Immittance Audiometry, ABRs, OAEs, Pediatric Audiology Flashcards
Purpose of Immittance Testing
- Primary:
- Evaluates health and function of the middle ear system
- Secondary:
- Evaluates the acoustic reflex pathway which includes the 7th and
8th cranial nerves and brainstem
Advantages
▪Objective
▪Not time consuming
▪Noninvasive
▪Easy to administer
▪Used to detect presence of ___Conductive_________ component
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Immittance Concepts
Measurement of how easily a system can be set into vibration by a driving
force
▪ IMPEDANCE
❖Measures ___Blockage_______ of energy flow through a system
▪ ADMITTANCE
❖Measures___Easy_______ of energy flow through a system (compliance)
* Admittance and impedance are reciprocal terms
Impedance Matching Transformer
Back to Anatomy and Physiology!
Impedance Matching Transformer
* Matches __Low___acoustical impedance of air to
__High___ acoustical impedance of cochlear fluid.
* Without a middle ear, most of the incoming signal.
would be reflected back due to the much
higher impedance of the cochlear fluids.
Much less sound energy would be
transmitted to the cochlea.
Middle Ear Anatomy
The air pressure
Air pressure must be equal
on both sides of the ear
drum in order to optimize
mobility of the whole
system
Immittance Audiometry
Assesses how well sound energy
flows through the __Outer_____and __Middle_____ ear to the
cochlea.
❖Assesses how well the ear is performing its ___IMPEDANCE____
matching function.
Instrumentation
What does the probe do?
Electro-acoustic Device
➢Compares probe signal introduced into
ear canal with the resultant signal
reflected off the TM
➢Measurement of the signal reflected
back to the probe provides information
about efficiency of the middle ear
system.
Probe Tube Assembly
- Three holes
- Speaker – generates a fixed tone of 85
dB SPL at 226 Hz. - Microphone – picks up sound
reflecting off TM - Air pump – changes air pressure from
positive to room or atmospheric air
pressure to negative air pressure
Tympanometry
Tympanometry reflects change in the physical properties of the middle ear
system and tympanic membrane as air pressure in the external ear canal is
varied
Tympanometry Prodecure
- A probe tip seals the external auditory canal.
- A change in air pressure will be presented
going from positive to negative - A known signal (220 Hz at 85 dB SPL) will be
presented through the probe tip - A microphone will record the amount of the
signal that is reflected back
Tympanogram
X and Y axis
A plot of middle ear admittance as a
function of ear canal pressure.
* X axis: Air Pressure
* Swept from +200 – 400 daPA
* Y axis: Compliance
* Measured in cm3 or ml
* Peak is the point where air pressure
is equal on both sides of the TM
Tympanometry
What we get from it
Middle Ear Pressure (TPP)
٭Static Acoustic Compliance (SAC)or (Ytm)
٭Ear Canal Volume (ECV or PVT or Veq)
٭Tympanometric Width (TW) / Gradient
Middle Air Pressure
Tympanic Peak Pressure (TPP)
Tympanic Peak Pressure (TPP)
* Decapascals (daPa)
* Referenced to normal atmospheric
pressure
* Provides information regarding the
functioning of the Eustachian tube
Tympanic Peak Pressure (TPP)
Maximum tympanic membrane mobility at TPP
* Air pressure is equal on both sides of the tympanic membrane
Abnormal Tympanic Peak Pressure (TPP)
Why and what will the probe do
If eustachian tube is not functioning properly, negative pressure will build up in the
ME space.
* When the probe tone in the ear canal reaches negative pressure, matching the
negative air pressure in the ME, the TM will vibrate most efficiently at a negative air
pressure.
* This is represented by the negative peak on the tympanogram
Type C
Static Acoustic Compliance (SAC)
- Height of the tympanogram peak
- How compliant or mobile is the TM /
ME System - Provides information about
- The ossicular chain
- Tympanic membrane health
- Middle ear pathology
Static Acoustic Compliance (SAC) Norms
- Normal
- .3 – 2.5 ml
- Pathology – Decreased TM Mobility
- <.29ml Fixation of the ossicles
- Fluid in the middle ear
- Pathology – Increased TM Mobility
- > 2.5ml
- Increased TM mobility
- Ossicular disarticulation
Ear Canal Volume (ECV)
What info does it give us?
