True about Vestibular Schwannoma is
Meniere's disease is an impoant differential for acoustic neuroma as the patients suffer from similar symptoms. Meniere's is a cochlear pathology and acoustic neuroma is retrocochlear. Audiological diagnostics: Test Cochlear Retro- Cochlear S.I.S.I Positive ( >70%) Negative A.B.L.B Laddergram Converging Diverging Tone Decay Negative( <25 dB) Positive ( >25dB) Speech Audiometry SDS = 60-80% <40%, Roll over phenomenon B.E.R.A ( Wave V Latency) </= 4.2 msec >4.2 msec
Converging ABLB Laddergram
Recruitment phenomenon is present
High SISI score
Rollover phenomenon is seen
Diseases of Inner Ear and Vestibular Schwannoma