SNHL

1. SNHL Saisuree Nivatwongs ENT-PMK

2. Sensorineural hearing lossIntroduction • History • Physical examination • Auditory testing • Vestibular testing • Laboratory testing • Radiographic testing

3. Etiology Development & Hereditary disorder Infectious disorder Pharmacologic disorder Trauma Neurologic disorder Vascular & Hematologic disorder Immune disorder Bone disorder Neoplasms Endocrine & Metabolic disorder Disorder of unknown etiology Sensorineural hearing loss **Sudden Sensorineural hearing loss**

4. Unilateral / Bilateral Chronicity Tinnitus / Vertigo Otalgia / Otorrhea Headache Eye symptoms Underlying disease Ototoxic drugs Hx of trauma Noise exposure Family Hx History

5. Physical Examination • Weber / Rinne test • Otoscopy • Cranial nerve • Stigmata of associated disease • Generally no abnormality**

6. Auditory Testing • Conventional audiometry • Tympanometry • Acoustic reflex threshold • Auditory brainstem response • Electrocochleography • Otoacoustic emission

7. Laboratory testing Fluorescent treponemal antibody absorption test : FTA-ABS Microhemagglutination test for Treponema pallidum : MHA-TP Venereal disease research laboratory : VDRL Routine hematologic studies Routine metabolic studies Vestibular testing Adjunct in selected patients Radiographic testing MRI with Gadolinium  Retrocochlear hearing loss? Computed tomography  Labyrinthine abnormality? Clinical evaluation

8. Etiology • Development & Hereditary disorder • Infectious disorder • Pharmacologic disorder • Trauma • Neurologic disorder • Vascular & Hematologic disorder • Immune disorder • Bone disorder • Neoplasms • Disorder of unknown etiology

9. Development & Hereditary disorder • Waardenburg syndrome • Large vestibular aqueduct syndrome • Usher syndrome • Alport syndrome

10. Etiology • Development & Hereditary disorder • Infectious disorder • Pharmacologic disorder • Trauma • Neurologic disorder • Vascular & Hematologic disorder • Immune disorder • Bone disorder • Neoplasms • Disorder of unknown etiology

11. Labyrinthitis Serous labyrinthitis Abnormal process within the labyrinth Endolymphatic hydrops Hearing loss and vestibular dysfunction Permanent or transient Sudden onset of sensorineural hearing loss and acute vertigo Viral labyrinthitis is common Suppurative labyrinthitis Bacterial invasion of the inner ear Profound hearing loss and acute vertigo Caused by a fistula between the middle ear and the labyrinth Alternatively, the route of invasion can be meningogenic Most common etiology of deafness associated with meningitis Infectious disorder

12. Herpes zoster oticus Varicella-zoster infection Most commonly associated with facial paralysis HL and vertigo can occur Infectious disorder

13. Infectious disorder Measles • Not uncommon cause of deafness in children • Bilateral HL • Moderate-to-profound HL • Vestibular function can be similarly affected Mumps • Paramyxovirusinfection • Unilateral SNHL • Unilateral deafness in otherwise healthy children • Sudden deafness in adult  Subclinical mumps infection in those without previous immunity

14. Cytomegalovirus Common cause of congenital and progressive HL in children Sudden SNHL in adults Hearing loss associated with AIDS may represent reactivation of latent CMV infections Infectious disorder

15. Syphilis Congenital or acquired syphilis 80%  Symptomatic neurosyphilis HL in syphilis  Meningolabyrinthitis Syphilitic HL Indistinguishable from Ménière’s disease Hennebert’s sign (a positive fistula test without middle ear disease) Tullio’s phenomenon (vertigo or nystagmus on exposure to high-intensity sound) Infectious disorder

16. Etiology • Development & Hereditary disorder • Infectious disorder • Pharmacologic disorder • Trauma • Neurologic disorder • Vascular & Hematologic disorder • Immune disorder • Bone disorder • Neoplasms • Disorder of unknown etiology

