A presentation shows an overview about vestibular schwannoma, including investigations required & management approaches.

1. Vestibular
Schwannoma
Oussama Alserwy

2. Overview
• Composed of Schwann cells and involve the vestibular rather than the
acoustic division of the 8th cranial nerve.
• Benign and usually slowly growing.
• Arises in the IAC can reach up to the CPA compressing the brain stem.
Here, complications start.
• Incidence is increasing and approaches 20 per million/yr.

3. Predisposing Factors
1. Congenital de novo from a mutation and usually
associated with (NF2)
2. Acquired due to ionizing radiation, exposure to
extremely loud noise at work, female hormones
and mobile phone use of at least 10 years’ duration.

4. Tumour Size
• Only the extracanalicular portion of the tumor
should be measured.
• Tumors limited to the IAC should be reported
as "intracanalicular tumors.“
• Axial CT or MRI is used to estimate tumor size.

5. Presenting symptoms
• Unilateral hearing loss and tinnitus, followed by vertigo,
dizziness, or unstable gait.
• Later symptoms include those due to facial and
trigeminal nerve compression (.e.g diminished corneal
reflex).
• The time from initial symptoms to tumour diagnosis
varied from 1 month to 20 years.

6. Investigation
• PTA showing ‘Roll over
phenomenon’.
• Confirm by MRI.

7. Management
Goal: completeness of tumor
resection along with
preservation of facial nerve
function and hearing.
Conservative

8. Microsurgery
• Consider the risk-benefit ratio.
• Large or cystic tumors that require
decompression of the brain stem.
• Risk profile including facial nerve palsy,
dizziness, stroke, death and late tumour
regrowth.
• Noting that the recurrence rate is
considerably higher in large tumors.
• Preservation of the facial and trigeminal
nerves is attempted for all patients in fear of
the combined cosmetic and functional
problems to the patients.
Considerations

9. 3 surgical approaches to the CPA have been proposed;
retrosigmoid (traditional), translabyrinthine, and middle fossa (rare)
Retrosigmoid (Suboccipital) Translabyrinthine
Advantages • Possibility of hearing
preservation.
• Any size of tumour can be
removed.
• Excellent view, allowing early
identification and preservation
of nerves.
• Any size of tumour can be
removed.
• No cerebellar retraction is
required.
Disadvantages • Cerebellar retraction and the
increased incidence of
chronic post-craniectomy
headache.
• Loss of any residual hearing.
• loss of the ipsilateral peripheral
balance function.

11. Stereotactic
Radiosurgery
‘Gamma Knife’
• Consider the risk-benefit ratio.
• Control of smaller tumors, by increases in
tumor diameter from tumor capsule expansion
associated with central tumor death .
• Control of larger tumours will need more
radiation dose that will carry a huge side
effects on the adjacent vital tissues.
• Noting that the recurrence rate is considerably
low.
• Preservation of the facial nerve & hearing is
the best comparing microsurgery.
Considerations

13. Microsurgery Gamma Surgery
Advantages • Any size of tumour can be
removed.
• No need to general anesthesia.
• Short recovery time.
• Possibility of preserving any
residual hearing.
• Very low risk profile than
surgery.
Disadvantages • Need of general anesthesia.
• Longer recovery time.
• High risk profile.
• Inability to treat large lesions.