Ear Canal Volume (ECV) or (Veq)
* Measurement of the physical volume of the ear
canal
* Provides information regarding
* Cerumen impaction or ear canal blockage
* Tympanic membrane perforation
* Pressure equalization tube patency.
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Ear Canal Volume (ECV
Equivalent volume of air space from end of
probe tip to the TM
* Measured at +200daPa when TM is __stiff____ and
more/ sound is reflected back to TM
* Equivalent volume of air space is predicted by
intensity of reflected sound
Ear Canal Volume – Too Small, Too Large or Just Right
Normal Ear Canal Volume
* Adult: .5 – 2.5 cc
* Pediatric : .3 – 1.5 cc
* Too Small – Ear Canal Blockage
* Adult: < .5 cc
* Pediatric: <.3 cc
* Too Large – TM Perf or Patent PE Tubes
* Adult: > 2.5 cc
* Pediatric: > 1.5 cc
Tympanometric Width (TW)
or Gradient
❖Describes shape of tympanogram
in region of the peak
❖Tympanometric width at 50% of
peak static admittance
❖Expressed in daPa
Pathology:
* Middle Ear Fluid - TW >200daPa
Key Points
- Tympanometry is not dependent on hearing
- It is an indirect measurement of middle ear function, based on the
movement of the tympanic membrane in response to air pressure
change. - Integrity of the tympanic membrane is essential to immittance testing
- Pathology of the tympanic membrane will interfere with obtaining
reliable measurements
Tympanogram Classification
- Based on tympanometric
shape - Each shape is consistent
with a specific disorder - Main types: A, As, Ad, B, C
Type A Tympanogram
Normal Middle Ear Pressure and Compliance
ECV
* Adult .5 – 2.5 ml or cm3
* Pediatric .3 – 1.5 ml or cm3
SAC
* .3 – 2.5 ml or cm3
Pressure
* -199 to +50daPa
* Normal ____________
* ___Sensorineural________Hearing Loss
Type As Tympanogram
- ECV: Normal
- SAC: .1 – 2.9
- ME Pressure: Normal
- Pathologies:
Otosclerosis
Thickened or scarred TM
Tympanosclerosis - ____________ Hearing Loss
Type Ad Tympanogram
Type Ad Tympanogram
Increased Tympanic Mobility
* ECV: Normal
* SAC: >2.5
* ME Pressure: Normal
* Pathologies:
Ossicular Disarticulation/Discontinuity
Thinly healed tympanic membrane
* ____________ Hearing Loss
Type C Tympanogram
Type C Tympanogram
Negative Middle Ear Pressure
* ECV: Normal
* SAC: Normal
* ME Pressure: >-199 daPa
* Pathologies:
Eustachian tube dysfunction
* ____________ Hearing
Loss
Type B Tympanogram
- SAC: No Peak
- Pressure: No Peak Pressure
Pathologies - Normal ECV: Middle ear effusion
- Reduced ECV: <.3 Child <.5 Adult
Wax obstruction, foreign body, or
improper probe position - Large ECV: >2.5
TM perforation, Patent PE Tube - _____________ Hearing Loss
Acoustic (Stapedial) Reflex Measurement
- Tympanometry uses air pressure to stiffen the tympanic membrane
- Acoustic Reflexes uses loud sounds to stiffen the tympanic membrane
- Acoustic (Stapedial) Reflex Threshold
- Lowest high-intensity stimulus level to elicit contraction of the stapedial
muscle which stiffens the ME system - Immittance instrument measures this change in admittance
Stapedial Muscle/Reflex
- Stapedial muscle is attached to the stapes and
contracts to loud sounds - Contraction of the stapes stiffens the middle ear
ossicles which limits the movement of the
tympanic membrane. - Stiffening of the middle ear system reduces
efficiency of sound transmission to the cochlea. - The probe microphone measures the greater
reflection of the signal.
Acoustic Reflex is a Bilateral Phenomenon
- Stimulation of one ear results in
contraction of both ears - Evaluates the acoustic reflex pathway
- Presence or absence of the acoustic
reflex can provide additional diagnostic
information for CHL or SNHL
The Acoustic Reflex Arc
- Reflex arc:
- Peripheral ear,
- VIIIth n.
