otology: diseases of the ear

• The medial geniculate body, also known as the medial geniculate nucleus, is one of the thalamic nuclei. It acts as the principal relay nucleus for the auditory system between the inferior colliculus and auditory cortex. Together with the lateral geniculate body, it forms the metathalamus.
• Primary (lemniscal) Auditory Pathway ‘ECOLI MA’

  -Eight Nerve

  -Cochlear nucleus (some fibres decussate)
• Primary (lemniscal) Auditory Pathway ‘ECOLI MA’

  -Eight Nerve

  -Cochlear nucleus (some fibres decussate)

  -olivary complexes (superior olive)

  -Lateral leminiscus

  -Inferior colliculus

  -Medial Geniculate

  -Primary Auditory Cortex

  
• • Acute Otitis externa is an external ear disease
  • common occurs in adults, particularly swimmers
  • symptoms are itch and pain
  • commonly caused by pseudomonas or staph aureus
• how to treat acute otitis externa

  • clean - microsuction
  • swabs
  • topical ear drops - ciprofloxcin +/- dexamethasone
  • aural hygiene advice
  • may advise a wick if there is gross ear swelling to get the medications through
• Acute otitis media - middle ear

  commonly seen in children - 2 reasons

  1. Eustaschian tube is wider, shorter and more horizontal
  2. immature immune system

  commonly following URTIs by viruses or pyrogenic bacteria like Haemophilus influenzae or streptococci
• how does acute otitis media progress

  middle ear infection -> inflammation -> increased pressure -> pain -> perforates the ear drum and discharge leaks out
• treatment for acute otitis media:

  • pain relief (for the bulging and pain caused)
  • delayed antibiotics
  • delayed surgery if complications

  
• otitis externa

  ear is naturally acidic so if alkaline things like shampoo get it it disrupts the flora
• Acute otitis media

  may see bulging of the ear drum - lose sight of the malleus
• Otitis externa - things to consider

  • otomycosis - fungal infection of the ear, aspergillus (yellow-black spores), candida (thick white cream)
  • necrotising otitis externa
  • cholesteatoma
• osteomyelitis - infection/inflammation of the bone tissue
• Necrotising otitis externa is an osteomyelitis and can cause the erosion of cranial bones and spread to the skull base causing cranial nerve palsies (VII, IX, X, XI, XII).

  Presents with persistent severe pain

  risk factors: diabetes, immunosupression, elderly and frequent ear syringing

  normally caused by pseudomonas
• how to treat necrotising otitis externa ?

  • protracted systemic antibiotics
  • topical antibiotic drops
  • microsuction
  • diabetes control if diabeteic
• the facial nerve is at high risk with necrotising otitis externa
• What is a cholesteotoma?

  accumulation of benign keratinising epithelial cells, hyper-proliferation causes and enzyme secretion is locally destructive

  keratin debris can become infected and cause chronic ear discharge

  more common in males and surgery needed
• what are the two types of choleastomas?

  congenital - epithelial cells are left in the middle ear during embryonic development

  acquired - eustachian tube dysfunction -> retracts the tympanic membrane -> affects the migration of keratin -> keratin is trapped
• cholesteotomas - common in those with a retracted ear drum and the skin is normally trapped in the attic
• what is Exostosis

  aka surfer's ear, abnormal bone growth within the ear canal. This thickening and constriction causes conduction hearing loss.

  Ear wax and other debris can become trapped in the canal, which can cause frequent ear infections.

  This is a periosteal reaction to repeated cold water exposure

  risk of wax impaction
• what is this?

  Osteoma - benign bony neoplasm

  incidental, unilateral, soliatry

  
• what is Exostosis 


  aka surfer's ear, abnormal bone growth within the ear canal. This thickening and constriction causes conduction hearing loss.

  Ear wax and other debris can become trapped in the canal, which can cause frequent ear infections.

  This is a periosteal reaction to repeated cold water exposure

  risk of wax impaction and normally bilateral

  
• list complications to acute otitis media

  • vertigo
  • facial nerve palsy
  • perforation
  • hearing loss
  • intra-cranial infection
  • acute mastoiditis

  
• viral infection superimposes a bacterial infection -> causes inflammation -> increases pressure -> erodes through the mastoid bone -> acute mastoiditis
• what is the management for a perforation (acute otitis media)


  management

  conservative - reassurance and water percaution

  topical antibiotics if intermittent discharge

  myringoplasty - type 1 tympanoplasty, repair the ear drum if recurrent discharge, a graft is placed to allow the epithelium to regrow
• chronic suppurative otitis media

  • (suppurative = forming/discharging pus) - risk of episodes of discharge, problematic as this can cause erosion to the ossicles which can lead to more severe hearing loss
  • may complain of increasing deafness
  • risk of intra/extracranial spread
• Acute mastoiditis

  mastoiditis can occur from the spread of infection from the middle ear to the mastoid process

