsides after a few hours, although occasionally it can persist if permanent hearing loss has occurred. Continuous, bilateral, high-pitched tinnitus frequently accompanies hearing loss from chronic noise exposure, presbycusis, and ototoxic chemicals or drugs. A continuous, unilateral, high-pitched tinnitus may be the first symptom of a vestibular schwannoma and may precede loss of hearing or distortion of hearing by several years.

Cochlear and retrocochlear lesions producing tinnitus are usually associated with sensorineural hearing loss or distortion of sounds. The perceived pitch of the tinnitus frequently corresponds to the frequency of greatest hearing impairment. CNS lesions producing tinnitus may not be associated with hearing loss but are almost always associated with other neurologic signs and symptoms. Although some patients with tinnitus do not have associated hearing loss, this finding may represent limitations in testing equipment that typically does not measure hearing beyond 8000 Hz. Many drugs produce tinnitus without associated hearing loss, including salicylates, indomethacin, quinidine, propranolol, levodopa, carbamazepine, aminophylline, and caffeine. The exact anatomic site where tinnitus is produced by the actions of these drugs in unknown, but the drugs probably have both peripheral and central effects.

The treatment of tinnitus may be frustrating. All efforts should be made to diagnose associated, treatable conditions. Several medications taken systemically may suppress tinnitus temporarily, but treatment requires high doses that may be near the toxic range. No drugs are available to "cure" tinnitus, but amitryptyline and alprazolam may reduce the severity of tinnitus. These medications are typically reserved for patients with severe tinnitus because they may have significant side effects. Ambient or environmental noise is most helpful in suppressing tinnitus. Wide-band, or white, noise suppresses tinnitus, not only while the noise is present but for some time after its cessation. Maintaining background noise from a radio or television set or from a device generating the sound of the ocean or falling rain may be helpful, particularly before sleep. A hearing aid may not only improve hearing but also suppress tinnitus. Tinnitus masking devices worn by the patient may be helpful. These devices are similar to hearing aids, but they produce a lower level of continuous white noise for tinnitus suppression. The patient with tinnitus is helped most by the physician's reassurance that no underlying condition exists. Proper evaluation and tests are necessary and can readily be obtained. Consultation with an otolaryngologist is often indicated.

[edit] OTOLOGIC INFECTIONS

Ear infections and their sequelae are relatively common problems in all age groups and represent one of the largest categories of illness in the pediatric population. Effective treatment depends on the specific anatomic structures involved, the agents responsible for infection, and appropriate treatment strategies. Ear infections may involve structures of the external ear, the tympanic and mastoid cavities, or even the labyrinth and temporal bone. Infectious agents may be viral, bacterial, or fungal.

[edit] External Ear Infections

External ear infections involve the skin lining, the external auditory ear canal, and the periosteum of the bone immediately beneath the skin. After cleansing the ear canal, the diagnosis is established by the presence of characteristic diffuse inflammation of the ear canal skin, with or without involvement of the tympanic membrane. Edema may occur, and frequently moist otorrhea is present. If the tympanic membrane cannot be seen or otitis media cannot be ruled out, treatment must be directed at both external and middle ear infection. Use of a systemic agent is required (see Middle Ear Infection). Absorbent wicks (otowicks) that expand in the external auditory canal are often used when the edema is severe (Table 178-2).

Table 178-2 External Ear Infections

The infected ear must be kept dry. No swimming is allowed, and care must be taken while bathing or hair washing to keep water out of the ear. The external meatus can be temporarily occluded with a cotton ball coated with petroleum jelly. All secretions and debris must be removed at least once or twice a week until the infection resolves. Specific treatments are directed at the infecting organisms (most often Pseudomonas aeruginosa) and inflammatory effects. Cortisporin Otic suspension or Col-Mycin usually eradicates the infection; 3 or 4 drops in the ear four times a day for 7 to 10 days is the typical course. Other medications include Vasocidin, Cetapred, VoSol, Domeboro, Garamycin, and boric acid with alcohol.

[edit] Viral Agents.

Viral infections of the external ear are rare. They include varicella, measles, and occasionally herpesvirus. Unless secondary bacterial infections develop, treatment is essentially supportive and specific only for symptoms (e.g., pain). In patients with weeping lesions or edema, astringent agents such as Burow's solution are applied liberally every 4 hours in drops or soaks. Use of steroids is controversial. Symptoms of herpes zoster oticus (Ramsay Hunt syndrome) include severe otalgia, facial paralysis or paresis, decreased lacrimation on the involved side, loss of taste on the anterior two thirds of the tongue, and vesicles on the external ear canal and posterior surface of the auricle. The likelihood of good facial function after Ramsay Hunt syndrome is 40%. Treatment with acyclovir and occasionally steroids has been advocated but is controversial. Occasionally, surgical decompression of the facial nerve is necessary to preserve nerve viability and function. Symptomatic treatment for pain and provision of artificial tears are required pending the resolution of symptoms. Any patient with facial nerve paresis or paralysis should be seen in an urgent consultation with an otolaryngologist, who will evaluate the viability of the nerve and determine whether decompression is required.

[edit] Bacterial Agents.

The most common pathogen involved in an external ear infection is P. aeruginosa. Its frequency of involvement, however, may represent opportunistic contamination within the environment in a moist ear. Other bacterial agents include Staphylococcus aureus and Streptococcus species. Occasionally, enteric organisms may be present. External ear infections are painful; the pathognomonic sign is pain with manipulation of the auricle. Analgesia must be adequate. Codeine may be required, as appropriate for age and weight. In general, analgesic eardrops are not effective because inflamed tissue resists local anesthetic agents. All moist infected ears should be swabbed to obtain specimens for culture and sensitivity determinations. All foreign materials, debris, and secretions must be removed.

