Answers:
Which ossicle requires the longest period of development?
A) Incus
B) Stapes
C) Malleus
D) They are all equal
The stapes requires the longest period of embryologic development. Additionally, it is derived from both branchial arch and otic capsule precursors which makes it's embryologic origins more complex. This is thought to be the reason why congenital anomalies of the stapes (40% of congenital ossicular lesions) are more common than that of either the incus or the malleus.
What does a "high riding" bulb refer to?
“High riding” bulb = jugular bulb (at junction of sigmoid sinus and inferior petrosal sinus) that rises above the inferior aspect of the bony annulus or the basal round of the cochlea.
-Present in 5% of people, may be related to poor pneumatization of mastoid.
-Can present with tinnitus, vestibular symptoms and CHL (due to compression of middle ear contents)
-Most commonly discovered incidentally on exam.
-Classically a blue mass is seen posteroinferior quadrant of TM.
-At risk of inadvertent laceration during myringotomy.
MC Questions:
All of the following are true with regards to congenital cholesteatomas except...
A) Often discovered incidentally
B) Does not usually present with TM perf
C) Patients w/ congenital cholesteatoma tend to have well aerated mastoids
D) Can present in anterior or posterior quadrants
E) All of the above are true
A) Incus
B) Stapes
C) Malleus
D) They are all equal
The stapes requires the longest period of embryologic development. Additionally, it is derived from both branchial arch and otic capsule precursors which makes it's embryologic origins more complex. This is thought to be the reason why congenital anomalies of the stapes (40% of congenital ossicular lesions) are more common than that of either the incus or the malleus.
What does a "high riding" bulb refer to?
“High riding” bulb = jugular bulb (at junction of sigmoid sinus and inferior petrosal sinus) that rises above the inferior aspect of the bony annulus or the basal round of the cochlea.
-Present in 5% of people, may be related to poor pneumatization of mastoid.
-Can present with tinnitus, vestibular symptoms and CHL (due to compression of middle ear contents)
-Most commonly discovered incidentally on exam.
-Classically a blue mass is seen posteroinferior quadrant of TM.
-At risk of inadvertent laceration during myringotomy.
MC Questions:
All of the following are true with regards to congenital cholesteatomas except...
A) Often discovered incidentally
B) Does not usually present with TM perf
C) Patients w/ congenital cholesteatoma tend to have well aerated mastoids
D) Can present in anterior or posterior quadrants
E) All of the above are true
Free Response Question:
Where are congenital cholesteatomas "classically" found? What do they look like on otoscope exam?
Quick Facts:
Where are congenital cholesteatomas "classically" found? What do they look like on otoscope exam?
Quick Facts:
Round Window Anomalies
-Aplasia/hypoplasia associated w/ endemic cretinism and mandibulofacial dysostosis.
-Nonsyndromic cases are rare (less than 10 cases reported)
-Management unclear.
-Often associated w/ stapes ankylosis and diagnoses in retrospect after stapedectomy unsuccessful.
-Better to managem w/ amplification as surgical fenestration has led to poor results and carries risk of SNHL.
-Aplasia/hypoplasia associated w/ endemic cretinism and mandibulofacial dysostosis.
-Nonsyndromic cases are rare (less than 10 cases reported)
-Management unclear.
-Often associated w/ stapes ankylosis and diagnoses in retrospect after stapedectomy unsuccessful.
-Better to managem w/ amplification as surgical fenestration has led to poor results and carries risk of SNHL.
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