Download Types

Early Hearing Detection and Intervention –
The Role of the Primary Care Physician
AAP CME Teleconference, Part I
October 15, 2003
Types of Congenital/Early Onset Hearing
Loss and Why It Is Important to Know
the Difference
Gravel
Hearing Loss
Characterized broadly by degree, configuration and
type,
– Degree: amount of hearing loss in relationship
to normal auditory function
– Configuration: overall ‘shape’ or pattern of the
hearing loss as displayed on the conventional
audiogram in dB HL as a function of frequency
– Type: site (location) of the auditory disorder
Degree: Categories of HL
•
•
•
•
•
•
•
Normal
Borderline (Minimal)
Mild
Moderate
Moderate-severe
Severe
Profound
•
•
•
•
•
•
•
-10 to 15 dB HL
16 to 25 dB HL
26 to 40 dB HL
41 to 55 dB HL
56 to 70 dB HL
71 to 90 dB HL
> 90 dB HL
New York State Department of Health
Hearing Loss
Characterized broadly by degree, configuration and
type,
– Degree: amount of hearing loss in relationship
to normal auditory function
– Configuration: overall ‘shape’ or pattern of the
hearing loss as displayed on the conventional
audiogram in dB HL as a function of frequency
– Type: site (location) of the auditory disorder
Configuration: Sloping
High frequency thresholds >20 dB poorer than low frequency
Frequency in Hz
Hearing Level (HL) in dB
.25k
Stach, 1998
-10
0
10
20
30
40
50
60
70
80
90
100
110
.5k
1k
2k
4k
8k
Hearing Loss
Characterized broadly by degree, configuration and
type,
– Degree: amount of hearing loss in relationship
to normal auditory function
– Configuration: overall ‘shape’ or pattern of the
hearing loss as displayed on the conventional
audiogram in dB HL as a function of frequency
– Type: site (location) of the auditory disorder
Types of Hearing Loss:
Conductive
• Reduction of air-conductive sound delivered to the
normal cochlea during transmission through a
disordered outer ear and/or middle ear
• Sound reaching cochlea attenuated to some degree
(in OME or debris ~25 dB HL; in complete
atresia, maximally ~60 dB HL)
• Excellent speech perception when incoming
acoustic signal is sufficiently intense
Type of Hearing Loss:
Sensory
• Damage to outer or outer and inner hair cells
of the cochlea
• Differing impact on speech perception
depending on degree and configuration of
hearing loss
• Multiple audiometric configurations
• Any degree of hearing loss
Types of Hearing Loss:
Mixed
• Both sensory component and overlying
conductive component
• Example: child with sensory loss who
experiences OME
Types of Auditory Disorders:
• Neural
– Outer ear, middle ear and cochlea (OHCs) intact
– Deficit in neural transmission (auditory
neuropathy)
• Central
– Conductive, sensory & neural pathway intact
– Processing deficit at higher levels of the central
nervous system
Hearing Loss:
Characterized by Ear(s) Affected
• Bilateral
• Unilateral (in one ear only)
What are the major genetic and
environmental causes of congenital
hearing loss ?
Vohr
Characteristics of Children with Hearing Loss
Site
Rate
Well Baby Nursery
1 per 1000
NICU
10 per 1000
Total population
2-3 per 1000
# infants ident annually US
8,000-16,000
Average career pediatrician
12 patients
JCIH Risk Factors for Infants birth to 28 days
• Any illness requiring admission to the NICU for
> 48 hours.
• Stigmata associated with a syndrome known to
include SNHL or conductive HL
• Craniofacial anomalies including the pinna and
ear canal
• In utero infections including CMV, herpes,
toxoplasmosis and rubella
• Family history of permanent HL
Most Common Specific Environmental Risk Causes
CMV
> 1 risk factor
Meningitis
Perinatal Asphyxia
Prematurity < 1500 g
Ototoxic medications
Some Infants pass their hearing screen and have
late onset hearing loss
Some of these infants have a risk
factor and some have no risk factor
known to the family or physician.
Risk indicators from 29 d to 2 years of age
•
•
•
•
•
•
•
Stigmata or Syndrome associated with HL
In-utero infections
Postnatal infections
Neonatal indicators such as ECMO
Neurodegenerative disorders
Head trauma
Recurrent or persistent OM
Risk Indicators obtained from the family
• Parent or caregiver concern regarding hearing,
speech, language, or developmental delay (parent
concern has been shown to be a good predictor).
• Family history of permanent HL in first or second
degree relatives with onset by 30y or age.