In general the most effective antibiotic agents are those applied topically, but occasionally systemic agents may be required. Some of the most effective topical antibiotic agents currently available are mixtures: neomycin and bacitracin or polymyxin with hydrocortisone. Since neomycin is ototoxic, some suggest that it should not be used with a coexistent perforation; however, most otolaryngologists have used neomycin for many years without difficulty. Steroid compounds are included in topical medications to decrease inflammation. A small percentage of patients have an idiosyncratic sensitivity to neomycin and develop erythema, swelling, and pain at the site of application. If these or other severe external ear symptoms develop or persist for more than 1 or 2 weeks after starting the medication, it should be discontinued and another medication substituted. Alternative medications for treatment of otitis externa include Vasocidin, Cetapred, Domeboro, chloramphenicol otic solution, acetic acid solutions with or without hydrocortisone, and Burow's solution. These agents have either a bacteriostatic effect or the ability to reduce the pH of the external canal, thus restoring an acid pH to the milieu of the canal skin. Some of these medications also have a mildly astringent effect that aids in drying the skin and decreasing edema. All medications are given in a dosage of 3 or 4 drops three or four times per day. Burow's solution used alone should be applied every 2 to 3 hours for the first 48 hours. Acetic acid, in the form of white vinegar, may be used alone; it is painful if it enters the middle ear. All medications are instilled into the ear canal with the ear up to allow the medication to contact all portions of the ear canal. The patient should keep the head turned to the side or lie on the side with the treated ear up for 2 to 5 minutes after instillation. Then the medication is allowed to run out by turning the head the opposite way.

External ear infections rarely may extend to involve external ear structures and surrounding tissue. Systemic antibiotics are then necessary. Unless culture and sensitivity reports suggest other treatment, penicillinase-resistant penicillin (dicloxacillin orally or oxacillin or cephalosporins parenterally) is usually best. Occasionally, hospitalization is necessary; applying continuous Burow's solution soaks to the affected area is soothing and helps reduce inflammation, swelling, and pain.

An external ear infection that may have lethal consequences is necrotizing otitis externa (malignant otitis externa). This soft tissue infection, which usually affects elderly, diabetic, or immunocompromised patients, is typically caused by Pseudomonas alone or with other organisms. It may begin with an indolent course, have minimal symptoms (e.g., otorrhea, inflammation), and appear benign. This course progresses relentlessly, if untreated, to invasion and necrosis of contiguous soft tissue structures, including the auricle, scalp, and parotid gland. Further extension occurs to structures of the middle and inner ear with eventual extension to the brain. Facial nerve paralysis may be an early sign. Diagnosis requires a high index of suspicion and the demonstration of granulation tissue. Effective treatment involves a prolonged course of systemic antibiotics and aggressive debridement of necrotic tissue and drainage to prevent further progression. Without treatment, the disease is uniformly fatal, but with aggressive treatment the majority of patients survive.

[edit] Fungal Agents.

Fungal infections of the external ear frequently elicit pruritus. Black, white, or yellow spores may be seen. Contact sensitivity reactions to the fungus may be present. Pain is usually minimal. Mild fungal infections are best treated by general aural hygiene, which includes removal of all cerumen and debris. A dry ear with a normal mildly acidic pH is restored with Burow's solution, VoSol, Domeboro or boric acid, and alcohol irrigations two to four times a day. Persistent mycoses may benefit from a brief course of tincture of cresylate, 3 or 4 drops twice a day for 1 to 2 weeks; cresylate should not be used if the eardrum is perforated. Clotrimazole, 1% lotion in a similar dosage, may also be effective. If systemic mycotic allergy is present and associated with local inflammatory changes in the external ear, immunotherapy with desensitization injections can produce dramatic relief of symptoms.

[edit] Middle Ear Infections (Table 178-3)

[edit] Bullous Myringitis.

Small blebs or blisters are present on the tympanic membrane in this extremely painful condition. Bullous myringitis, once thought to result from a Mycoplasma infection, is caused by a bacterial middle ear infection. Treatment is both supportive and antibacterial. Medications used to alleviate pain include acetaminophen (Tylenol), ibuprofen, and possibly codeine. Erythromycin, penicillin, or amoxicillin (30 to 50 mg/kg/day) is given. Resolution or rupture of the bulla should not be induced unless the pain is severe; lancing the bulla promptly alleviates the pain.

Table 178-3 Middle Ear Infections

[edit] Acute Suppurative Otitis Media.

Acute middle ear infections are one of the most common problems seen by the pediatrician or family physician. Infections typically develop as a result of bacterial contamination through the eustachian tube in the presence of preexisting inflammation in the middle ear. This inflammation results from eustachian tube dysfunction, and oxygen is absorbed from the air in the middle ear space. A negative partial pressure results, which induces an inflammatory response. This response in turn produces a sterile transudate within the middle ear, which may evolve into an exudative process. Concurrent or subsequent contamination of the middle ear from infective nasopharyngeal contents may occur by aspiration or insufflation during nose blowing or crying. In infancy it may be produced by the flow of milk or other liquids into the eustachian tube while the infant is lying supine with a bottle propped in the mouth to induce sleep. The major bacterial pathogens in acute suppurative otitis media include Streptococcus pneumoniae, Moraxella catarrhalis, Haemophilus influenzae, and group A S. pyogenes. Staphylococcus aureus, Mycoplasma pneumoniae, Corynebacterium diphtheriae, and gram-negative bacilli are less frequent causes. The most frequent viruses producing otitis media are the parainfluenza viruses, respiratory syncytial virus, adenoviruses, and coxsackieviruses.

