True about Vestibular Schwannoma is
Converging ABLB Laddergram
Recruitment phenomenon is present
High SISI score
Rollover phenomenon is seen
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
Diseases of Inner Ear and Vestibular Schwannoma