- Cochlear nucleus
- Superior Olivary Complexes
- Motor Nuclei of VII CN
- VIIth nerves to stapedial
muscle of both middle ears
Set-Up for Acoustic Reflex Measurement
2 ways of doing it
IPSILATERAL TESTING
* Probe and stimulus in same ear
CONTRALATERAL TESTING
* Probe in test ear, stimulus in
non test ear
Acoustic Reflex Threshold Measurement
What frequencies are the reflexes tested?
- Reflexes are typically tested at: 500, 1000,
2000, AND 4000 Hz - Lowest level in dB HL at which change in
admittance can be read - The probe tip measures the increased
reflection of the signal and records it as
needle deflection
Acoustic Reflex Elicitation
Depends on
*Depends on the integrity of:
* The hearing in the stimulus ear
* The middle ear status of the probe ear
* The integrity of the central reflex arc
Interpretaton
Acoustic reflex
- Interpretation: Compare the ART to the PT threshold at the frequency tested and determine the SL.
- Normal Hearing: 70-100 dB HL or SL
- Cochlear Pathology: <65dB dB SL (Reflex present at normal dB HL
- Significant SNHL: Absent (moderately-severe and above)
- Conductive HL: Absent
Electrophysiological
Measures
The 2 types of
- Otoacoustic Emissions
- Auditory Brainstem Response
Test (ABR)
What
are
OAE’s
- Sounds produced in a healthy cochlea that
can be measured in the external ear canal. - Generated by the outer hair cells of a
healthy cochlea. - Objective measure that evaluates outer
hair cell (cochlear) integrity.
Otoacoustic
Emissions
What can they tell us, when does it happens and in what HL are they present
- Pre-neural phenomenum
- Differentiates between sensory and
neural - Present in ears with normal hearing
- If present may rule out mild or
greater sensory impairment. - Absent in ears with conductive loss
- Absent in ears with SN hearing loss
- Does not quantify degree of HL
Back to A& P of the
Cochlea!
- In a healthy cochlea, sound stimulates
movement of the outer hair cell. - The mechanical movement or motility of
the OHCs amplifies soft sounds for
transmission to the cochlea and
sharpens and improves frequency
resolution
Outer Hair Cell Motility
How the ear generates the OAE
- Mechanical movement or motility of
the OHC generates a byproduct
called otoacoustic emissions - These emissions travel from the
cochlea through the OW, across the
ossicular chain and vibrate the
tympanic membrane - The OAE is converted to an acoustic
signal that can be recorded in the ear
canal
RECORDING OAEs
- Probe tip containing microphone
and speaker seals the ear canal - Speaker delivers signal and the
microphone records sound present
in the ear canal - Signal averaging separates emission
response from the noise floor - Can be obtained in sleep or
sedated states - Objective
- Ear specific
- Frequency Specific
(somewhat)
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Types of Evoked OAES
- Evoked OAE’s
- Transient (TEOAE’s)
* Elicited with click stimuli - Distortion Product (DPOAE’s)
* Elicited with pairs of tones
Distortion Product Otoacoustic Emissions
- A pair of tones at 2 different frequencies are sent into the
ear. - The frequencies are separated by a ratio of 1.2
(Ex. F1=1000Hz and F2=1200Hz) - Outer hair cells generate a third tone, the distortion product,
resulting from the formula
(2f1-f2) (2X1000 – 1200) = (2000-1200)
DP = 800Hz - Results plotted as DP- gram
Interpretation
of OAE’s
- Present Otoacoustic Emissions
- Hearing is 30-35 dB HL or better
- Partially Present Otoacoustic
Emissions
* May have HL at particular
frequencies - Absent Otoacoustic Emissions
- Cochlear disorder, Conductive
pathology
- Cochlear disorder, Conductive
APPLICATION
OF OAEs
- Pediatric assessment and the difficult-to-test
population - Monitor ototoxiciy
- Differential DIagnosis– Use with ABR to
separate cochlear and neural components of
SNHL (Auditory Neuropathy) - Hearing screenings
- Newborn hearing screening
- Identify functional or non-organic hearing loss
Auditory
brainstem
response
(ABR)
- Auditory evoked potential (AEP)
that measures electrical
response to sound as it travels
to the brainstem. - Noninvasive
- Ear specific
- Performed with AC and / or BC
- Frequency specific stimuli
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Auditory
evoked
potentials
(AEP)
Auditory system
* Converts acoustic stimuli into electrical signals (voltages or
potentials) to be processed by brainstem structures and the
brain
- AEPs measure electrical activity in the auditory system
- Provide information about hearing and the integrity of the
structures carrying the electrical signals. - Signal Averaging
- AEPs are only a small part of the electrical activity generated
by brain and environment - Signal averaging averages out random background
activity and amplifies the time locked amplified
auditory signal
Auditory Brainstem Response
The waves
The time and if it’s affected by anything
- Consists of a waveform with a series of 5
positive peaks - The waves correspond to different structures
of the brainstem - Occurs within the first 10 msec following
signal onset - Unaffected by sleep and pharmacotherapy
- Relates to behavioral threshold
- May be about 10 to 20 dB poorer
than behavioral measures
Auditory Brainstem Response Waves
Wave I: Afferent activity of the CN VIII fibers as they leave the
cochlea and enter the internal auditory canal.
