Comparative value of facial nerve grading systems

The Fisch Detailed Evaluation of Facial Symmetry (DEFS) and House-Brackmann grading system (HBGS) were compared by statistical examination for their reliability and interobserver variability. Furthermore, the correlation and agreement with a standard global evaluation were compared. Therefore 47 patients with facial palsy of different cause have been evaluated with the two systems, and the global overall evaluation was done by five otolaryngologists familiar with facial palsy. The DEFS showed a high reliability of 0.93 compared with a reliability of 0.77 with the HBGS (international standard requires a reliability of at least 0.8). The mean interobserver variability is 5.24% (SD = 3.2%) with the DEFS and 9.26% (SD = 5.0%) with the HBGS; with a confidence interval of 95%, it is 11.6% and 19.26%. The correlation of both gradings with the global evaluation was high, with r = 0.98 and r = 0.97. The DEFS shows an excellent agreement with the global overall evaluation in 41 (87%) of 47 cases and the HBGS in 32 (66%) of 47 cases.