Nontypable H. influenzae (nonencapsulated) strains constitute most middle ear isolates. These strains are not associated with invasive or disseminated infections and are responsible for a small but significant proportion of middle ear infections in older children and adults. Their frequency appears to be increasing. The drug of choice, as recommended by the American Academy of Otolaryngology, is amoxicillin. The resistance of H. influenzae type B to amoxicillin is increasing and averages approximately 30% in the United States. Augmentin, cefaclor, Biaxin, or Lorabid is used to treat amoxicillin-resistant H. influenzae.

[edit] Diagnosis.

Examination and confirmation of otitis media are best accomplished using a pneumatic otoscope. When fluid is present in the middle ear space, mobility of the tympanic membrane is reduced. Additional signs include a bulging, inflamed tympanic membrane or a severely retracted tympanic membrane. Bubbles or an air-fluid level may be seen. With a perforated membrane a pulsatile discharge may be seen, usually in the anteroinferior segment of the membrane. Although otalgia is present, pain or tenderness is not present on manipulating the auricle. Pain is intensified by the insufflation of air with the pneumatic otoscope. %Tympanometry is an objective test in which the mobility of the tympanic membrane is assessed by means of a signal reflected from it while the pressure against the eardrum is continuously changed. The test can be performed by an audiologist, a technician, a nurse, or a physician with only brief training. The margin for artifact and error is less than 10%. Common tympanograms include type A (normal), type B (flat, consistent with middle ear effusion), and type C (retracted, consistent with negative middle ear pressure). Less common tympanograms include type Ad, consistent with a disarticulated ossicular chain leading to hypermobility of the tympanic membrane (Fig. 178-6). This test has a higher reliability in identifying middle ear fluid than many physicians and can be helpful in supporting a clinical diagnosis.

Figure 178-6 Tympanometry. Typical tympanograms include types A, normal; B, flat, consistent with middle ear effusion; C, retracted, consistent with negative middle ear pressure; and Ad, consistent with disarticulated ossicular chain.

In most cases, tympanocentesis or myringotomy is not indicated in the diagnosis of otitis media. These procedures remove secretions from the middle ear to allow bacteriologic studies and are rarely necessary for diagnosis and treatment. Almost all cases of otitis media respond quickly to proper management and may even resolve spontaneously. Virtually all bacteria implicated in middle ear infections are sensitive to common antibiotics. For these reasons, the risk associated with myringotomy cannot be justified in the typical patient. These procedures are usually performed by an otolaryngologist using a binocular operating microscope. Tympanocentesis or myringotomy can be helpful, however, in middle ear infections in neonates, immunocompromised or immunosuppressed and leukemic patients, patients who do not respond to adequate doses of antibiotics, and patients who have developed a complication such as meningitis. Tympanocentesis may offer specific identification of the etiologic organism and thereby promote an effective choice of antibiotic.

[edit] Therapy.

Antibiotics are the most effective measure in all cases of acute otitis media. Depending on allergic history and the patient's age, any of several antibiotics can be used. Amoxicillin, 20 to 40 mg/kg/day in divided doses by mouth for 10 days, effectively manages most infections in all age groups. The usual dosage in older children and adults is 250 to 500 mg every 8 hours. If there is a high local prevalence of amoxicillin resistance, amoxicillin plus clavulanate (Augmentin), cefaclor, clarithromycin (Biaxin), or loracarbef (Lorabid) should be substituted. The combination of trimethoprim (8 mg/kg) and sulfamethoxazole (40 mg/kg) in two divided doses per day covers most pathogens implicated in otitis media, including H. influenzae. Some physicians have recommended avoidance of this medication because of the potential for aplastic anemia. All medications are given for at least 10 days. A longer course of antibiotic treatment may satisfactorily resolve otitis media and prevent chronic middle ear effusions (serous otitis media), reducing the need for myringotomy and pressure-equalizing tubes.

Satisfactory analgesia usually can be provided with acetaminophen or ibuprofen, supplemented by low doses of codeine as necessary. Codeine should be avoided in very young children, and aspirin is typically avoided because of the potential for Reye's syndrome. Antihistamines and decongestants are usually of no help in acute otitis media except for relieving associated coryza symptoms. Antihistamines may actually impair middle ear clearance by interfering with mucociliary flow through the eustachian tube, but this theory is controversial.

Each patient should be evaluated in 2 weeks. If an effusion persists beyond 4 weeks, the patient is treated for chronic serous otitis media and chronic middle ear effusion (see later). Repeated episodes of acute bacterial otitis media with clearing of middle ear effusions between each attack usually can be managed by chronic, low-dose prophylactic amoxicillin. Alternatives to antibiotic therapy exist. If acute bacterial otitis media develops in a patient receiving prophylactic therapy, a myringotomy and insertion of a ventilation tube may be indicated to restore middle ear ventilation and function.

If the tympanic membrane is perforated and drainage is present, this drainage can be cultured for guidance in treatment. Most perforations heal spontaneously. If perforation persists longer than 3 months, the patient should be referred to an otolaryngologist for consultation and treatment.

[edit] Acute Mastoiditis.

Virtually all cases of bacterial otitis media have an associated medical mastoiditis, an infection of the soft tissue surrounding the air spaces in the mastoid bone. Since this air cell system is confluent with the middle ear space, medical mastoiditis is treated concurrently with therapy for otitis media. No radiographs are indicated or necessary but usually reveal clouding of the mastoid air cell system when otitis media is present.