(latency of 1.5 msec)
Wave II: Auditory N / Cochlear Nucleus
(latency of 2.5 msec)
Wave III: CN and Superior Olivary Complex
(latency of 3.5 msec)
Wave IV: Lateral Lemniscus
(latency of 4.5 msec))
Wave V: Inferior Colliculus.
(latency of 5.5 msec)
Recording the ABR
- Electrode placement
- Vertex
- Forehead
- Earlobe/mastoid
- Earphones placement
- Delivers a series of tones/clicks to
each ear separately - Patient lying still or asleep
- 30 minutes or longer
APPLICATION
OF ABRs
- Assess Neurologic Integrity
- Latency and morphology of waves
- Hearing Threshold Estimation
- Wave V
- Infant Screening
Neurologic
integrity
Waveform latency
Waveform morphology— Shape or definition of the
wave
ABR Indicators for
Retrocochlear Pathology
- Prolonged interpeak latencies
- Wave V latency is significantly
different between ears - Poor waveform morphology
ABR Sensitivity in diagnosing
VIIIth Nerve (Retrocochlear) Tumors
- In a 2001 report by Schmidt, Sataloff, Newman, Spiegel, and Myers, the sensitivity
was 58% for tumors smaller than 1 cm, 94% for tumors 1.1-1.5 cm, and 100% for
tumors larger than 1.5 cm. The overall sensitivity was 90%. - CONCLUSION: Auditory brainstem response testing cannot be relied on for
detection of small acoustic neuromas
Hearing Threshold Estimation
Wave V
- Wave V is the most robust
component - Can be observed close to
behavioral thresholds. - Used to estimate hearing
sensitivity in infants, young
children and difficult-to-test
patients
Infant Hearing Loss
- 3 infants out of every 1,000 have a hearing loss
- HL is one of the most common congenital disorders
- Only 50% have an identified risk factor
- 90% of infants born with HL have 2 hearing parents.
- Early intervention (programs and services for families before 6
months of age provides improved communication outcomes.
The Case For
Early
Identification
and
Intervention
Children whose hearing loss was identified
and habilitated before 6 months of age
achieved better receptive and expressive
language skills than children whose
hearing loss was identified after 6 months
of age.
* Early identification advantage persists into
the School Years
Longitudinal Outcomes of children with
hearing impairment (LOCHI) Study
- The earlier hearing aids or cochlear implants were fitted, the better the
speech, language and functional performance outcomes. - Better speech perception was also associated with better language and
higher cognitive abilities. - Better psychosocial development was associated with better language and
functional performance. - Higher maternal education level was also associated with better outcomes.
- Qualitative analyses of parental perspectives revealed the multiple facets of
their involvement in intervention.
Early Hearing Detection and Intervention (EHDI)
- First three years are critical period for
development of speech and language - Goals 1 – 3 - 6:
- Hearing screening by 1st month of life
- Diagnostic evaluation before 3 months
- Treatment before 6 months of age
- Amplification
- Early intervention services
SLP Role
in the
EHDI
Process
- SLP role includes but is not limited to:
- Administration of hearing screening to
newborns and toddlers - Provision of speech-language therapy
for children exhibiting communication
delays as a consequence of pediatric
hearing loss - Parent counseling regarding the
importance of hearing screening and
follow-up.
