acoustic neuroma

ACOUSTIC NEUROMA

Vestibular schwannomas are benign, encapsulated tumors that arise from schwann cells of vestibular nerve

Most of vestibular schwannomas originate in the region of the internal auditory canal

Constitutes 80% of all CP angle tumors and 10% of all brain tumors

Cerebellopontine angle

Vestibular schwannoma

Classification

Growth of tumorClassification- Intracanalicular Small (upto 1.5 cm) Medium (1.5 to 4 cm) Large (over 4 cm)

Vestibular schwannoma

• Origin-Schwann cells of vestibular nerve

Vestibular schwannoma

Clinical Features:-

Age and sex. 40 to 60 years

Progressive unilateral sensorineural hearing loss

Tinnitus

Difficulty to understand speech

Vertigo/imbalance

Cranial nerve involvement

Brainstem involvement

Cerebellar involvement

Vestibular schwannoma

Acoustic neuroma

Clinical Features

Vestibular schwannoma

Investigations:

Pure tone audiometry

Speech audiometry

Recruit phenomenon

SISI Index

Threshold tone decay test

Caloric test

RADIOLOGICAL TESTS; Plain x-rays

CT Scan

Vestibular schwannomaM R I SCAN

Tests to differentiat cochlear from retro cochlear pathology

Tests Normal Cochlear Retro cochlear

PTA Normal S.N.loss S.N.loss

S.D.S 90 to 100% Below 90% poor

Recruitment absent present absent

SISI score 0 to 15% >70% 0 to 205

TDT 0to 15 dB <25 dB > 25 dB

SR Normal normal abnormal

BERA Normal abnormal abnormal

Vestibular schwannoma

• Differential Diagnosis

Vestibular schwannoma

TREATMENT

• Careful serial observation.

• surgical excision of the tumor

• Arresting tumor growth using stereotactic radiation therapy