13.03.05 Hearing loss

Causes of sensorineural hearing loss

• • MS

  • Acoustic neuroma

  • Ménière's

  • Ototoxins

    • Streptomycin

    • Gentamycin

    • Salicylates

    • Thalidomide

    • Cis-platin

    • Vincristine

  • Infection

    • Meningitis

    • Mumps

    • Measles

    • Flu

    • Herpes

    • Syphilis

  • Metastatic cancer (brain)

  • Cochlear vascular disease

  • Presbycusis

Ménière's

• • Triad

  • Recurrent vertigo

    • Fluctuating sensorineural hearing loss (Low frequency loss initially, develops to full-range)

  • Tinnitus

  • Sensation of aural fullness

  • Usually unilateral but may extend to both ears in 25-75%

  • Genetic component

Weird/wonderful diseases causing hearing loss

• • Osteogenesis imperfecta

    • Blue sclera (very thin sclera, can see blood)

  • Waardenburg syndrome

    • Heterochromia

    • Wide-set eyes

    • Low hairlines

    • Monobrow

  • Usher syndrome

    • Visual as well as hearing loss (leading cause of deaf-blindness)

  • Pendred syndrome

    • Goitre / hypothyroidism

  • Alport syndrome

    • Type IV collagen deficiency => Poor basement membrane

    • Glomerulonephritis

    • Endstage kidney disease

  • Cogan syndrome

    • Recurrent corneal inflammation

    • Fever, fatigue, weight loss, dizziness

  • Behçet's disease

    • Mucous membrane ulceration and ocular problems

Patterns of hearing loss

• • Barotrauma => Mid-range

  • Presycusis => High-end

  • Otosclerosis => Low-end

  • Meniere's => Low-end then full-range

  • Acoustic neuroma => High-end (these fibres are on the outside of the nerve => hit first)

Auditory brainstem response

• • Recorded via electrodes placed on the scalp

  • Newborn hearing screening, auditory threshold estimation, intraoperative monitoring, determining hearing loss type and degree, auditory nerve and brainstem lesion detection

Otosclerosis

• • Bilateral

  • Progressive

  • Low-frequency dip

  • Stapidectomy + metal replacement

Blood supply of the ear

Notes

• • Facial nerve runs through the ear

    • cf Taste to anterior 2/3

  • Cochlear implant indications

    • Children

    • Bilateral deafness

    • Loss of another sense

  • Wax is skin