Ans. is 'b' i.e., Corneal o Earliest nerve involved by acoustic neuroma - Vth nerve/trigeminal nerve. o The earliest manifestation of V* nerve involvement is decreased corneal sensitivity leading to loss of corneal reflex, Clinical features of acoustic neuroma o The clinical features depend on the extent of the tumor and involved structure When tumor the is still confined to the internal auditory canal Cochleovestibular symptoms are the earliest symptoms of acoustic neuroma when tumour is still confined to the internal auditory canal. The commonest presenting symptoms are unilateral deafness or tinnitus, or a combination of both. Hearing loss is retrocochlear sensorineural type. There is marked difficulty in understanding speech, out of proportion to the pure tone hearing loss, a characteristic feature of acoustic neuroma. Vestibular symptoms are imbalance or unsteadiness. True vertigo is very rare. When the tumor extends beyond 1AC and involves other structures 1cranial nerve It is the earliest nerve to be involved. There is reduced corneal sensitivity and loss of corneal reflex which is the earliest sign of acoustic neuroma. Numbness or paraesthesia of face may occur. Involvement of Vth nerve indicates that tumor is roughly 2.5 cm in diameter and occupies the CP angle. VIIth nerve:- Sensory fibers of the facial nerve are involved. There is hypoesthesia of the posterior meatal wall (Hitzelberg's sign), loss of taste, and loss of lacrimation on Schirmer's test.:- Motor fibers are more resistant. IXth and Xth nerves:- Dysphagia and hoarseness due to palatal, pharyngeal and laryngeal paralysis. Brainstem Ataxia, weakness, numbness of arms & legs, exaggerated tendon reflexes. Cerebellum Ataxia, Dysdiadochokinesia, Nystagmus. Due to raisedICT:- Headache, neusea, vomiting, diplopia due to VI* nerve involvement, and papilloedema.