Presbycusis

Basics

Description

  • Age-related hearing loss (HL). It often presents as difficulty communicating in noisy conditions.
  • Central and peripheral causes:
    • Central presbycusis: age-related change in the auditory portions of the central nervous system, negatively impacting auditory perception, speech-communication performance, or both
    • Peripheral presbycusis: age-related, bilateral sensorineural HL (SNHL) typically symmetric
  • Represents a lifetime of insults to the auditory system from toxic noise exposure and natural decline
  • Initially presents as high-frequency SNHL with tinnitus (ringing)
  • Impacts the “clarity” of sounds (i.e., ability to detect, identify, and localize sounds)
  • Due to mild and progressive nature, presbycusis is often treated with amplification alone.
  • Can lead to adverse effects on physical, cognitive, emotional, behavioral, and social function in the elderly (e.g., depression, social isolation) and is a contributor to all-cause dementia (1)

Epidemiology

Prevalence

  • 40% in the population >65 years of age
  • Only 10–20% of older adults with HL have ever used hearing aids (HAs).
  • Predominant sex: male > female
  • Hearing levels are poorer in industrialized societies than in isolated or agrarian societies.

Etiology and Pathophysiology

  • The external ear transmits sound energy to the tympanic membrane. The middle ear ossicles amplify and conduct the sound waves into the inner ear (cochlea) via the oval window. The organ of Corti, located in the cochlea, contains hair cells that detect these vibrations and depolarize, producing electrical signals that travel through the auditory nerve to the brain. Toxic noise exposure traumatizes the hair cells and leads to cell death and HL. Research also suggests that over excitation of the neuro synapses causes increased glutamate, which is also neurotoxic (2).
    • Sensory presbycusis: primary loss of the hair cells in the basal end of the cochlea (high-frequency HL)
    • Neural presbycusis: loss of spiral ganglion cells
    • Strial (metabolic) presbycusis: atrophy of the stria vascularis (the cochlear tissue that generates the endocochlear electrical potential)
    • Cochlear conductive (mechanical) presbycusis: no morphologic findings (presumed stiffening of the basilar membrane)
    • Indeterminate presbycusis: no morphologic findings (presumed impaired cellular function)
  • Presbycusis is caused by the accumulated effects of noise exposure, systemic disease, oxidative damage, ototoxic drugs, and genetic susceptibility.

Genetics
Presbycusis has a clear familial aggregation.

Risk Factors

  • Noise exposure (military, industrial, etc.)
  • Ototoxic substances
    • Organic solvents, heavy metals
    • Carbon monoxide
  • Drugs
    • Aminoglycosides, cisplatin (dose dependent), salicylates, diuretics
  • Tobacco smoking
  • Alcohol abuse
  • Lower socioeconomic status
  • Family history of presbycusis
  • Head trauma (temporal bone fractures)
  • Cardiovascular disease (hypertension, atherosclerosis, hyperlipidemia); labyrinthine artery is terminal artery to the cochlea.
  • Diabetes mellitus
  • Obesity
  • Autoimmune disease (auto cochleitis/labyrinthitis)
  • Metabolic bone disease
  • Endocrine medical conditions: levels of aldosterone
  • Otologic conditions (e.g., Ménière disease or otosclerosis)

General Prevention

  • Avoid hazardous noise exposure.
  • Use hearing protection.
  • Maintain healthy diet and exercise.
  • Screening
    • Hearing Handicap Inventory for the Elderly Screening (3)
    • RCT published in 2010 on screening for HL, HA use was significantly higher in three screened groups (4.1% in those using a questionnaire, 6.3% using handheld audiometry, and 7.4% using both modalities) versus unscreened control participants (3.3%) at 1-year follow-up (4)[B].
    • Based on a 2021 review, according to the USPSTF, there is an insufficient evidence to assess the relative benefits and harms of HL screening in adults ≥50 years (5)[B].

Commonly Associated Conditions

  • A 2018 meta-analysis showed that ARHL had significant associations with accelerated multidomain cognitive decline, cognitive impairment, and dementia (6)[A].
  • In a 2021 systematic review, there were findings to suggest that presbycusis not only is associated with a variety of cognitive, behavioral, and psychosocial disorders but may also be associated with increased prevalence of suicidal ideation (7).

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