1 / 44

Acoustic Neuroma

Acoustic Neuroma. Introduction. A.K.A.: vestibular schwannoma / neurilemmoma Benign, encapsulated, slow growing tumour arising from Schwann cells of superior vestibular division of 8 th nerve within internal auditory canal Rarely from inferior vestibular or cochlear division.

tgrove
Download Presentation

Acoustic Neuroma

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Acoustic Neuroma

  2. Introduction A.K.A.:vestibular schwannoma / neurilemmoma Benign, encapsulated, slow growing tumour arising from Schwann cells of superior vestibular division of 8th nerve within internal auditory canal Rarely from inferior vestibular or cochlear division

  3. Tumour growth Tumor expansion within internal auditory canal  causes widening & erosion of I.A.C.  appears in cerebello-pontine angle (> 2.5 cm)  involves 5th, 7th, 9th, 10th, 11th cranial nerves  displacement of brainstem & cerebellum  raised intracranial pressure Involvement of 6th & 3rdcranial nerves

  4. Classificationas per size 1. Intra-canalicular: confined to I.A.C. 2. Small: up to 1.5 cm 3. Medium: 1.5 to 4 cm 4. Large: over 4 cm

  5. Tumor size

  6. Intra-canalicular

  7. Small

  8. Medium

  9. Large

  10. Epidemiology • 10% of all brain tumors • 80% of all Cerebello-pontine angle tumors • Age: 40-60 yrs • Male : Female = 3:2 • Unilateral (90%); Bilateral (10%) • Bilateral = von Recklinghausen’s neurofibromatosis

  11. Clinical Staging • Otological stage: due to pressure on 8th nerve • Other Cranial nerve involvement • Brainstem + Cerebellar involvement • Raised intra-cranial tension • Terminal stage: failure of vital centres of brainstem & cerebellar tonsil herniation

  12. Otological symptoms & signs • Progressive, unilateral sensorineural deafness • Poor speech discrimination (disproportionate) • Tinnitus • Mild vertigo • Nystagmus Vestibular symptoms appear late due to slow tumor growth & vestibular compensation

  13. Other Cranial nerve palsy Trigeminal: first nerve to be involved • Loss of corneal reflex • Pain, numbness and paresthesia of the face Facial: • Hypoaesthesia of posterior external auditory canal wall (Hitselberger’s sign) • Facial weakness, Loss of taste, ed lacrimation

  14. Other Cranial nerve palsy Glossopharyngeal, Vagus & Accessory Spinal: • Dysphagia • Hoarseness • Nasal regurgitation • Decreased gag reflex Abducent & Oculomotor: • Diplopia

  15. Brainstem involvement  Ataxia  Weakness of arms & legs  Tendon reflexes exaggerated Cerebellar involvement  Ataxic gait (fall on affected side)  Intention tremors  Past-pointing  Dysdiadochokinesia Increased Intra-cranial tension  Headache  Projectile vomiting  Blurred vision  Papillodema  Abducent nerve palsy

  16. First Symptoms Hearing loss: 80-100 % Vertigo: 10-50 % Tinnitus: 5-10 % Ear ache: 5 % Sudden hearing loss: 5% Facial paralysis: 1-2 %

  17. Investigations • Pure Tone Audiometry:high frequency SNHL • Speech audiometry:SD scores < 30% • Tone decay test:positive • Stapedial Reflex: Decay > 50 % in 10 sec • B.E.R.A.:wave V >4.2 ms; inter-wave V >0.2 ms • Caloric test:I/L canal paresis or no response • C.T. scan with contrast: for tumor > 0.5 cm • M.R.I. with gadolinium contrast:best

  18. Pure Tone Audiogram

  19. Speech Audiometry Roll over phenomenon

  20. Calorigram

  21. Brainstem Evoked Response Audiometry (B.E.R.A.)

  22. Contrast C.T. Scan

  23. Contrast M.R.I.: neuro-anatomy

  24. Contrast M.R.I. : intra-canalicular

  25. Contrast M.R.I. : small

  26. Contrast M.R.I. : Medium

  27. Contrast M.R.I. : Large

  28. Bilateral tumor: small

  29. Bilateral tumor: large

  30. Treatment 1. Observation 2. Microsurgical removal: (partial or total) • Trans-labyrinthine approach • Retro-sigmoid or Sub-occipital approach • Middle Cranial Fossa approach • Combined approach 3. Stereotactic Radiotherapy 4. Brainstem Implant: after B/L tumor excision

  31. Observation Indications: • Age > 60 years with small tumor & no symptoms • Tumour in only hearing / better hearing ear Serial MRI used to follow growth pattern. Treatment recommended if hearing is lost or tumor size becomes life threatening.

  32. Incisions Middle cranial fossa Retro-sigmoid Trans-labyrinthine

  33. Retro-sigmoid Approach

  34. Sub-occipital approach

  35. Trans-labyrinthine approach

  36. Middle cranial fossa approach

  37. Surgical Approach Protocol 1. Intra-canalicular: Middle cranial fossa approach 2. Small (<1.5 cm): Retrosigmoid approach 3. Medium (1.5 - 4 cm) a. Hearing fine**: Retrosigmoid approach b. Hearing bad:Trans-labyrinthine approach 4. Large (>4 cm): Trans-labyrinthine/ Combined **Pure Tone Average < 30 dB, S.D. Score >70%

  38. Intra-operative photograph

  39. Proton stereotactic radiotherapy Single high dose of radiation delivered on a small area to arrest or kill tumor cells. Minimal injury to surrounding nerves & brain tissue Gamma Knife: radioactive cobalt LINAC X-knife: linear accelerator Cyber-Knife: robotic radio-surgery system Indication: 1. Surgery refused / contraindicated 2. Post-operative residual tumour

  40. Treatment Planning

  41. Treatment Planning

  42. P.S.R.T. in progress

  43. Pre & Post treatment

  44. Thank You!

More Related