The value of electroneurography in acute peripheral facial nerve palsy

Objective: To evaluate the use of electroneurography (ENoG) as a prognostic indicator in acute peripheral facial paralysis in a general hospital. Design: Retrospective study. Participants: The patients had been treated for a sudden onset unilateral facial paralysis during an 18 month period (2005. 7-2006.12). Main outcome measures: ENoG was performed 7 to 14 days after the onset facial palsy. The recovery of facial nerve function was documented by Yanagihara's grading system. All patients were followed monthly until recovery or up to 6 months after onset. Results: One-hundred ten patients with acute peripheral facial paralysis, including Bell's palsy (86%), Ramsay-Hunt Syndrome (6%), trauma (6%), and others (2%) underwent ENoG test. Patients were divided into 5 classes according to the ENoG value; [40%-] 41%, [20-40%] 24%, [10-20%] 9%, [0-10%] 11%, [0%] 15%. The recovery rate in each group was; [40%-] 98%, [20-40%] 96%, [10-20%] 90%, [0-10%] 58%, [0%] 24%. The patients whose ENoG values were greater than 10 % showed a 96 % chance of recovery (sensitivity 0. 88, specificity 0. 86). Patients with a greater ENoG value recovered significantly faster. Conclusion: ENoG provides accurate information predicting the prognosis and recovery rate of patients with facial palsy.