ACOUSTIC NEUROMA

dr Ika Yuliartanti.,SpTHT-KL.,M.Kes

INTRODUCTION Represent 10% of all intracranial tumors. Vestibular schwannomas (=acoustic

neuromas) 78% of CPA vestibular branch of the 8th cranial nerve.

STAGING

VESTIBULAR SCHWANOMA Autopsy series: 1,7% to 2,7% of

undiagnosed & clinically silent Incidence of 0.7 to 1/100.000 population arise from the vestibular segment of the

8th nerve from schwann cells (the most commonly)

TUMOR BIOLOGY

The molecular genetics:• Occur as a sporadic variety (95%)• Bilateral in case of type 2 neurofibromatosis• Younger patient & in association with other

intracranial meningioma & spinal cord tumor.• Genetic defect: autosomal dominant & long

arm of chromosome 22.

Symptoms

Related to tumor size & growth. Intracanalicular: HL, tinnitus, & vestibular

dysfunction CPA: Severe HL & dysequilibrium Brainstem: Midfacial hypesthesia,

hydrocephalus, headache, & visual loss.

Hearing Loss

Unilateral HL (> 85%) Loss of speech discrimination (the most

common) Tinnitus (second) : (56%) unilateral vascular occlusion of the labyrinthine

artery

Sudden SNHL (26%)

Vestibular symptoms

Dysequlibrium 56% Vogue Transientlight headness Meniere’s disease (spread into labyrinth)

Other symptoms

Facial numbness N V-2 (maxillaris) Occular symptoms diplopia or visual

blurring Cerebellar involvement late

Incoordination, fall toward the affected side

Audiometric testing65% High tone SNHL & 5% normal

hearingSpeech discrimination scoreAcoustic-reflex threshold & decayABR (the most sensitive & specific)

DIAGNOSTIC TESTING

VESTIBULAR TESTING

ENG Dynamic postulography Rotary chair testing Caloric test Spontaneous nystagmus large tumor

IMAGING

Plain film CT scan MRI

contrast iophendylate

contrast air cisternography

Gadolinum DTPA

63% accurate a convex bulge of a mass

MANAGEMENT

1. Preserve life2. Avoid serious neurologic sequele3. Complete tumor removal4. Preserve facial nerve function5. Preserve hearing

SURGERY

Primary treatment A team: a neurosurgeon & neurootologist Use of microsurgical technique &

intraoperative monitoring of the facial nerve

Middle Cranial Fossa Approach

Retrosigmoid Approach

Complications:

Facial nerve paralysis (the most common)

Leakage of LCS (4% to 14%) Meningitis rare