Significance and reliability of the House-Brackmann grading system for regional facial nerve function

Abstract

Objective: To determine the reliability of the House-Brackmann facial nerve grading scale in the setting of differential function across its branches. Study Design: Prospective. Subjects and Methods: Eleven physicians with different levels of clinical experience and three upper-level medical students were provided with digital video clips of 11 patients with differential facial nerve functioning, and asked to report facial nerve function as a traditional global score and as a regional score on the basis of the House-Brackmann scale for the forehead, eye, nose, and mouth. Agreements between the traditional global score and the regional scores, as well as inter-rater agreement, were analyzed. Results: In patients with variable facial weakness, a single House-Brackmann score did not fully communicate facial function. The single House-Brackmann score most strongly correlated with the regional scoring of the nose/midface (59%), followed by the mouth (51%), eye (48%), and forehead (35%). Overall inter-reader reliability was relatively strong for the midface (kappa = 0.503) and global scores (kappa = 0.541), followed by the mouth (k = 0.419), the forehead (k = 0.330), and the eye (k = 0.302). There was a marked tendency for reader agreement to increase among those with more clinical experience. Conclusion: Regional assessment using the House-Brackmann grading scale more fully communicates facial function and increases in reliability with experience.