Acoustic neuroma Chunfu dai m,d ph. d
Acoustic neuroma Chunfu Dai M.D & Ph.D
Background Originate from vestibular branch of acoustic nerve Histologic feature schwannoma neuroma, neurolemmoma Predilection :30-50 Unilateral: majority Bilateral: Type II acoustic neuroma
Background ◼ Originate from vestibular branch of aucoustic nerve ◼ Histologic feature: schwanoma, neuroma, neurolemmoma ◼ Predilection: 30-50y ◼ Unilateral: majority ◼ Bilateral: Type II acoustic neuroma
Pathology Predominate, internal auditory canal Extension to CPA Compression on brainstem and brain hydrops Anterior trigeminal nerver Medial: abducent nerve Inferior:ⅨXXI,XI
Pathology ◼ Predominate: internal auditory canal ◼ Extension to CPA ◼ Compression on brainstem and brain hydrops ◼ Anterior: trigeminal nerve, ◼ Medial: abducent nerve ◼ Inferior: IX, X, XI, XII
Clinical presentations Hearing loss and tinnitus Progressive HL 90% SDS reduction 10% of patients complain of sudden HL Unbalance Otalgia and compression due to depression of sensor fiber of facial nerve Involvement of trigeminal nerve Compression of cerebellum and brainstem ataxia, nystagmus and intracranial hypo- pressure
Clinical presentations ◼ Hearing loss and tinnitus ◼ Progressive HL 90% ◼ SDS reduction ◼ 10% of patients complain of sudden HL. ◼ Unbalance ◼ Otalgia and compression due to depression of sensor fiber of facial nerve ◼ Involvement of trigeminal nerve ◼ Compression of cerebellum and brainstem: ataxia, nystagmus and intracranial hypopressure
Work-up Audiometry PTA: threshold elevated in high frequency a tone decay test: positive Speech audiometry u Acoustic impedance ABR: latency of wave V prolongs, or wave V disappears Acoustic emission
Work-up ◼ Audiometry ◼ PTA: threshold elevated in high frequency ◼ tone decay test: positive ◼ Speech audiometry ◼ Acoustic impedance ◼ ABR: latency of wave V prolongs, or wave V disappears ◼ Acoustic emission
Work-up Vestibular function Neurologic exam Image study 口 CT shows enlargement of internal auditory canal MRI
Work-up ◼ Vestibular function: ◼ Neurologic exam ◼ Image study ◼ CT shows enlargement of internal auditory canal ◼ MRI
Managements u Surgery Middle cranionectomy useful hearing Translabyrinectomy a no useful hearing Nice exposure of facial nerve
Managements ◼ Surgery ◼ Middle cranionectomy: useful hearing ◼ Translabyrinectomy: ◼ no useful hearing ◼ Nice exposure of facial nerve
Managements i Retro-sigmoid sinus approach Inferior occipital approach Big tumor >3cm Nice exposure tumor
Managements ◼ Retro-sigmoid sinus approach: ◼ Inferior occipital approach: ◼ Big tumor >3cm ◼ Nice exposure tumor
Managements No surgical intervention y-Knire a observation
Managements ◼ No surgical intervention ◼ -Knife ◼ observation
