Application Of Facial Nerve Grading System2.0in Analyzing Post-operative Facial Nerve Function Of Vestibular Schwannomas

Objective:To compare Facial nerve grading system2.0(FNGS2.0) with House Brackmann grading system (HBGS) in analyzing post-operative facial nerve function of vestibular schwannomas(VS).Methods:28post-operative patients of Vestibular Schwannoma who were involved in department of neurosurgery during December2012to December2013were selected for the analyze of facial nerve function. Videos were used for grading metarial and a series of motions were captured as standard motion including eyebrow raising, eye closure, snarl, whistle, wide smile et al. Translation were done from English to Chinese for the sake of reading and grading.10raters rating the facial movement videos of28post-operative patients using the two scale. Methods for statistical calculation and analyze including Intraobserver agreement, interobserver correlation, reliability calculations for multiple raters, Sensitivity analysis and interobserver agreement between each region in FNGS2.0, with the assistance of SPSS.Result:28patients were analysed with two method resulting in560data. HBGS give a result of grade â…  in45cases, and grade â…¡ in67, grade â…¢in104, grade â…£ in56and grade â…¤ in8, no grade Vlwere fund. FNGS2.0give a result of grade â…  in34cases, and grade â…¡ in62, grade â…¢in112, grade IV in71and grade V in1, no grade â…¥were fund. The grade assigned using HBGS was the same as the grade assigned using FNGS2.0in356of560(62.57%) cases. Intraobserver agreement were high with a mean r of0.802. The range of interobserver correlation was0.578to0.923(mean0.744) for HBGS and0.791to0.943(mean0.866) for FNGS2.0. Reliability calculations for multiple raters and Sensitivity analysis were good for both HBGS and FNGS2.0. Percentage of exact agreement was35.7%for HBGS and0%for FNGS2.0. The interobserver agreement between each region in FNGS2.0were high, with a mean r of0.819in brow area and0.845in eye area. In NLF area it was0.829. In mouth area it was0.800. and in synkinesis it was0.731.Conclusion:The FNGS2.0and HBGS are both excellent facial nerve grading system with good reliability and sensitivity. The FNGS2.0shows high agreement with HBGS while maintain a good continuity of data, meanwhile FNGS2.0has a better control of interobserver bias with high%of exact of agreement. Another point is that FNGS2.0has detailed facial evaluation, which could define tiny changes on motion. All in all, FNGS2.0is a good replacement of HBGS in the evaluation of facial nerve of post-op VS patients.