Botulinum toxin-type A: could it be an effective treatment option in intractable trigeminal neuralgia?

Abstract

BackgroundBotulinum toxin type A (BTX-A) has been reported to have analgesic effects independent of its action on muscle tone, mostly by acting on neurogenic inflammatory mediators and controlling the neurotransmitter release of sensory and autonomic nerve terminals that are involved in many chronic painful conditions as chronic intractable trigeminal neuralgia (TN).The aim of our work was evaluating the efficacy, safety, and tolerability of BTX-A for the treatment of intractable idiopathic TN.MethodsThis was a randomized, single-blinded, placebo-control study carried out on 20 Egyptian patients with intractable TN. Patients received a one-time subcutaneous administration of BTX-A using “follow the pain” method. The primary efficacy measure was reduction in pain severity on the 10-cm VAS score as well as in paroxysms frequency from the baseline to week 12 (endpoint last observation carried forward [LOCF]). Secondary efficacy measures included QoL assessment and number of acute medications received from baseline to the endpoint.ResultsPain reduction at the 12-week endpoint was significant in BTX-A group (p<0.0001); VAS scores at endpoint LOCF relative to baseline for BTX-A group showed a decrease of 6.5 compared with a decrease of 0.3 for placebo, also there was a significant decrease in the number of acute medications and an increase in QoL functioning scale.ConclusionThese results indicate that BTX-A has a direct analgesic effect in patients with TN and can represent a therapeutic option for intractable cases.

The efficacy and safety of botulinum toxin type A in treatment of trigeminal neuralgia and peripheral neuropathic pain: A meta‐analysis of randomized controlled trials

“…with hemifacial spasm associated with trigeminal neuralgia secondary to an ectatic basilar artery was treated with BTX-A, and relief was gained not only from twitching but also from pain (Micheli, Scorticati, & Raina, 2002 BTX-A, VAS score, surface area of pain, and therapeutic coefficient F I G U R E 7 Forest plots of standard mean difference in pain score for BTX-A versus placebo at 1 month (a), 2 months (b), and 3 months (c), excluding the single-blind study (Shehata et al, 2013) F I G U R E 8 Forest plot of odds ratio (OR) in adverse events comparing BTX-A with placebo were reduced in all patients and for all branch trigeminal nerves studied (Piovesan et al, 2005). These findings indicated that BTX-A has a beneficial effect in the treatment of TN.…”

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.…”

“…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.…”

Trigeminal Neuralgia☆

“…Botulinum toxin A has shown favorable results as a therapy in a limited number of individuals (Allam et al, 2005;Guardini et al, 2014;Piovesan et al, 2005;Shehata et al, 2013). Botulinum toxin A has shown favorable results as a therapy in a limited number of individuals (Allam et al, 2005;Guardini et al, 2014;Piovesan et al, 2005;Shehata et al, 2013).…”