Continuous Increase of Efficacy under Repetitive Injections of Botulinum Toxin Type/A beyond the First Treatment for Adult Spastic Foot Drop.

The objective of this study was to quantify the increase in efficacy during the first four cycles of treatment with botulinum toxin type/A (BoNT/A) in 24 free-walking BoNT/A naïve adult patients with post-stroke hemispasticity and spastic foot drop. Patients were followed over 390 days and received five injections of 800 U aboBoNT/A every three months. Patients assessed the treatment effect at eight visits using a global assessment scale, physicians scored the muscle tone at the ankle joint, measured active and passive ranges of motion (aRoMs, pRoMs) at the knee and ankle joint and determined the distance patients succeeded to walk during a minute. Patients' assessments significantly (p < 0.006) increased with time and significantly correlated with all parameters measured. The best correlation (r = 0.927; p < 0.0001) was found with the sum of the aRoMs of knee and ankle joint. After one year of treatment outcome measures were better than and significantly correlated with the peak effect of the first injection. This correlation was higher for pRoMs (r = 0.855; p < 0.00001) compared to aRoMs (r = 0.567; p < 0.009). When BoNT/A treatment of the spastic foot in chronic hemispasticity is performed regularly every three months for at least one year, patients will experience a significant increase of benefit beyond the first treatment, but have to learn how to adapt to and use the new degree of freedom induced by the injections.

Comparing soleus injections and gastrocnemius injections of botulinum toxin for treating adult spastic foot drop: a monocentric observational study.

OBJECTIVE: Outcome differences between selective abobotulinumtoxin type A (aboBoNT/A) injections into the soleus (SOL) and gastrocnemius (GAS) muscles were investigated in post-stroke patients with spastic foot drop. METHODS: A monocentric observational study was conducted at a university hospital botulinum toxin clinic including 24 free-walking adult, botulinum toxin-naive patients with post-stroke hemiplegia. AboBoNT/A (800 MU in 4 mL saline) was injected into the SOL or GAS muscle under electromyographic guidance. After 30 days post-injection, the effect of aboBoNT/A injection was assessed by patients. The treating physician scored spasticity and measured angles at the knee and ankle joint and gait speed. RESULTS: After 30 days, significant improvements of subjective and objective outcome measures were observed. No significant difference was observed in the modified Ashworth scale, gait speed, ankle and knee angles, or their angle combinations between the SOL and GAS groups. Tendencies toward greater active range of motion (RoM) improvement in the SOL group and passive RoM improvement in the GAS group were observed. The difference between active and passive ankle extensions plus knee flexions was significantly larger in the SOL group. CONCLUSIONS: Selective 800 MU aboBoNT/A injections into the SOL or GAS muscle were effective but without relevant clinical difference.