AcousticNeuroma (Misnomer)VestibularShwannomaThetumor is a result of hyper proliferation of schwann cells of the balance nerve.The tumor starts as an intrameatal (internal auditory meatus) lesion and thanpresents with deafness and tinnitus. Later on at may silently grow in the cerebellopontine angle and achieve a great volume without the patient knowing it. Asfar as it remains a meatal tumor its diameter is upto 2cm. As it enlarges itputs pressure on the trigeminal nerve. At this stage sensory changes appear onthe face and particularly the corneal reflex gets depressed. Effects on the Inner Ear Pressureon internal auditory artery results in ischemia on inner ear. Stages of the tumor 1. The otological stage –In which changes are confined to the verstibulo-cochlear nerve and the facialnerve to a limited extent. This includes all intrametal lesions and extrameatal tumors upto about 2cm. 2. Stage of trigeminal nerve involvement -Suggesting a diameter of 2cm or greater. 3. Stage of brainstem &cerebellar compression eg. ataxia, direction changing nystagmus and long tractsigns and of involvement of the lower cranial nerves. 4. Stage of increasingintra-cranial pressure with failing vision, headache & vomiting. 5. Terminal Stage – withsevere disturbance to vital brain stem structures and tonsillar herniation. Otologic Stage (1)Unilateraldeafness and tinnitus. The patient may volunteer the information that hisability to discriminate speech seems disproportionately poor specially whileconversation over the telephone. ImbalanceTheslowly growing tumor destroys the vestibular nerve from which it arises sogradually that the CNS is able to compensate for the unilateral loss ofperipheral input. Facialnerve involvement Althoughthe facial nerve is compressed obvious facial weakness is uncommon. Trigeminal Nerve Involvement (Stage 2)Theearliest sensory change occurring when the tumor has reached 2- 2.5cm is nearlyalways in the cornea and may result in irritation in the eye. Brainstem & Cerebellar CompressionStage 3Asthe tumor grows larger more evidence of neurological involvement appear. Ataxia of the ipsilateral upper & lowerlimbs is manifested as clumsiness due to dysmetria, dyssenergia & dysdiadokokineness and with disturbances of gait. Increasing Intra-Cranial Pressure Stage 4Asthe intracranial pressure rises headache become more severe & in thesuboccipital area. This is associated with nausea & nomiting. Terminal Stage (Stage 5)Failiureof vital centres in the brain. Examination Cutaneouslesions suggestive of neurofibromatosis 2 cutaneous, neurofibromas & caféaulait blemishes ears. Tympanicmembrane appear normal Cranialnerves TrigeminalNerve Allthe 3 divisions shoul be tested by pin prick and fine tough. The most importantarea for sensory loss is the cornea. Facial nerve severe facial weakness israre. Testingfor nerves intermedias involves schirmers where lacrimation can be evaluated. Eyes Suprisingnumber of cases presently at a stage of increased intracranial pressure andfailing vision. Cordination & GaitFingernose test for cerbellar involvement. Dysdiadokokiness.Unterbergertest – A more sensitive test. Investigation & Diagnosis Audiovestibular investigation Speechdiscrimination Electricresponse audiometry. Remains the most reliable audio logical tool.RadiologicalInvestigation CTScan MRI,Treatment Surgery Middlecranial fossa approachTranslabyrinthineapproach RetroSigmoid approach. Differential Diagnosis MeningiomaPrimaryCholesteatomas Arachnoidcysts Glomusjugular.