Comparative Value of Facial Nerve Grading Systems
The Fisch grading system (Fisch 1981) and the House-Brackmann grading systems were compared by statistical examination for their reliability and interobserver variability. Furthermore their correlation and their agreement with a standard global evaluation were compared. Forty-seven patients with facial palsies of different etiology were evaluated with the two systems and with a global overall evaluation performed by five ENT surgeons familiar with facial palsy. The Fisch grading system showed a high reliability of 0.93 compared to a reliability of 0.77 with the House grading system (the international standard requires a reliability of at least 0.8). The mean interobserver variability was 5.24% (SD = 3.2) for the Fisch grading system and 9.26% (SD = 5.0) for the House-Brackmann grading system. With a confidence limit of 95% the interobserver variability is not more than 11.6% for the Fisch grading system and 19.26% for the House grading system. The correlation of both gradings with the global evaluation was high with r=0.98 and r=0.97, respectively.