All of the following are true about Schwannomas except
Option A: Vestibular schwannoma is benign neoplasm of unceain etiology that most often affects Inferior vestibular nerve. Option B: Cochleovestibular symptoms are earliest symptoms when tumour is still intracanalicular and are caused by pressure on cochlear or vestibular nerve fibres or on the internal auditory aery. Option C: MRI with gadolinium contrast is superior to CT scan and is gold standard for diagnosis of acoustic neuroma. Option D: VIIth nerve involvement: Sensory fibres are affected early. There is hypoaesthesia of posterior meatal wall (Hitzelberger's sign), loss of taste (as tested by electrogustometry) and reduced lacrimation on Schirmer test. Motor fibres are more resistant and are affected late. Delayed blink reflex may be an early manifestation.
Commonly arises from Superior vestibular nerve
Leads to Retrocochlear hearing loss
Gd enhanced MRI is the most sensitive investigation
Hitzelberg's sign is due to involvement of 7th nerve
Diseases of Inner Ear and Vestibular Schwannoma