Two doses of botulinum toxin type A for the treatment of trigeminal neuralgia: observation of therapeutic effect from a randomized, double-blind, placebo-controlled trial

Abstract

BackgroundIn the majority of cases, trigeminal neuralgia (TN) is a unilateral condition with ultra-short stabbing pain located along one or more branches of the trigeminal nerve. Although prophylactic pharmacological treatment is first choise, considering of insufficient effect or unacceptable side effects, neurosurgical treatment or lesion treatment should be considered. In addition to all these procedures mentioned above, one approach has been based on local intradermal and/or submucosal injections of Botulinum Toxin Type A (BTX-A).MethodsWe conducted a randomized, double-blind, placebo-controlled 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, and the overall duration of the study for each patient were 8 weeks to observe the pain severity, efficacy and adverse reactions at endpoint.ResultsThe visual analogue scale (VAS) scores of 25U and 75U groups reduced significantly compared to placebo as early as week 1, and sustained until week 8 throughout the study. There was no significant difference in VAS between 25U and 75U groups throughout the study. The response rates of 25U group (70.4%) and 75U group (86.2%) were significantly higher than placebo group (32.1%) at week 8, and there was no significant difference between 25U and 75U groups. Evaluation of the Patient Global Impression of Change (PGIC) demonstrated that 66.7% (25U group) and 75.9% (75U group) of the patients reported that their pain symptoms were ‘much improved’ or ‘very much improved’ versus 32.1% of the placebo group, and there was also no significant difference between 25U and 75U groups. All adverse reactions were graded as mild or moderate.ConclusionsBTX-A injection in TN is safe and efficient. It is a useful treatment for refractory TN. Lower dose (25U) and high dose (75U) were similar in efficacy in short-term.

OnabotulinumtoxinA for trigeminal neuralgia: a review of the available data

“…The abscesses resolved with no further complications after antimicrobial therapy, but the fact that this complication occurred prompted us to stop injecting BoNT/A in the dental arches and gums. This complication was not reported by Li et al 22 or Zhang et al 24 , whose studies included some patients who received BoNT/A submucosally. None of the pa- 10 reported any side effects.…”

“…There was no difference in functional impact scores between the BoNT/A and placebo groups. Finally, Zhang et al 24 studied the effects of different dosages of BoNT/A in 84 patients with classical TN who had failed to respond to recent treatment for TN (mean pain intensity score ≥ 4, mean attack frequency ≥ 4/day; course > 4 months) and were randomized to receive saline, 25 U/mL or 75 U/mL of BoNT/A intradermally and/or submucosally (total doses were divided by 20 and applied at 20 points). Subjects were excluded if they had coagulopathy or severe heart, liver, kidney or other organ dysfunctions; were at risk if exposed to BoNT/A (e.g., myasthenia gravis); had skin problems at injection sites; had used drugs that damage neuromuscular junctions in the previous seven days; had a significant unstable medical condition or mental disease; had a history of substance abuse; or were pregnant, nursing, planning a pregnancy or using unreliable contraception methods.…”

Two Doses of Botulinum Toxin Type A for the Treatment of Trigeminal Neuralgia: Observation of Therapeutic Effect from A Randomized, Placebo-Controlled Trial

“…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][4][5][6][7][8][9][10][11][12][13]. In 2012, our team conducted the first RCT study in this field, and obtained the prima facie evidence of BTX-A for TN.…”

“…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.…”

“…But until 2012, it still has doubts about the effect of BTX-A in treatment of TN [21]. Several RCT studies [4,6,9,22] including us, seem to prove the role of BTX-A in the treatment of TN, but it doesn't seem to be universally accepted. Because the sample of the studies which was mentioned before is small and the design has many limitations, so it is difficult to be widely accepted.…”