All about Cochlear implants/why does this child not have a Cochlear Implant? Dr.S.Rangan Consultant Audiovestibular Physician (Paediatrics) St Catherine s Health Centre WUTH/BAPA Outline How does the ear work basics Types and degrees of hearing loss how to interpret a hearing test How do we test a child s hearing and how do we diagnose a hearing loss Management options for a child with hearing loss Indications for a Cochlear Implant and referral criteria/candidacy Child has had the Cochlear Implant what next? ANATOMY OF EAR 1
Organ of Corti Single row of Inner Hair cells 3-5 rows of outer hair cells Outer Hair cells from www.physiol.ucl.ac.uk Types of hearing loss Conductive Sensori-neural Mixed Central 2
Types of hearing loss Conductive sound not conducted efficiently through outer ear canal or middle ear Pathology in Outer Ear canal Middle ear Tympanic membrane Ossicles Cavity Sensorineural Damage to Cochlea (hair cells) or nerve pathways from Cochlea to brain Causes Hereditary/Congenital Ototoxicity Infective Noise exposure Mixed Combination of Conductive and sensori-neural Central Normal peripheral hearing, difficulty in processing sounds 3
Normal Hearing from www.audstudent.com from www.audstudent.com from www.audstudent.com 4
from www.audstudent.com Degrees of hearing loss Normal : 20 db or better Mild : 21 40 db Moderate : 41 70 db Severe : 71 95 db Profound : > 95dB 5
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Diagnosing hearing loss in a child Age appropriate hearing tests Newborn Newborn Hearing Screening OAE AABR Confirmation of hearing loss by ABR Over 3 months ABR under sedation Behavioural hearing assessment Behavioural hearing assessment Which test to choose? Behavioural observation audiometry (BOA) (3 months to 6 months) Visual re-inforcement audiometry (VRA) (6 months to 2 ½ years) Distraction test (DT)(6 months to 2 years) Performance test (30 months to 5 years) Pure tone audiometry (3 years upwards) Speech discrimination tests (from 2 ½ yrs upwards) Co-operative test (30 months to 42 months) 4 toy eye pointing (30 months to 42 months) McCormick Toy test (also Kendall and E2L Toy tests) ( from around 3 years upwards) Manchester picture test (4 ½ years upwards) Diagnosing congenital deafness Epidemiology Incidence of children born with PHI in UK about 1 in 1000, but 50-90 % more children identified in early childhood (Fortnum HM et al, 2001) Newborn Hearing Screening Programme (NHSP) - deaf children being identified earlier earlier identification of hearing loss earlier intervention better outcome median age (in England) has come down from 18 months to 10 weeks 8
Diagnosing congenital deafness Hearing tests in babies OtoAcoustic Emissions Auditory Brainstem Response Audiometry Automated Diagnostic Diagnosing congenital deafness Hearing screened at birth Fail screening (refer) pass screening Further assessment - ABR No risk factors - Discharged Risk factors targeted follow up Normal hearing Hearing loss confirmed PCHI Manage as appropriate Risk factors for hearing loss Congenital infections CMV, Toxoplasma, Rubella Craniofacial abnormality cleft palate Syndrome associated with hearing loss Down Family History especially first degree relatives Prolonged SCBU/NICU stay/extreme prematurity Jaundice at exchange transfusion level Bacterial Meningitis Ototoxicity Others 9
Management of hearing loss Conductive hearing loss Correction of pathology if possible Sensori-neural hearing loss Counselling and Hearing tactics Hearing aids, Cochlear Implants Environmental aids School appropriate seating Environmental aids Hearing aids Hearing aids 10
Hearing aids Bone conduction Hearing device Hearing Aids Always try Hearing Aids in the first instance Selectively amplify sounds across the frequency range Non-invasive (make use of the natural hearing mechanisms) Becomes part of child s routine & helps prepare for CI use Cochlear Implants 11
Nucleus System 6 Advanced Bionics System 12
Assistive Listening Devices Telecoil / Loop Streaming / Bluetooth Conventional FM Systems Dynamic FM Systems + (e.g. Roger) Streaming devices FM Receivers 13