17. Aminoglycosides Streptomycin, Kanamycin, Neomycin, Amikacin, Gentamicin, Tobramycin, and Netilmycin Death of the hair cell Different patterns of ototoxicity with different aminoglycosides Unilateral or asymmetric Reversibility of the HL Risk factors (1) presence of renal disease (2) longer duration of therapy (3) increased serum levels (4) advanced age (5) concomitant administration of other ototoxic drugs Ototopical preparations Neomycin, Gentamicin, and Tobramycin-containing Cochlear or vestibular ototoxicity Avoid the use of aminoglycoside-containing topical preparations in uninflamed ears with tympanic membrane perforations Ingredients of ototopical preparations also have ototoxic potential Polymyxin B, Propylene glycol, Acetic acid, Antifungal agents Pharmacologic disorder

18. Loop diuretics Effect by blocking sodium and water reabsorption in the proximal loop of Henle Reversible SNHL Bilateral and symmetric Sudden in onset Alteration of endolymphatic ion concentration and endocochlear potential Risk factors (1) Renal failure (2) Rapid infusion (3) Aminoglycoside administration Antimalarials Quinine  Tinnitus, SNHL, & Visual disturbances Chincinonism  Tinnitus, headache, nausea, and disturbed vision Quinine appears to be primarily on hearing and usually is transient Permanent hearing loss may occur with large doses or in sensitive patients Pharmacologic disorder

19. Salicylates Aspirin  Tinnitus and reversible SNHL HL  Dose-dependent Moderate-to-severe range SNHL, loss of otoacoustic emissions, reduced cochlear action potentials Alteration of the “tips” of auditory nerve fiber tuning curves Alteration in turgidity and motility of outer hair cells Nonsteroidal antiinflammatory drugs Naproxen, Ketoralac & Piroxicam Ototoxicity resulting from use of NSAIDs is rare Only reversible physiologic changes, without major morphologic changes Pharmacologic disorder

20. Vancomycin Almost received Vancomycin & loop diuretics or aminoglycosides Ototoxicity  Intravenously Permanent or transient SNHL Excreted by the kidney Renal failure  Vancomycin half-life  Increase ototoxicity Itself ototoxic  Unclear Erythromycin Uncommon Partially Intravenously Reversible on discontinuation No reports - Newer macrolide - Clarithromycin - Azithromycin Pharmacologic disorder

21. Nitrogen mustards Antineoplastic agents Mechlorethamine has Serious ototoxicity Limited use  Severe toxic Shrinkage of the organ of Corti Loss of inner and outer hair cells Cisplatinum Cell-cycle nonspecific cancer chemotherapeutic agent Dose-limiting SNHL Adults (25% to 86%) Children (84% to 100%) Bilateral / Irreversible Tinnitus or vertigo HL  Dose-related Progressive outer hair cell loss Inner hair cells, neural structures and the stria vascularis are affected Pharmacologic disorder

22. Vincristine and vinblastine The vinca alkaloids Potent neurotoxicity Peripheral neuropathy Cranial neuropathies, ataxia, and hearing loss Loss of hair cells and primary auditory neurons Eflornithine Drug treatment of trypanosomiasis Some Pneumocystis carinii pneumonia, Cryptosporidiosis, Leishmaniasis, and Malaria Cause major and dose-related SNHL Pharmacologic disorder

23. Deferoxamine Iron-chelating agent Auditory and visual neurotoxicity Particularly with larger doses in younger patients The SNHL is reversible in some patients when the dosage is reduced Lipid-lowering drugs Wallerian-like degeneration High doses of HMG-CoA reductase inhibitors Optic& vestibulocochlear nerve degeneration No clinically significant effect on vision or hearing Pharmacologic disorder

24. Etiology • Development & Hereditary disorder • Infectious disorder • Pharmacologic disorder • Trauma • Neurologic disorder • Vascular & Hematologic disorder • Immune disorder • Bone disorder • Neoplasms • Disorder of unknown etiology

25. Head injury Blunt head injury alone  Concussive injury of the labyrinth Labyrinthine injury  SNHL Temporal bone fracture  Labyrinthine concussion Longitudinal fractures  Similar to acoustic trauma  Limited to the high F  Worse at 4 kilohertz Transverse fractures  Complete loss of auditory & vestibular function Penetrating injuries  Subluxation ofthe stapes into the vestibule  Profound SNHL Trauma

