A proof-of-concept study on the effectiveness of botulinum toxin on spasticity plus syndrome in multiple sclerosis

Background: Botulinum toxin (BoNT) might improve spasticity-plus syndrome (SPS) in multiple sclerosis (MS) through peripheral inhibition of muscle contraction and central modulation of pain pathways, as hypothesized for migraine headaches. Hereby, we aim to explore changes in migraine headaches and SPS symptoms after BoNT treatment for MS-related spasticity. Methods: We recruited 9 people with MS who received BoNT injection due to spasticity and with significant impact due to migraine headaches (mean age 48.6 ± 6.4 years; 55.5% females; median EDSS 6.0). At the time of BoNT injection and after 1 and 3 months, patients filled in the Migraine Disability Assessment Test (MIDAS), the short form Headache Impact Test (HIT-6), the Migraine Specific Quality of Life Questionnaire (MSQ), the Beck Depression Inventory-II (BDI-II), the Fatigue Severity Scale (FSS), and the Pittsburgh Sleep Quality Index (PSQI). Results: On linear mixed-effect models, we observed significant improvements in MIDAS (Coeff=-2.61; 95%CI=-4.39, -0.83; p = 0.004), HIT-6 (Coeff=-1.89; 95%CI=-3.34, -4.45; p = 0.010), FSS (Coeff=-3.14; 95%CI=-5.62, -0.66; p = 0.013), and sleep efficiency (Coeff=-2.28; 95%CI=-4.17, -0.39; p = 0.018) and disturbance (Coeff=-0.18; 95%CI=-0.30, -0.06; p = 0.002), which were proportional to BoNT dosing. Conclusion: BoNT may represent a promising treatment for the management of SPS symptoms, possibly thanks to its peripheral and central effects.