Abstract: Objective To compare the therapeutic effects and adverse events of gentamicin and betamethasone on primary trigeminal neuralgia.Methods Forty patients with primary trigeminal neuralgia were allocated into two groups to receive a peripheral nerve block with lidocaine combined with gentamicin or betamethasone,respectively,once a week for 5 weeks.Their pain intensity were assessed using visual analogue scale(VAS)before treatment and once a week just prior to every treat.We continued to make such assessments every month until 3 months after treatment.Their pain relief rate and the occurrence of adverse events were also evaluated.Results The VASvalue of patients in gentamicin group and betamethasone group decreased significantly after treatment.Compared with the betamethasone the decreases in VASvalue induced by gentamicin were lower during the first 2 weeks,but there were no significant differences between these two groups at other observing points.In addition,no severe adverse events was observed in patients with either drug at the dosage we used.Conclusion Gentamicin is the optimal choice for patients with primary trigeminal neuralgia cases that can not be treated by corticosteroids.

Key words: primary trigeminal neuralgia, gentamicin, betamethasone, nerve block