Surgical mastoiditis is an osteitis and periostitis (occasionally associated with thrombophlebitis of the horizontal and sigmoid venous sinuses) that follows acute otitis media. Surgical mastoiditis can be diagnosed clinically by the marked swelling, pitting edema, erythema, and percussion tenderness of the skin over the mastoid bone. Occasionally, edema and displacement of the posterosuperior external canal wall may occlude the canal. The swelling produces an anterior and inferior displacement of the auricle. Facial nerve paresis or paralysis may be present and typically signifies the need for more aggressive management. A fever of 104° to 105° may have a spiking pattern. Surgical mastoiditis is a medical and surgical emergency. Intravenous cephalosporins or ampicillin, in divided doses appropriate for weight, is begun immediately. An antistaphylococcal antibiotic should be given if S. aureus is suspected, pending culture results. Antibiotics are continued for 21 days. An otolaryngologist should be consulted on an urgent basis because surgery is often necessary, including myringotomy, mastoidectomy, incision and drainage of any abscess, and debridement of devitalized bone. These procedures must be performed as soon as possible.

[edit] Acute and Serous Otitis Media.

As discussed, middle ear effusion develops with persistent negative intratympanic pressure. This condition results from eustachian tube dysfunction, which may be associated with such conditions as upper respiratory infection, chronic rhinosinusitis of bacterial or allergic origin, dysfunction of the soft palate (from clefts or surgical defects), and masses in the nasopharynx from adenoid hypertrophy or benign or malignant tumors. When an effusion persists beyond a few days or weeks, its character changes from a serous transudate to an increasingly mucoid, protein-laden exudate with an increasingly gluelike consistency. Although their role is not clear, bacteria are present in approximately one third of persistent effusions.

The diagnosis of middle ear effusion is established on examination. The tympanic membrane is classically thickened, with a gray or amber fluid seen in the middle ear. Sometimes a fluid meniscus, air bubbles, or bluish fluid may appear behind the tympanic membrane. Mobility of the membrane is always impaired. The membrane is frequently retracted by negative pressure, and if this condition is prolonged, retraction of the pars flaccida area may lead to the formation of a cholesteatoma (keratoma). Tympanometry is helpful in supporting the clinical impression of serous otitis media, especially in young children. Hearing may be evaluated by tuning forks and audiograms.

Chronic middle ear effusions represent a special problem in young children because effusions are most common in the early years, when significant speech development occurs. Persistent effusions and mild conductive hearing losses are associated with prolonged impairment of language acquisition skills, and these deficits may last for years. The patient's speech is less well developed than in peers of a similar age. Therefore, if medical management does not resolve middle ear effusions within 3 to 4 months, surgical intervention with myringotomy and possibly tubes should be considered.

Chronic middle ear effusions in adults may be secondary to a nasopharyngeal tumor, most often a poorly differentiated squamous cell carcinoma. This diagnosis must be suspected, actively sought, and then ruled out in every adult with a chronic unilateral middle ear effusion. Although the most common causes of middle ear effusions in adults are allergies, eustachian tube dysfunction, and barotrauma, nasopharyngeal tumor must be considered.

[edit] Therapy.

In general, acute effusions are self-limited, resolving in about 2 weeks. A brief course of decongestants (e.g., pseudoephedrine, three or four times a day) or topical nasal spray may be helpful. If their use is prolonged, however, topical medications may promote reactive mucosal edema and prolong eustachian tube dysfunction. Typically, we do not recommend use of over-the-counter nasal sprays for more than 2 to 4 days. Antihistamines are of no proven benefit, except in the management of coryza or allergic symptoms. If bacterial infection is suspected or cannot be ruled out, antibiotics are used as in acute bacterial otitis media.

Certain measures can sometimes prevent the more severe manifestations in patients prone to develop acute effusions during air travel or diving. Young patients should be awakened when the airplane begins descent and given a bottle or other drink or chewing gum to promote eustachian tube opening with deglutition. Older patients can be instructed in autoinflation exercises. These exercises should be mastered before the flight. The ingestion of alcohol must be avoided, since the vascular dilation in the nasopharyngeal mucosa produces some edema and impairs eustachian tube opening. Patients of any age should be awake during the descent to promote eustachian tube activity by chewing, swallowing, or practicing autoinflation exercises. Topical decongestant medications such as nose sprays work rapidly and should be applied before short flights or just before descent. They are used similarly before diving.

Reestablishing proper aeration of the middle ear is the ultimate therapeutic goal in the management of chronic effusion. Effective therapy depends on establishing, if possible, the cause of eustachian tube dysfunction. Likely causes include chronic rhinosinusitis of bacterial or allergic origin, palatal dysfunction, and hypertrophied adenoid tissue or nasopharyngeal tumors. In infants, milk or other fluids may produce local irritation and flow into the eustachian tube with bacteria.

In older children and adults, autoinflation exercises may be helpful. These exercises include blowing the nose forcefully while the mouth and nares are kept closed. A hand-held nasal balloon "toy" that children enjoy using can be quickly constructed with a soft, flexible plastic tube such as a disposable medicine dropper. The tip of the bulb is removed with scissors, and the balloon or a rubber finger cot is secured over the opposite end with rubber bands. The tube is then placed in one nostril while the other is pinched closed, and the balloon is inflated through the nose. This procedure is repeated several times on both sides. Swallowing and motion of the palate (enhanced by the patient producing a "gunk" sound) while simultaneously maintaining balloon pressure or blowing the nose may open the eustachian tube. Once the patient has mastered such exercises, they should be repeated four to ten times a day.

