Deafness and its management

Deafness and management

1. DEAFNESS AND ITS MANAGEMENT

2. DEFINITION The WHO definition COMPLETE LOSS OF HEARING ABILITY IN ONE OR TWO EARS . Hearing loss more than 90 dB in better ear (profound impairment) or total loss of hearing in both the ears. Hearing handicapped- HEARING IMPAIRMENT OF 70 DB AND ABOVE, IN BETTER EAR OR TOTAL LOSS OF HEARING IN BOTH EARS

3. PREVALENCE Hearing disability was the 2 nd  most common cause of disability Top most cause of sensory deficit. In urban areas, loss was 9% of all disability In rural areas, it was 10%  7% of people were born with a hearing disability.

4. CLASSIFICATION AMOUNT OF HEARING LOSS SLIGH t : between 16 and 25 dB HL MILD: for adults: between 26 and 40 dB HL for children: between 20 and 40 dB HL MODERATE : between 41 and 54 dB HL MODERATELY SEVERE : between 55 and 70 dB HL SEVERE : between 71 and 90 dB HL PROFOUND : 91 dB HL or greater TOTALLY DEAF : Have no hearing at all. This is called  anacusis .

5. CLASSIFICATION SITE OF INVOLVEMENT There are four main types of hearing loss,  CONDUCTIVE HEARING LOSS  SENSORINEURAL HEARING LOSS  CENTRAL DEAFNESS MIXED: Combinations of conductive and sensori -neural hearing losses.

6. NON-ORGANIC :   Apparent hearing loss with no evidence of known disorder or insufficient evidence to explain it .  PSYCHOGENIC : CONVERSION DISORDER PATIENT IS UNAWARE OF IT. MALINGERING : CONSCIOUSLY PRETENDING TO BE DEAF. MOTIV PRESENT. VOICE – NORMAL COCHLEO-AURICULAR REFLEX – PRESENT ABR, OAE HELPS TO DIFERRENTIATE GROSS DISCREPENCY BETWEEN AUDIOGRAM AND SPEEC AUDIOMETRY

7. CONDUCTIVE CONGENITAL

8. ACQUIRED EXTERNAL EAR: MIDDLLE EAR: TYMPANIC MEMBRANE. CAVITY- AIR, FLUID, MASS. OSSICLES .

9. SENSORI-NEURAL SENSORY NOISE INJURY DRUGS : OTOTOXIC DRUGS AGE DISEASES: SYSTEMIC NEURAL/ RETRO-COCHLEAR PERIPHERAL: VIII NV . CENTRAL: CONNECTIONS

10. CUASES OF SNHL CONGENITAL PRE-NATAL CAUSES INFANT FACTORS MATERNAL FACTORS PERINATAL CAUSES: POST NATAL CAUSES: GENETIC NON-GENETIC AQUIRED INLAMMATION OTOTOXIC DRUGS NOISE TRUAMA SUDDEN HEARING LOSS PRESBYCUSIS

11. CUASES OF SNHL

12. MANAGEMENT HISTORY: CONGENITAL/ AQUIRED STATIONARY/PROGRESSIVE SYNDROME -/+ FAMILY HISTORY -/+ OCCUPATIONAL HISTORY DRUG MEDICAL HISTORY CLINICAL EXAMINATION: SERIAL TUNING FORK TEST: PURE TONE AUDIOMETRY: TYMPANOMETRY:

13. ABR: AUDITORY BRAINSTEM RESPONSE SCREENING PROCEDURE THRESHOLD OF HEARING NONORGANIC RETROCOCHLEAR LESIONS ; ACOUSTIC NEUROMA EXACT ANATOMICAL SITES OF LESION E – VIII nv . DISTAL E- PROXIMAL C- COCHLEAR NUCLEUS O- OLIVARY COMPLEX L- LATERAL LAMNISCUS I- INFERIOR COLLICULUS

14. OAE: OTOACOUSTIC EMISSIONS TESTS THE FUNCTIONS OF OUTER HAIR CELLS TESTS FROM EAC TO OUTER HAIR CELLS SCREENING PROCEDURE PARTIAL ESTIMATION OF HEARING SENSITIVITY DIFEERENTIATE BETWEEN SENSORY AND NEURAL COMPONENT TESTS FOR FUNCTIONAL HEARING LOSS BEDSIDE SCREENING

15. CONDUCTIVE MEDICAL: NOT FIT FOR SURGERY AGED PATINETS MEDICAL DISEASES HEARING DEVICES SURGICAL: ACCORDING TO CAUSES-

16. REHABILITATION INSTRUMENTAL DEVICES HEARING AIDS CONVENTIONAL BAHA HA IMPLANTS VIBRATING SOUND BRIDGE B.IMPLANTS: COCHLEAR IMPLANTS AUDITOPRY BRAINSTEM IMPLANTS C. ASSISTED DEVICES TRAINING: SPEECH READING AUDITPRY TRAINING SPEECH CONSERVATION

17. HEARING AIDS CONVENTIONAL INDICATIONS: SNHL CONDUCTIVE LOSS DEAF CHILD TYPES:

18. BAHA

19. IMPLANTABLE HEARIND AIDS

20. COCHLEAR IMPLANT : SEVERE TO PROFOUND HAERING LOSS NOT IMPROVED BY HA NO MEDICAL CONTRAINDICATION REALIKSTIC EXPECTATION GOOD FAMILY AND SOCIAL SUPPORT ADEQUATE COGNITIVE FUNCTION

21. FUTURE …… STEM CELL TRANSPLANT AND GENE THERAPY . GENE THERAPY : A 2008 study has shown that gene therapy targeting  Atoh1  can cause hair cell growth and attract neuronal processes in embryonic mice

22. PREVENTION