Safety and efficacy of botulinum toxin A for the treatment of spasticity in amyotrophic lateral sclerosis: results of a pilot study

Spasticity can be a very disabling problem in some amyotrophic lateral sclerosis (ALS) phenotypes, such as upper motor neuron-dominant ALS (UMN-D ALS) and primary lateral sclerosis (PLS). Our aim is to describe the safety and efficacy of botulinum toxin A (BoTox-A) for improving gait in those ALS phenotypes. UMN-D ALS and PLS outpatients experiencing gait disturbances, secondary to moderate-to-severe spasticity despite optimized oral medication, were offered BoTox-A treatment. Stretching exercises were indicated to complement BoTox-A effect, and ankle–foot orthotics were prescribed when appropriate. Tolerance (muscle strength, disease progression rate) and efficacy (10-m walk test) were measured at baseline and after treatment. Eight out of 122 ALS outpatients were offered BoTox-A treatment. One declined and the other seven were administered BoTox-A in the lower limbs, every 5–8 months. All of them experienced improvement in the clinical outcome and all but one referred subjective improvement. Moreover, after a median follow-up of 16 months and three injections, BoTox-A effect was maintained with no adverse events. This study provides class IV evidence that BoTox-A is safe , and could be beneficial in the short term and long term in a subset of ALS patients with moderate-to-severe spasticity.