Clinical Factors that Influence the Prognosis of Facial Nerve Paralysis and the Magnitudes of Influence

Objective: To show the significance of various factors when predicting the outcome of facial nerve paralysis. Design: Retrospective chart review. Setting: Nihon University Itabashi Hospital in Tokyo. Subjects Four hundred sixty‐seven patients with facial paralysis who visited the hospital within 14 days of disease onset. Methods: The failure rate of complete recovery was studied for each of these nine factors: sex, age, varicella‐zoster virus (VZV) infection as the cause of paralysis, initial severity of paralysis, number of days from onset of paralysis to the beginning of medical treatment, nerve excitability test (NET), stapedial reflex, lacrimal secretion, and severity of facial paralysis 1 month after onset. These factors were analyzed by logistic regression. Results: Logistic regression clarified that age, VZV infection, NET response, loss of stapedial reflex, and the state of paralysis 1 month after the onset had statistical significance for the prognosis of facial paralysis. The poor recovery rate was greater than 50% in the patients who exhibited abnormal responses on NET or failed to attain recovery to grade III or better during the 1‐month period after the onset of paralysis. These findings were therefore considered as high risk factors for the prognosis. The poor recovery rate was between 25% and 50% in patients who were 50 years or older or whose initial grading of paralysis was V or worse. These findings were classified as moderate risk factors. Patients with VZV‐caused paralysis and loss of stapedial reflex had poor recovery rates of below 25%, and these were classified as low risk factors. Conclusion: It is possible to predict the prognosis of facial paralysis on the basis of several clinical findings. NET response, severe initial paralysis, age 50 years or older, and, as a second‐stage factor, severity of facial paralysis 1 month after the onset were found to be especially important factors for predicting the prognosis of facial paralysis.