ENT

Question 1

Describe the anatomy of the inner and outer ear.

Answer 1

Question 2

Describe the anatomy of the tympanic memrbane.

Answer 2

Question 3

What are the DDx for dizziness?

Answer 3

Question 4

What are the DDx for otalgia?

Answer 4

Question 5

What are the DDx for hearing loss?

Answer 5

Question 6

What are the DDx for tinnitus?

Answer 6

Question 7

What are the 5 D’s of vertebrobasilar insufficiency?

Answer 7

• Drop attacks
• Diplopia
• Dysarthria
• Dizziness
• Dysphagia

Question 8

What are the DDx for a neck mass?

Answer 8

Question 9

Describe normal hearing physiology?

Answer 9

• Conductive pathway (external auditory canal to cochlea): air conduction of sound energy down the EAC → vibration of the tympanic membrane (area effect) → sequential vibration of the middle ear ossicles: malleus, incus, stapes (lever effect) → transmission of amplified vibrations from the stapes footplate in the middle ear to the oval window of the cochlea in the inner ear → pressure differential on cochlear fluid creates movement along the basilar membrane within the cochlea from base to apex
• Neural pathway (nerve to brain): basilar membrane vibration stimulates overlying hair cells in the organ of Corti → stimulation of bipolar neurons in the spiral ganglion of the cochlear division of CN VIII → cochlear nucleus → superior olivary nucleus → lateral lemniscus → inferior colliculus → Sylvian fissure of temporal lobe

Question 10

What are the DDx for a neck mass?

Answer 10

• congenital
  
  • lateral (branchial cleft cyst, lymphatic/venous/venolymphatic malformation)
  • midline (thyroglossal duct cyst, dermoid cyst, laryngocele)
• infectious/inflammatory
  
  • reactive lymphadenopathy (20 to tonsillitis, pharyngitis)
  • infectious mononucleosis
  • Kawasaki, Kikuchi, Kimura
  • HIV
  • salivary gland calculi, sialadenitis
  • thyroiditis
• granulomatous disease
  
  • mycobacterial infections
  • Sarcoidosis
• neoplastic
  
  • lymphoma
  • salivary gland tumors
  • thyroid tumors
  • metastatic malignancy (“unknown primary”)

Question 11

Describe the difference between inflammatory vs malignant neck masses?

Answer 11

Question 12

Name the anatomy

Answer 12

Question 13

name the anatomy

Answer 13

Question 14

Name the anatomy

Answer 14

Question 15

Name the anatomy

Answer 15

Question 16

Name the anatomy

Answer 16

Question 17

What parts of the ear do conductive and sensorineural hearing loss affect?

Answer 17

• Conductive losses affect outer and middle ear function
• Sensorineural losses affect the cochlea in the inner ear.

Question 18

How do cochlear implants work?

Answer 18

Cochlear implants provide a direct electrical stimulation to the auditory nerve fibres in the cochlea to reproduce the action of the hair cells that are damaged in cases of sensorineural loss.

Question 19

What are some causes of hair cell damage in the ear?

Answer 19

Causes of hair cell damage include:

• gentamicin toxicity
• bacterial meningitis
• skull fracture
• noise exposure
• presbycusis
• genetic syndromes
• hereditary deafness, and
• many of the ‘unknown’ causes of hearing loss.

Question 20

Otosclerosis results in what type of hearing loss?

Answer 20

Otosclerosis results from an overgrowth of bone in the middle ear fixing the foot plate of the stapes at the oval window, hence resulting in a conductive hearing loss.