Download 1 - ENT Expert

EVALUATION OF A DEAF
CHILD AND
REHABILITATION OF A
DEAF CHILD
DEAFNESS
.Common childhood problem
.1 in 1000 birth
.Permanent hearing impairment >40
dbHL.(AVG.OF .5,1,2,4,Khz)
.60%--moderate HL
.Rest –severe /profound HL
.BIRTH TO 5 YEARS PERIOD
.. EARLY IDENTIFICATION
..EARLY ASSESMENT
..EARLY REHABILITATION
..
AETIOLOGY
..DEVELOPING WORLDINFECTION
..DEVELOPED WORLDGENETIC CAUSE
CAUSE S OF PERMANENT CHILDHOOD
HEARING IMPAIRMENT
..Congenital causes...genetic
syndromic /nonsyndromic–A.R.(77%)
30%)
-A.D.(22%)
-X-linked(1%)
-mitochondrial (<1%)
..Nongenetic -congenital rubella syndrome
cytomegalovirus
congenital syphilis
..Enviormental causes—
..perinatal causes -- hypoxia
-- hyperbilirubinemia
-- low birth weight
..acquired causes –infections-chr.otitis media
-meningitis
-mumps
-measles
-AIDS
-ototoxic drugs
-trauma
-neoplastic disease
..idiopathic
SYNDROME ASSOCIATED
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Waardenburg,s
syndrome
Usher,ssyndrome
Jarvel and lange
nielson,syndrome
Penderd syndrome
Alport syndrome
Treacher collin
syndrome
crouzon.,s syndrome
Apert syndrome
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Wildervanch syndrome
Brachio oto renal
syndrome
Stickler,syndrome
Vanderhoeve syndrome
Pierre robbin sequence
Goldenhar,s syndrome
(oculo-auriculoverteberal syndrome )
Down ,s syndrome
Klippel feil syndrome
A CLASSIFICATION OF CONGENITAL
MALFORMATIONS OF THE INNER EAR
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I. Malformations limited to the membranous labyrinth
A. Complete membranous labyrinthine dysplasia
(Siebenmann-Bing)
B. Limited membranous labyrinthine dysplasia
1. Cochleosaccular dysplasia (Scheibe)
2. Cochlear basal turn dysplasia (Alexander)
II. Malformations of the osseous and membranous
labyrinth
A. Complete labyrinthine aplasia (Michel)
B. Cochlear anomalies
1. Cochlear aplasia
2. Cochlear hypoplasia
3. Incomplete partition (Mondini)
4. Common cavity
C. Labyrinthine anomalies
 1. Semicircular canal dysplasia
 2. Semicircular canal aplasia
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D. Aqueductal anomalies
 1. Enlargement of the vestibular aqueduct
 2. Enlargement of the cochlear aqueduct
E. Internal auditory canal abnormalities
 1. Narrow internal auditory canal
 2. Wide internal auditory canal

Mondini dysplasia
Cochlear hypoplasia with
enlarged vestibule
Cochlear hypoplasia
with Enlarged vestibule

Non syndromic hearing lossDisorder DFNB1-mutation in GJB2 gene
(connexin 26)
-mutation in GJB6 gene
(connexin 30)
50% of AR nonsyndronic HL
NONGENETIC CAUSES

PERINATAL FACTOR
-overall incidence remain unchanged
-pre term/low birth weight …succeptible to
hypoxia and hyperbilirubinaemia
-hypoxia –neuro developmental deficit
-hyper bilirubinaemia ….cross immature blood
brain barrier ..grey matter …SNHL
-DAVIS and WOOD …(babies admitted to NICU
more than 48 hours …10.2 more succeptible
-ototoxic drugs ..some genetic succeptibility
MATERNAL
CMV ..
.m.c.cause of non
herditary SNHL in
developed world
.22-65%in symptomatic
.6-23%in asymptomatic
.12 % congenital SNHL
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INFECTION
SYPHILIS
.developing world
.HL-late feature of
congenital syphilis
.hutchinson,s triad
(3%- least common )
.at 8-10 yr.age
.sudden onset
.Rx .penicillin
.identification and
eradication in mother
.prenatal screening