When autoinflation exercises are unsuccessful or cannot be performed, medical therapy may be helpful. Most cases of chronic effusion resolve spontaneously over several weeks. Although antihistamines and decongestants have been widely used, their efficacy is not supported in clinical studies. Antihistamines and decongestants, however, may be efficacious in the allergic patient. In other patients, these medications may inhibit resolution of the effusion by producing more viscid secretions. A 7-to 10-day course of tapered steroids also may greatly reduce allergic effusions.

A chronic, low-grade, "steady-state" infectious process may be involved in one third of chronic effusions, as shown by the finding of bacteria in the chronic effusion fluids and the response of effusions to antibiotic treatment. The initial therapy for chronic effusions persisting beyond 3 to 4 weeks should be the same as for acute otitis media. Effective medications include amoxicillin, Augmentin, cefaclor, trimethoprim-sulfamethoxazole, erythromycin, clarithromycin, and loracarbef over a 14-to 21-day course and then, if necessary, once nightly at bedtime for 4 to 6 weeks. The effusions frequently resolve with this treatment, which may implicate low-grade bacterial infections in chronic effusions.

If the effusion persists more than 10 to 12 weeks despite adequate medical therapy and autoinflation exercises, an otolaryngologist should be consulted. This recommendation is also true when multiple recurrent episodes of effusion are present, especially if complicated by acute otitis media. In these situations, myringotomy and insertion of ventilation tubes may be considered. This treatment is especially important whenever conductive hearing loss is present. The ventilation tube allows equalization of middle ear pressure. Conductive hearing loss secondary to the effusion and impaired tympanic membrane mobility usually is greatly improved immediately after surgery.

Chronic effusions may produce tympanic atelectasis when the membrane touches the medial wall of the middle ear space. Retraction pockets may form in the tympanic membrane, and a thick adhesive effusion with chronic inflammation and mucosal hypertrophy may impair its function. Myringotomy and ventilation tubes prevent further progression of these problems. Tubes reverse these conditions and help to prevent chronic hearing loss, cholesteatoma formation, and chronic suppurative otitis media.

In occasional patients with adenoidal hypertrophy, the adenoidal tissue may occlude the eustachian tube orifices. Chronically infected adenoid tissue also may produce local edema that interferes with tubal function and, with lymphatic drainage from the middle ear, contributes to recurrent ear infections. Adenoidectomy may be helpful in resolving the effusion and recurrent infection problem.

[edit] Chronic Suppurative Otitis Media.

Chronic suppurative otitis media always involves a tympanic membrane perforation or defect with chronic purulent otorrhea and middle ear inflammation. A mild to moderate conductive hearing loss is present. In general the condition is otherwise asymptomatic unless it progresses to involvement of the inner ear and produces sensorineural hearing loss, vertigo, and disequilibrium or facial nerve palsy. Cholesteatoma (keratoma) is the presence of normal squamous epithelium within the middle ear and may occur from retraction of the pars flaccida of the tympanic membrane with chronic negative pressure, with a sac being formed and gradually enlarging to enclose the trapped dead cells of desquamated skin. Alternatively, squamous epithelial tissue may migrate through a perforation of the tympanic membrane and slowly extend to form a large mass within the middle ear. The dead desquamated skin cells form an ideal medium for bacterial growth. The enlarging keratoma or cholesteatoma causes local destruction of bone and the ossicles and may progressively erode into the cranial cavity or inner ear, producing associated symptoms of meningitis and labyrinthitis. Epidural abscesses also may occur, since the ear and paranasal sinuses are the most common sites for these abscesses.

Chronic suppurative otitis media is characterized by a more complex bacteriology than simple otitis media. Cultures frequently reveal a mixed flora of aerobic and anaerobic organisms. The aerobic pathogens usually found include Escherichia coli, S. aureus, Proteus mirabilis, P. aeruginosa, and diphtheroid bacilli. Common anaerobes include Bacteroides fragilis, Bacteroides melaninogenicus, and Peptococcus magnus.

The diagnosis is established by examination and requires removal of secretions, crusts, and debris from the external canal and from against the tympanic membrane. Mucopurulent otorrhea is usually seen, and secretions may have a foul odor. After cleansing, the tympanic membrane is examined as previously described. A defect usually is seen in the superior, posterior, or inferior portion of the tympanic membrane. Mucopurulent fluid may be seen draining through the defect. The middle ear mucosa is extremely inflamed.

The initial treatment for chronic suppurative otitis media is medical. Topical antibiotics as given for external ear infections are helpful. In general, follow-up is by an otolaryngologist, who also should direct therapy. Surgery may be required for closure of a tympanic membrane defect or for exploration of the ear and mastoidectomy to eradicate chronic sources of infections, such as necrotic bone and cholesteatoma. The goal is to create a safe ear. A secondary but important consideration is improvement of hearing.

[edit] Inner Ear Infections (Table 178-4)

[edit] Acute Labyrinthitis.

Labyrinthitis is an inflammation of inner ear structures of the resulting from invasion of microorganisms or irritation of the inner ear by the passage of toxic products from middle ear infections.

Table 178-4 Inner Ear Infections

[edit] Viral Labyrinthitis.

Many viruses may produce a labyrinthitis, but the most common is the mumps virus. If labyrinthitis occurs, the infection may produce a sudden unilateral inflammation of the cochlea with severe and total sensorineural hearing loss. Vertigo is uncommon with mumps. If the hearing loss is limited to one ear, no specific measures are required. Bilateral hearing losses are unusual but, when persistent, require amplification. Although some advocate systemic corticosteroid therapy to diminish inner ear destruction from viral infection, no clear evidence supports its efficacy.

