7.2.2 Ear Diseases Flashcards
What is mixed hearing loss?
Mixed Hearing Loss
- Combination of CHL & SNHL
- Damage in the outer/middle ear AND in the inner ear/auditory nerve
Type of pathology of TM?
Atelectasis
Caused by negative pressure due to Eustachian tube dysfunction
What is the embyonic orgin of the pinna of the ear?
Hillocks of His
First arch (1-3)
Second arch (4-6)
What are the adult derivatives of the 1st, 2nd, and 3rd hillocks of His
- Tragus
- Helical Crus
- Helix
What is CHL?
Conductive Hearing Loss (CHL)
- Sounds is not easily sent through the ear canal to the eardrum and the tiny bones of the middle ear
- Makes sounds softer and less easy to hear
- Can be corrected medically or surgically
Conditions?
Left: Atresia
Right: Otitis Externa (Superficial infection of the skin of the EAC with two common initiating events: moisture trapping or trauma to the EAC )
What are the derivates of the 1st and 2nd arch found in the middle ear?
Ossicles (malleus, incus, stapes)
Tensor tympani
Stapedius
What are some characteristics of the EAC?
What is a surgical option for a 9 mo healthy infant w/ history of 4 episodes of AOM since birth. HPI pos for acute fever, tugging at ears, nasal congestion, rhinorrhea. Passes NBHS, no NICU. PE pos for erythematous and bulging tympanic membrane
Ear tubes
Type of pathology of TM?
Serous Otitis
What are the two regions of the tympanic membrane/
Pars Tensa (3 layers) & Pars flaccia (2 layers)
Condition?
Microtia
Congenital deformity where the pinna is underdevleoped (Most common major anomaly)
Conditions?
Left: ‘Lop’ Ear
Right: ‘Cup’ Ear
Type of pathology of TM?
Cholesteatoma
Pars Flaccida
Benign skin cyst caused by longterm trapping of skin cells in retraction pocket
What are the three layers of the tempanic membrane and their embryonic tissue of origin?
Outer ectodermal layer (groove)
Middle fibrous layer (arch/mesoderm)
Inner mucosal layer (pouch/endoderm)
Condition?
Pre-auricular pit
Epithelium between first and second hillocks does not resorb and cyst or sinus remains
What are the degrees of hearing loss and their corresponding range of loss in decibels?
Normal: -10 – 15 dB
Mild: 26-40 dB
Moderate: 41 – 55 dB
Moderate/Severe: 56-70 dB
Severe: 71 – 90 dB
Profound: >90 dB
What is the embryologic orgin of the external auditory canal (EAC)?
1st branchial groove (cleft)
Type of pathology of TM?
Retraction
Type of pathology of TM?
Temporal Bone Trauma
Hearing loss, vertigo, facial nerve palsy, battle sign, hemotympanum, & bloody otorrhea
What type of hearing loss?
Moderate to profound mixed hearing loss
What type of hearing loss can be detected by the Weber test? Rinne test?
Weber: Detects unilateral CHL or SNHL
Rinne: Detects CHL
What type of hearing loss is shown here?
Sensorineural hearing loss
What is the embryologic origin of the concha?
1st branchial groove
What these two key landmarks on a normal TM?
Top arrow: Malleus
Bottom arrow: Light reflection
Type of pathology of TM?
Acute otitis
What is the embryologic origin of the inner ear (vestibular organs & cochlea)?
Otic Vesicle
What are the derivatives of the 1st pouch located in the middle ear?
Tympanic cavity, Eustachian tube, Mastoid air cells
What is SNHL?
Sensorineural Hearing Loss (SNHL)
- Happens when there is damage to the inner ear (cochlea) or to the nerve pathways from the inner ear to the brain
- Even if speech is loud enough to hear, it may still be unclear or muffled
- Most common type of permanent hearing loss
- Most of the time cannot be corrected