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Otoacoustic Emissions
Vs
Auditory Brainstem Response
- Sounds are presented to the ear canal
- Small microphone measures the
cochlear response in the ear canal - Average test time: 5 – 15 min/baby
Auditory Brainstem Response
Sounds are presented and surface electordes
measure brainstem activity.
• Average test time: 20 min/baby
Definitions of Pediatrics
Congenital – Present at birth
Prenatal – Occurs to fetus before birth
Perinatal – Occurs in period shortly before or after
birth (8 wks before to 4 wks after)
Postnatal - Occurs after birth
Three germ layers in embryonic development
Ectoderm
Epidermis (skin, hair, nails) and nervous system structures
Ear: Outer ear skin and inner ear sense organs such as the hair cells
and innervating nerves
Mesoderm
skeletal, circulatory, reproductive organs and kidneys
Ear: Ossicles and temporal bone and cartilage
Endoderm
Epithelial linings of respiratory tract and digestive tract
Ear: Forms middle ear lining, aerated mastoid cavities and
eustachian tube
External Ear Development
External Ear Development
Ectodermal Tissue
Begins to form at 4th week of fetal
development
By 20th week of pregnancy, the auricle is
fully formed and open
External ear continues to grown in size
until 9 years of age
Middle Ear Development
Mesodermal and Endodermal Tissue
Begins developing at 3rd fetal week
By 8th week, malleus and incus are present in cartilage and
stapes by week 15.
By 9th week, 3 tissue layers of the TM are present
Development of ME continues through 37th week of
gestation
Inner Ear Development
Ectodermal Tissue
3rd week – IE begins to develop
6 weeks - vestibular structures
11th week - Presence of 2 ½ cochlear coils
Development of the inner ear is mainly in the first trimester and
mature by the 20th week
Some changes are still occurring between the 5th month (i.e. 20th week)
and the 8th month
KEY POINTS
Knowledge of the origins of auditory structures can be diagnostically
significant.
Ectoderm is responsible for development of outer skin layers and the inner
ear
Skin disorder and deafness - Keratitis Ichthyosis Deafness Syndrome
During the formation of the embryo, an abnormal formation of one organ
will many times indicate the abnormal formation of another.
Microtia, atresia and preauricular pits raise concerns about associated
IE disorders
More KEY POINT
Time of disruption of fetal development determines degree of
developmental malformations and susceptibility to hearing loss
For example, since kidneys and ear develop around the 5th to 8th week
of pregnancy, and because of their similar embryonic structure,
infection occurring at that time may affect development of both organs
at the same time.
Malformations occurring late in fetal development are simple while
those occurring early on are more complex and severe (ex. Rubella)
Additional Testing and Treatment
CT Scan Imaging – abnormally formed OC
Rule out syndromes, kidney disorders, facial defects
Interdisciplinary team for best coordinated care
ENT
Plastic Surgeon – surgical reconstruction
Audiologist- Amplification device to maximize hearing for speech and
language development
Speech Pathologist for possible communication delays
Pediatrician
Genetic counselor
Genetics and Hearing Loss
Genetic factors are responsible for over 50% of hearing
loss.
