Effects of Repeated Use of Botulinum Neurotoxin Type A (BoNT/A) Free of Complexing Proteins in the Spastic Equinovarus Foot in Stroke Patients: A Randomized Clinical Trial

Spasticity is present in 38% of patients at six months after stroke. Equinovarus foot, with or without claw toes and striatal foot, is especially common. There is a weak to moderate evidence in favor of the use of botulinum neurotoxin type A (BoNT/A) in the equinovarus foot, stiff-knee and in other patterns that may interfere with gait ability. Specifically, BoNT/A increases walking speed in stroke patients with spastic equinovarus foot.

Repeated use of BoNT/A may lead to the appearance of neutralizing antibodies, so its effect may decrease over successive infiltrations. Among the differential characteristics of incobotulinumtoxinA (Xeomin®) there is a reduced inactivated botulinum neurotoxin content and the lack of complexing proteins, which would diminish antigenicity and not suppose a decrease of the effect before successive infiltrations.

The objective of this project is to determine the effect on walking speed of repeated use of BoNT/A in post-stroke spinal equinovarus foot in three consecutive injections at 6-month intervals and to investigate whether the sustainability of the effect is greater in incobotulinumtoxinA (Xeomin®) than in onabotulinumtoxinA (Botox®). All patients will receive 200-300 units of BoNT/A (Xeomin ® or Botox ®) that will be distributed according to the individual clinical pattern of spastic equinovarus foot.