  • Inflammation of lining of mastoid air cells (can have associated abscess)
  • Presents with: tender, boggy, swollen mastoid process (± otalgia and discharge)
  • manage with aggressive antibiotics, may need a cortical mastoidectomy
• what is a cortical mastoidectomy


  surgical procedure performed to treat chronic or recurrent infections of the middle ear, such as chronic otitis media with cholesteatoma, a condition where a cyst-like mass of skin cells and cholesterol accumulates in the middle ear and mastoid. It may also be done to provide access to other structures during ear surgery, such as to repair the ossicles (small bones in the middle ear) or for cochlear implantation.

  procedure: incision behind ear, removes outer layer of bone to access mastoid cavity. Extent of bone removal depends on the specific condition.
• Acute mastoiditis

  mastoid process is part of the temporal bone, complications can be severe and include meningitis

  children with acute mastoiditis often are septic

  acute mastoiditis can be treated with grommets

  clinically - loss of suclus behind the ear is a good indicator

  
• Facial Nerve Palsy - CN7

  if it is forehead sparing it suggests an upper motor neurone lesion

  causes: Ear disease, trauma, surgery, cancer (of the ear or parotid), acoustic neuromas, viruses - Ramsy-Hunt syndrome/shingles
• Ramsay- Hunt Syndrome: LMN I think, not forehead sparing

  • HZV (Herpes-Zosta Virus) of facial nerve
  • Facial paralysis, Otalgia/jaw pain and vesicles close to ear canal/tongue/hard palate
  • may experience a change in taste to the front 2/3 of the tongue the chorda tympani is a branch of the facial nerve and this is where it gets its taste sensation from
  • Can spread to CN8, causing hearing loss, tinnitus, vertigo
  • House-Brackman Scoring Criteria - grade the palsy based on extent of symptoms
• Otitis Media with Effusion/ Secretory or serous otitis media

  • Most common cause of acquired conductive hearing loss in children -> Common in children with cleft palate or Down’s Syndrome -> due to associated craniofacial changes
  • Can be due to infection, URTI or
  • Eustachian tube dysfrunction -> affects drainage/ventilation of the middle
  • RED flag in adults especially if unilateral as it could be a nasopharyngeal tumour that can bloack drainage
  • most resolve spontaneously, if persist or bilateral consider grommets/ ventilation tubes
• Otitis media with effusion (OME)

  •   Ear Pressure/pain, disequilibrium, popping noise, deafness
  • TM dull/opaque, fluid levels/bubbles
  • Negative pressure in middle ear, narrowing of eustation tube, sucks from middle ear

  
• foreign body removals

  
• VERTIGO IS A SYMPTOM - sensation of room spinning

  • There can be many causes (Central vs. Peripheral)

  • Can be associated with vomiting

  Dizziness has many reasons: cardio, neuro

  Tumor stroke (central, brain)
• Describe peripheral and ENT causes of vertigo

  •BPPV (Benign paroxysmal positional vertigo): Episodic, lasting seconds, when turning head

  • Neuronitis: just vertigo, Labyrinthitis: vertigo and hearing loss
  • Meniere’s Disease: Change of pressure inner ear endolymphatic system. Recurrent, episodic (minutes to hours), nausea/vomiting, Aural fullness, hearing loss
• BPPV - Benign paroxysmal positional vertigo

  •Common - caused by dislodgement otoconia (move with gravity causing fluid in the semicircular canals to move )

  •Diagnosed with Dix Hallpike Test

  •Treated with Epley Manouevre +/- Brandt Daroff Exercises
• what is the dix hallpike test

  • Patient on exam table with head to one side and your legs stretched
  • Dr turns their head at a 45-degree angle, to either the right or left.
  • At this point, keep ask them to their eyes open. (important you observe their eyes)
  • Gently hold their head and lean them back with one ear pointing toward the floor. Hold for a minute or two.
  • While you’re in this position, check your eyes for nystagmus 

  Positive = nystagmus, and BPPV. If negative, something else.

  
• Epley manoeuvres - done by specialists and hope to dislodge canaliths out of the canals and stop BPPV, not sure if this is exactly the reason some say that repeat exposure to dizziness reduces its intensity improving symptoms overall, Brandt Daroff Exercises are provided for the patient to do alone

  
• outline to the Epley Manoeuvre:

  • Turn your head toward the side that causes vertigo.
  • Quickly lay you down on your back with your head in the same position just off the edge of the table. You will likely feel more intense vertigo symptoms at this point.
  • Slowly move your head to the opposite side.
  • Turn your body so that it is in line with your head. You will be lying on your side with your head and body facing to the side.
  • Sit you upright.
• vestibular neuronitis - inflammation of the vestibular nerve

  • other proceeded by viral symptoms
  • constant vertigo

  labyrinthitis - inflamamtion of the entire labyrinthine apparatus

  • continuous hearing loss and vertigo

  PERSISTENT VERTIGO: rule out central cause, such as posterior circulation stroke or tumour