Low-dosed botulinum toxin in migraine without aura: A randomized, double-blind placebo-controlled crossover study

Botulinum toxin is a therapeutic option in chronic migraine. Dose-finding studies have not been conducted so far. Some authors reported that one injection in the corrugator muscle would do. Issue: We studied the effect of botulinum toxin (BTX) injections in patients with strictly unilateral migraine. Patients and Methods: 22 patients (ITT) were treated in a crossover design for 4 months with 2×5 units Botox® (injected in the corrugator muscle and next to occipitalis major nerv ipsilaterally). Aside from patient data and ADR (adverse drug reactions), we registered IQOLA SF36, SF-MQ SADP, OLBPDQ, VAS (intensity of pain and every day activities). The statistical evaluation was done by SPSS (V.13). Results: Nineteen patients (PP) could be assessed, aged 45.2±11.1 years, 17 of them female. There were no clinically relevant and/or statistically significant differences regarding the target parameters in the two injection intervals (example: VAS pain intensity p=0.702) with notable evidence of placebo effect (VAS with placebo before injection 61.4– after 6 weeks 45.1– good or excellent improvement (TOQ) 36.8% in the placebo group after 6 weeks). BTX proved superior in merely two aspects. The pain quality throbbing (SF-MPQ SA had initially been rated to be of strong intensity by 11 patients, after BTX only 4 of them still maintained this. Pain intensity (PPI) was described as being restrictive or horrible by 42.2% before injection, by 26.3% after 6 weeks and by 21.1% after 4 months. This was quoted in the beginning by 31.6% of the placebo group, after 6 weeks by 31.6% and after 4 months by 42.2%. 84.2% of the BTX-group and 63.2% of the placebo group wished for a reinjection when the study was finished. All in all, the injection of low-dosed botulinum toxin in unilateral migraine without aura does not produce any relevant or significant effects. An injection into the corrugator muscle alone can be considered ineffective. The place-value of the two injection sites remains undetermined. The study was funded by the work group Botulinum Toxin of DGN (German Society for Neurology).