Autosomal Recessive – 80% and more severe HL
Autosomal Dominant – 18% and less severe HL
X Linked - 1 to 3%
Mitochondrial - <1%
2/3 of hereditary HL is non-syndromic and 1/3 is syndromic
Hereditary Hearing Loss
Chromosomes
All hereditary material, in the form of DNA, is carried as genes on the
chromosomes
All human body cells contain 23 pairs of
chromosomes (46 total)
22 pairs (44) autosomes
2 sex chromosomes
Female – two X chromosomes (46,XX)
Male – one X and one Y (46,XY)
Autosomal Dominant Inheritance
Vs Autosomal Recessive Inheritance
One parent carries the trait
Child needs to inherit one copy of
dominant trait to have disorder
50% chance that the offspring will
have the trait
Accounts for 20% of genetic HL
Autosomal Recessive Inheritance
2 parents carry recessive gene
Child receives both copies of the genes
25% chance that fetus will inherit both genes
50% chance that child will be a carrier
25% chance child is genetically normal
Accounts for 80% of childhood deafness
X-linked Recessive Inheritance
Affects only males
Trait is on the Mother’s X chromosome
Males infected through carrier female
50% chance of son expressing trait
50% chance that daughter is a carrier
Accounts for 2-3% of deafness
Syndromic vs Non-syndromic HL
NON-SYNDROMIC
No associated abnormalities
SYNDROMIC
Presence of other abnormalities
external ear, skull, facial deformities, cleft palate,
optic disorders, changes in eye, hair and skin pigmentation,
thyroid disease,
disorders of the heart,
musculoskeletal anomalies,
mental retardation,
difficulty with balance
Alport
ASSOCIATED ANOMALIES: Kidney problems
INHERITANCE: X Linked, AR, AD
Branchio-oto-renal (BOR)
ASSOCIATED ANOMALIES: Neck cysts and/or ear tags and kidney problems
INHERITANCE: AD
Jervell and Lange-Nielsen
ASSOCIATED ANOMALIES: Cardiac problem. Prolonged QT intervals
INHERITANCE: AR
Neurofibromatosis II
ASSOCIATED ANOMALIES: Tumors on Auditory Nerve
Balance, tinnitus, ABI candidates
INHERITANCE: AD
Pendred
ASSOCIATED ANOMALIES: Thyroid enlargement or low thyroid function Associated with EVA or mondini dysplasia
INHERITANCE: AR
Stickler
ASSOCIATED ANOMALIES: Connective tissue disorder with craniofacial abnormalities, cleft
palate, eye problems (myopia, retinal detachment, glaucoma,
cataracts), arthritis, over-flexible joints
INHERITANCE: AD
Treacher Collins
ASSOCIATED ANOMALIES: Craniofacial abnormalities
ME abnormalities
INHERITANCE: AD
Usher
ASSOCIATED ANOMALIES: Progressive blindness, Clumsy gait
INHERITANCE: AR
Waardenburg
ASSOCIATED ANOMALIES: White patch of hair or light-colored skin patches;, different color
eyes, widely spaced eyes, flattened nose bridge. Can show some,
one, all, o none of typical features. do well with CI.
INHERITANCE: AD
Non-Syndromic Hearing Loss
Connexin 26 HL
Connexin 26 HL
Autosomal Recessive
Mutation in GJB2 (gap junction beta 2) gene that provides instructions for
making a protein called connexin 26
Connexin 26 is important for the proper flow of potassium in the cochlea
Most common cause of congenital hearing SNHL
70% with severe to profound HL (>75dB HL)
Normal inner ear structures
CHARGE Association
C – Coloboma of the eye
H – Heart defects
A – Atretic choanae
R – Retarded postnatal growth
G – Genital and or urinary abnormalities
E – Ear anomalies and deafness
CHL – Common
SNHL – 90% Malformed cochlea
Cochlear Malformations
Mondini – incomplete formation
1.5 turns to the cochlea instead of 2.5.
Scheibe Dysplasia
Organ of corti is completely missing
SCCs and utricle are normal
Michel Deformity
Complete absence of IE
Enlarged Vestibular Aquaduct (EVA) Syndrome
The vestibular aqueduct, is a fluid filled tube that connects
the inner ear to the endolymphatic sac, is enlarged.
Leading cause of congenital progressive SNHL
Head trauma can cause fluctuation and progression of HL
can occur following head trauma
May be mixed component
Can occur alone or be associated with Pendred and other
syndromes
Detected with CT/MRI scan and history
Counseling – Children should avoid activities that can lead to
head injuries, wear protective head gear
TORCH Infections
Toxoplasmosis
Other infections
Syphilis, Hepatitis B
Herpes Zoster
Rubella
Cytomegalovirus (CMV)
Herpes Simplex Virus
Perinatal Birth Trauma
Anoxia
Prematurity
High Forceps Delivery
Hyperbilirubinemia
Kernicterus
What is Cytomegalovirus (CMV)
Very common typically harmless virus
Member of the herpes virus family
Can cause cold-like symptoms
Most US adults have been exposed
CMV can be transmitted from person to person in bodily fluids
Congenital Cytomegalovirus (cCMV)
When a pregnant women or woman about to be pregnant has CMV cold
virus circulating in their system, it can pass through placenta to growing
fetus.
