Outer Ear Disorders

Outer Ear Disorders

• Often seen with the naked eye or otoscope.
• Can be congenital or acquired; congenital issues may indicate other auditory system abnormalities.
• Typically cause conductive hearing loss by blocking normal sound vibrations.

Congenital Disorders of the Auricle

• Pre-auricular pits and tags are common.
• Microtia: small pinna.
• Anotia: absent pinna.

Malignant Disease of Outer Ear

• Basal cell carcinoma occurs on skin with high UV exposure, primary occurrence on the helix and is curable w early treatment.
• Can develop on the pinna and external ear canal.
• Unusual growths should be checked by a doctor immediately.

Atresia

• Lack of canalization; treatable with hearing aids.
• Associated with Treacher Collins syndrome, CHARGE syndrome, burns, trauma, or frostbite.

Acquired Disorders of the Pinna

• "Cauliflower ear" results from trauma.
• Infections that could occur are herpes zoster, staph infection.
• Cancers can also develop.

Stenosis

• Narrowing of the EAC.

Collapsing Auditory Canals

• Collapsing Auditory canals may be seen 4% of audiology caseload.

External Otitis

• Also known as "swimmer's ear", often occurs when water is trapped in the ears.

Cerumen (Ear Wax)

• Produced by modified sweat glands in the lateral two-thirds of the ear canal.
• Removal should be done by a professional using curettes, suction, or irrigation.

Thickening of the Tympanic Membrane (TM)

• Can result from infection or negative response to surgical/medical treatment of infection.
• Interferes with vibration and may or may not cause hearing loss.

Bony Abnormalities of EAC

• Common in the external ear canal: osteomas and exostoses.
• Osteomas: growths projecting into the ear canal on a stalk, typically in the outer portion.
• Exostoses: hard growths with a broad base projecting outward from the canal wall, deep in the ear canal close to the tympanic membrane and usually do not cause hearing loss.

Disorders of Middle Ear

• More likely to cause hearing loss than outer ear disorders.
• Can be congenital or acquired.
• First line of treatment is typically medical or surgical; if cleared by an ENT, hearing aids may help.
• Disorders involve the TM, ossicles, middle ear space, and nearby continuous spaces.
• Conductive hearing loss is a common finding.
• Dysfunction in the middle ear results in a conductive component to hearing loss.

Eustachian Tube Dysfunction (ETD)

• Poor eustachian tube function.
• It may result from edema (swelling) caused by allergies, infection, or blockage.
• Audiometric manifestations include slight conductive hearing loss and Type C tympanogram.
• In children, ETD is common due to craniofacial anatomy not being fully developed, resulting in negative pressure in the middle ear space and possible conductive hearing loss (Type C tympanogram).

Eustachian Tube Dysfunction (ETD): Adults

• Associated with changes in air pressure.
• Movement of the mouth and jaw, like yawning and swallowing, help equalize pressure between the middle ear and the outside environment by utilizing eustachian tube muscles.

Otitis Media (OM)

• Middle ear inflammation that encompasses various disease conditions.
• More common in children; 70% of children in the US experience it before age 2.
• Middle Ear Effusion (MEE) does not always indicate an infection; sterile fluid can be present.
• If there is an infection it is called Acute Otitis Media (AOM).

Otitis Media: Risk Factors

• Age under two years.
• Bottle feeding
• Exposure to secondhand smoke.
• Time spent in day care centers with repeated exposure to other children.
• Craniofacial abnormalities like cleft palate.
• A common cause of conductive hearing loss.
• Almost always presents with some hearing loss.
• Treated with watchful waiting, antibiotics, myringotomy, pressure equalization (PE) tubes (tympanostomy tubes, ventilation tubes) with or without adenoidectomy and/or tonsillectomy.
• Remember: Watchful waiting is sometimes done with MEE if there is no infection

Untreated Otitis Media

• Conductive hearing loss.
• Language delay.
• Behavior problems.
• Auditory processing disorders.
• TM perforation.
• Glue ear.
• Mastoiditis
• Meningitis
• Encephalitis
• Watchful waiting is usually not the best course, especially with language delay, even without infection. Hearing loss in children with otitis media with effusion (OME) typically ranges from 25 to 30 dB.

TM Perforations

• Small perforations in the TM produce surprisingly little hearing loss.
• Cause varying amounts of conductive hearing loss, with small holes possibly having normal hearing.
• Result from acute infection or trauma.
• Results in a type B tympanogram with a large ear canal volume measurement.

Nonorganic Hearing Loss

• Malingerer: Someone who lies about their hearing loss.
• It is not the role of the professional to make psychiatric diagnoses or value judgments.
• Do not accuse the patient; instead, offer an "out" if suspected.
• Not everyone is a malingerer; be open to other possibilities, such as conversion disorders or emotional crises.
• There is a 25% chance of a nonorganic component with compensation-related issues.
• Signs include SRT and PTA not in alignment, inconsistent performance/intensity functions with tests, inconsistent physiological tests and pure tone results, and lack of crossover.

