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EARLY DETECTION OF DEAFNESS IN CHILDREN AND ROLE OF COCHLEAR IMPLANTATION PowerPoint Presentation
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EARLY DETECTION OF DEAFNESS IN CHILDREN AND ROLE OF COCHLEAR IMPLANTATION

EARLY DETECTION OF DEAFNESS IN CHILDREN AND ROLE OF COCHLEAR IMPLANTATION

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EARLY DETECTION OF DEAFNESS IN CHILDREN AND ROLE OF COCHLEAR IMPLANTATION

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  1. EARLY DETECTION OF DEAFNESS IN CHILDREN AND ROLE OF COCHLEAR IMPLANTATION Dr. Bayya Srinivasa Rao MS(PGIMER)

  2. Introduction • Childhood deafness presents special problems:

  3. Need for evaluation & treatment

  4. Anatomy • Scalatympani • Scalavestibuli • Cochlear duct • Basilar membrane • Tectoralmembrane • Hair cells (outer/inner) • Cochlear nerve fibers

  5. Physiology of Hearing

  6. Neural plasticity For speech articulation: 2-3 years For Listening : 6-8 years.. 2-3 per 1000 newborns will have permanent childhood hearing loss .

  7. Causes of hearing impairment in childhood • Congenital - Genetic {syndromic or non syndromic / recessive or dominant} - Non genetic • Acquired

  8. GENETIC NON SYNDROMIC MEMBRANOUS LABYRINTH DEFECTS BING SIEBENMANN SCHEIBE ALEXANDER FAMILIAL PERCEPTIVE DEAFNESS(HEREDODEGENERATIVE DEAFNESS) MEMBRANOUS &OSSEOUS LABYRINTH DEFECTS MICHEL MONDINI COCHLEAR APLASIA COCHLEAR HYPOPLASIA

  9. Syndromes associated with genetic hearing loss

  10. CONGENITAL • DEVELOPMENTAL:NON GENETIC: • PRE NATAL • INFECTIONS –Toxoplasmosis, rubella, cytomegalovirus, herpes1&2, syphilis, hiv, measles, chickenpox, parvo • Environmental hazards, radiation, diabetes,toxaemia,ototoxicdrugs,teratogenic chemicals • PERINATAL: • Low birth weight, hyperbilirubinaemia, anoxia • NEONATAL: • INFECTIONS – Meningitis,encephalitis,septicemia • Delayed auditory maturation • MISCELLANEOUS- Congenital cholesteatoma

  11. Acquired • Meningitis • Encephalitis • Infantile measles and mumps • Ototoxic drugs • Erythroblastosisfoetalis • trauma • Hypoxia • Infections of inner ear • Noiceinduced • Otitis media • Functional

  12. speech and language milestones • Birth to 3 months • Startles to loud noise (Moros Reflex) • Awakens to sounds(Arousal Test) • Blinks or widens eyes in response to noises(Cochleo Palpebral Reflex) • 3-4 months • Quiets to mother's voice • Stops playing, listens to new sounds • Looks for source of new sounds that are not in sight

  13. 6-9 months Enjoys musical toys Coos and gurgles with inflection Says "mama" 12-15 months Responds to his or her name and the word "no" Follows simple requests Uses expressive vocabulary of 3-5 words Imitates some sounds

  14. 18-24 months Knows body parts Uses expressive vocabulary with 2-word phrases (minimum of 20-50 words) 50% of speech intelligible to strangers By 36 months Uses expressive vocabulary of 4- to 5-word sentences (approximately 500 words) 80% of speech intelligible to strangers Understands some verbs

  15. Failure to achieve these speech and language milestones may indicate hearing loss and necessitate a hearing evaluation

  16. Hearing assessment in children • A) Neonatal screening procedures: Arousal test Auditory response cradle Electric response audiometry B) Behaviour observation audiometry: Moro’s reflex, Cochleo-palpebral reflex, Cessation reflex C) Distraction techniques: D) Conditioning techniques: Play audiometry ,Visual reorientation audiometry E) Objective tests: Evoked response audiometry Impedance audiometry, Otoaoustic emissions Heart rate audiometry

  17. DPOAE

  18. Why Intervene Early? Early experiences have a decisive impact on the architecture of the brain • In the first year of life, neurons in the auditory brainstem are developing • Billions of major neural connections are being formed(number of synapses increases 20 fold to 1,000 trillion). • Newborn brain is in a subcortical state; Areas of cortex responsible for language are well developed by 12 months of age.

