12/3/2013

12/3/2013

Answers:

What is the most common cause of SNHL?
A) Congenital 
B) Intense Noise Exposure
C) Ototoxic medications 
D) Presbycusis 
E) HIV related hearing loss

All of the listed answers are causes of SNHL, however presbycusis (age related hearing loss) is the most common cause of SNHL.

The intensity of sound is signaled to the brain by what three mechanisms?

1. The amount of neural activity in individual neurons. 
2. The number of neurons active. 
3. Specific neurons which are activated.

MC Questions:
SNHL along with thyroid abnormalities most likely signifies what syndromic form of hearing loss?
A) Jervell Syndrome 
B) Alport Syndrome 
C) Waardenburg Syndrome 
D) Usher Syndrome 
E) Pendred Syndrome

Free Response Question:
What is the maximum average dB exposure allowed for workers over an 8 hour period that does not require ear protection?

Quick Facts:
SNHL Diagnosis
-Look for retraction pockets of pars flaccida/pars tensa.
-Unilateral serous effusion in adults should prompt scoping patient to assess for
neoplasms.
-Tuning fork exams can be useful.
-Rinne shows BC>AC when CHL greater than 30db-5db
difference in hearing needed for weber test
-Audiogram should always be performed.
-CT scans can be used to determine the caliber of the EAC and for detection of bone erosion for cholesteatoma and chronic OM.
-MRI is better for detecting retrocochlear pathology.

12/2/2013

12/2/2013

Answers:

All of the following increase the risk of perilymphatic gusher's during stapedectomy except...
A) Meniere's Disease 
B) Mondini malformation 
C) Enlarged Vestibular Aqueduct Syndrome 
D) Congenitally Fixed Footplate

Pts are at an increased risk of having a "perilymphatic gusher" if they have a mondini malformation, enlarged vestibular aqueduct syndrome or congenitally fixed footplate. As a "gusher" can lead to significant SNHL, these conditions are contraindications to surgery. If a "gusher" occurs intraop, a fat or muscle graft can be used to seal the leak, postop the pt should maintain head elevated
position and by placed on stool softeners.

What are three nonsurgical treatment options for otosclerosis?

Sodium Fluoride = reduces osteoclastic bone resorption and increased osteoblastic bone formation. Also thought to inhibit proteolytic enzymes that are cytotoxic to cochlea which can because SNHL.


Bisphosphonates=potent antiresorptive which inhibit osteoclastic activity.
Amplification=most pts have normal cochlear function with good speech discrimination so they are good hearing aid candidates and patients are encouraged to try hearing aids prior to surgery as risk are low.

MC Questions:
What is the most common cause of SNHL?
A) Congenital 
B) Intense Noise Exposure
C) Ototoxic medications 
D) Presbycusis 
E) HIV related hearing loss

Free Response Question:
The intensity of sound is signaled to the brain by what three mechanisms?

Quick Facts:
Prevention of SNHL 

Vaccination
-H. flu vaccine prevents a major cause of SNHL.
-Other vaccines (strep pneumo, MMR) also have important impact and may decrease ear infections.

Noise Avoidance
-Using earplugs and earmuffs can decrease noise damage.
-High risk activities = wood/metal working, target practice, engines, snowblowers,
chainsaws etc.
-Exposure over an 8hr period averaging 85db requires protection.