True about Vestibular Schwannoma is: (A) Converging ABLB Laddergram, (B) Recruitment phenomenon is present, (C) High SISI score, (D) Rollover phenomenon is seen
Answer is D. 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