  19. Organ of Corti Cochlea Cross-Section No Hair Cells!

  20. What is a Cochlear Implant? • A cochlear implant is an electronic device, that bypasses the damaged hair cells of the cochlea and stimulates the auditory nerve directly. • It can provide the child with useful “hearing” and improved communication abilities in the implant user. • It is a safe, reliable, and an effective treatment for profound hearing loss in children (and adults).

  21. Components of the Implant System Implant body(receiver/stimulator) RF Transmission Coil Speech Processor(BTE shown) Electrode array(inserted to cochlea)

  22. Cochlear: E.N.T. NURSING HOME

  23. MEDEL: E.N.T. NURSING HOME

  24. Advanced Bionics: E.N.T. NURSING HOME

  25. Selection criteria - Children • Twelve months of age or older • Bilateral severe to profound sensory neural hearing loss- congenital or acquired • No or less benefit with the most optimised hearing aid • Aided audiometric thresholds that fall outside speech range at 2kHz • No medical or radiological contraindications • Motivation and good family support.

  26. SELECTION CRITERIA - ADULTS • 18 years old and older (no limitation by age) • Bilateral severe-to-profound sensorineural hearing loss (70 dB hearing loss or greater with little or no benefit from hearing aids for 6 months) • Psychologically suitable • No anatomic contraindications • Medically not contraindicated

  27. CandidacyGuideline Audiograms

  28. Pre surgical Evaluation: • Ear examination to determine cause of hearing loss and absence of infection. • Medical examination for eligibility for surgery and anesthesia. • Hearing ability testing, with and without best-fit hearing aid. • Evaluation of communication skills. • CT scan to determine patency of the cochlea. • MRI • Internal auditory canal contents • Presence of auditory nerve. • Detection of endocochlear obstruction.

  29. The Cochlear Implant Team“Cochlear Implant Program is a Team Approach Program” • The Parents • Need to be involved in all evaluation processes and decisions. Must have realistic expectations and fully understand all aspects of process. • The Surgeon • Full medical and surgical evaluation, surgery and post surgical care • The Audiologist • Full audiological evaluation, hearing aid fitting, Pre implantation counseling, mapping, Hearing habilitation Planning and ongoing follow up • The Auditory Verbal Therapist • Pre and post surgery listening training, Auditory Verbal Practice for individual and full home training program for parents

  30. Normal Cochlea-CT Findings: E.N.T. NURSING HOME

  31. Hi Resolution 3D MR Imaging Technology

  32. Abnormal cochlea Abnormal Cochlear aqueduct

  33. Ossified Cochlea Common Cavity E.N.T. NURSING HOME

  34. Common Cavity:

  35. Mondini Dysplasia:

  36. Michale Deformity:

  37. Posterior tympanotomy E.N.T. NURSING HOME

  38. Cochleostomy

  39. Electrode Array in the Cochlea

  40. Scala Tympani is Good Modiolar Wall Lateral Wall 1 Scala Vestibuli Reissner’s Membrane Scala Media Hair Cells Spiral Ganglion nerve cells Basilar Membrane Scala Tympani To auditory nerve

  41. Scala Tympani isGood Modiolar Wall Lateral Wall 1 Scala Vestibuli Scala Media Scala Tympani

  42. Scala Tympani isGood Electrode 1 Scala Vestibuli Scala Media Electrode Scala Tympani Modiolar Wall Lateral Wall