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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 Waardenburg,s syndrome Usher,ssyndrome Jarvel and lange nielson,syndrome Penderd syndrome Alport syndrome Treacher collin syndrome crouzon.,s syndrome Apert syndrome 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 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 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 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 child's speech is unclear and/or difficult to understand child's vocabulary is less than other children of his age 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 child does not follow directions and/or needs several repetitions before doing so child often says "Huh?". child does not appear to respond appropriately unless looking directly at you. 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 $ 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 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. 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 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 OTOACOUSTIC EMISSIONS (OAE) 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: 40-60% of normal cochlea Emission occurs at 10 -25 dB Age limited Evoked OAE: 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 ABR does not assess the hearing in perceptual sense but assess the integrity of neural elements Child must be asleep/ sedated . Unaffected by sleep/drugs/GA each ear's response to sound using electrodes that rest on the child's head. >1 duration hour 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 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. 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 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 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 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 Microphone; acoustic ---- weak electrical energy Amplifier : Weak Receiver strong ----- mechanical energy ----- strong 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 ANALOG VS DIGITAL In analog hearing technology sounds are simply amplified in specific ways Digital hearing technology uses digital signal processing (DSP) techniques to manipulate sounds. 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. 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 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"? 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. Feedback occurs when sound amplified by the hearing aid returns to the hearing aid and is re-amplified many times. Wearers of analog hearing aids usually turn down the volume on the hearing aid to stop the feedback. Many digital hearing aids, however, are designed to minimize this problem. 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