Causes of Permanent Hearing Loss in 100
Infants
50%
Environmental
50%
Genetic
50
30% syndromes (>300)
30
20% >75 genes ident
20
½ are GJB2 – Connexin 26
Genetic Causes
Single gene
Connexin 26
Gene + environment
Mitochondrial + ototoxic
Gene + gene
Gene + other gene
The Connexin 26 Gene
• It is estimated that 50-80 % of all autosomal
recessive congenital deafness may to due to
mutations in th3e Cx-26 gene on chromosome
13q11-q12
• The Cx gene produces a gap junction protein
expressed between the outer hair cells and
supporting cells and is involved with auditory
transduction.
• The estimated carrier frequency in the general
population is 1 in 31. (Estivill et al, 1998)
Genetic Testing
• Obtaining an adequate sample for DNA
testing is now quite easy
• Bilateral buccal smears with a Q tip provide
adequate genetic material for testing.
• The follow-up genetic counseling is key to
the success of genetic testing.
New technologies used in hearing
screening
Gravel
Otoacoustic Emissions (OAE)
• By-product of the active processing of healthy
OHC
• Recording of an OAE
– Indicates healthy OHCs (cochlea)
– Presence highly correlated with normal hearing
sensitivity or no greater than a mild hearing loss
• Sensorineural hearing losses of greater than about
30 dB HL generally result in absent OAE.
• Since recording OAE requires normal forward and
backward transmission of energy to and from the
cochlea, conductive hearing loss associated with
middle or outer ear abnormality can result in
absent OAE
Types of OAE
• Spontaneous OAEs
• Evoked OAEs
– Transient OAE (TEOAE, TOAE, or
click-OAE: COAE)
– Distortion Product (DPOAE)
TEOAE
• Elicited by transients or brief stimuli
– Clicks: rapid onset, broadband stimulus
containing energy from low through high
frequencies (i.e., across speech frequency
range)
– Tone bursts: more frequency-specific
Distortion-Product OAE (DPOAE)
• Occur as a result of nonlinear processes of
the cochlea
• When 2 tones are presented to the cochlea,
“distortion” occurs in the form of other
tones (harmonics) that are not present in the
2 eliciting tones
Screening Technologies - Neonates
Evoked Otoacoustic Emissions
EOAE Advantages:
• Quick
• Inexpensive
• Frequency-specific
• Identifies cochlear and
conductive losses: mildmod?
• Pass-refer screening
devices available
EOAE Disadvantages:
• Sensitive to ear canal and
middle ear conditions
• Sensitive to noise (internal
& external)
• Cannot identify neural
disorders including auditory
neuropathy
• High fail rates in some
programs.
Device Options for OAE Screening
Types
• Handheld
• Portable screening devices
• PC-based hybrids
• PC-based clinical systems
Auditory Brainstem Response (ABR)
• Recording (through surface
electrodes) of the micro-volt
electrical activity generated
by the cochlea and
transmitted by the auditory
nerve and brainstem
pathways in response to brief
clicks.
• Clicks produce a
synchronized response from
neural fibers; a tracing of the
response is a series of waves
Screening Technologies – Neonates
Screening (Automated) Auditory Brainstem
Response (SABR or AABR)
ABR Advantages:
ABR Disadvantages:
• Identifies cochlear,
•
conductive and neural
•
losses: ? mild-mod.
• Pass-refer screening
•
devices. Some test both ears
simultaneously.
•
• Relatively insensitive to
transient ear canal, middle
ear & external noise.
•
• ? Lower fail rate than OAE
Test time
Disposable costs
Infant state/myogenic
artifact
Requires electrode prep,
placement & removal
Click can miss unusual
configurations of HL
Examples of screening
ABR technology
In-Hospital Screening:
Two Technology Protocol
OAE + ABR
Advantages:
OAE + ABR
Disadvantages:
• Low fail rate
• Time
• Depending on test order, • Equipment and disposable
identifies cochlear, neural
costs
and conductive losses
• Reduced effects of noise
• Pass-refer screening
devices available for both
technologies
Why is diagnostic confirmation by an
audiologist skilled in evaluating infants and
young children important?
Vohr
A failed hearing screen may be a false positive or an
actual fail. These 2 findings need totally different
management.
Therefore, an accurate diagnosis of normal hearing,
SNHL, auditory neuropathy or conductive loss is
important as soon as possible to minimize
parental stress and to decrease the time interval
between screen fail and starting treatment.
Parents of late identified children have feelings of
guilt and frustration.
Early Identification of Hearing Loss is
Important because
• Delayed identification, even of mild HL
results in
language delays
developmental skill delays, and
behavior problems.