Viral labyrinthitis involves damage to both the cochlea and the vestibular system. This condition is permanent and needs to be differentiated from the transient vertigo that occurs in vestibular neuronitis.

[edit] Bacterial Labyrinthitis.

Bacterial labyrinthitis may represent a complication of acute or chronic otitis media or of meningitis. Typical symptoms include hearing loss and severe vertigo associated with nausea and emesis. Labyrinthitis complicating acute otitis media requires more aggressive therapy than oral antibiotics. An otolaryngology consultation must be obtained on an urgent basis. Treatment requires myringotomy and intravenous (IV) administration of appropriate antibiotics, as determined by culture, sensitivity, and Gram's stain studies of the middle ear exudate. These tests must be performed immediately and before the the institution of the IV medication. If chronic suppurative otitis media is associated with a sudden development of labyrinthitis, effective therapy requires surgical debridement of the diseased tissue by mastoidectomy, in addition to the appropriate use of IV antibiotics, as determined by a culture and Gram's stain.

[edit] VERTIGO

Vertigo is the cardinal symptom of a disturbance of the vestibular system. The word refers to any hallucination of movement, whether a sensation of spinning, tilting, swaying, or falling. The pathology may exist anywhere in the vestibular pathway, from the vestibular end organs to the highest cerebral representation of the vestibular system in the temporal lobe. Thus the major priority in the management of the vertiginous patient is anatomic localization. With careful history taking and methodic physical examination the physician can select the most useful tests.

Normal equilibrium requires accurate information from the vestibular system as well as sensory input from the proprioceptive, visual, and cerebellar systems. Thus, although disequilibrium is often associated with vertigo, many disorders of balance may occur in the absence of vertigo. For instance, a lesion of the dorsal columns, which relay proprioceptive sensation, may cause marked disequilibrium but will not be associated with vertigo. Vertigo is the result of a conflict between the input to the brain from the vestibular system and from other systems concerned with the maintenance of normal balance.

The vestibular system may be divided anatomically into two parts, peripheral and central. The peripheral system comprises the vestibular end organs (semicircular canals, utricle, saccule, endolymphatic sac) and their first-order neuronal supply (afferent fibers, Scarpa's ganglia, centrally connected fibers). The central system is formed by the vestibular nuclei and their central projections. The examining physician must be familiar with the important practical differences between lesions of these two divisions of the vestibular system.

[edit] History

Obtaining an accurate history from the vertiginous patient is essential. Many patients have considerable difficulty in describing their symptoms, and such descriptions are often charged with emotion. Taking a careful history is tantamount in developing a clinical plan to diagnose and treat the problem efficiently.

[edit] Otologic History.

The date and circumstances of onset should always be ascertained, as well as the frequency, severity, and duration of attacks. Peripheral lesions cause the greatest systemic upset because they are often associated with pallor, sweating, nausea, and vomiting. Episodic vertigo lasting a few seconds and associated with position changes is typically associated with benign positional vertigo. Vertigo lasting 30 minutes to 12 hours typically is seen in Ménière's disease, whereas that lasting several days suggests vestibular neuronitis or labyrinthitis (Table 178-5). Vertigo of psychogenic origin may have been present for several years. Factors that precipitate or aggravate attacks should be determined, such as association with a particular position or movement. The patient should be asked what he or she does to alleviate symptoms.

Table 178-5 Typical Duration of Vertigo in Common Ear Problems

Because of the close anatomic relationship between the hearing and vestibular systems, vertigo may be associated with auditory symptoms. Such symptoms often provide valuable information about the localization of a lesion within the vestibular system (Table 178-6). Even the most subtle impairment of hearing, particularly if unilateral, is important because it may be the presenting feature of vestibular schwannoma. Tinnitus may accompany vertigo and may sometimes change character before or during a vertiginous episode. Other derangements of hearing, such as diplacusis (hearing the same pitch differently in each ear) or paracusis (distortion), are useful because they tend to suggest cochlear pathology. Symptoms suggestive of suppurative ear disease (e.g., earache, discharge) should be investigated. An expanding cholesteatoma (a collection of keratinizing squamous epithelium) may erode the bony labyrinth and cause a fistula in the semicircular canal.

Table 178-6 Usual Hearing Status in Syndromes Associated With Vertigo

Ototoxicity as a cause of vertigo is likely to be determined only by direct questioning. The vestibulotoxic effects of some drugs may not become apparent until several weeks after administration. Labyrinthine membrane rupture (oval or round windows) is an often unrecognized cause of vertigo that is eminently treatable. It should be suspected in patients whose symptoms occur after head injury, barotrauma (flying or diving), or unusual physical exertion. Patients should be referred without delay to an otolaryngologist. Previous otologic surgical procedures (e.g., mastoidectomy, stapedectomy) may have a direct effect on a patient's symptoms.

[edit] General History.

Assessment of the vertiginous patient demands evaluation of other systems integrally related with the vestibular system. Patients should be questioned about certain symptoms that may suggest disease within the CNS or cardiovascular system. For example, loss of consciousness during an episode of vertigo strongly suggests a CNS lesion. It is important, however, not to confuse double vision with the disordered visual sensations that are a feature of vertigo. Numbness or weakness in the arms or legs and difficulty with swallowing or speech suggest CNS disease. Syncopal attacks associated with vertigo may be of cardiogenic origin, and such patients need cardiologic evaluation.

