Hearing Loss Associated with Endocrine Disorders

Question 1

What is the 2nd most common form of AR syndromic deafness?

Answer 1

Pendred syndrome

Question 2

Does pendred syndrome have phenotypic variability within families?

Answer 2

Yes

Question 3

What is the pendrin gene primarily involved in?

Answer 3

The transport of chloride and iodine ions

Question 4

What are some clinical features of pendred syndrome?

Answer 4

The main feature is a thyroid goiter (80% of affected individuals)
Delayed onset, typically not present at birth but may present by early puberty
Hypothyroidism is reported in about 40% of affected individuals
Variable expressivity of the thyroid manifestation is reported, which may have led to an under-diagnosis of Pendred syndrome

Question 5

Can both hyper and hypo-thyroidism cause a goiter?

Answer 5

Yes

Question 6

What are the audiologic findings of pendred syndrome?

Answer 6

SNHL that is profound and progressive
More severe in high frequencies
Mondini malformation
EVA

Question 7

What is a differential diagnosis of pendred syndrome?

Answer 7

DFNB4
Prelingual profound nonsyndromic SNHL and temporal bone abnormalities, typically EVA
No thyroid defects

Question 8

What is an EVA?

Answer 8

Enlarged vestibular aqueduct
Causes the endolymphatic duct and sac to grow large too

Question 9

What should patients with EVA do to reduce the likelihood of hearing loss progression?

Answer 9

Should avoid contact sports that might lead to head injury
Wear head protection when engaged in activities such as bicycle riding or skiing that might lead to head injury
Avoid situations that can lead to barotrauma (extreme, rapid changes in air pressure), such as scuba diving or hyperbaric oxygen treatment

Question 10

What does DIDMOAD stand for?

Answer 10

Diabetes Insipidus, Diabetes Mellitus, Optic Atrophy, SNHL (Deafness)

Question 11

What is another name for DIDMOAD syndrome?

Answer 11

Wolfram syndrome

Question 12

What is diabetes insipidus?

Answer 12

It is an uncommon condition in which the kidneys are unable to prevent the excretion of water

Question 13

Is Wolfram syndrome AR?

Answer 13

Yes

Question 14

What are the audiologic and vestibular symptoms of wolfram syndrome?

Answer 14

Bilateral, sensorineural, slowly progressive hearing loss (60-85%)
Onset in 2nd decade of life with atrophy of the stria vascularis
Reduced excitability of the vestibular system is reported

Question 15

What audiological effects can EVA have?

Answer 15

Unilateral or bilateral SNHL hearing loss
Moderate to profound, often with progression or fluctuation
Vestibular symptoms like paroxysmal vertigo may also occur