26. Noise-induced HL & Acoustic trauma First published in the 1930s Common occupationally-induced disabilities Common in industry Caused by excessive noise exposure Temporary SNHL that recovers over the next 24 to 48 hours High intensity & repeated  Permanent Outer hair cell  Most effect More damage in - High-frequency sound - Continuous sound - Pure tones Symmetric & Bilateral HL Limited to 3 kHz, 4 kHz, and 6 kHz Greatest loss 4 kHz Progress rapidly in first 10 to 15 years of exposure Trauma

27. Noise-induced HL & Acoustic trauma Common patterns  Flat & downsloping losses Acoustic trauma  Unilateral or asymmetric OSHA does not allow unprotected exposures greater than 90 dBA based on an 8 hour/day time weightedaverage (TWA) Variability  Age, gender, race, and coexisting vascular disease No known way to predict susceptibility to NIHL Protection  Earplugs or earmuffs Many hazardous noise exposures are not occupational in origin Trauma

28. Barotrauma Unequalized pressure differentials between the middle and external ears Occurs during flying or underwater diving Pain, hyperemia and possible perforation of the tympanic membrane Edema and ecchymosis of the middle ear mucosa Conductive HL may result Perilymphatic fistula Pathologic communication between the perilymphatic space of the inner ear and the middle ear Congenital or acquired Occur at either the round or oval windows Trauma

29. Congenital Occur in the stapes footplate with labyrinthine anomalies Such as Mondini dysplasia Communicate with the subarachnoid space and result in cerebrospinal fluid leak and possible meningitis Profound hearing loss Acquired Result of - Barotrauma - Direct trauma of temporal - Indirect trauma of temporal - Complication of stapedectomy Sudden SNHL and vertigo after a head injury, barotrauma, or heavy lifting or straining May be spontaneously Diagnosis  Middle ear exploration Perilymphatic fistula

30. Irradiation Conventional fractionated irradiation of the temporal bone Fractionated irradiation  Limited extent to treat vestibular schwannoma Difficult to determine because of the limited data available Stereotactic irradiation (“radiosurgery”) for vestibular schwannoma This modality  Risk of SNHL  High as with microsurgical removal Trauma

31. Etiology • Development & Hereditary disorder • Infectious disorder • Pharmacologic disorder • Trauma • Neurologic disorder • Vascular & Hematologic disorder • Immune disorder • Bone disorder • Neoplasms • Disorder of unknown etiology

32. Multiple sclerosis Multiple areas of CNS demyelination, inflammation, and glial scarring Age  20 to 30 years More common in women Cause  Unknown 4% to 10% of MS  SNHL Progressive or sudden Bilateral, unilateral, symmetric, or asymmetric Speech discrimination  Normal or reduced Abnormalities of the ABR MRI  Periventricular white-matter plaques on T2-weighted images Neurologic disorders

33. Benign intracranial hypertension Pseudotumor cerebri Increased intracranial pressure Without evidence of mass lesion, obstructive hydrocephalus, intracranial infection, or hypertensive encephalopathy Headache and visual blurring Pulsatile tinnitus SNHL and vertigo More in young, obese women SNHL  Fluctuating, low-F Unilateral or bilateral Vertigo and aural fullness Diagnosis  Papilledema  CSF pressure > 200 mmH2O  ABR abnormalities Management - Weight loss - Acetazolamide - Furosemide - Lumbar-peritoneal shunting Neurologic disorders

34. Etiology • Development & Hereditary disorder • Infectious disorder • Pharmacologic disorder • Trauma • Neurologic disorder • Vascular & Hematologic disorder • Immune disorder • Bone disorder • Neoplasms • Disorder of unknown etiology

35. Migraine Headache and visual aura Basilar migraine  Vertigo, SNHL  Tinnitus, aural fullness  Distortion & recruitment 46%  Bilateral, low-F-SNHL Fluctuated HL Similarity, between basilar migraine and Ménière’s Dz. Drugs in basilar migraine  No systematic study Vertebrobasilar arterial occlusion Brainstem syndromes Anterior inferior cerebellar artery (AICA) Occlusion of AICA  SNHL Thrombosis or embolism Area infarcted  Inferior pons Acute AICA infarction Acute vertigo with N/V Facial paralysis, SNHL Tinnitus, gaze paralysis Loss of pain and temperature sensation on the face Ipsilateral Horner’s syndrome Vascular and hematologic disorders

