Outer Ear Disorders Flashcards
Aural Atresia Symptoms
can involve 1 or both ears and is the absence of EAC or presence of blind pouch in the canal.
Will give a conductive loss and if bilateral and untreated it can significantly delay speech.
Stenosis of the ear can also lead to collection of skin epithelial cells in external auditory canal (External canal cholesteatoma) –> inflammation, pain and/or discharge
If it involves the ME, then TM is absent and ossicles can be malformed or absent
If involving inner ear, less common due to distinct embryologic tissues
Aural Atresia Incidence/Prevalence
males affected more frequently, unilateral is 3x more common than bilateral, right ear tends to occur more than left, atretic portion of canal is usually bony not membranous, occurs 1/10,000-20,000 births
Aural Atresia Etiology
congential can occur in conjunction with syndromes (CHARGE, Pierre Robin, VATER, Goldenhar, Treacher Collins)
-Ossicles form from 4th gestational week-16th, at week 8 first brachial groove forms plug of cells migrates medially to oppose development of middle ear cleft --> cells hollows out to form epithelial lined EAC during 6th month of gestation ---any interruption results in ossicular malformation or atresia of canal
Aural Atresia Type A
a. Type A: meatal atresia, lateral cartilaginous portion of canal (narrowed preventing cerumen and skin cells to exit external canal)
Aural Atresia Type B
b. Type B: partial atresia, narrowing of cartilaginous and bony portion of canal (narrowed ear canal allows visualization of TM but malformations of ossicles are common)
Aural Atresia Type C
c. Type C: total atresia, complete atresia of cartilaginous and bony portions of canal, but ME and mastoid are aerated, TM typically absent and ossicles fused and adherent to atretic plate (bone adjacent to ME)
Aural Atresia Type D
d. Type D: hypopneumatic atresia similar to type c but mastoid is poorly pneumatized and facial nerve has aberrant course within temporal bone
Audiology of Atresia
- Audiology: Evaluate infant with ABR (typically present significant conductive loss), after perform BC on atresia side and place masking on the other side, bilateral atresia need to use BC ABR but cannot know for certain which ear has better hearing
Medical Assessment of Atresia
Need to examine if there are any craniofacial anomalies, facial nerve, any degree of microtia, CT scanning to determine location and severity of compromise
Possible surgical intervention depending on SN function and inner ear malformations: a score of 5 or less (grading scale based on point for normal radiographic appearance) disqualifies someone from surgery –> aural atresia typically repaired at age 1-2 years of age and microtia repaired 6-7 years of age —> Drill new EAC within temporal bone and carefully avoiding mastoid air cells, middle cranial fossa dura mater and facial nerve, TM graft made
Aural Atresia
ear canal fails to develop resulting in abnormally closed/absent canal
Eustachian Tube Dysfunction
Eustachian tube with ME opening in anterior medial aspect of ME, proximal 1/3 of tube passes through petrous portion of temporal bone, distal 2/3 is primarily cartilaginous, terminates in superior lateral aspect of nasopharynx, tensor veli palatini and levator veli palatini responsible for opening/closing of Eustachian tube. AT REST=CLOSED, negative pressure retracts TM (otitis media)
Eustachian Tube functions
Functions: 1. ventilation of ME 2. protection from nasopharynx 3. clearance of secretions of ME
Eustachian Tube Dysfunction Symptoms
negative ME pressure (pain, pressure in ear), serous fluid collection (otitis media with effusion), autophony (perception of one’s breath and speech excessively loud)–constantly open tube
Eustachian Tube Dysfunction Incidence
affects 70-90% of kids by age 2 years, more common in kids under 5, males and Native americans, low SES
Etiology of Eustachian Tube
shorter in kids, accounting for increase of prevalence in kids, reaches adult size by age 7 – more flat in kids than adults (45 degree angle), patulous eustachian tube associated with weight loss, pregnancy, stroke, degenerative neurologic disorders can lead to muscle atrophy
buildup of negative middle ear pressure–effusion
Site of Lesion for Eustachian tube dysfunction
nasal cavity, inflammation/mass effect obstruction, tube can be obstructed to inflammation within tube itself or functionally not open because of peritubal muscle function
Audiology of Eustachian tube dysfunction
take baseline tymp – creating positive/negative pressure asking patient to swallow several times – no change in peak pressure suggests dysfunction – if HL it will be conductive or mixed
Otitis Media
inflammation of ME –> purulent effusion can develop because of bacteria can resolve into serous effusion before complete resolution
Chronic Otitis media
presence of OM for 30 days or more
Acute Otitis Media
3 or more bouts within 6 months or 4 or more in 1 year
Chronic Suppurative OM
persistent inflammation and disease of ME
Symptoms of Otitis Media
fever, otalgia, pressure, irritability, conductive HL or asymptomatic
Incidence of OM
over 90% of caucasian and african american kids in first 2 years of life
up to age 3 kids usually experience one episode of acute otitis media per year,
middle ear with effusion occurs most in kids under 6
more often in pediatric pts in IC
Etiology of OM
Eustachian tube dysfunction, upper respiratory infection can occur in conjunction
diseases that impair the immune system, smoke exposure, lower SES
Audiology of OM
tymp, audio eval, negative ME pressure
early on to a flat tymp, typically mild range but can fluctuate
Medical Exam & Management
purulent OM may not be easily visualized due to thickening of TM
Management: antibiotics, PE tubes with 3 or more episodes in 6 months or 4 or more in 1 year
Cholesteatoma
collection of keratin-producing squamous epithelial cells within ME – can manifest with persistent perf of TM, erosion of ossicles
ME granulation tissue
Primary Acquried Cholesteatoma
squamous collection within retracted TM pocket
Secondary Acquired Cholesteatoma
squamous cell migration through TM perf into ME
Symptoms of Cholesteatoma
typically cause conductive HL when impinge on ossicles
secondary choelsteatoma with bacterial colinization leads to persistent foul-smelling otorrhea, pain and possible ossicle erosion — can damage VII when erodes bone and CAN LEAD TO MENINGITIS
Incidence of Cholesteatoma
3/100,000 for ACQUIRED
9.2/100,000 for all ages with male predominance
Etiology of Congenital Cholesteatoma
remnant of embryonic epithelial cells nests trapped in ME during development
Etiology of Secondary Cholesteatoma
result of long term Eustachian tube dysfunction
invagination of squamous epithelium with retracted TM, bacteria, ossicles can be eroded – perf TM
Site of Lesion for Cholesteatoma
Congenital: anterior mesotympanum/ protympanum
Primary acquire: most common is posterior epitympanic space / Prussak’s space
Secondary acquired: posterior aspect of pars tensa – can extend into petrous portion of temporal bone
Audiology for cholesteatoma
tymp, eval, complicance is typically reduced
amplification required depending on medical management
Medical Management of Cholesteatoma
Tympanoplasty
Mastoidectomy – maybe ossiculoplasty depending on outcome of surgery
Mastoidectomy
removal of Cholesteatoma and any diseased mucosa within air cells of mastoid by drilled cholesteatoma and diseased muscosal away
after 6-12 months can inspect ossicles
mastoid bowl must be examined regularly to remove debris and need to keep it completely dry
Glomus Tumors
benign, slow growing, very vascularized tumor, arise from collection of neuroendocrine paraganglial cells – originating from neural crest cells surrounded by dense collection of capillaries and venules