Trigeminal neuralgia (TN) is severe and recurring pain distributed unilaterally along a branch of the trigeminal nerve [1,2]. The application of BTX-A to relieve TN was first reported in 2002, and its safety and effectiveness was later confirmed by series studies [3-13]. In 2012, our team conducted the first RCT study in this field, and obtained the prima facie evidence of BTX-A for TN. Subsequently, we took a different dose of BTX-A to carry out a larger RCT study, so far it is the only attempt [6]. The aim of this study was to explore an effective and safe dose of BTX-A for the treatment.

For this purpose, we conducted the RCT study since November 2012, and adopted local multi-point injection in 84 cases of classical TN with different doses of BTX-A. Eighty four patients were randomized into following groups: placebo (n=28); BTX-A 25U (n=27); BTX-A 75U (n=29). Follow-up visits were conducted every week after the injection to observe the pain severity, efficacy and adverse reactions at endpoint. The result showed BTX-A injection in TN is efficient and no significant difference between 25U and 75U groups. All adverse reactions were graded as mild or moderate.