Leading cause of intrauterine fetal demise, stillbirth and pregnancy loss
Most common congenital viral infection and the leading cause of non-
genetic hearing loss in newborns
1 out of 200 babies is born with cCMV
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Possible Neurodevelopmental Outcomes
Visual
Impairment
Hearing
Impairment
Cerebral
Palsy
Epilepsy
Learning disabilities
Intellectual disabilities
Vestibular disorders
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Presentation with cCMV
10 % are born symptomatic
* Small for gestational age
* Microcephaly
* Petechiae/purpura
* Hepatosplenomegaly
* Seizures
* Intracranial abnormalities
* Laboratory abnormalities
90% are born asymptomatic
* Up to 25% of children with asymptomatic cCMV, will develop progressive or late onset
hearing loss in childhood,
Testing for cCMV
Diagnosis is only possible when the infant is <21 days
Difficult to distinguish cCMV vs post natal CMV after 3 weeks of
age
Test by urine, saliva, or blood
cCMV Newborn Screening
ALBANY, N.Y. (September 29, 2023) – The New York State
Department of Health announced that effective October 2, 2023,
all babies will be screened for Congenital Cytomegalovirus
(cCMV), making New York the second state in the nation, after
Minnesota, to screen all babies for the virus.
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CMV Risk Reduction
Avoid kissing toddlers on the lips
Don’t put a pacifier in your mouth
Wash hands well after a diaper change
Don’t share food, straw, or utensils
Postnatal Infections
Viral Infections
Mumps – unilateral HL
Measles
Pertussis
Rubella
Chicken Pox
Postnatal Bacterial Infections
Meningitis
Sequelae to otitis media
Inflammation of the meninges
of the brain
Bilateral, symmetrical and
irreversible SNHL
HL may range from mild to
profound
Labyrinthitis
Infections of the labyrinth
Affects auditory and vestibular
system
Hearing loss and vertigo
Cause often unknown
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Ototoxic Medications
Aminoglycoside Antibiotics
Gentamycin, tobramycin, kanamycin, streptomycin
Diuretics
Furosemide (Lasix)
Chemotherapy
Cisplatin
Chemotherapy drug puts young children with cancer at high risk of hearing loss
75% of patients five years old and younger had experienced cisplatin-related hearing
loss three years after starting therapy
www.sciencedaily.com/releases/2021/09/210907110725.htm
CASE HISTORY
Comprehensive Audiological Evaluation
Case history
Interview and observation
Otoscopic examination
Audiometry
Type and degree of hearing loss, speech discrimination, and auditory
perception
Objective measures
Immittance, otoacoustic emissions (OAEs), evoked auditory potentials (EAPs)
Pediatric Case History
Information derived from a comprehensive case history
includes:
Factors that increase the possibility of HL
Clues about the etiology of HL
Other developmental concerns or issues
How the family views HL
Pediatric Assessment - Test Techniques
BOA
Behavioral Observation Audiometry
COR/ VRA
Conditioning Orienting Reinforcement/ Visual Reinforcement
Audiometry
CPA
Conditioned Play Audiometry
Conventional Audiometry
Behavioral Observation Audiometry (BOA)
Birth to 6 months (developmental)
Unconditioned response
Sudden novel sound presented
Observe baby’s response to sound
Minimum response level (MRL)
Softest level that elicits a change in behavior
Typically, louder than threshold
Variables
Infant’s behavioral state and responses
Method of stimulus presentation
Observer bias
Visual Reinforcement Audiometry (VRA)
Chronological or cognitive age of 6 months - 2 ½ years
Conditioned response
Child conditioned to look or turn towards a sound source and
is reinforced by a lighted animal or video
Signal presented through speaker in soundfield or
through earphones
Threshold responses
Child faces midline when not
responding to sound
Role of assistant is to distract
the child usually with a toy
Distraction toy should not be
too interesting that it interferes
with responsiveness to signal
Conditioned play audiometry (CPA)
Child performs a specific
play activity in response to
sound (i.e. throwing a block
in a bucket)
Chronological or cognitive
age of 2-4 years
Threshold test
Speech Recognition / Awareness Thresholds
SDT/SAT
Can be 10-15dB lower than SRT
Stimuli used are child’s name, continuous discourse, CV syllabi or short
phrases
SRT
Gain information about child’s hearing sensitivity in the frequency range
of 500-2000Hz
Spondee picture card or pointing to objects representing the spondee
words can be used for children with expressive or receptive speech and
language deficits
Word Recognition Scores (WRS)
Impact of HL on speech understanding abilities of the
child
Helps determine type and severity of HL
Provides valuable information for AR recommendations
(HA, ALD, CI)
Word Lists
Phonetically Balanced Kindergarten (PB-K)
Age 4 and older who can provide verbal response
Northwestern University Children with Hearing
Impairment (NU-CHIPS)
4 item closed response task
Age 2 ½ and older
Word Intelligibility by Picture Identification (WIPI)
6 item closed response picture identification task
Age 5 and older
Objective test measures
Immittance Measures
Presence of middle ear pathology
Auditory Brainstem Response (ABR) Test
Close to behavioral thresholds
Can obtain bone conduction thresholds
Sedated vs non sedated
Otoacoustic Emissions
Normal or near normal level of hearing
Can be obtained within first several hours after birth and are not dependent on maturation of
the auditory system
Useful in monitoring effects of ototoxic medications in cases of premature or ill infants
Otitis Media in Children
Number 1 reason for children’s visits to a pediatrician in
the US
Before the age of 6 years, approximately 85-90% of
children will have at least one bout of OM
Nearly 20% of children with recurrent OM will require
the placement of PE tubes.