CONGENITAL RUBELLA SYNDROME
1st trimester infection
 Deafness .
 Ocular (cataract )
 CVS.(PDS/PAS/VSD)
 CNS- microcephaly
 Skin changes
 Prevention approach

ACQUIRED CAUSES
=Meningitis –m.c.cause of acquired PCHI
-approx.10%
- early assesment of hearing
-if necessary..early cochlear implant
=MEASLES –high fever,running nose .koplik,s
spots ,maculopapular spots
--mucous membrane over body
--severe to profound b/l HL
--conductive(csom,perforation,mastoiditis )
--report of virus in cochlea (SNHL)
=MUMPS --non suppurative enlargement of
salivary gland esp.parotid
--SNHL ..5/100000 (u/l>b/l)
POSSIBLE SIGNS THAT MAY
SUGGEST CHILD HAS A HEARING
LOSS ARE
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child's speech is unclear and/or difficult to understand
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child's vocabulary is less than other children of his age
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child does not respond consistently when you call him .
does not hear household sounds heard by other members of the family
consistently; or, needs the sound of the TV or radio, etc. turned up very loudly
to hear well
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child does not follow directions and/or needs several repetitions before doing so
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child often says "Huh?".
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child does not appear to respond appropriately unless looking directly at you.
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Child has difficulty in school/exhibits poor academic achievement
Child sleep through loud noise unperturbed
Fail to startle to loud noise
Fail to develop speech at 1 year age
Perform poorly in school and labelled as mentally retarded
EVALUATION OF A DEAF CHILD
$ history –paediatric ..pregnancy/delivery
postnatal
developmental milestone
noise exposure
ototoxic drugs
head injuries
ear disease
infections
family history .1st /2nd relative
$ clinical examination
$ audiology .age appropriate assessement
$ imaging ..MRI inner ear /CT petrous temporal bone
$ ECG.
$ urine for microscopic haematuria
$ connexin 26/30 mutation testing with genetic counselling
$ opthalmic assessement
$ referral to clinical geneticist
$ vestibular investigations
METHODS OF HEARING ASSESSEMENT IN
INFANTS AND CHILDERN
$ Neonatal screening procedure
arousal test
auditory response cradle
ABR/OAE,S
$ Behaviour observation audiometry
moro,s reflex
cochleopalpeberal reflex
cessation reflex
$ Distraction techniques
$ Conditioning technique,s
visual reinforcement audiometry
play audiometry
$ objective tests
ABR
OAE,S
impedance audiometry
NEONATAL
SCREENING PROCEDURES
$ Risk factors
(U.S.joined commiittee on infant hearing position
statement 2000)
NICU/SCBU admission >48 hrs
family history of permanent childhood SNHL
craniofacial anomaly i.e.cleft palate
morphological abnormality of pinna/ear canal
stigmata/findings a/c syndrome
in utero infection i.e. cmv./rubella
Arousal test
a high frequency noise is
presented to infant for 2
sec.
^
normal infant can be
aroused twice when three
such stimuli are presented
Auditory resdponse
cradle (newborn )
baby is placed in a cradle
^
behaviour (triunk and limb
movement ,head jerk
,respiration )are monitored
by transducers in response
to auditory stimuli
^
screen baby with
moderate /severe /profound
hearing loss
BEHAVIOUR OBSERVATION AUDIOMETRY
(KEY DEVELOPMENTAL AGE 0-6 MONTH )
$ Observed change in activity in response to sound
$ up o 4 month age
eye widening ,eye blink reflex
arousal from sleep
startle or shudder of body
definite movement of arm /leg /body
$ 4-7 month
lateral inclination of head toward sound
MORO REFLEX
The Moro reflex is a normal reflex for an infant
when he or she is startled or feels like they are
falling.
 The infant will have a "startled" look and the
arms will fling out sideways with the palms up
and the thumbs flexed.
 Absence of the Moro reflex in newborn infants is
abnormal
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$ Auropalpebral reflex
child response by a blink to a loud sound
$ cessation reflex
infant stop activity or start crying in
response to a sound of 90 db
DISTRACTION TEST OF HEARING
KEY DEVELOPMENATAL AGE 6-18 MONTH)
$
EWING AND EWING (1944)
$
MCCORMICK (MODIFIED)
emphasise on use frequency specific,
caliberated sound stimuli
distractor
s
cg
ss
ss
*tester and equipment do not come into the child’s visual
field at any time
*distractor should not look at tester at any time
*there should be no chance for tactile stimulation
*continuous distraction,varying in intensity becomes
necessary,as child gets older and in particular over1215 months of age
VISUAL REINFORCEMENT
AUDIOMETRY (VRA).
6 months to 36 months
 Child on parents lap
 One examiner –attention of child
 Each time a child hears a sound and looks toward
the source of the sound he is rewarded by seeing
a motivational toy such as a moving clown or
illuminated toy
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This method reduces the habituation to sound
seen in children over 1 year of age, and reinforces
the localization of a sound stimulus
The distractor is still essential during the test to
control the child’s prestimulus activity and
attention
Once child demonstrate successful conditioning ,
aim is to establish minimum response level
(MRL) for each frequency