• Subsequent delays in literacy, and
academic performance
Grade Equivalents
Reading Comprehension Scores of
Hearing and Deaf Students
Deaf
Hearing
10.0
9.0
8.0
7.0
6.0
5.0
4.0
3.0
2.0
1.0
8
9 10 11 12 13 14 15 16 17 18
Age in Years
Deaf Children in America 1986
Unilateral or Mild Loss
• 50% of children either repeat a grade or
need resource support in school
• Increased behavioral and linguistic
problems compared to hearing controls.
Bess F, Pediatrics 1984
Early “Early Intervention” for Hearing
Loss is Important because
• There are dramatic benefits associated with early
identification and intervention for hearing loss
before 6 months of age.
• Children identified and receiving services < 6 m
have larger vocabularies, better comprehension
and better expressive language than children
identified > 6 m.
Are Interventions Available to
Improve Outcome?
White - language scores of sev to profound
(14 vs 26 m)
Apizzo - better language scores at 4 if ident <2 m
Moeller - 100 D/HH children with early ident - better
outcomes
Yoshinago-Itano - better scores at 36 m if ident <6 m
Early “Early Intervention” is better !!!!
AAP & JCIH Recommendations Components
of EHDI Programs in the US
•
•
•
•
•
Universal Newborn Hearing Screening< 1 m
Effective Tracking and Follow-up as a part of the
Public Health System
Appropriate and Timely Diagnosis of the HL < 3m
Prompt Enrollment in Appropriate EI < 6m
All infants will have a medical home
Importance of Diagnostic Audiologic
Confirmation of Hearing Loss
Gravel
Comprehensive Audiologic Assessment
(includes case history)
Birth - 5 mos
6 mos - ~ 24 mos
~ >24 mos
EOAE
EOAE
EOAE
Acoustic Immittance
Acoustic Immittance
Acoustic Immittance
ABR: FS (AC & BC) & Neuro
Visual Reinforcement Audiometry (VRA)
Play Audiometry
Observation of Behaviors to acoustic signals
(cross-check &
auditory function)
ABR: FS (AC & BC) & Neuro
(cross-check & document
physiologic function)
ABR: FS (AC & BC) & Neuro
(cross-check & document
physiologic function)
Gravel, 2000; Gravel & Hood, 1998
“Audiologists should have experience with the
assessment of infants & children with HL and the
knowledge and equipment necessary for use with
current pediatric assessment methods”.
“Facilities that lack the expertise or
equipment for assessing infants & children
should establish consortial arrangements
with those that do”.
Pediatric Working Group, 1996
What are the components of the medical
home work-up for children with congenital
hearing loss?
Vohr
EHDI and the Medical Home
Parent Groups
Mental Health
Primary
Provider
Child/Family
3rd Party
Payors
Deaf
Community
Interpreters
Hospital
Screening
Deaf
Services
EI
Therapists
Audiology
ENT
Genetics
The Medical Workup
• Complete prenatal & perinatal hx
• Family Hx of onset of HL < age 30
• Physical for stigmata, ear tabs, cleft
•
•
•
palate, cardiac, skeletal, microcephaly
Refer to ENT / CT of temporal bones
Refer to Genetics and Opthalmology
Other: CMV, EKG
What are some of the questions to ask ?
• Antenatal history- maternal illness during
the pregnancy or delivery
• Neonatal complications, prematurity,
jaundice, asphyxia, assisted ventilation,
ECMO
Examination for Causes
• Evaluate for dysmorphic features, minor and
major stigmata and syndromes
• Other anomalies – visual, facial, endocrine,
cardiac, kidney, hair, and skin
• Particular attention to the head and neck. HL
may be associated with abn. pinna, atresia or
stenosis of the ear canal, ear tags, and bony
growths in the ear canal.
• Cleft lip and palate may have middle ear fluid
What to ask about family history ?
• Is there a family hx of onset of permanent
HL < 30 years of age ( over 3 generations)
• Are there other family members with
syndromes or anomalies ?
Which families may benefit from a Genetic
Referral ?
• All families with a child with congenital or
late onset hearing loss
• Families of a child with stigmata or a
syndrome will benefit from the information.
• Families with a child with non-syndromic HL
want to know the cause ?
• Some parents who are culturally deaf wish
information on the risk or cause of HL.
When to refer to Ophthalmology
• First- Follow periodicity schedule for all patients
• Some syndromes with permanent HL have
specific eye findings such as heterochromia in
Wardenburgs.
• In Ushers the child is at risk of late onset vision
loss secondary to retinitis pigmentosa. (If sign is
the primary communication mode they will
obviously have a problem.
