Vestibular Schwannoma

Question 1

What is another term for vestibular schwannomas?

Answer 1

Acoustic Neuromas

Question 2

What are vestibular schwannomas?

Answer 2

They are defined as benign tumours of the vestibulocochlear nerve – arising from Schwann cells of the nerve sheath

Question 3

Which three cranial nerves tend to be compressed by vestibular schwannomas?

Answer 3

CN V

CN VII

CN VIII

Question 4

What two risk factors are associated with vestibular schwannomas?

Answer 4

Neurofibromatosis Type Two

Head & Neck Ionising Radiation

Question 5

Are the clinical features of vestibular schwannomas unilateral or bilateral?

Answer 5

Unilateral

However, in neurofibromatosis type two, there is development of bilateral vestibular schwannomas and therefore there are bilateral clinical features

Question 6

What are the seven clincial features of vestibular schwannomas?

Answer 6

Vertigo

Tinnitus

Sensorineural Hearing Loss

Corneal Reflex Loss

Facial Pain

Facial Numbness

Facial Weakness

Question 7

Which vestibular schwannoma clinical feature is related to cranial nerve palsy V?

Answer 7

Absent corneal reflex

Question 8

Which vestibular schwannoma clinical feature is related to cranial nerve palsy VII?

Answer 8

Facial pain

Facial numbness

Facial weakness

Question 9

Which vestibular schwannoma clinical feature is related to cranial nerve palsy VIII?

Answer 9

Vertigo

Tinnitus

Senorineural hearing loss

Question 10

What three investigations are used to diagnose vestibular schwannoma?

Answer 10

Hearing Tests

Pure Tone Audiometry

Cerebellopontine Angle MRI Scans

Question 11

What two hearing test results indicate vestibular schwannoma?

Answer 11

Positive Rinne’s Test, AC > BC

Weber’s Test Lateralises To Unaffected Ear

Question 12

What pure tone audiometry result indicates vestibular schwannoma?

Answer 12

Sensorineural hearing loss

Question 13

What is the gold standard investigation used to diagnsoe vestibular schwannoma?

Answer 13

Cerebellopontine Angle MRI Scans + Gadolinium Contrast

Question 14

What is the feature of vestibular schwannoma on cerebellopontine angle MRI scans?

Answer 14

A white lesion in the cerebellopontine angle

Question 15

When is the conservative management option of vestibular schwannomas recommended?

Answer 15

It is recommended to manage small tumours with no impairment to facial nerve function or hearing defects

Question 16

What is the conservative management option of vestibular schwannomas?

Answer 16

It involves active surveillance with annual neuroimaging, in order to monitor tumour growth

Question 17

What are the two surgical management options of vestibular schwannomas?

Answer 17

Microsurgery

Stereotactic Radiosurgery

Question 18

What is the gold standard management option of vestibular schwannomas?

Answer 18

Microsurgery

Question 19

What is microsurgery?

Answer 19

It involves surgical excision of the tumour, through retrosigmoid, translabyrinthine and middle fossa approaches – dependent upon the location and size of the tumour

Question 20

When is stereotactic radiosurgery used to manage vestibular schwannomas?

Answer 20

It is recommended to manage small tumours which measure less than 3cm in diameter

Question 21

What is stereotactic radiosurgery?

Answer 21

It involves the administration of high energy gamma rays to deliver a single dose of radiation to the tumour

Question 22

What are the three complications associated with vestibular schwannomas?

Answer 22

Hearing Loss

Facial Paralysis

Hydrocephalus