Acoustic neuroma commonly arises from:

Ans. B Inferior vestibular nerve Vestibular schwannomas are benign, well circumscribed, encapsulated tumors that arise from Schwann cells of the vestibular nerve, hence the term vestibular schwannoma or vestibular neurilemmoma. Historically, the superior vestibular nerve sheath was thought to be the site of origin, giving rise to nearly two-thirds of tumors. More recent reviews show the inferior vestibular nerve to be the predominant site of origin for these tumors. The nerve or origin is identifiable in 33 to 74% of cases, and when clearly seen, shows the tumor originating from the inferior vestibular nerve over twice as often and in upto 94% in some repos. Rarely the cochlear poion of the eight cranial nerve/facial nerve is the site of schwan noma origin.