Disorders of equilibrium may signal an underlying stress phenomenon, often marital or employment difficulties. The old adage that "for every mistake made by not knowing, ten are made by not looking" can be aptly applied to the examination of the vertiginous patient. Particular attention must be paid to the otologic, neurologic, and cardiovascular systems, since the underlying disorder frequently resides in one of these areas.

[edit] Otologic Examination

The primary care physician should be able to perform a basic examination of the auditory and vestibular systems. The examination is initiated by inspecting the pinna for stigmata of previous surgery (e.g., postauricular incision scars) or for ecchymosis or hematoma (Battle's sign) in injured patients. The ear canal is examined by gently retracting the pinna upward and backward and gently introducing an otoscope. Cerumen may be removed with a wax hook or by syringing gently. The irrigation device is not aimed directly at the tympanic membrane because perforation can occur. The tympanic membrane is inspected in its entirety. Signs of an effusion are sought, and the mobility of the membrane is tested with the pneumatic otoscope. The physician should scrutinize the uppermost portion of the tympanic membrane (Shrapnell's membrane, or pars flaccida) because cholesteatomas frequently develop here. A cholesteatoma may cause a fistula into the lateral semicircular canal; increasing the pressure in the external canal (e.g., by tragal pressure or with a pneumatic otoscope) may induce vertigo (a positive fistula sign). Patients with this clinical presentation require urgent referral to an otolaryngologist.

[edit] Deafness.

It is mandatory to test hearing in the vertiginous patient. Each ear should be tested separately while masking the opposite ear (placing a sound into the nontest ear). The patient is asked to repeat phonetically balanced words (e.g., send, thick, daybreak). In general, the patient should not miss more than one word in ten; otherwise, referral to an otolaryngologist should be arranged.

Tuning fork tests (Weber's and Rinne) should never be omitted (Table 178-7). They are simple to perform and can help differentiate between normal hearing and conductive and sensorineural hearing loss. Weber's test is performed by placing a vibrating tuning fork at the center of a patient's forehead. If the patient has a unilateral conductive hearing loss, the sound localizes to that ear because the better ear is being masked, or "distracted," by the ambient noise. Alternatively, if the patient has a unilateral sensorineural hearing loss, the sound localizes to the opposite ear, which has a better cochlear reserve. A patient who senses the sound in the midline may have normal hearing or bilateral hearing loss (either conductive or sensorineural) of equal severity.

Table 178-7 Types of Hearing Loss Associated With Vertigo

The Rinne test compares the patient's hearing by air and bone conduction. In normal circumstances, sounds are better perceived by air conduction. A vibrating tuning fork is placed on the patient's mastoid process; the examiner should be sure that the patient is hearing it in the test ear. Then the tuning fork is placed opposite the patient's ear canal, and the patient is asked in which position the sound was heard clearest and longest. Patients with normal hearing or with sensorineural loss hear the sound better by air conduction (positive Rinne test). In conductive hearing loss, bone conduction is heard better than air conduction (negative Rinne response).

[edit] Nystagmus.

Nystagmus and ataxia are the most objective signs of vertigo. Nystagmus refers to involuntary, repetitive movements of the eye and may be spontaneous or induced. A wide variety of disordered patterns of eye movement have been described; only those forms of nystagmus often encountered in primary practice are discussed here.

[edit] Peripheral Nystagmus.

Disease of the labyrinth or of its central connections may cause a jerky or "sawtooth" nystagmus, in which the eyes move slowly in one direction (the vestibular component) and rapidly return to a midline position (the central component). By convention, the direction of a nystagmus is the direction of the fast component or the central component. Knowledge of the features of this type of vertigo are of the utmost importance (Table 178-8).

Table 178-8 General Characteristics of Peripheral and Central Nystagmus

To assess spontaneous nystagmus, the patient should sit opposite the examiner in a well-illuminated room. Vestibular nystagmus is enhanced by loss of optic fixation and may be achieved by having the patient use a Fresnel lens. These glasses have +20 diopter lenses, which prevent the patient from focusing and have the advantage of giving the observer a clear view of ocular movements. A simple hand lens may be helpful if Fresnel lenses are not available. While holding a finger at least 18 inches from the patient, the examiner asks the patient to follow it through an arc within 30 degrees of the primary position. Only sustained nystagmus within this range should be considered pathologic. Outside the range of 30 degrees, nystagmus is a finding in normal subjects and is associated with loss of binocular vision.

[edit] Central Nystagmus.

The essential features of central nystagmus should be carefully contrasted with those of peripheral nystagmus (Table 178-8). Multidirectional or vertical nystagmus is a sinister finding indicating brainstem pathology. Nystagmus only in the abducting eye when the adducting eye is weak indicates internuclear ophthalmoplegia. This finding strongly suggests multiple sclerosis. Nystagmus occurring in the absence of vertigo is most likely caused by a central lesion.

[edit] Positional Nystagmus.

Spontaneous nystagmus may be induced by the Dix-Hallpike maneuver. While the subject sits on a couch or examination table, the head is rapidly lowered to below the horizontal and turned to either side. The examiner should check the mobility of the cervical spine before performing this maneuver. In labyrinthine disorders, nystagmus is induced after a latent period of a few seconds, when the affected ear is undermost, and has all the hallmarks of a peripheral nystagmus. Further, the nystagmus is fatigable, since it diminishes in severity each time the test is repeated. Positional nystagmus caused by central pathology may be vertical or multidirectional, is not fatigable, and may not be associated with vertigo.

[edit] Caloric Testing.

