Acoustic Neuroma or Vestibular Schawnnoma cerebellopontine angle tumor cranial nerve 8 tumor

1. Vestibular schwannoma
Acoustic Neuroma
Int. Sunder Chapagain

2. Internal acoustic meatus

3. Cerebellopontine angle
• Location-almost triangular space located In
posterior cranial fossa and contains CSF
• Relations-
Central structures- CNVII & CNVIII
Superiorly- CNV
Inferiorly-CNIX,CNX &CNXI

4. Vestibular Schwanoma
• Vestibular neuroma is a benign, slow growing,
encapsulated tumor of vestibulocochlear (8th
CN) cranial nerve.
• It is also known as
-Acoustic neuroma
-Acoustic neurilomma
-CPA tumor
-Angle tumor

5. Epidemiology
• 10 in 1 millions
• In USA-2000-30000 cases are diagnosed each year
• 95%-Sporadic
• 5%- associated with NF2-usually bilateral-early
incidence
• Epidemiological classification
1.silent tumors
2. symptomatic undiagnosed tumors
3.diagnosed tumors

6. Classification
• According to size of tumor
a. intracanalicular- confined with in IAC
b. small size- (up to 1.5 cm)
c. medium size- (1.5-4 cm)
d. large size- (>4 cm)

7. Classification
Jackler classification
Intrameatal tumour Extrameatal size mm
Grade 1 Small 1-10
Grade 2 Medium 11-20
Grade 3 Moderately large 21-30
Grade 4 Large 31-40
Grade 5 Giant >40

8. Pathogenesis
• Growth pattern
• Intrameatal compression
• Extrameatal compression

10. Pathology
• Gross
-Small to large size
-encapsulated
-slowly growing
-medial to IAC and lateral to CPA
• Microscopic
-Antoni A cells
-Antoni B cells

11. Menifestations
• Medial
• Cystic

12. Clinical Presentation
1. Age and sex
2. Vestibulocochlear symptoms
3. Cranial nerve involvement
4. Brainstem involvement
5. Cerebellar involvement
6. Raised ICP

13. • Vestibulocochlear symptoms
-Hearing loss-sensoryneural,usually unilateral
-tinnitis
-unsteadyness
• Cranial nerve involvement
7th CN-Hitzelberger’s sign
-loss of taste sensation
-reduced lacrimation
-delayed blink reflex

14. 5th CN - numbness of face
-reduced corneal reflex
9th & 10th CN-dysphasia
-horseness of voice
11th & 12th ,3rd, 4th, 6th CN –if tumor is very large
• Brainstem involvement
-ataxia
-weakness and numness of arms and legs
-exagerated tendon reflex

15. • Cerebeller involvement
-ataxic gait
-postural imalance
-asynergia
-dysmetria
-adiadochokinesia
• Raised ICP- Headache, vomiting,diplopia
papiloedema,bluring of vision

16. DIAGNOSIS
• History
• Investigation

17. History
• unilateral or bilateral sensorineural hearing
loss, tinnitus with(out) imbalance

18. Investigation
• Audiological tests
– PTA
– Speech audiometry(SD score)
– Roll over phenomenon
– Recruitment phenomenon
– Short Increment Sensitivity Index(SISI)
– Threshold tone decay test
– Stapedial Reflex Decay Test
– Brain stem evoked response audiometry

19. Roll over phenomenon

20. Brain stem evoked response audiometry

21. • Vestibular Tests
– Caloric test
• Neurological tests
– Cranial nerves
– Cerebellar functions
– Brainstem signs

22. • Radiological tests
– Plain X-rays
– CT scan
– Gadolinium Enhanced MRI
• most sensitive
• Gold standard
– Vertebral Angiography
• CSF analysis

23. DDx
• Meningioma
• Cochlear pathology(meniere’s disease)
• Lipoma
• Epidermoid
• Cholesterol granuloma
• Cholesteatoma
• Arachnoid cyst
• Aneurysm
• Metastasis
• Schwannoma of other cranial nerves(V,VII,IX,X and XI)

24. MANEGMENT
Surgical
Radiological

25. Surgical
• 1st treatment of choice
• Surgical approach depends upon size and
extent of tumor.
• Approaches:
– Middle cranial fossa approach
– Translabyrinthine approach
– Suboccipital(retrosigmoid) approach
– Combined translabyrinthine-suboccipital approach

26. Post operative complications
• Common: SNHL,temporary facial nerve palsy
and balance problem, CSF leak, meningitis
• Rare: stroke, intracranial bleeding,
pneumocephalus, cerebellar ataxia, and even
death.

27. Radiological
• X-knife or Gamma knife surgery- 2nd treatment
of choice
• Cyber knife

28. THANK YOU