When to get an EKG ?
• This is ordered to rule out long QT ( Jervell
and Lange-Nielsen )syndrome.
• This syndrome may manifest itself with
apnea, passing out episodes, or a history of
sudden death in a relative.
Should there be additional workup ?
• This needs to be individualized.
• For example, A NICU infant with IUGR
should have an MRI and TORCH titers to
rule out CMV, toxoplasmosis etc.
Children with Cochlear Implants and Meningitis
• The incidence of meningitis is higher among
children with cochlear implants.
• The incidence of Streptococcus pneumoniae
meningitis was 30 times the incidence in the
general population. NEJM, July 2003
Recommendations for children with Cochlear
Implants
• Children < age 2 years should get
pneumococcal conjugate vaccine (Prevnar)
according to the routine schedules
• There are guidelines for older children (CDC)
• Children with cochlear transplants should be
monitored and treated promptly for any
bacterial infections.
Amplification Choices for Families
including Hearing Aids, FM Systems and
Cochlear Implantation
Gravel
What is the Goal of
Hearing Aid Fitting
Ensure children receive full-time use and consistent
audibility of the speech signal at safe and comfortable
listening levels as soon as hearing loss is confirmed.
PWG, 1996
When are Hearing
Aids Fit?
For newborns identified by UNHS,
fit hearing aids within one month of
confirmation of hearing loss, preferably before
4 months and no later than 6 months of age.
JCIH, 2000
Which infants are candidates for amplification?
• Significant, permanent • Some children with
bilateral peripheral
unilateral hearing loss,
hearing loss.
and minimal HL
• Mild hearing loss in
• Need based on
some cases
audiogram plus
additional information:
– Family choice
– other disabilities/ongoing medical issues
– performance
PWG, 1996
Pre-Selection Children’s Hearing Aids Should Include:
• Binaural fitting unless clear
contraindication
• Behind-the-ear style of choice
PWG, 1996
Pre-Selection Children’s Hearing Aids Should Include:
• Flexible response characteristics
• Compression to limit overall output
sound pressure level of the hearing aid
(safety and comfort)
PWG, 1996
Directional Microphone Technology
• Improves directional hearing abilities
– Hear parent speaking from front; noise from
shopping mall at back of child reduced.
Multiple Memory Hearing Instruments
• Allows storage of
more than one
electroacoustic
response setting
• Allows switching
between memories for
various listening
situations
Digital Signal Processing (DSP) Technology
• Newer hearing aids that use digital
processing of incoming
• No studies, to date, demonstrate better
performance of digital instruments over
conventional hearing aids in either adults
or children
• Considerably more expensive
What Other Features Should
Children’s Hearing Aids Include?
• Safety-related features: tamper
resistant
– battery compartment
– volume control
• Physical fit (size) and color
• Earmolds made of soft material
PWG, 1996
How Do We Fit Hearing Aids to Infants & Young
Children?
• Use computerized prescriptive fitting procedure
• Requires only minimal threshold data to begin, so
fitting can begin early.
From: Seewald, 2003
Prescriptive Fitting Procedure
• Incorporate simple probe
microphone measurements
• Allow audiologist to:
– Pre-select the response
characteristics of the hearing
aids
– Refine or ‘individualize’ the
hearing aid for the unique
acoustic characteristics of
each infant’s ear
– Verify that the prescriptive
frequency-gain and output
targets have been achieved
From: www.babyhearing.org
Goals of FM Fitting
• Child hears primary talker at level that is
consistently audible above the background
noise
• Child able to monitor his/her own voice
• Child hears voices of others who are not
wearing the FM microphone
Lewis et al., 1998 (Phonak AG)
Why Does the Acoustic Climate (of the Home,
Daycare Setting, etc.) Need to be Considered?
• Infants and young children with
congenital/early onset hearing loss
– Are learning language for the first time
– Have greater difficulty understanding
speech in background noise than adults
– Require a more audible (intense) signal
than adults to understand speech
Fail Neonatal Screening
Fail Outpatient screening
FS-ABR,EOAE AC & BC, tymps
Repeat FS-ABR, EOAE,RECD with
insert, for HA selection, tymps
Observe auditory behaviors & tymps
Behavioral & tymps
(with mold to insert coupling)
1m
Counseling
2m
3m
Counseling; medical/ENT referral
Begin processes for HA procurement
Mold impressions, EI Program
4m
HA Fitting
5m
HA Check & (molds)
Review habilitation, language milestones
6m
Behavioral & tymps
(with mold-to-insert coupling)
7m
RECD,
HA modification, (molds)
Review habilitation, language milestones
8m
Behavioral & tymps
(with mold-to-insert coupling)
9m
RECD,
HA modification, (molds)
Review habilitation, language milestones
10m
Behavioral & tymps
(with mold-to-insert coupling)
11m
12m
RECD, HA Check, (molds)
Validation measures, language milestones
Set habilitation goals for year 2
Gravel, 2000
Qualifications of
Audiologists and Facilities
• No facility should fit hearing aids to children
if it lacks the equipment for behavioral,
electrophysiologic, electroacoustic, and probemicrophone/real-ear evaluation.
