Otology Flashcards
What are the types of tuning fork tests?
Weber test
Rinne test
What is the Weber test?
Detect unilateral conductive hearing loss (middle ear hearing loss) and unilateral sensorineural hearing loss (inner ear hearing loss).
In Weber test what does the sound being heard in the affected ear suggest?
Conductive hearing loss
In Weber test what does the sound being heard in the unaffected ear suggest?
Sensorineural hearing loss
What is the Rinne test?
Test that compares loudness of perceived air conduction to bone conduction in one ear at a time
What is a positive Rinne test?
Louder by air conduction
Sensorineural hearing loss or normal hearingt
What is a negative Rinne test?
Louder by bone conduction
Conductive hearing loss
What are the causes of conductive hearing loss?
Impacted earwax (cerumen)
Foreign body
Tympanic membrane perforation
Infection
Cholesteatoma
Middle ear effusion
Otosclerosis
What are the causes of sensorineural hearing loss?
Age related
Noise exposure
Meniere’s disease
Labyrinthitis
Neurological disorders
Trauma to head or ear
Malignancy
Systemic infections
Autoimmune (MS)
Hereditary
What are the types of audiometry?
- Pure tone audiometry
- Visual reinforcement audiometry
- Play audiometry
- Tympanometry
What is tympanometry?
Objective test that pushes air pressure into ear canal making ear drum move back and forth.
The test measures the pressure within the middle ear and the mobility of the eardrum
What is the organ of corti?
The receptor organ for hearing and is located in the cochlea
What is the hearing mechanism in the cochlea?
- Stapes footplate move sin and out of oval window
- This movement creates a wave in the scala vestibuli and scala tympani
- Wave causes movement of basilar membrane and inner and outer hair cells in Organ of Corti
What is tonotopic arrangement?
For every frequency there is a specific place on the basilar membrane where the hair cells are maximally sensitive to that frequency
What are the 2 otolith organs?
Utricle
Saccule
What is the macula?
Sensory epithelium on the Otolith organs
What is the orientation of the macula on each otolith organ?
Horizontal in Utricle
Vertical in Saccule
What are otoliths?
Calcium carbonate crystals embedded on the surface of the otolith organs
What is the vestibulo-ocular reflex?
Stabilises gaze by moving eyes in order to compensate for head and body movements
This fixes imagine on retina for clear sight
What conditions affect the external ear?
Auricular haematoma
Foreign body
Otitis externa
Malignant otitis externa
What conditions affect the middle ear?
Otitis media with effusion
Acute suppurative otitis media
Chronic suppurative otitis media- perforation of cholesteatoma
Tympanosclerosis
Otosclerosis
What conditions affect the inner ear?
Benign paroxysmal positional vertigo (BPPV)
Vestibular neuritis
Meniere’s disease
What is otorrhoea?
Discharge from the ear
Where does mucus discharge come from?
Middle ear