Thompson & Weber(1974) reported median
thresholds to sound through a loudspeaker of
45-55 db
3-5 months
35-45 db
6-11 months
35-40 db
12-17 months
CONDITIONED PLAY AUDIOMETRY
(CPA)
Teach the child to complete a motor act
 Each time a child hears a
sound, she is conditioned to place an object in a
box or a ring on a stick
 a variety of other games.
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Weber & Thompson – median thresholds to noise
on play field audiometry
26 db
24-29 months
13 db
30-35 months
TANGIBLE
REINFORCEMENT OPERANT
CONDITIONING AUDIOMETRY
Child is taught to push a button when sound is
heard
 Reinforcement with chocolate
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PURE TONE AUDIOMETRY
(KEY DEVELOPMENTAL AGE -3 YEARS ONWARD)
$ HUGSON AND WESTLAKE descending
/ascending technique using 10/5/step should be
adopted
$ no standard for interpretation in childern
$ NIELSON AND OLSER
accepted normal range 15 to 30 db HL
AUDITORY SPEECH
DISCRIMINATION TEST
$ The co-operative test (18-30month) –
EWING AND EWING
to discriminate 3 different simple instruction
started at suprathresold level ,then voice dropped
cover mouth to remove visual clue
normal –35-40 db
$ Toy discrimination test (30 month onward)
S.D score (at level of 80 % correction )
normal at <40db
$ consonant discrimination test (over 6 years )
auditory discrimination of consonant
HEARING ASSESSMENT IN CHILD WITH
SPECIAL NEEDS
$
$
$
approx. 30% HI child have additional disability
use test most suited to their developmenlal age
motor delay /physical disability i.e.cerebral
palsy……
in distraction test >partial response=normal
in VRA >visual reward closer to eye
$ visually impaired childern:
locate sound from 8 month
response to familiar sound /if reinforced by
tactile reward
use brightly illuminated reinforcer in darkened
room in partially sighted
$ autistic disorder
DRAWBACKS OF BOA
Threshold estimation
 Each ear
 Unilateral, asymmetrical, mild hearing loss
 Differentiate normal & conductive
 Observer bias
 Cochlear pathology with recruitment
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OTOACOUSTIC EMISSIONS (OAE)
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screening but not for confirmation
Takes only a few minutes
child is awake.
child must be still.
A normally functioning cochlea will produce an echo or
emission & suggests that the hair cells in the cochlea of the
inner ear are functioning.
If the computer does not record an emission, it suggests
that the hair cells are not working, meaning the child may
have a hearing loss.
OTOACOUSTIC EMISSIONS (OAE)
 `Energy leakage sec to cochlear travelling wave released
from cochlea - Ossicular chain -Tympanic membrane - EAC
Spontaneous OAE:
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40-60% of normal cochlea
Emission occurs at 10 -25 dB
Age limited
Evoked OAE:
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Transient – measure response to click /tone brust
response to transient clicks Emissions are undetectable if HL
is more than 30 dB
Distortion product OAE2 pure tone (f2>f1)are presented simultaneously
absent in patient with SNHL >50-60 DB
AUDITORY BRAINSTEM RESPONSE
(ABR) EVALUATION
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ABR does not assess the hearing in perceptual sense but assess
the integrity of neural elements
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Child must be asleep/ sedated
.
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Unaffected by sleep/drugs/GA
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each ear's response to sound using electrodes that rest on the
child's head.
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>1 duration hour
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Consist of presenting sound stimuli at gradually increasing
intensity , ascertaning at which minimum intensity of sound ,the
