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Presbyacusis
Dr. Vishal Sharma
Synonyms
 Age-related sensori-neural hearing loss
 Age-associated hearing loss (AAHL)
 Presbycusis (in USA)
 No official agreed age above which a person
suffers from presbyacusis & below which he/she
does not. Arbitrary agreed age is 50 years.
Definitions
 Presbyacusis: B/L symmetric, progressive SNHL
due to aging, in absence of other etiologies
 Socioacusis: B/L symmetric SNHL due to non-
occupational noise, fatty diet & lack of exercise
 Nosoacusis: B/L symmetric SNHL due to diseases
with ototoxic effects
 SNHL after 50 yrs age = presbyacusis +
nosoacusis + socioacusis + occupational NIHL
Diagnosis of exclusion
Exclude other causes of hearing loss in elderly:
 Noise induced hearing loss
 Atherosclerosis (hyperlipidemia), diabetes,
hypertension, myxoedema, Paget’s bone disease
 CSOM, Meniere’s disease, acoustic neuroma,
cochlear otosclerosis, ear trauma & ototoxic drug
History
 Toynbee (1849) first wrote about age-related
hearing loss & prescribed a treatment (application
of silver nitrate solution to external auditory canal)
 Zwaardemaker (1891) gave first accurate
description of presbyacusis. He detected high
frequency involvement & origin in cochlea.
Mechanism of
Presbyacusis
Age-related arteriosclerosis
 hypo-perfusion &  oxygenation of cochlea
 formation of reactive oxygen metabolites &
free radicals
 damage inner ear structures & mitochondrial
DNA of inner ear
 Presbycusis
Genetic Predisposition
 Genetic programming for early aging of parts of
auditory system  early development of
presbycusis
 Genetically programmed susceptibility to
environmental factors (noise, ototoxic drugs,
stress) may be involved
Types of Presbyacusis
(Gacek & Schuknecht, 1993)
 Sensory
 Neural
 Metabolic or strial or vascular
 Mechanical or cochlear conductive
 Mixed
 Indeterminate or intermediate
Sensory Presbyacusis
 Loss of sensory hair cells in organ of Corti due to
accumulation of lipofuscin pigment granules
 Process originates in basal turn (for a length > 10
mm) & slowly progresses toward apex
 Audiogram: abrupt, steep, high-frequency SNHL
 Speech discrimination score: good
Sensory Presbyacusis
Neural Presbyacusis
 Atrophy of spiral ganglion & cochlear neurons (>
50%) mainly in basal turn of cochlea
 Slowly progressive HL (Pure Tone Average not
affected until 90% neurons are destroyed)
 Audiogram: ski-slope toward high frequencies
 Speech discrimination score: poor (disproportionate)
Neural Presbyacusis
Metabolic Presbyacusis
 Atrophy of stria vascularis (> 30% destroyed)
 Stria vascularis maintains chemical + bioelectric
balance & metabolic health of cochlea
 Results in slowly progressive deafness
 Audiogram: Flat (as entire cochlea is affected)
 Speech discrimination score: good
Metabolic Presbyacusis
Mechanical Presbyacusis
 Slowly progressive SNHL due to thickening &
stiffening of basilar membrane of cochlea
 More severe in basal turn of cochlea where basilar
membrane is narrow
 Audiogram: ski-slope toward high frequencies
 Speech discrimination score: slightly impaired
Mechanical Presbyacusis
Other Types
Mixed Presbyacusis:
 Many ears have a combination of 4 pathologies
Indeterminate or Intermediate Presbyacusis:
 SNHL which progresses with age, without light
microscopic evidence of cochlear pathology
 Pathology: altered cellular metabolism / ed
synapse numbers / change in endolymph
composition / central auditory pathway changes
Other age-related changes
 Outer ear: ed cerumen formation, ed epithelial
migration, ed hair growth, collapse of EAC
 Middle ear: stiffening of TM, Arthritis + ossicular
joints ossification, degeneration of middle ear
muscles
They do not make marked contribution in deafness
Clinical Features
 Gradually progressive hearing loss
 Difficulty in understanding conversation around
high level of ambient background noise
 Recruitment: abnormal growth in perception of
loudness (at high intensity) in pt with hearing loss
 Tinnitus (30-50%): indicate worsening of deafness
 Social isolation & depression
Investigations
 Pure Tone Audiometry
 Speech Audiometry: diminished scores
 MRI: to rule out vestibular schwannoma
Indications of MRI in presbyacusis pt:
– Asymmetry > 10 dB of PTA between both ears
– Asymmetry > 20 dB of any single frequency
– Unilateral tinnitus
Audiogram
Treatment
 Medical: no medical cure
 Diet modification & supplementation
 Psychological counseling
 Amplification devices or hearing aids
 Lip reading & assisted listening devices
 Cochlear Implantation
 Tinnitus retraining therapy
 Avoidance of aggravating factors
Dietary advice
 30% caloric dietary restriction
 Use of antioxidant dietary supplements (vitamins
A, C, E; selenium) reduce production of reactive
oxygen metabolites that harm inner ear & lead to
age-related hearing loss
 Neuro-vitamins & Gingko biloba have no role
Hearing Aids
Binaural hearing aids give more benefit
Candidacy for hearing aids:
 speech reception threshold > 30 dB in better ear
 hearing level > 40 dB at 3 & 4 kHz in better ear
Pt with poor speech discrimination score are poor
candidates for hearing aids
Body worn
Spectacle
Spectacle
Completely in canal
Completely in canal
Completely in canal
Behind the ear
In the ear
In the canal
Completely in canal
Lip reading or speech
reading
Skill of understanding spoken message by
looking at speaker's lips, jaws, tongue, teeth,
facial expressions, gestures & body language
Lip reading is helpful in patients with diminished
speech discrimination & hearing aid users who
have hearing difficulty in noisy environments
Assisted Listening
Devices
 They are NOT hearing aids
 They are NOT used instead of hearing aids
 Help pt with hearing loss to function better in
communication situations to overcome distance,
background noise, or poor room acoustics
 Can be used with or without hearing aids
Vibrating wrist watch & alarm
clock
CO2 & smoke alarm with
strobe light
Amplified & captioned
telephone
T.V. & F.M. amplifiers
Personal & multi-user
amplifier
Alerting Devices
Amplified Stethoscope
Cochlear Implantation
 Patients with cochlear damage & relatively intact
spiral ganglia + central pathways are best
candidates
 Cochlear implantation have been performed on
patients up to 85 years old, with good results
Pawel Jastreboff: 1990
Tinnitus Retraining
Therapy (TRT)
 Based on neuro-physiological model of tinnitus
 Blocks tinnitus-related neuronal activity from reaching
cerebral cortex (where it is perceived) & from activating
limbic & autonomic nervous systems
 Uses combination of low level, broad-band noise &
counseling to achieve habituation of tinnitus. Tinnitus
never masked in TRT. Retraining takes 12 -18 months.
 Success rate = 60 - 80%
Avoidance
Avoid following aggravating factors:
 Noise exposure
 Ototoxic drugs
 Uncontrolled diabetes mellitus
 Hyperlipidemia
Future research
 Gene therapy to avoid early hair cell death in
cochlea
 Medications to stimulate a genetic cascade for
hair cell regeneration
 Better programmed hearing aids
Alden, Alfred, Arthur, Eastman, Fletcher, Hisswald,
Luke, Matthew, Oom, Richard, Shirmer & Theodore