Pediatric Hearing Loss 1 Flashcards
(36 cards)
Mild (or worse) unilateral or bilateral hearing loss threshold sensitivity
> 25dB
Moderate (or worse) bilateral hearing loss threshold sensitivity
> 40dB
Conductive hearing loss
Refers to impairment of the outer and/or middle ear conductive mechanism only
Sensory hearing loss
Refers to damage to the cochlea (outer hair cells or outer and inner hair cells)
Mixed hearing loss
Refers to the presence of both conductive and sensory impairment
*Otitis media, cleft lip
Neural hearing loss (2)
- Refers to damage to the auditory neurons (spiral ganglia) and/or the auditory branch of the 8th nerve
- Auditory neuropathy and dysynchrony are examples of neural hearing loss
* High frequency but difficulty distinguishing words
Central hearing loss
Refers to damage to auditory structures in the brainstem, thalamo-cortex and/or cortex
*Intracranial bleeds and brain tumors
Later onset hearing loss
A hearing loss that is not present at birth and the newborn hearing screening would result in ‘pass’
Auditory neuropathy hearing loss (2)
- Children with auditory neuropathy have evidence of normal cochlear function, but show impairment in the function of the auditory nerve. Functional hearing can often be quite impaired and diagnosis and treatment can be confusing and complicated
- Will need accommodations to be in the front of the room of a class
Risk Indicators for Hearing Loss (11)
- Caregiver concern* regarding hearing, speech, language, or developmental delay.
- Family history* of permanent childhood hearing loss.
- Neonatal intensive care of more than 5 days or any of the following regardless of length of stay: ECMO*, assisted ventilation, exposure to ototoxic medications (gentamycin and tobramycin) or loop diuretics (furosemide), and hyperbilirubinemia with exchange transfusion.
- In utero infections, such as CMV*, herpes, rubella, syphilis, and Toxo
- Craniofacial anomalies, including those that involve the pinna, ear canal, ear tags, ear pits, and temporal bone anomalies.
- Physical findings, such as white forelock, that are associated with a syndrome known to include a sensorineural or permanent conductive hearing loss.
* White forelock – waardenburg syndrome - Syndromes associated with hearing loss or progressive or late-onset hearing loss, such as neurofibromatosis, osteopetrosis, and Usher syndrome, other frequently identified syndromes include Waardenburg, Alport, Pendred, and Jervell and Lange- Nielson.
* Alport syndrome → presents with hematuria
* Jervell and Lange-Nielson syndrome both present with long QT syndrome - Neurodegenerative disorders* such as Hunter syndrome, or sensory motor neuropathies, such as Friedreich ataxia and Charcot-Marie Tooth syndrome.
* Hunter syndrome → coarse features, large tongue, toxic metabolites, hearing loss
* Due to mucopolysaccharides (the toxic metabolites) - Culture-positive postnatal infections associated with sensorineural hearing loss*, including confirmed bacterial and viral (especially herpes viruses and varicella) meningitis. 1
- Head trauma, especially basal skull/temporal bone fracture§ that requires hospitalization.
- Chemotherapy
Newborn screening before 1 month: Automated Otoacoustic Emissions (O-OAE) (4)
- This test measures a response produced by the cochlea (outer hair cells) when a sound is presented to the ear.
- To conduct the test, a tiny probe is placed just inside the baby’s ear canal and a soft click is presented, a tiny microphone measures the response produced by the baby’s ear.
- The test is quick (about 5 to 10 minutes), painless, and may be done while the baby is sleeping or lying still.
- Thus, OAEs reflect the status of the peripheral auditory system extending to the cochlear outer hair cells.
Newborn screening before 1 month: Automated Auditory Brainstem Response (A-ABR) (3)
- This screening test measures how the hearing nerve responds to sound
- Clicks are presented to the ear through a probe or soft earphones, and the neural response is measured through three electrodes placed on the baby’s head.
- Automated ABR measurements reflect the status of the peripheral auditory system, the eighth nerve, and the brainstem auditory pathway
ABR Screening characteristics (4)
- Lower fall rate
- More sensitivite to neural loss
- Requires electrodes
- Less sensitive to ear canal and middle ear conditions
OAE Screening characteristics (3)
- Frequency specific
- Less invasive
- Faster and less expensive
Several common reasons why a baby with normal hearing would fail the newborn hearing-screening test (3)
- Vernix in the ear canal
- Fluid in the middle ear
- Movement and/or crying during the test
Newborn screening (7)
- If a newborn does not pass their in-hospital newborn hearing screen, the PNP should assure that the baby is rescreened before one month of age.
- This may be done in the hospital, with an audiologist who has experience with infants and in some circumstances at the Primary Care facility.