wave V of bera just appear .called BERA THRESOLD.
Average
puer tone hearing thresold is with in 5-10 db
In most childern of deafness > 90 db …flat bera even on
maximum sound stimulus 110-120 db …severely deaf but no
idea nature of disease
BERA
advantage
.objective
.individual ear can be
tested seperately
Limitation
.not frequency spcific
(low frequency missed .
.patient related varible
i.e.age ,sex
.identification of wave V
is difficult in few
(i.e. muscular
contraction may cause
artifact )
.time consuming (> I
hr.)
ARE THE HEARING SCREENING
TESTS 100% ACCURATE
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no screen is 100% specific or sensitive.
TIME LIMIT FOR NEWBORN
SCREENING
•completed by 4 weeks of age for well babies in hospital based
programmes
• 5 weeks of age for babies in community based programmes.
• SCBU or NICU for more than 48 hours screening should be
completed by 44 weeks gestational age
"1-3-6" GOAL.
Screen all babies for hearing loss by 1 month of
age,
 evaluate or assess by an audiologist by 3 months
of age,
 intervene by 6 months of age.
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IMAGING
C.T.SCAN
Large vestibular aqueduct –
m.c.isolated finding
 Cochlear dysplasia –
m.c.abnormality
 Others finding –
.lateral S.C.C. canal dysplasia
.otic capsular lucency
.small I.A.C.
.hypoplastic cochlea
.40% childern with L.V.A.develop
profound S.N.H.L.
S/O penderd syndrome thyroid
abnormality
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M.R.I.SCAN
Detect primarily C.N.S
abnormality
$
$
Serology rubella specific igM within 3
weeks of life
genetic screening
. disorder DFNB 1
. mitochondrial aminoglycoside
succeptibility gene mutation (A1555G)
$ blood test
.full blood count
.thyroid function test
.E.S.R.
.syphilitic blood test
.cholesterol /triglyceride levels
.blood urea /eletrolyte
$ genetic counselling
MANAGEMENT
$ Aims of habilitation
development of speech and language
adjustment in society
useful employment in a vocation
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Parental guidance
@ dealt with sympathetically
@ told of child disability and how to care
@ habilitation require lot from parents
periodic placement of H.A.
change of ear moulds
follow up visit
education at home
selection of vocation
DEVELOPMENT OF SPEECH AND LANGUAGE
@ auditory –oral communication
.used by normal person
. in deaf with moderate /severe hearing
loss/in post lingual deaf
. H.A. augments auditory perception
.training in speech reading i.e. lip/face /
natural gestures of hand and body
.expessive skill
-via oral speech
FACULTIES OF A HEARING IMPAIRED PERSON
(UTILISED FOR RECEPTIVE AND EXPREESIVE
SKILLS IN COMMUNICATION )
Expressive
receptive
skills
skills
Written
language
Oral speech
Lip reading
Visual acuity
Sign language
Hearing aid
Sound signal
Auditory
acuity
Cochlear
implant
Vibrotactile
aid
Hearing
impaired
Sign language
Finger
spelling
Tactile
facuilty
Written
communicatio
$ Manual communication
sign language
finger spelling method
disadvantage –difficult to express abstract idea
-general public do not understand
$ Total communication
use all modalities of sensory inputs
(auditory ,visual ,tactile kinaesthetic )
pre lingual severe to profound deafness
taught oral speech ,lip reading ,sign
language
$ vibrotactile aidsfor totally deaf and blind
attached to child hand or sternum
tactile stimulation
EDUCATION OF DEAF
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residential and day school for deaf
radio hearing aid
.. microphone and transmitter are worn by
teacher
.. Receiver and amplifier by child
REHABILITATION OF DEAF CHILD
$ 1- instrumental device
hearing aid
cochlear implant
assistive device
$ 2- training
speech reading
auditory training
speech conservation
HEARING AIDS
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Microphone;
acoustic ---- weak electrical energy

