Botulinum Toxin In Trigeminal Neuralgia: Which is the Best Way of Delivery?

Context: Botulinum toxin has been widely shown to have analgesic effects independent of its action on muscle tone, mostly by acting on neurogenic inflammatory mediators and reducing the release of neurotransmitters at the sensory nerve or the autonomic nerve terminals. Objective: The aim of this study is to try and understand the differences that could exist between injecting the painful zone or injecting a possible trigger zone (TZ) in case of trigeminal neuralgia. Methods: 28 patients (26 female, 2 male), with an average age of 61 years (41-88 years), were injected with type A botulinum toxin, the dose which was used varied between 15 and 50 U Botox* . 16 (57%) were injected over the entire painful area and only 12 (43%) were injected in the TZ. Results: Overall, we can note an efficacy of 100% in the case of injection in the area of referred pain and 83% in the case of injection in the TZ alone, the calculation of the p-value in Fisher’s exact test showing no statistically significant difference between the two techniques. Conclusion: This study confirms the efficacy of the toxin and the lack of significant difference between injecting the painful zone or injecting a possible TZ. In this later case, treating it directly would seem to be the first choice, according to the average dose of botulinum toxin used.