- Parents have found that it is helpful to be given guidance to obtain timely follow-up.
- There is never a reason not to retest an infant who does not pass their newborn hearing screen.
- Providing written information to parents and assisting in making the appointment can be helpful.
- Phone follow-up is important.
- The results of this rescreen should be confirmed with the state EHDI program
Follow up after Failing Newborn Screen (9)
- Administering a battery of audiologic tests is critical: all measures are important to the provision of appropriate audiologic follow-up.
- Test results should be in accord; findings that lack agreement need to be further explored before the audiological diagnosis can be completed.
- Audiologic assessment of infants and young children is an ongoing process; frequent follow- up visits are needed to accurately determine auditory status and monitor the development of auditory skills.
- Delays between visits and in the provision of intervention should be avoided.
- Amplification fitting should proceed as soon as the hearing loss is confirmed even when the audiological evaluation is ongoing
- Ear canal acoustics (developmental changes in the size and impedance characteristics of the external ear) affect the acoustic characteristics of all stimuli delivered to the closed ear canal, as is the case with insert ear phones and ear mold coupling.2
- Otitis media with effusion (OME) should be managed aggressively in infants and children with permanent hearing loss3; audiological evaluations should not be postponed however, due to the presence of OME.4
- The Auditory Brainstem Response (ABR) Test can be done on young infants without sedation.
- The goal is to get amplification and to get hearing aids early on for the child presenting with out hearing.
* A lot of policies do not cover the entire payment of hearing aids, which are very expensive.
Rescreening
Readmissions in the first month of life for all infants (NICU or well-baby) when there are conditions associated with potential hearing loss
- Hyperbilirubinemia requiring exchange transfusion
- Culture positive sepsis
Current National Recommendations regarding Evaluation (3)
- Provide universal screening by 1 month of age
- Follow-up audiologic diagnostic assessment by 3 months of age
- Initiation of or referral for appropriate early intervention by 6 months
Comprehensive ABR, ASSR, Evaluation (5)
- For pediatric audiologic screening and assessment, the most useful attribute of the ABR is the relation of the wave V threshold to hearing sensitivity. Therefore, the ABR is used widely to estimate the overall degree of hearing loss.
- ASSR is very similar to ABR.
- In ASSR, frequency modulated tones are delivered to the infants’ ears. Collection algorithm looks for phase locking of the neuronal potential to the modulated tones.
- This phase locking is indicative of a true response to a stimulus. From the phase locking pattern, hearing thresholds are estimated.
- The advantages of ASSR:
a. Stimuli are frequency specific.
b. Louder stimulus intensity can be delivered. Therefore, ASSR can delineate between a severe versus profound hearing loss more accurately.
What to do at 3 months of age to confirm hearing loss (4)
- If the infant does not pass the outpatient rescreen, they need to be referred to an audiologist who has experience with infants.
- In some cases, referral to Early Intervention can facilitate further evaluations and early treatment.
- If hearing loss is confirmed, medical and ENT evaluation should be done and HEARING AIDS should be fitted if desired.
- Information should be confirmed with the state EHDI program and referral to Early Intervention is essential.
Acoustic reflex test (9)
- Do at 3 months
- The acoustic reflex is an involuntary contraction of the middle ear muscles (primarily the stapedius muscle) in response to intense sound stimulation.
- The test is completed during the measurement of middle ear function (tympanometry).
- Acoustic reflex thresholds can be recorded in children with hearing threshold levels of 50 dB HL or better.
- With worsening hearing sensitivity, the ART can be elevated or absent.
- When conductive hearing loss is present, the ART may also be absent.
- ART testing can be used in infants and children as a passive test of middle ear function and the associated neural pathways.
- Thus, it is a useful component in the test battery for differentiating among conductive, mixed, sensory and neural forms of hearing loss.
- Does not provide hearing sensitivity
Identification of Pediatric Audiology facilities that can take care of Pediatric Patients
Early Hearing Detection and Intervention EHDI-PALS (pediatric audiology level of services) is a web-based directory and search engine developed by the CDC and NCHAM. Facilities listed in EHDI-PALS must have the appropriate equipment and be able to provide audiology services to evaluate and treat children who are younger than 5 years of age.
Why is hearing loss a developmental emergency? (5)
- Adept Language Learners
a. Research documents that 6- to 8-month-olds learning English can successfully discriminate contrasts in a language never heard (e.g.. Hindi).
b. By 10 to 12 months, they can no longer do so, and are sensitive only to English contrasts. - Newborn Hearing Screening
- Untreated Hearing Loss
- Quality of Life
- Delayed in Onset of Canonical Babble