36. Waldenström’s macroglobulinemia Abnormally large amounts of IgM in the plasma Increased blood viscosity Subsequent ischemic lesions Progressive & sudden SNHL SNHL  responded to alkylating agents or plasmapheresis Vascular and hematologic disorders

37. Sickle cell anemia Incidence of SNHL ~22% of sickle cell disease Progressive or sudden Associated with sickle cell crises Vascular and hematologic disorders

38. Leukemias & Lymphomas SNHL  Leukemic infiltrates  Inner ear hemorrhage  Vascular occlusion  Labyrinthine ischemia Vascular and hematologic disorders

39. Etiology • Development & Hereditary disorder • Infectious disorder • Pharmacologic disorder • Trauma • Neurologic disorder • Vascular & Hematologic disorder • Immune disorder • Bone disorder • Neoplasms • Disorder of unknown etiology

40. Cogan’s syndrome Attacks of acute non-syphilitic interstitial keratitis Auditory and vestibular dysfunction Unilateral or bilateral SNHL Severe vertigo, nausea, vomiting, and tinnitus Progresses to a profound loss over months Ophthalmologic findings If treated  SNHL is responsive Aggressive treatment with steroids Immune disorders

41. Polyarteritis nodosa Necrotizing vasculitis of small- and medium-sized arteries Myriad of findings, including weight loss, fatigue, fever, anorexia, arthritis, neuropathy, hypertension, renal failure, abdominal pain, and SNHL Biopsy  Necrotizing vasculitis Unilateral or bilateral Facial paralysis also may be seen Management - Aggressive doses of steroids - Immunosuppressive drugs Immune disorders

42. Relapsing polychondritis An inflammatory reaction in multiple cartilages The auricles  1st affected Arthritis and eye findings HL  Conductive  Sensorineural  Mixed HL SNHL  Sudden or progressive May be associated with vestibular disturbances Rx  Steroids  Immunosuppresive  Dapsone Immune disorders

43. Wegener’s granulomatosis Necrotizing granulomatous vasculitis involving principally the lungs, airway, and kidneys Usually  Conductive HL CHL  Involvement of the eustachian tube or middle ear SNHL  If extends into the inner ear Immune disorders

44. Primary autoimmune inner ear disease McCabe  Bilateral SNHL responsive to immunosuppressive drugs Sudden or progressive HL Involves both ears Associated with vestibular symptoms Strongly mimic Ménière’s disease Humoral autoimmunity  Abnormal Responsiveness of the HL to steroids or cytotoxic drugs  The hallmark Used Methotrexate  Reduce the need for continued high-dose steroids Immune disorders

45. Etiology • Development & Hereditary disorder • Infectious disorder • Pharmacologic disorder • Trauma • Neurologic disorder • Vascular & Hematologic disorder • Immune disorder • Bone disorder • Neoplasms • Disorder of unknown etiology

46. Otosclerosis Primarily causes  CHL Uncommonly  Progressive SNHL Especially in late disease CT images  Radiolucent area surrounding the cochlea Advanced otosclerosis  Bilateral profound mixed hearing loss Bone disorders

47. Paget’s disease Osteitis deformans Most common in older ~50% of Paget’s disease  Conductive, SNHL or mixed Rarely fixed stapes footplate RX  Calcitonin  Eidronate disodium Bone disorders

48. Etiology • Development & Hereditary disorder • Infectious disorder • Pharmacologic disorder • Trauma • Neurologic disorder • Vascular & Hematologic disorder • Immune disorder • Bone disorder • Neoplasms • Disorder of unknown etiology

49. Vestibular schwannoma Most common neoplasm  SNHL Originate from 8th CN Within the CPA or the IAC Approximately 80% of all CPA neoplasms Progressive unilateral SNHL Principally the high frequencies Neoplasms

50. Vestibular schwannoma Speech discrimination is reduced out of proportion to the pure tone thresholds Sudden SNHL  10% of patient Unilateral or asymmetric tinnitus With or without hearing loss Mild or severe vestibular symptoms or may have none Neoplasms