Ototoxicity, Otosclerosis and Otitis Media in Hearing aid Fitting

Kath Woolley M.Sc.North West School of Audiology

Definition of Ototoxicity

Damage to the ear- cochlea, auditory nerve or sometimes the vestibular system.

Drugs

Aminoglycosides e.g. Gentamycin ‘Mycin’

Loop Diuretics e.g. Furosemide

Chemotherapy Agents e.g. CisplatinPlatinum based

Symptoms

Discovery of Ototoxicity

Adverse Effect of Aminoglycosides

Damage to the vestibular system Headache Ear fullness Imbalance Inability to tolerate head movement Problems walking in dark

Nystagmus

Involuntary rhythmic shaking or wobbling of the eyes

Oscillopsia

Oscillo- to swing Opsis-vision Objects in sight appear to oscillate

Blur

Dizzy

Nausea

Acute Cochlear Damage

Tinnitus > 4000 Hz Low frequencies affected later Profound? Loss usually permanent

Ototoxicity Process Poorly understood

Kanamycin, Neomycin, Amikacin toxic to the cochlea

Free Radical

Other Ototoxicity

MercuryLead Styrene Manganese Xylene

The Risk of Noise and Chemicals Together

Noise alone- Risk factor 4.1

Solvent mixture alone- Risk factor 5.0

Noise and Toluene- Risk factor 10 to 27.5

Toluene

2.6 million tons produced annually

Variables in Ototoxicity

Bilateral, symmetrical, asymmetrical Time of onset Single dose. After completion of course. Monitor hearing for 6 months after. Benefits vs. risks Mouth vs. injection Susceptible Genetic link

Prevention of Ototoxicity Aminoglycoside, loop diuretics,

chemotherapy, aspirin, quinine – infusion rates, monitor drug levels, kidney history & hearing

Daily administration Lowest effective dose Other ototoxic agents High risk- alternatives Avoid noise for 6 months

General Monitoring High frequencies affected first- high

frequency audiometry No tinnitus monitoring Dizziness Handicap Inventory

Ototoxicity and Hearing Aid Fitting

Recruitment Tinnitus

Frequency selectivity reducedSpeech in noise unclearDead regions

Consider hearing aid output

What is Otosclerosis?

A disorder affecting collagen Cause? Remodelling faulty Oval window/round window Sensory, neural, mixed Gradual Progressive

Incidence Hereditary in 70% cases Dominant gene Virus? Unilateral 10-15% Caucasians Present in 10% of pop. Age of onset – approx. 30 years Females Worse in pregnancy

Symptoms & Diagnosis

Progressive conductive hearing loss

Carhart’s notch @ 2 kHz

Tinnitus in 4/5

Paracusis Willisi

Symptoms & DiagnosisSchwartze’s sign

Dizziness in 1/ 4 Weber lateralised to

affected ear Sometimes bluish cast

over eye whites Difficulty hearing when

chewing?

Risk Factors & Treatment

More common in White & Asian

Women Age-15 – 35 years +ve family history Drinking non-

fluoridated water-very controversial

Hearing aids BAHA Surgery Fenestration Stapedectomy Stapedotomy Fluoride therapy Oestrogen blockers Biphosphonates

Possible Complications of Surgery

Loss of hearing in 1 in 100

Dizziness

Taste disturbance

Reaction to ear dressings

Tinnitus

Considerations of Otosclerosis and Hearing Aid Fitting Type of hearing loss Conductive = more gain REM’s and conductive- careful

interpretation NAL- not for conductive losses BSA Guidance on REM’s (2007) Progressive- increase amplification

Otitis Media Eustachian tube

Otitis Media- inflammation of the middle ear

Eustachian tube dysfunctionair in middle ear absorbed-ve mepexudate fills up middle ear

Acute (Suppurative) Otitis Media

Acute – rapid onset following a short but severe course

Suppurative- formation of pus or discharge

Inflammation of mucous membrane lining middle ear cleft

Bacteria Responsible

Adenovirus Rhinovirus Pneumococcus Haemophilus Influenzae Streptococcus Staphylococcus

Signs

TM inflamed, bulging or opaque Purulent ear discharge Perforation Mastoid tenderness

Symptoms

Pain Temperature Earache Pressure build up Perforation Discharge containing pus escapes Antibiotics

Risk Factors Age Adenoids Frequent URTI Prematurity Craniofacial abnormalities Nurseries Poor socio-economic conditions Cold weather Pre-existing middle ear effusion

Chronic Suppurative Otitis Media

Chronic- long-standing Suppurative – formation of pus or

discharge Acute infection Irritation of lining of

middle earinfection

destroys bone Infectiongranulation

Bacteria responsible

Pseudomonas aeroginosa Staphylococcus aureaus Proteus species Klebsiella pneumonia Diptheroids

Symptoms: hearing loss; fever; vertigo; pain

‘Safe’Ear and ‘Unsafe Ear’

Perforation in pars tensa

No local destruction

Perforation in attic region (pars flaccida)

Infection of attic, antrum, mastoid

Possible cholesteatoma

Cholesteatoma Looks like an onion Produces osteolytic enzymes Complications include: Hearing loss Vertigo Headaches Facial nerve palsy Meningitis Epidural abscess

Otitis Media with Effusion Effusion-seeping of watery fluid from

tissue OME is thick or watery fluid in middle ear

with NO infection No pain No fever

Unilateral fluid in an Adult requires further investigation

Considerations of Otitis Media and Hearing Aid Fitting No active infection Conductive hearing loss and fluctuating Follow up fine tuning appointments Rigidity of TM and presence of fluid

increase the risk of feedback

Thank you for listening

Any questions?