Recovery rate and prognostic factors of peripheral facial palsy treated with integrative medicine treatment: a retrospective study

Abstract

Introduction: This study aimed to identify prognostic factors and develop a classification model for predicting recovery in patients with peripheral facial palsy.

Methods: Data from patients who received integrative medicine treatment with Bell's palsy and Ramsay-Hunt syndrome were collected. The change of House-Brackmann Grade (HB Grade) for 2 years from the onset and the factors presumed to be related to the prognosis were analyzed by reviewing electrical medical records retrospectively. The estimated recovery rates to HB Grade 2 and 1 were calculated by the Kaplan-Meier method. The factors affecting the prognosis were selected by using univariate Cox regression analysis. Subsequently, multivariate Cox regression analysis was performed on the selected factors. The factors derived from the Cox regression model were applied to the survival tree analysis model to establish the criteria for the classification of patients according to prognosis.

Results: 768 participants were included after screening. Based on the Kaplan-Meier method, the estimated recovery rates for HB Grade 2 and 1 for the 2 years were 98.2 and 83.3%, respectively. The univariate Cox regression analysis indicated that ten factors, including sex, diabetes, hemoglobin A1c, diagnosis, periauricular pain, hearing impairment, taste disorder, initial HB Grade, and average axonal loss (AAL) and maximum axonal loss (MAL) of nerve conduction study (NCS), affected prognosis. Finally, multivariate Cox regression showed that the AAL and MAL were related to prognosis. Five classification models predicting the 2-year estimated recovery rate established from the survival tree analysis were as follows: 100% (AAL < 70% and MAL < 80%), 87.1% (AAL < 70% and MAL ≥ 80%), 86.8% (70% ≤ AAL < 80%), 55.0% (80% ≤ AAL < 90%), and 24.2% (AAL ≥ 90).

Conclusion: The present results demonstrated that AAL and MAL of the NCS were significant factors in predicting the prognosis of peripheral facial palsy.

Keywords: Bell’s palsy; House-Brackmann facial grading system; Ramsay-Hunt syndrome; integrative medicine; prognostic factor; recovery.

Figure 1

The procedure of the integrative medical treatment.

Figure 2

Study flowchart.

Figure 3

The estimated recovery rate of all participants. (A) The left graph depicts the estimated recovery rate to House-Brackmann Grade 2. (B) The right graph depicts the estimated recovery rate to House-Brackmann Grade 1. The estimated recovery rates at 3-month intervals are shown at the bottom of both graphs. The estimated recovery rates and graphs were analyzed using the Kaplan–Meier method.

Figure 4

Estimated recovery rate by types of diagnosis. (A) The left graph depicts the estimated recovery rate to House-Brackmann Grade 2. (B) The right graph depicts the estimated recovery rate to House-Brackmann Grade 1. The estimated recovery rates at 3-month intervals are shown at the bottom of both graphs. The estimated recovery rates and graphs were analyzed using the Kaplan–Meier method. BP, Bell’s palsy; RHS, Ramsay-Hunt syndrome.

Figure 5

Classification according to prognosis using survival tree analysis. AAL, Average axonal loss; MAL, Maximum axonal loss.

Figure 6

Estimated recovery rate of five classifications by survival tree analysis. The Kaplan–Meier curves shows the 2-year estimated recovery rates in each group classified by AAL and MAL. The estimated recovery rates for each group at 3-month intervals are shown at the bottom of the graph. AAL, Average axonal loss; MAL, Maximum axonal loss.

Figure 7

Estimated recovery rate of three classifications by survival tree analysis. The Kaplan–Meier curves show the 2-year estimated recovery rates in each group classified by HB Grade. The estimated recovery rates for each group at 3-month intervals are shown at the bottom of the graph. HB Grade, House-Brackmann Grade.