12/9/2103

12/9/2013

Answers:

What is the mode of transmission for most forms of hereditary hearing loss?
A) Autosomal Recessive 
B) Autosomal Dominant 
C) X-linked 
D) Mitochondrial 
E) Syndromic

Most congenital hearing loss is nonsyndromic and within that group 80% are transmitted via autosomal recessive inheritance.

What is the classic appearance on an audiogram for nonsyndromic congenital hearing loss?

The classic appearance is a "cookie bite" or U shape.

MC Questions:
A 10 year old boy is found to have severe bilateral hearing loss and a large goiter. What is the most likely diagnosis?
A) MENIIB 
B) Neurofibromatosis Type I 
C) Neurofibromatosis Type II 
D) Pendred Syndrome 
E) Waardenburg Syndrome 
D) Treacher Collins Syndrome

Free Response Question:
What factors help categorize the four categories of Waardenburg Syndrome?

Quick Facts:
Branchio-Oto-Renal Syndrome = Branchial anomalies, otologic anomalies, renal malformations.  
-Most often mixed hearing loss.

Neurofibromatosis Type II = bilateral tumors of CNVIII and meningiomas, schwannomas, gliomas or juvenile subcapsular cataracts.  
-Symptoms begin in late childhood.  
-Unilateral hearing loss in 50% of patients.

12/6/2013

12/6/2013

Answers:

Which category of presbycusis is only theoretical?
A) Strial Presbycusis 
B) Neural Presbycusis 
C) Sensory Presbycusis 
D) Conductive Presbycusis

Conductive Presbycusis is thought to be due to changes
in mechanical characteristics of basilar membrane which may cause gradually sloping high frequency hearing loss. No discernable pathology exists however and this hearing loss mechanism is only
theoretical.

What is the most common cause of sudden SNHL in the elderly?

Thrombotic/embolic events of the internal auditory artery is the most common cause. Partial losses may be reversible, but total losses rarely recover.

MC Questions:
What is the mode of transmission for most forms of hereditary hearing loss?
A) Autosomal Recessive 
B) Autosomal Dominant 
C) X-linked 
D) Mitochondrial 
E) Syndromic

Free Response Question:
What is the classic appearance on an audiogram for nonsyndromic congenital hearing loss?

Quick Facts:
Syndromic HHI
-can be conductive, sensorineural or mixed.
-Pendred = most common syndromic form of deafness (10%), SNHL + goiter, often before puberty. Hearing loss is congenital, bilateral, mod-profound and sloping in
higher frequencies. Often have enlarged vestibular aqueduct and mondini-type
malformations.
-Waardenburg = 2-5% of pts w/ congenital hearing loss. Dystopia canthorum, pigmentary abnormalities and SNHL.  
Four subtypes:
-Type I = + dystopia canthorum, PAX3
-Type II = no dystopia canthorum, MITF, SNA12
-Type III = + dystopia canthorum, + upper limb abnormalities, PAX3
-Type IV = - dystopia canthorum, + Hirschsprung disease, EDNRB, EDN3,
SOX10