Botulinum toxin for the management of spasticity in multiple sclerosis: the Italian botulinum toxin network study

Background: Botulinum toxin (BT) is an effective and safe treatment for spasticity, with limited evidence in multiple sclerosis (MS). We aim to describe the use of BT for the management of MS spasticity in the clinical practice, its combination with other anti-spastic treatments in MS and possible MS clinical correlates. Methods: This is a multicentre cross-sectional observational study including 386 MS patients, receiving BT for spasticity in 19 Italian centres (age 53.6 ± 10.9 years; female 228 (59.1%); disease duration 18.7 ± 9.2 years; baseline Expanded Disability Status Scale (EDSS) 6.5 (2.0–9.0)). Results: BT was used for improving mobility (n = 170), functioning in activities of daily living (n = 56), pain (n = 56), posturing-hygiene (n = 63) and daily assistance (n = 41). BT formulations were AbobotulinumtoxinA (n = 138), OnabotulinumtoxinA (n = 133) and IncobotulinumtoxinA (n = 115). After conversion to unified dose units, higher BT dose was associated with higher EDSS (Coeff = 0.591; p < 0.001), higher modified Ashworth scale (Coeff = 0.796; p < 0.001) and non-ambulatory patients (Coeff = 209.382; p = 0.006). Lower BT dose was used in younger patients (Coeff = − 1.746; p = 0.009), with relapsing-remitting MS (Coeff = − 60.371; p = 0.012). BT dose was higher in patients with previous BT injections (Coeff = 5.167; p = 0.001), and with concomitant treatments (Coeff = 43.576; p = 0.022). Three patients (0.7%) reported on post-injection temporary asthenia/weakness (n = 2) and hypophonia (n = 1). Conclusion: BT was used for spasticity and its consequences from the early stages of MS, without significant adverse effects. MS-specific goals and injection characteristics can be used to refer MS patients to BT treatment, to decide for the strategy of BT injections and to guide the design of future clinical trials and observational studies.