Priority Medicines for Europe and the World "A Public Health Approach to Innovation" Update on 2004 Background Paper Background Paper 6.21 Hearing Loss By Béatrice Duthey, Ph.D 20 February 2013 Update on 2004 Background Paper, BP 6.21 Hearing Loss Table of Contents Executive Summary ............................................................................................................................................ 4 1. Introduction ................................................................................................................................................. 5 1.1 Hearing Loss definitions .................................................................................................................... 5 1.2 Possible Causes of hearing loss ......................................................................................................... 7 1.2.1 Ear infections................................................................................................................................... 7 1.2.2 Untreated infections during childhood ....................................................................................... 8 1.2.3 Congenital hearing loss ................................................................................................................. 8 1.2.4 Injury/trauma .................................................................................................................................. 9 1.2.5 Aging ................................................................................................................................................ 9 1.2.6 Exposure to prolonged or excessive noise .................................................................................. 9 1.2.7 Medications and other chemicals that are toxic to the ear ........................................................ 9 1.2.8 Nutritional Deficiency Causes .................................................................................................... 10 1.3 Diagnosis ........................................................................................................................................... 11 1.3.1 New borns and Infants Diagnosis .............................................................................................. 11 1.3.2 Children and Adult Diagnosis ................................................................................................... 11 2. What are the Epidemiological Trends for Europe and the World? ................................................. 11 2.1 General ............................................................................................................................................... 11 2.2 Prevalence .......................................................................................................................................... 12 2.2.1 Prevalence in the world ............................................................................................................... 12 2.2.2 Prevalence in Europe ................................................................................................................... 15 3. What is the control Strategy? .................................................................................................................. 17 3.1 Prevention Measures ........................................................................................................................ 17 3.1.1 Primordial Prevention ................................................................................................................. 17 3.1.2 Secondary Prevention .................................................................................................................. 18 3.1.3 Tertiary prevention ...................................................................................................................... 18 3.2 Therapies ............................................................................................................................................ 19 4. What is known of the Availability, Feasibility and Sustainability of the Control Strategy? .... 20 4.1 The European Burden of Hearing Loss and cost .......................................................................... 20 4.2 Feasibility and Control Strategy ..................................................................................................... 21 5. Why does the Disease Burden Persist? ................................................................................................. 22 5.1 Lack of awareness of the problem .................................................................................................. 22 5.2 Poor Diagnosis .................................................................................................................................. 23 5.3 A lack of epidemiological data ....................................................................................................... 23 5.4 Poor living conditions and lack of vaccination coverage ............................................................ 23 5.5 Underuse of hearing devices ........................................................................................................... 23 5.6 Exposure to noise .............................................................................................................................. 24 5.7 Aging of the population ................................................................................................................... 24 6.21-2 Update on 2004 Background Paper, BP 6.21 Hearing Loss 5.8 Gaps of research into pharmacological interventions ................................................................. 24 6. Past/Current Research into Pharmaceutical Interventions for this Condition .............................. 25 6.1 Antioxidants and ROS scavengers ................................................................................................. 25 6.1.1 Sodium thiosulfate (STS) ............................................................................................................. 25 6.1.2 Alpha Lipoic Acid ........................................................................................................................ 26 6.1.3 N-acetylcysteine ........................................................................................................................... 27 6.1.4 Ginkgo Biloba ............................................................................................................................... 27 6.1.5 Dietary supplements: Vitamins and minerals .......................................................................... 27 6.2. Anti-inflammatory agents ............................................................................................................... 28 6.2.1 Salicylate/Aspirin ......................................................................................................................... 28 6.2.2 Steroids .......................................................................................................................................... 28 6.2.3 TNF-α inhibitors ........................................................................................................................... 29 6.3 Anti-apoptotic agents ....................................................................................................................... 30 6.4 New Promising drug candidates from animal studies ................................................................ 30 6.4.1 RNA interference .......................................................................................................................... 30 6.4.2 Nanotechnology for drug administration to the cochlea ........................................................ 31 6.4.3 D-methionine ................................................................................................................................ 31 6.4.4 Resveratrol .................................................................................................................................... 31 6.4.5 Neurotrophic factors .................................................................................................................... 31 6.4.6 Caspase Inhibitors ........................................................................................................................ 31 6.4.7 Stem cell transplantation ............................................................................................................. 32 6.4.8 Targeted Neural Stimulation ...................................................................................................... 32 7. What is the Current “Pipeline” of Products that Are to Be Used for this Particular Condition? .. ...................................................................................................................................................................... 33 7.1 Extended Wear Hearing Aids ......................................................................................................... 33 7.2 Cochlear Implants ............................................................................................................................. 34 7.3 Middle Ear Implants ........................................................................................................................ 35 7.4 Sign Language ..................................................................................................................................