This test is performed with the patient lying supine on an examination couch with the head raised 30 degrees (in this position, the lateral semicircular canals are in the vertical plane). Each ear is irrigated with cold and warm water. Cold water causes nystagmus to the opposite side, whereas warm water results in nystagmus to the same side as the irrigated ear (COWS: cold, opposite, warm, same). Caloric testing evaluates impaired responsiveness of a labyrinth to caloric stimuli and assessment of the involved side.

[edit] Physical Examination

Every patient with vertigo requires a full physical examination. Blood pressure should be determined in both arms and in the lying and standing positions. The neck should be auscultated carefully for bruits and for evidence of a subclavian steal syndrome. In the neurologic examination, all the cranial nerves should be tested, signs of cerebellar dysfunction sought, and the peripheral nervous system evaluated, with particular reference to the maintenance of posture and gait (Table 178-9). Complete blood count, erythrocyte sedimentation rate, glucose tolerance testing, blood urea nitrogen, and thyroid function tests are done as indicated by the primary care physician. It is important to consider neurosyphilis as a cause of vertigo; in suspected cases a fluorescent Treponema antibody absorption test should be obtained (VDRL misses congenital syphilis in about 50% of cases). Examination of the cerebrospinal fluid may be valuable in multiple sclerosis (elevated levels of IgG or oligoclonal bands, which are suggestive but not pathognomonic of the diagnosis).

Table 178-9 Outline of Neurologic Examination

The radiologic investigations should be appropriate to the nature of the suspected underlying pathology. When a lesion of the internal auditory canal is suspected, an auditory brainstem response is typically obtained. This test is accurate in 96% of cases and has a false-negative rate of approximately 1% to 2%. It is considered an excellent screening test to evaluate for tumors on the cochleovestibular nerve. In either case, magnetic resonance imaging (MRI) with gadolinium may reveal subtle pathology in exquisite detail and currently is the procedure of choice. In patients who cannot undergo MRI, CT with dye enhancement may be necessary.

[edit] Disorders Associated With Vertigo (Table 178-10)

[edit] Ménière's Disease.

Ménière's disease consists of four main symptoms: vertigo, hearing loss, tinnitus, and fullness. Classically, all these symptoms must be present for the correct diagnosis to be made. Ménière's disease has been further subclassified into cochlear and vestibular forms to differentiate patients who have only cochlear symptoms from those with only vestibular symptoms. The symptoms are generally attributed to distention of the membranous labyrinth (endolymphatic hydrops). The vertigo may be violent and is usually associated with nausea and vomiting. It rarely lasts less than a half hour or persists for more than 12 hours. The deafness in Ménière's disease is of a fluctuating sensorineural type, most marked initially in the low tones, and is accompanied by loudness recruitment. Hearing loss may be permanent. Every patient with suspected Ménière's disease should be evaluated by an otolaryngologist early.

Table 178-10 Disorders Associated With Vertigo

The treatment of Ménière's disease is controversial. In the natural history of the disease, spontaneous remission occurs in 50% to 60% of patients, making it difficult to evaluate the true efficacy of any treatment modality. After full evaluation, reassurance is sufficient for many patients. Salt-restricted diets and triamterene with hydrochlorothiazide (Dyazide) may be beneficial. The most frequently used vestibular suppressants are the antihistamines, such as meclizine (Antivert) and cyclizine (Marezine). Diazepam (Valium) is a valuable adjunct to treatment in the acute attack and in patients with anxiety. These drugs should be used only for a limited period. Surgical therapy is indicated when symptoms are disruptive to a patient's life and persist despite appropriate medical therapy. The procedure undertaken depends on the level of hearing and whether the disease is unilateral or bilateral. Some procedures decompress the labyrinth (endolymphatic sac surgery, cochleosacculotomy) and strive to preserve hearing. Total destruction of the labyrinth (labyrinthectomy) is an effective procedure in an ear with total or near-total sensorineural hearing loss. Vestibular nerve section has the advantage of treating vertigo while preserving cochlear function. Recently, there has been a renewed interest in the transtympanic use of oto/vestibulotoxic drugs such as gentamicin and less frequently streptomycin.

[edit] Vestibular Neuronitis.

The cause of vestibular neuronitis is uncertain, but some evidence implicates a viral or vascular etiology. The symptoms, severe vertigo with nausea and vomiting, usually last for 2 to 3 days. An important feature is the absence of cochlear symptoms or signs. After the acute episode subsides, the patient may experience minor episodes of disequilibrium over the ensuing months to years. The condition is self-limiting, and symptomatic initial treatment with vestibular suppressants followed by vestibular rehabilitation with vestibular exercises is usually sufficient.

[edit] Multiple Sclerosis.

The diagnosis of multiple sclerosis may be difficult, and suspected cases should be referred to a neurologist. A plaque of demyelination in the brainstem may cause an acute vertiginous episode. Patients typically are young, healthy adults with no previous neurologic history. The accompanying nystagmus, which may persist after the vertigo has abated, is central. The finding of nystagmus in the abducting eye, with weakness in the adducting eye (internuclear ophthalmoplegia), strongly suggests the diagnosis. Auditory brainstem response may show changes in the auditory system that are not detectable by conventional testing. MRI may demonstrate pathognomonic plaques within the brain and spinal cord.

[edit] Benign Positional Vertigo (Cupulolithiasis).

Patients with cupulolithiasis complain of vertigo when they adopt particular positions (e.g., turning in bed, bending, stooping). It often occurs after head injury. Cupulolithiasis may be caused by release of otoconia (statoconia) from a disrupted utricle into the endolymph. Otoconia then become deposited on the cupula of the posterior semicircular canal, making it unduly sensitive to head movement. It is important to distinguish this condition from postural hypotension, in which there are no auditory