Functional Hearing Loss

• The exaggeration or feigning of hearing impairment
• A factitious disorder involves feigning a hearing loss to assume a sick role, with internal motivation rather than external.
• A conversion disorder is a rare, unintentional hearing loss with little to no organic basis, resulting from psychological distress.
• Reasons for displaying nonorganic hearing loss: monetary compensation, desire for affection/attention, psychological disorder, to avoid an undesirable task.

Tests for Nonorganic Hearing Loss

• Objective tests which require no patient participation are: acoustic reflex test, auditory evoked potentials, and otoacoustic emissions; however, exaggeration of thresholds can still occur with absent OAEs.
• Behavioral tests that require patient participation include the Stenger Test, Speech Stenger Test, Doerfler-Stewart Test, Lombard Test, Delayed-Speech Feedback Test, Pure-Tone Delayed Auditory Feedback (DAF) Test, Békésy Audiometry modifications with conventional audiometer, Varying Intensity Story Test.

Stenger Test

• Widely used for unilateral hearing loss.
• Highly reliable and can be done using a two-channel audiometer.
• Based on the Stenger principle: if two tones of the same frequency are introduced at the same time in both ears, only the louder will be heard.
• Positive Stenger suggests nonorganic hearing loss.
• Negative Stenger suggests that the hearing loss is "real" (organic).

Speech Stenger Test (Aka Modified Stenger)

• Done in the same manner as a pure-tone Stenger using spondaic words.
• It will identify the presence of a nonorganic loss and can approximate the true threshold of hearing.

Managing Patients with Nonorganic Hearing Loss:

• Do not blame the patients.
• State that the results of the tests are inconsistent.
• Place the blame on equipment but do not accuse them of lying.
• Refer to counseling if suspected emotional problems with kids.
• Avoid assuming the role of psychiatrist or prosecutor.
• Use "nonorganic" instead of "malingering" in patient notes.

Hearing Conservation

• Identify people at risk for NIHL
• Reduce the risk of NIHL via engineering controls, which dampen or reduce noise levels.
• Administrative controls limit the amount of time in hazardous areas.
• Personal Protective Equipment (PPE) includes earplugs, earmuffs, double protection, special helmets, and electronic noise-canceling headsets or helmets (some with communication equipment).

Noise-Induced Hearing Loss (NIHL)

• Repeated exposure to loud sounds (factory workers, musicians, truck drivers, theme parks, airports, weapons).
• Temporary Threshold Shift (TTS) vs. Permanent Threshold Shift (PTS).
• Mainly affects higher frequencies first (basal portion of the cochlea) due to hair cell damage.
• Affects men more than women.
• Noise Exposure Limits are set by Federal Law.

OSHA (Occupational Safety and Health Administration)

• Relies on a 5dB time-intensity measure (doubling rule).
• Is backed by Federal legislation (LAW)
• OSHA 5 dB time-intensity measure is the one used in industry.
• 85 dB for 8 hours
• 90 dB for 4 hours...

Noise Exposure Monitoring

• Sound Level Meters use the dBA weighting scale, which mimics human hearing sensitivity in a sound field/free field.
• Sound Dosimeters: a device a person wears that measures sound exposure over time.

Sound/Vibration/Blasts

• Damage to more than just hearing.
• Vestibular damage.
• Soft organ damage.
• Brain damage.
• Damage to hands and fingers caused by vibrating tools, which could cause Reynaud’s phenomenon

Tinnitus

• Auditory perception generated internally without an external stimulus.
• Subjective is common (phantom sounds) whereas objective tinnitus is caused by bodily sounds.
• Most tinnitus is subjective (no test to confirm it).
• It sounds different for everybody.
• Noise exposure is the most common correlate of tinnitus.
• High correlation with pain, TMJ, teeth grinding, anxiety, depression, poor sleep, and certain medications.

Terms Related to Tinnitus

• Hyperacusis: poor tolerance to sound.
• Misophonia: reaction to sounds (chewing, typing, repetitive noises).
• Phonophobia: fear of sound.
• Hypervigilance: elevated state of constantly assessing potential threats around you.

Management of Subjective Tinnitus

• Education/counseling.
• Hearing aids.
• Enivornmental / Background noise.
• Cognitive Behavioral Therapy (CBT) however there is no "one size fits all" treatments.
• Objective tinnitus (less common) is caused by vibration of tissue or structures in the head/neck.
• Usually vascular abnormality.
• Treatment is medical management.

