Botulinum Toxin Treats MS Spasticity, But Support and Rehab Seen as Crucial to Long-term Use

Spasticity in multiple sclerosis (MS) patients can be eased through a combination of botulinum toxin type A (BoNT-A) injections and rehabilitation. However, caregiver support is required to keep patients on this treatment, according to results of a retrospective analysis.

The study “Determinants of botulinum toxin discontinuation in multiple sclerosis: a retrospective study” was published in the journal Neurological Sciences.

Spasticity, a muscle control disorder characterized by tight or stiff muscles, is a major MS symptom. The condition is significantly detrimental to patients’ quality of life, affecting their general mobility and balance.

Several oral anti-spasticity drugs are available. However, “treatment of spasticity in MS is frequently challenging because of the complex clinical picture and the undesired effects associated with oral therapy, such as fatigue, dizziness, and hypotension,” the researchers wrote.

Previous studies show that BoNT-A, a toxin that blocks nerve activity in muscles, is an effective therapy for the management of MS-related spasticity.

The long-term effectiveness and persistence of BoNT-A use in patients with MS-related spasticity, however, remains poorly investigated.

The research team in Italy proposed “to investigate the long-term persistence to treatment with BoNT-A for MS-related spasticity and the determinants of BoNT-A discontinuation in daily clinical setting.”

It performed a retrospective analysis of data on MS patients who had undergone BoNT-A injections and were routinely followed in the clinic (at least two visits per year). Before starting the injections, patients were clinically evaluated, including an assessment of their level of spasticity (using the Modified Ashworth Scale or MAS), and degree of disability (through the Expanded Disability Status Scale or EDSS).

In total, the researchers reviewed data from 185 patients, out of which 121 were considered in their final analysis.

They observed that, at the end of the follow-up period (12 years), 44% of the patients in the analysis were still being treated with BoNT-A, but 56% had discontinued treatment.

Among those who stopped, 37% did so due to loss of treatment efficacy, and 13% for logistic problems. Only 6% of patients discontinued the treatment due to adverse events, which were categorized as mild to moderate and fully reversible.

These results, the team wrote, support BoNT-A as a safe and well-tolerated treatment, even when administered for long periods.

The analysis also identified the absence of caregiver support and lack of regular rehabilitation as two independent predictors for BoNT-A discontinuation.

Overall, these results “confirm the beneficial effect of combining BoNT-A injections with rehabilitation and highlights the crucial role of caregivers for achieving better long-term outcomes in people with MS suffering from spasticity,” the team concluded.