Meniere's Disease

Question 1

Meniere’s disease

Answer 1

complex idiopathic disorder of the inner ear
onset around 40 years old
difficult diagnosis
etiology unknown

Question 2

symptoms of Meniere’s disease

Answer 2

unilateral hearing loss
tinnitus
vertigo

Question 3

histopathologic feature of Meniere’s disease

Answer 3

endolymphatic hydrops

Question 4

Meniere’s disease audiogram

Answer 4

early: fluctuating low frequency sensorineural hearing loss
middle: peaked pattern, high and low tones lost
late: flat pattern

Question 5

causes of Meniere’s disease

Answer 5

ballooning of endolymph canals
possibly due to increased production or malabsorption

Question 6

What is endolymph?

Answer 6

produced by the stria vascularis
resorbed in the endolymphatic sac

Question 7

obstacles to identifying complex disease genes

Answer 7

no animal model
sporadic cases
small complex pedigrees: not typical autosomal
incomplete penetrance
phenocopies: have the symptoms but not the disease
environmental triggers: Mexican food, pizza, high stress situations

Question 8

genetic evidence of Meniere’s disease

Answer 8

most cases are sporadic but clusters of affected individuals can occur in families
family history is seen in 5-14% of cases
25% of sporadic patients report of positive family history of MD or MD-like symptoms

Question 9

candidate gene for Meniere’s disease

Answer 9

SLC45A3: prostein
carbohydrate transporter
previously known to be prostate specific expression
now known to be expressed in the ear: may play a role in osmotic regulation of endolymph in the inner ear