Good Morning! Welcome Applicants!November 3, 2011

Patient’s Audiogram Normal Audiogram

Classification

*Conductive→ involving any cause that in some way limits the amount of external sound that gains access to the inner ear (usually temporary)• More common in children

Sensorineural→ involving the inner ear, cochlea, or the auditory nerve (more likely permanent)

Mixed→ which is a combination of conductive and sensorineural hearing loss.

Central→ involving higher brain centers.

Conductive (outer and middle ear)

Sensorineural (inner ear)

Congenital microtia/atresia Genetic disordersExternal otitis In utero infection (CMV,

measles, mumps, rubella, varicella, syphilis)

Otitis media +/- effusion Anatomic abnormality of cochlea or temporal bone

Trauma Ototoxic drugsForeign Body (cerumen) Hyperbilirubinemia

*Ossicular disruption (usually after trauma)

Infection (meningitis, Lyme, Fifth dz, syphilis)

Cholesteatoma Noise exposureTM perforation Radiation

Temporal bone trauma Ischemia

Differential of Hearing Loss

Introduction

Hearing loss in the first years of life can cause delays in speech, language, and cognitive development

1 to 6 per 1,000 newborns and 2 per 1,000 young children

With early intervention, hearing-impaired can reach same skill level of hearing peers

Question3-day-old infant failed otoacoustic emission

testing (OAE). Prenatal and family histories are negative. Physical exam is normal.

The next most appropriate step is:• A. Confirm the hearing loss with an auditory

brainstem response test• B. Perform renal ultrasound• C. Refer to audiology at 1 year of age• D. Repeat OAE in 6 months• E. Treat with oral abx for possible middle ear

effusion

Screening

AAP recommends congenital hearing loss be detected by 1 month, diagnosed by 3 months, and intervention started by 6 months

Every state has universal newborn hearing screening• Otoacoustic emission testing (OAE) – detects evoked

sound from the cochlea in response to clicks and tones• Auditory brainstem response (ABR) – measures the

electroencephalographic waveform response from the vestibulocochlear nerve Used to confirm abnormal OAE

All children ages 4 years and older should be screened regularly for hearing loss

Acquired Hearing Loss

History• Onset• Drainage• Tinnitus, vertigo, disequilibrium• Kidney or cardiac disease• Congenital infection, recurrent OM, meningitis• Trauma – noise exposure• Prematurity, hyperbilirubinemia• Family hx of hearing problems

Acquired Hearing Loss

Physical exam• Good head and neck exam• Ear exam

Pneumatic otoscopy is performed with positive and negative pressure to evaluate mobility of the tympanic membrane

Diminished or absent tympanic membrane mobility can be caused by fluid, mass in the middle ear cavity, perforation, pressure equalization tube, or sclerosis of the tympanic membrane.

Increased mobility of the tympanic membrane can indicate ossicular chain disruption.

Question

Which of the following statements regarding hearing loss in infants and children is TRUE?• A. Chidren with external ear anomalies have

sensorineural hearing loss more than conductive hearing loss

• B. Cholesteatoma is the most common cause of conductive hearing loss

• C. Language delay does not occur unless hearing loss is severe or profound

• D. Newborn hearing screens should be performed only on premature infants or those with family hx

• E. Parental concern for language delay is sufficient cause for auditory testing

Office Hearing Tests

256 Hz and 512 Hz tuning forks• Hearing loss at

256 Hz is equivalent to approximately 10 to 15 decibels (dB), and hearing loss at 512 Hz is equivalent to 20 to 30 dB

Office Hearing Tests

Pure tone audiometry • Softest decibel threshold

at which the child can hear a sound 50 percent of the time for each tested frequency

• Normal hearing threshold is between 0 to 20 dB

• Accurate results are dependent upon cooperation from the child

• Any threshold >20 dB suggests a hearing loss (conductive, sensorineural, or mixed).

Office Hearing Tests

OAE Tympanometry • Valuable in

conjunction with pneumatic otoscopy

• *Flat tympanograms (type B tympanograms) and/or abnormal OAE testing may indicate conductive hearing loss, usually due to middle ear effusion

Referral

Any abnormal hearing screenings in the office should be followed by formal audiology

Lab work-up

Lab work-up

Etiologies of Acquired Conductive Hearing Loss

*Otitis media with effusion• Fluid filling the middle ear space prevents the

tympanic membrane from vibrating adequately• Persistence of asymptomatic effusion following

an episode of acute otitis media: 40% at 1 month 20% at 2 months 10% at 3 months• These pts. may benefit from tympanostomy tubes

Etiologies of Acquired Conductive Hearing Loss

TM Perforation

Foreign Body

Etiologies of Acquired Hearing Loss

Cholesteatoma• Benign growth of

stratified, squamous epithelium filled with desquamated cells and keratin

• Erodes ossicular chain

• Results from poor eustachian tube function

Question

A newborn who failed hearing screen, also has microcephaly, enlarged liver, and weight at 5th percentile. Pregnancy was uneventful, with normal prenatal labs, and there is no family history of hearing impairment.

Most likely cause of hearing impairment is:• A. Alport syndrome• B. Congenital CMV• C. Middle ear effusion• D. Prenatal measles exposure• E. Waardenburg syndrome

Etiologies of Hereditary Sensorineural Hearing Loss

Usher syndromePendred syndromeWaardenburg syndrome →*Alport syndrome• Glomerular disease, ocular abnormalites, SNHL

(progressive), family hx of hematuria, renal failure and deafness

Mitochondrial disorders

Etiologies of Acquired Sensorineural Hearing Loss

Bacterial meningitis• *Most common cause of acquired deafness in

childhood• 2.5 to 18%• Occurs early in the course (within first 48 hours)• *Prompt and complete hearing evalutaion initially

and regular follow-up

Etiologies of Acquired Sensorineural Hearing Loss

*Ototoxic drugsAminoglycosides (gent, tobra, amikacin, neomycin)

ErythromycinVancomycinTetracycline

Chemotherapy (cisplatin)Salicylates (reversible)

Antimalarials

Etiologies of Acquired Sensorineural Hearing Loss

Noise exposure (acoustic trauma)• *High frequency hearing

loss• Constant exposure to loud

noises (personal listening devices, power tools, firearms) greater than 85 dB Or sudden noise

(firecracker) greater than 140 dB

• 12.5% of kids (age 6 to 19) have hearing loss in one or both ears

Etiologies of Acquired Sensorineural Hearing Loss

Trauma• Temporal bone fracture

Bleeding from ear or hemotympanum

Treatment

Multidisiplinary approach• Audiology• ENT• Speech• Genetics

Optho referral• Patients rely on sight for communication and learning

Treatment based on etiology Hearing aids Cochlear implant

Noon conferenceToddler Behavior, Dr. Nass

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