What causes hearing and balance issues?

Causes of Hearing and Balance Issues

Hearing and balance disorders are caused by multiple etiologies including aging, genetic factors, infections, vascular issues, autoimmune conditions, ototoxic medications, noise exposure, and trauma, with the specific diagnosis requiring systematic evaluation of symptoms, medical history, and physical findings.

Common Causes of Hearing Loss

Age-Related Factors

• Presbycusis (age-related hearing loss) is the most common cause of hearing loss in older adults, characterized by gradual decline in high-frequency tone perception due to hair cell degeneration 1
• Mitochondrial mutations play an important role in age-related hearing loss 2

Infectious Causes

• Meningitis (infectious, inflammatory, neoplastic) can cause bilateral sudden hearing loss 1
• Viral infections including cytomegalovirus (CMV), which may be the most common cause of congenital deafness 3
• Bacterial infections including Lyme disease and syphilis 1
• Herpes zoster oticus (Ramsay-Hunt syndrome) 1
• HIV-related otitis 1

Vascular/Ischemic Causes

• Labyrinthine infarction related to anterior inferior cerebellar artery (AICA) distribution 1
• Stroke or transient ischemic attacks affecting the vestibular structures 1
• Bilateral synchronous internal auditory artery occlusion 1

Autoimmune/Inflammatory Conditions

• Autoimmune inner ear disease causing fluctuating bilateral hearing loss 1
• Cogan syndrome (nonsyphilitic interstitial keratitis with hearing loss and vertigo) 1
• Sarcoidosis affecting the auditory system 1

Ototoxic Medications

• Aminoglycoside antibiotics (can affect up to 55% of treated patients) 3
• Cancer drugs, particularly cisplatin 4
• Loop diuretics such as furosemide 4
• Phosphodiesterase-5 inhibitors such as tadalafil 4
• Risk increases with dose, duration of exposure, age, dehydration, and reduced drug elimination 4

Noise Exposure

• Occupational or recreational noise exposure exceeding 75-80 dBA 3
• Risk increases with noise level, duration, and number of exposures 3
• Can cause permanent cochlear synaptopathy (hidden hearing loss) even without permanent threshold shifts 1

Trauma

• Head trauma affecting inner ear structures 1
• Barotrauma 1
• Temporal bone fractures 1

Genetic Factors

• Syndromic genetic disorders with associated hearing loss 1
• Non-syndromic genetic hearing loss 1
• Mitochondrial DNA mutations affecting energy production in inner ear cells 2

Other Causes

• Vestibular schwannoma (acoustic neuroma) 1
• Meniere's disease (characterized by episodic vertigo, fluctuating hearing loss, tinnitus, and aural fullness) 1
• Hyperviscosity syndrome 1
• Lead poisoning 1
• Metabolic disorders like MELAS (Mitochondrial Encephalopathy, Lactic Acidosis, and Stroke-like episodes) 1

Common Causes of Balance Disorders

Peripheral Vestibular Disorders

• Benign Paroxysmal Positional Vertigo (BPPV) - characterized by brief episodes of vertigo triggered by head position changes 1
• Vestibular neuritis - viral infection of vestibular system causing acute prolonged vertigo without hearing loss 1
• Labyrinthitis - infection causing both vertigo and hearing loss 1
• Meniere's disease - episodic vertigo with fluctuating hearing loss, tinnitus, and aural fullness 1

Central Vestibular Disorders

• Vestibular migraine - attacks of vertigo lasting minutes to hours, often with migraine history 1
• Stroke affecting vestibular pathways in the brainstem 1
• Multiple sclerosis affecting central vestibular pathways 1

Other Causes

• Ototoxic medications affecting vestibular hair cells 4
• Aging of the vestibular system 5
• Congenital vestibular deficits (often in deaf individuals) 5

Diagnostic Approach

For proper diagnosis, the following systematic evaluation should be performed:

1. Detailed history:

   • Prenatal history (maternal infections, medications)
   • Neonatal history (prematurity, hyperbilirubinemia, sepsis)
   • Postnatal history (infections, head trauma, noise exposure, ototoxic medications) 1
   • Family history of hearing/balance disorders 1

2. Physical examination:

   • Ear examination
   • Neurological assessment
   • Balance testing
   • Evaluation for dysmorphic features suggesting syndromic causes 1

3. Audiometric assessment:

   • Type of hearing loss (sensorineural, conductive, mixed)
   • Pattern (progressive, fluctuating, sudden)
   • Laterality and symmetry 1

4. Vestibular testing when balance issues are present:

   • Vestibular-evoked myogenic potentials (VEMPs)
   • Modified Clinical Test of Sensory Integration of Balance (mCTSIB) 5

5. Genetic testing when hereditary causes are suspected:

   • Comprehensive hearing loss gene panels
   • Genome-wide testing in selected cases 1

Important Clinical Considerations

• Sudden bilateral hearing loss is relatively rare and should raise concern for specific causes including vascular, metabolic, autoimmune, infectious, or toxic etiologies 1
• Deaf individuals may have significant vestibular deficits even when they report good balance function 5
• Drug-induced hearing loss is dose-dependent and can worsen even after drug discontinuation 4
• Ear drops containing ototoxic substances can cause irreversible hearing loss, especially with perforated eardrums 4
• Noise exposure and ototoxic medications can interact synergistically, producing more severe hearing damage 3
• Hearing regeneration is limited as the pool of adult stem cells in the inner ear drops dramatically after birth 6

Understanding these diverse causes is essential for proper diagnosis, management, and potential prevention of hearing and balance disorders.