Aetiology

• causes of subjective tinnitus (1)
  • otologic disorders - the most common cause of subjective tinnitus
    • hearing loss
      • causes of conductive hearing loss
        • cerumen impaction (ear wax)
        • otitis externa
        • perforation of tympanic membrane
        • middle ear fluid
        • otosclerosis
      • causes of sensorineural hearing
        • noise-induced hearing loss
        • presbycusis
    • Meniere's disease
    • acoustic neuroma
  • ototoxic drugs
    • aspirin, aminoglycosides, chloramphenicol, erythromycin, tetracycline, vancomycin, methotrexate, vincristine, furosemide, etc. (1)
  • infectious
    • otitis media, ,syphilis, Lyme disease, meningitis (2)
  • neurological causes
    • multiple sclerosis, head trauma
  • metabolic causes
    • thyroid diseases
    • hyperlipidaemia
  • psychological
• causes of objective tinnitus (rare)
  • vascular abnormalities
    • these are associated with pulsatile tinnitus
    • causes include :
      • arteriovenous malformation, vascular tumours (Glomus tumour)
  • neurological diseases
    • idiopathic stapedial muscle spasm
  • eustachian tube dysfunction

Reference:

• (1) Crummer RW et al.Diagnostic Approach to Tinnitus. American Family Physician 2004; 69(1)
• (2) Lockwood AH et al.Tinnitus. N Engl J Med 2002;347:904