Dal Alert!

Receive alerts from Dalhousie by text message.

X

About the Ear and Its Disorders

Home to the organs of hearing and balance

The ear houses the organs of hearing and balance, as well as important cranial nerves such as:

  • the facial nerve, which moves the face
  • the lower cranial nerves, which coordinate and allow swallowing and speech
  • the carotid artery and jugular veins

The ear is divided into the external ear canal, the middle ear and the inner ear—and is connected to the brainstem via the cranial nerves.

  1. Semicircular canals
  2. Tympanic membrane (eardrum)
  3. External ear

View from superiorly in axial section

  1. Facial nerve
  2. Cochlea

Essentially, the function of the ear is to:

  • collect sound (pinna and external ear canal)
  • increase sound pressure so that it can drive vibrations in the fluid-filled inner ear (middle ear function)
  • convert sound into nerve impulses to the brain (inner ear)

The balance organs serve to sense rotational accelerations (semicircular canals) and linear accelerations, including gravity (saccule and vestibule).

Disorders of the ear

There are many disorders of the ear that manifest in numerous ways. Some common ones, along with common interventions, include:

Pinna and external ear

  • aplasia
  • microtia
  • hypoplasia
  • duplication of the external canal
  • neoplasms of skin and glands of the ear canal and pinna
  • otitis externa
  • necrotizing otitis externa
  • ketosis obturans
  • cholesteatoma of the external canal

Surgeries or interventions

  • pinna repair
  • pinna setback for outstanding ears
  • analoplasty and meatoplasty to open up the ear canal and its opening
  • atresia repair

Middle ear

  • cholesteatoma
  • conductive hearing loss from ossicular fixation
  • conductive hearing loss from ossicular discontinuity
  • otosclerosis
  • glomus tumors
  • middle ear adenomas
  • CSF leaks
  • brain hernias perforations of the tympanic membrane

Surgeries or interventions

  • tympanoplasty to repair the eardrum
  • myringotomy and tube
  • tympanomastoidectomy for cholesteatoma
  • ossiculoplasty to repair the ossicle
  • stapedotomy,
  • bone anchored hearing devices for conductive hearing loss
  • middle ear drivers for conductive hearing loss
  • hearing aid fitting for conductive hearing loss

Cochlea and auditory nerve

  • sensorineural hearing loss from:
    • genetic, congenital malformations
    • noise exposure
    • ototoxicity
    • trauma
    • barotrauma,
    • CSF leaks
    • schwannomas of the cochlea
    • vestibular schwannomas of the audiovestibular nerve
    • tinnitus

Surgeries or interventions

  • cochlear implantation
  • hearing aid fitting
  • vestibular schwannoma resection
  • stereotactic radiation

Vestibular system

  • vestibular neuronitis
  • benign positional vertigo
  • Meniere’s disease
  • migraine associated vertigo
  • superior canal dehiscence
  • otolith disorders

Surgeries or interventions

  • superior canal plugging
  • sac decompression for Meniere’s disease
  • labyrinthectomy
  • vestibular nerve section
  • intratympanic steroid injection
  • ablation with intratympanic gentamicin

Facial nerve

  • Bell’s Palsy
  • facial nerve schwannoma
  • facial nerve hemangioma
  • facial spasms

Surgeries or interventions

  • facial nerve decompression
  • stereotactic radiation for schwannoma

Eustachian tube

  • Eustachian tube dysfunction causing negative middle ear pressure
  • patulous Eustachian tube

Surgeries or interventions

  • balloon dilatation of the ET
  • ET plugging for patulous ET