Cochlear Implant and Hearing aids Hearing aids amplify sound Cochlear implants do not amplify sound and directly stimulate the auditory nerve Cochlear implants NICE Guidelines Referral criteria for individual centres Audiometric selection criteria Severe-to-Profound Hearing loss in both ears (>90dB HL at 2 and 4 khz) Inadequate benefit from conventional acoustic hearing aids Cochlear Implant centres UK Belfast Regional Cochlear Implant Centre Birmingham Adult Cochlear Implant Programme Birmingham Children's Cochlear Implant Programme Bridgend Cochlear Implant Programme Cardiff Adult Cochlear Implant Programme Cardiff Paediatric Cochlear Implant Programme Dublin Cochlear Implant Programme Emmeline Centre Cambridge Great Ormond Street Cochlear Implant Programme Manchester Cochlear Implant Programme Middlesbrough Midlands Cochlear Implant Centre 14
Cochlear Implant centres UK Newcastle North East Cochlear Implant Programme North Wales Cochlear Implant Programme Nottingham Cochlear Implant Programme Oxford Cochlear Implant Programme Portland Hospital Cochlear Implant Programme RNTNE/UCL Cochlear Implant Programme Scottish Cochlear Implant Programme South of England Cochlear Implant Centre St Georges Hospital Cochlear Implant Program St Thomas' Hospital Cochlear Implant Programme St Thomas' Hospital Cochlear Implant Programme West of England Adult Cochlear Implant Programme West of England Paediatric Cochlear Implant Programme Yorkshire Cochlear Implant Service Hearing Aid Evaluation Hearing aid evaluation is carried out after at least 3 months of consistent hearing aid use (within a stimulating environment). Cochlear Implants may be considered if little or no benefit is achieved from conventional acoustic hearing aids. Assessment Patients are assessed to establish candidature ChIP Children s Implant Profile used MRI absent Cochlear nerve -?Auditory Brain stem implant A robust Selection Criteria based on NICE Guidelines is used. Selection Criteria for Paediatrics is the same throughout the UK. 15
Other aspects of Assessment Child s ability to provide consistent behavioural responses / conditioned responses Child s potential to make use of auditory information & develop spoken language Ensuring that parents understand what is entailed, commitment and appropriate expectations Satisfactory Imaging Fitness for Surgery and GA Otology Referral Information Hearing History (aetiology, age at onset, progression, duration of profound loss, HA use). Mode of Communication (speech intelligibility, spoken language development etc.) Interpreter Services (BSL, foreign language, electronic note-takers) Enclose Reports (Audiology, Rehab, Child Development etc.) Distribution List (local team) Timing of Implant Aim to provide CI(s) between 12 and 18 months of age for congenitally deaf children Those with no functional spoken language & poor auditory experience may not be considered for cochlear implant after the age of 5 years. 16
Age at time of Cochlear Implant Cochlear Implant Process Assessment Surgery most children get bilateral implants Device Programming (Psychophysics) Rehabilitation Equipment Maintenance Initial fitting 4 weeks post-surgery switch-on External Equipment Issued Electrodes activated for the first time Mode of Stimulation, Stimulus Levels etc. Speech coding strategy (SPEAK, ACE etc.) 17
Rehabilitation Post operative rehabilitation very important Needs regular visits to Cochlear Implant centre Parental co-operation and commitment vital Specialist speech therapy input-liaison with local services Factors influencing referral Medical Parental/Social Financial Factors Influencing Outcome Hearing history Age at time of implant Home environment Device use Communication approach Co-existing morbidity 18
Cochlear implantation in ANSD Evidence supports CI in children with ANSD Direct stimulation of auditory nerve may overcome dys-synchronous firing Summary Early diagnosis and management better outcome for speech and language development Cochlear Implants may not be suitable for every child Multi disciplinary team Regular monitoring, post operative rehabilitation very important 19
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