Underlying cause of OM is related to ET dysfunction
which leads to the production of fluid by the
mucosal lining of the ME
ET in children is more horizontal, shorter and
composed of more flaccid cartilage compared to
adults
Typically, ET is fully developed by 7-8 years
Chronic condition may be related to allergies or
some other underlying medical condition (URI)
eust_tube_compare_sm
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Risk Factors for Otitis Media
Family history of OM
Low socioeconomic environments
Exposure to second hand smoke
Day care attendance
Children with Down Syndrome and craniofacial
anomalies
Audiological f/u Otitis Media
Ongoing audiological f/u for unresolved OM
Monitor for conductive HL and or other complications such as
cholesteatoma or perforated TM
Monitor for long-term effects such as speech and language
development and /or APD
Consider mild gain FM system in the classroom or Bone-
anchored HA (BAHA) for children with chronic OM
Unilateral HL in Children
2 out of every 1000 young children have permanent unilateral hearing loss.
Children with unilateral hearing loss are at 10 times the risk for learning problems
compared to children with 2 normal hearing ears
Difficulty with sound localization
Difficulty with speech recognition in noise
Exhibit educational and behavioral problems in school
May benefit from HA or ALD
Candidate for BAHA or CI
Use of communication strategies training to prevent communication breakdown
Auditory Neuropathy Spectrum Disorder (ANSD)
Audiometric profile:
SNHL that can range from mild to profound and may fluctuate
Normal OAEs
Absent or severely abnormal ABR
Absent ipsi and contra AR
Believed to be function of a lesion central to the cochlea and may
be result of lack of synchrony of neuronal firing.
Auditory Neuropathy Spectrum Disorder (ANSD)
Causes
Possible Causes
Prematurity
Hyperbilirubinemia
Hypoxia
Metabolic disorders
Genetic
Comorbid disabilities
Variability in function
Auditory Neuropathy Spectrum Disorder (ANSD)
Management options
Management options
Amplification (hearing aids)
Personal FM devices
Cochlear Implants
Sign Language
Visual cues and support
Lip reading
Cued speech
Teaching Strategies
Provide visuals
Written outline
Boards and projectors
Visual prompts and nonverbal cues
Flashing or turning off lights and pointing can be
used to indicate a transition to a new activity.
Teaching Strategies
Use the word ‘Listen: to indicate to students that they need to pay attention to the
information that will follow.
Repetition allows students to hear and process what has been said.
Repeat what other students in the class have said so student with HL does not miss
out on questions, comments, or class discussion
Listening buddy can repeat or clarify directions, as well as take notes for student
with HL
Students with HL should meet with teacher or a tutor before and after lessons to
verify comprehension and provide student with more practice and familiarity with
topics.
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More Teaching Strategies
Use secret or nonverbal signal between teacher and student with HL to
indicated comprehension of materials or a breakdown of understanding.
Make eye contact with students with HL before making important
announcement or giving directions to ensure that the students are attention
and prepared to listen
Face student when speaking to better project the voice as well as give
speechreading cues. Good lighting is important.
Speak at measured pace to allow student time to process what is being
said.
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