Amplifier :
Weak
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Receiver
strong ----- mechanical energy
----- strong
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Amplificaion
Before they are 1 month old.
MODE OF PLACEMENT
 BW
 BTE
 ITE
 ITC
 CIC
 Implantable
 Eye
spectacle aid
HEARING AIDS…
 While fitting a hearing aid consider:
Degree of hearing loss
Type of hearing loss
Presence of recruitment
Uncomfortable loudness level
Age and dexterity of pt.
Condition of outer and middle ear
Cosmetic acceptance of the aid
Type of ear mould
Type of fitting—Monoaural / Binaural / Binaural with
Y
connection / CROS Type
WHY BW IS PREFERRED IN
YOUNGER CHILDREN?
Separate air, bone receiver
 Least feed back
 High gain
 Parents control
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ANALOG VS DIGITAL
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In analog hearing technology sounds are simply amplified in
specific ways
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Digital hearing technology uses digital signal processing (DSP)
techniques to manipulate sounds.
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Sounds that are processed by a DSP hearing aid can be more
finely tuned to the individual's hearing loss than an analog
hearing aid.

better, cleaner and clearer sound quality.
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DSP is intelligent processing - determine if the sounds are speech
or noise using special techniques

If it perceives noise the DSP hearing aid will work to
automatically reduce amplification.
BETTER TO WEAR TWO HEARING
AIDS INSTEAD OF JUST ONE
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Normal hearing is with two ears which allows
to localize sounds, hear better in noisy
surroundings, hear the softest sounds and
experience an overall "natural" sound quality.
WHAT IS "FEEDBACK"?
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Feedback is the annoying whistling sound - cup hand around a
hearing aid, or when the hearing aid is not seated securely in ones
ear canal.
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Feedback occurs when sound amplified by the hearing aid
returns to the hearing aid and is re-amplified many times.
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Wearers of analog hearing aids usually turn down the volume on
the hearing aid to stop the feedback.
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Many digital hearing aids, however, are designed to minimize this
problem.
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Multi-Directional Active Feedback Cancellation System monitors
the sounds that go in and come out of the hearing aids to check
for feedback.
COCHLEAR IMPLANT
(NUCLEUS 24,CLARION ,MED-EL-COMBI 40+)
Cochlear
implant bypasses damaged
parts of the auditory system and
directly stimulates the spiral ganglion
cells and auditory nerve fibers
SELECTION OF CANDIDATES
Bilateral severe to profound sensorineural hearing
loss
 Age group > 12 months
 No appreciable benefit from hearing aid use (3-6
months)
 Normal neurological and mental development
 Proper morphological development of cochlea (HRCT
& MRI )
 Motivated parents

CONTRAINDICATIONS
Cochlear malformation
 Disorder or disease of auditory nerve / central
auditory pathway / mental retardation
 Any contraindication to GA
 Active middle ear infection (but can be operated after
succesful myringoplasty / removal of unsafe disease )

Component of cochlear
implant
-external component
microphone
speech processor
transmitter (RF)
- internal component
receiver/stimulator
eletrode (s.tympani)

AUDITORY BRAIN STEM IMPLANT
$
$
$
$
$
$
$
$
Indication –
. when C.N. 8 th have been severed in surgery
vestibular schwannoma
.bilateral acoustic neuroma
.neurofibromatosis -2
stimulate the cochlear nucleus complex in the
brain stem
implant placed in the lateral recess of 4th
ventricle
similar to multichannel cochlear implant
receiver /stimulator has removable magnet
not as efficient as multi channel C.implant
only limited number have been performed
under constant development
of
ASSISTIVE DEVICE
$
$
$
$
Assistive listening devices and system
hard wire system
induction loop
AM /FM/ infra red signals
alerting devices
hearing dog
alarm clock with flashing light
devices producing strong vibration
telecommunication devices
telephone amplifier
telephone coupler attached to H.AID
telecommunication devices for deaf (TDD)
close caption television decoder
TRAINING
$
speech reading
$
Auditory training
. Enhance listening skills
. Use with speech reading
speech conservation
.in sudden severe or profound hearing loss
.loss ability to monitor his speech production
.educate person to use tactile/proprioceptive
feedback system
$
(lip reading )
THANKS