Hearing improvement after middle fossa resection of vestibular schwannoma.

摘要: OBJECTIVE: The preoperative, intraoperative, and postoperative variables of patients experiencing hearing improvement after middle fossa resection vestibular schwannomas were evaluated as potential prognostic indicators. STUDY DESIGN: Retrospective case review with new objective data collected on documented improvement. SETTING: California Ear Institute at Stanford University Hospital, a tertiary referral center. PATIENTS: patient group consisted 30 consecutive undergoing approach to schwannoma between October 24, 1994, November 11, 1998. INTERVENTION: Hearing preservation surgery via the cranial was performed all patients. MAIN OUTCOME MEASURES: Pure-tone averages (PTAs) speech discrimination scores (SDS) used document preoperatively postoperatively. Preoperative electrophysiologic studies auditory brainstem response, electronystagmography, electrical neuronography, transient evoked otoacoustic emissions, distortion product emissions evaluated. Intraoperative continuous nerve action response tracings reviewed. Postoperative obtained when possible whose improved. Statistical analysis completed using Student's t test chi-square test. RESULTS: Seventeen (57%) tumors ranging from 2 31 mm maintained Among preservation, 7 (41% or 23% overall group) exhibited (PTA improved by > =5 dB and/or SDS =12%). Three these moved nonfunctional (AAOHNS class C/D) functional A/B) categories. All who enjoyed had preoperative absence abnormality ABRs. No normal ABR experienced also lower caloric function electronystagmography compared entire (p < 0.02) more likely have superior tumors. differences noted for neurography emissions. CONCLUSIONS: Middle offers possibility treatment. chance is significantly higher than other forms treatment such radiation therapy translabyrinthine surgery. Although may be an indicator poor prognosis those enjoy come abnormal Other factors identified associated include PTA 2, decreased electronystagmographic (as tumors). range surgical in some previously thought candidates attempts. continue many months