Disorders III

Question 1

what is large vestibular aquaduct syndrome

Answer 1

• aka enlarged vestibular aquaduct syndrome
• congenital malformation (dilation) of the vestibular aquaduct
• expansion of the endolymphatic sac and duct typically follow

Question 2

syndromes associated with LVAS (5)

Answer 2

• mondini syndrome
• pendred syndrome
• bracio-oto-renal syndrome
• CHARGE syndrome
• waardenburg syndrome

Question 3

audiologic symptoms with LVAS

Answer 3

• hearing symptoms are highly variable
• range anywhere from mild to profound, unilateral or bilateral, fluctuating, sudden, or progressive
• progressive losses are not uniform and may vary from side to side in each pt
• typically SNHL and first shows in early childhood

Question 4

associated vestibular symptoms with LVAS

Answer 4

• variable like hearing symptoms
• episodic spinning vertigo, mild unsteadiness trouble watching revolving objects, a feeling of vague instability, rocking sensations, jumping vision, decreased visual acuity in the presence of loud sounds, instability when leaning forward, vomiting, nausea, and drunken gait
• may see child grab his.her head and walk in circles
• vestibular symptoms are even more challenging to describe for children than for aults as children have limited language

Question 5

diagnosis LVAS

Answer 5

• MRI or CT
• MRI shwos duct and sac, CT shows bony portions
• 62% of LVAS occurs with co-morbid ear malformations, dont forget is is often associated with other syndromes
• 5-15% of children with SNHL have LVAS

Question 6

treatment/management of LVAS

Answer 6

• due to the fluctuant nature of LVAS it can be difficult to manage or treat symptoms, some do well with CI
• be weary of head injury risks and wear a helmet, also avoid potential barotrauma situations lie scuba diving

Question 7

what is superior canal dehiscence

Answer 7

• this is a “third window” disorder
• while this often occurs after a head trauma or intracranial pressure overload it is considered a congenital issue where there is a weak or the bony covering over the SSC and it breaks after the trauma or develops over time

Question 8

symptoms with superior canal dehiscence

Answer 8

• may complain of autophony, and other unusual complaints
• –own voice is too loud, can hear their eye movements or blinking
• describe vertigo and oscillipsia especially after loud sounds or changes in the middle ear or intercranial pressure
• –oscillopsia can occur with the pts pulse

Question 9

diagnosis of superior canal dehiscence

Answer 9

• case history: vestibular symptoms with changes in pressure or after injury/incident
• audio: low freq conductive loss with normal tympanometry
• positive fistula, or pneumatic otoscopy, tragus pumping
• cVemp: abnormally large response found at lower than expected thresholds (expected to be 90-95 dB)
• imaging: remember high resolution CT is superior for SSCD

Question 10

treatment for superior canal dehiscence

Answer 10

• surgical correction of the window will improve both the auditory and vestibular symptoms
• vestibular rehabilitation not likely to help as symptoms are fleeting
• avoidance of provoking situations such as changes in pressure, coughing, sneezing, bowel movements, laughing

Question 11

how do you tell superior canal dehiscence from a fistula

Answer 11

• hearing loss with SSCD= low frequency conductive loss
• hearing loss with fistula= SNHL
• –vemp being really big at low thresholds with SSCD

Question 12

how do we tell superior canal dehiscence from menieres

Answer 12

• both will likely have normal typms
• case history
• EcochG
• hearing loss with menieres=fluctuating and SNHL low frequency loss
• –SSCD is conductive