BACKGROUND: There are a lot of researches on the protective action of calcium channel blocker(CCB) on diabetic peripheral neuropathy, but the dosage and the effect on injured nerve need to investigate further in clinical application.OBJECTIVE: To observe the results of electrophysiologic assessment of the effect of CCB flunarizine at different dosages on Bell' s palsy after 1-month treatment.DESIGN: Randomized grouping, blank control and l-month follow up.SETTING: Department of Neurology, First Affiliated Hospital of Nanjing Medical University.PARTICIPANTS: Totally 35 patients with Bell' s palsy, including 19males and 16 females aged from 16 to 58 and the mean age of 32. 8, were selected from Outpatients of the Department of Neurology, the First Affiliated Hospital to Nanjing Medical University from November 1999 to May 2001. The course of disease was ≤ 3 days. Patients were without any treatment, and all of the facial nerve palsy was complete. According to random samplings, all patients were divided randomly into control group (basic treatment group) with 12 cases and treatment groups with 10 cases in first subgroup and 13 in second subgroup.METHODS: Basic treatment: 1 mg/kg per day prednisone(the maximal dosage ≤ 60 mg/day) was taken once every day and reducing dosage by half every 5 days, with a course of therapy for 15 days. 500 μg methycobal was taken orally three times a day and 25 mg fursulthiamine also orally three times a day. Ultrashort wave physiotherapy was taken once a day for 15 days. On the basis of the basic treatment, patients in the first subgroup accepted 5 mg flunarizine once every night, and 10 mg flunarizine once every night was given to the patients in the second subgroup. The latency and amplitude of Blink response were checked before treatment and after 1-month treatment.MAIN OUTCOME MEASURES: The latency and amplitude of Blink response in every group after 1-month treatment.RESULTS: According to the imagery analysis, 35 patients entered the resulting analysis. Before treatment, the 3 groups of blink responses were all efferential blocking in facioplegic side, and in addition, R1 and R2 all disappeared. After treatment for 1 month, Blink response of R1, R2 appeared. The latency of R1 and R2 in the second treatment group was better than that in control group[ (9. 608 ± 0. 575) ms, (31. 869 ± 2. 934) ms,(11.208±1.490) ms and (37. 583 ±5. 408) ms, P ＜0.01], but there were no differences in this respect between the first treatment group and the control group. The ipsilateral amplitudes of Blind response in the three groups were not different after 1-month treatment.CONCLUSION: After 1-month treatment with flunarizine(10 mg/day),the recovery of facial nerve function can be promoted, but the protective effect of flunarizine(5 mg/day) on peripheral nerve is not superior to that with normal treatment. The mechanism and the proper dosage are not observed further in this study.