• Facilities that lack the expertise or equipment
should establish consortial
arrangements with centers that do.
PWG, 1996
Considerations in Determining the
Appropriateness of Cochlear
Implantation including Risks, Benefits &
Timing
Gravel
What are the Candidacy Criteria for a
Cochlear Implant?
From: www.babyhearing.org
• Limited benefit from conventional amplification
following a minimum of 3-6 months use
– May be sooner following deafness from meningitis
• Profound hearing loss:
– 12-18 months
• Severe-to-Profound hearing loss
– >18 months
• Motivated, involved family with child enrolled in
an intervention program emphasizing spoken
(oral-aural) language development
Cochlear Implants
• Acoustic signal picked up by microphone located in
headset worn at ear level
• Cord carries sound from microphone to a speech
processor
• Speech processor digitizes sound into coded signals
• Coded signals sent up to the transmitting coil
• Coil sends coded signals as FM radio signals to CI
under the skin
• CI delivers electrical energy to the electrode array
inserted into the cochlea
• Electrodes along the array stimulate remaining nerve
fibers in cochlea
Cochlear Corp. 2002
Selecting a Cochlear Implant Center
• Experienced cochlear implant team
– Audiologist, speech-language pathologist, surgeon
– Others: educator of the deaf, psychologist, social
worker
• Comprehensive program covering eligibility,
surgery, device activation, and long-term
habilitation.
– Multi-disciplinary, family centered approach.
– Knowledgeable regarding deafness, child development,
and speech, language and auditory development
– Offers intervention program and continued
– Follow-up for changes in cochlear implant mapping
Benefits
• Similar to early amplification provision,
children implanted at early ages with more
experience tend to do better than older
children who receive implants after greater
period of deafness
Listening to Parental Concern About
Delayed Language Development
Gravel & Vohr
Listening to parent concern about
language development
• Parent concerns about hearing, speech,
language, or developmental delays are
strong predictors of an actual problem.
• Providers must avoid statements like
“Babies develop at different rates. Lets take
another look in about 6 months”
Clinical signs of Hearing Loss
•
•
•
•
•
Delayed early language milestones
Unintelligible speech
Uncharacteristic voice patterns
Child turns TV volume very loud
Child only responds to loud sounds/words
or in a very quiet environment
Myths about hearing and early speech
language delay
• We don’t have to worry because:
• His older brothers and sisters talk for him
• Boys develop speech much later than girls
• Twins always have language delays
• Grandma says that her Dad did not speak until
he was 3 years old.
• She has great motor milestones
• I know he hears because he gets upset every
time I turn on the vacuum.
Assessment of language delay
•
•
•
•
Administer a speech language screen
Check middle ear status for MEE: Rx
MEE for > 3 m refer to otolaryngology
If receptive /expressive delay refer back to
audiology for repeat diagnostic
• Refer to early intervention for speech
language therapy
• Assess for other possible dx: PDD, autism
• Continue to follow-up on speech/language
It is important to respond to concerns about language
immediately !
Most children with delays of speech and
language respond to appropriate medical,
audiologic, and educational interventions.
A successful early screening, identification,
and intervention program will ultimately
permit every child with HL to develop to
his/her potential.
• All in-hospital screening failures should receive
follow-up
– Failure rate at discharge, once high has decreased to 2%
or less.
– Probability 1 in 5 that infant who fails NHS has hearing
loss
• Regardless of screening outcome, if parent is
concerned regarding hearing or speech-language
development, child should be referred for
audiologic evaluation
Question-and-Answer
Early Hearing Detection and Intervention
CME Teleconference Series, Part II
November 12, 2003
12:00 – 1:00 pm, Central Standard Time
Topics:
Implementing newly developed AAP guidelines; important
referrals; the role of early intervention; primary care’s role
in coordination of services; parenting issues and reactions;
knowledge of and support for communication choices; cost
and reimbursement issues; and national resources.
Faculty: Al Mehl and Mary Pat Moeller