Clinical Considerations for Tinnitus

• Unilateral hearing loss (with normal tympanometry) may prompt consideration of an MRI to rule out acoustic neuroma.
• Consider normal (transient) vs. pathological (there all the time) tinnitus.
• The Tinnitus Handicap Inventory helps evaluate disruption in daily life; a high score could signal the importance of seeking out additional help (mental) to help them cope.
• Case History is the biggest tool.
• The Douk and Reid study (1968): pitch of hearing loss is associated with the degree of hearing loss; the type of sound could indicate disease.
• Pitch Matching with tinnitus roughly 75% of matches were above 4kHz.
• Loudness matching can be less reliable.

Considerations cont.

• Minimal Masking Level (MML): minimum level of acoustic masking, with noise, to suppress the patient's tinnitus.
• The five outcomes of Tinnitus matching: congruence, distance, persistence, convergence, divergence.
• Residual inhibition: simulating the absence of tinnitus by presenting sound at a level, then turning it off and it goes away for a little bit.
• Tinnitus is a symptom of hearing loss.

Tinnitus Rehabilitation

• Address their tinnitus and reassure them they are NOT crazy
• State the facts and prevalence (30 million ppl have it).

Therapy Approaches

• Sound therapy.
• Tinnitus Retraining Therapy (TRT).
• Cognitive Behavioral Therapy (CBT).
• Can exacerbate: caffeine, alcohol, nicotine, sugars, and sleep deprivation.

Week 9 : Vestibular Disorders

• Balance Mechanism:
  • Vestibular System
  • Vision
  • Proprioception (Somatosensory) : Lower leg muscles, Neck muscles
• CNS ( Central Nervous System) coordinates
• Nystagmus: Rapid, oscillatory eye movement, usually side to side.

Vestibular Assessments

• Clinical Examination with Frenzel Goggles: permit clear visualization of eye movements during two steps of a vestibular procedure known as the Dix Hallpike maneuver ( aka lenses magnify eye movements)

Measuring Nystagmus

• Spontaneous nystagmus is usually a sign of an imbalance or asymmetry in the peripheral vestibular system, with less or greater activity on one side than the other.
• Nystagmus is also effectively elicited with irrigation of the external ear canal with caloric stimulation, consisting of warm and cool water or air.
• The ENG/VNG Test Battery can describe techniques for recording changes associated with eye movements during vestibular testing.
• ENG/VNG includes positional testing, tracking movement with the eyes, and caloric testing.
• Computerized dynamic posturography is performed to evaluate the balance, which is the ability of a person to remain in a vertical position over the body’s center of gravity.

Balance is Maintained by Coordination of:

• The somatosensory sense.
• The visual sense.
• The vestibular sense.
• Vestibular evoked myogenic potential (VEMP) testing provides information on the function of structures and pathways not assessed with other vestibular procedures, such as ENG/VNG.
• VEMP is recorded by stimulating the ear with a very high-intensity sound as changes in tension of the sternocleidomastoid muscle.

Benign Paroxysmal Positional Vertigo (BPPV)

• BPPV is one of the most common causes of vertigo.
• Calcium carbonate crystals [otoconia or otoliths (ear rocks)] normally reside in the vestibule (utricle and saccule).
• Sometimes the otoconia become dislodged from the utricle and migrate into a semicircular canal.
• The movement of the otoconia with head movement causes sloshing of the vestibular endolymph, which causes the firing of the afferent nerves and causes vertigo.
• Since BPPV is in the inner ear, it is a peripheral, not a central, disorder.
• Treat BPPV via the Epley Maneuver.

Other Balance Disorders:

• Orthostatic Hypotension.
• Vestibular Migraine.
• Labyrinthitis
• Vestibular Neuritis.
• Meniere’s Disease, aka endolymphatic hydrops
• Labyrinthitis: swelling and inflammation of the labyrinth, part of the inner ear that helps control balance.
• Vestibular neuritis: inflammation of the vestibular nerve, which is in the inner ear and carries balance signals from the inner ear to the brain.
• Migrainous vertigo is the most common cause of recurrent spontaneous vertigo and the second most common vestibular disorder after benign paroxysmal positional vertigo.

Meniere’s Disease

• Meniere’s Disease affects both the vestibular and the hearing organs
• Endolymph is continuous from the cochlea through the vestibular system.
• Endolymphatic Hydrops is synonymous with Meniere’s disease.
• May be treated with a low-salt diet, injections, and/or surgery.
• The hearing component may be treated with hearing aids.
• Vestibular Rehabilitation is the usual treatment for vestibular disorders.
• Audiologists and physical therapists can provide vestibular rehabilitation.

Forms of Vestibular Rehabilitation

• Habituation/adaptation exercises.
• Canalith repositioning.
• Balance retraining.

Goals for Treatment

• Decrease frequency, intensity, and duration of dizziness episodes.
• Improve functional balance.
• Decrease the severity of related symptoms, such as nausea.
• Improve daily living.
• Develop compensation strategies.