Effects of botulinum toxin guided by electric stimulation on spasticity in ankle plantar flexor of children with cerebral palsy: a randomized trial

Abstract

To compare the effects of botulinum toxin A (BTX-A) injection guided by electric stimulation combined with physiotherapy, with physiotherapy only on the spasticity of the ankle plantar flexor in children with cerebral palsy (CP). After signing the informed consent, 43 children with CP, aged 52.4 +/- 13.2 months (35 to 82 months), were randomly assigned into 2 groups, (1) BTX-A group (n = 23) treated with BTX-A injection guided by electric stimulation and (2) physiotherapy alone group (n = 20). Children in BTX-A group received injection of HengLi BTX-A in the ankle plantar flexors. A maximum dose of 12 units of BTX-A per kilogram body weight and maximumly 10 units of BTX-A per site were administered. Localization technique was the use of electrical stimulation guidance. Physiotherapy and ankle-foot orthosis were applied to children at 72 hours after injection in BTX-A group and at the time of being recruited into physiotherapy group. Ten days after entering into the study, the program was applied by the parents. Demographic data, including age, gender, number of the spastic lower limbs, affected side (left or right) were recorded. Clinical assessments included the range of passive movement (PROM) measured by goniometer while children maintained the knee extended, modified Ashworth scale (MAS), composite spasticity scale (CSS), D and E dimensions of the Gross Motor Function Measure (GMFM), and walking velocity (WV) was determined before treatment and at 2 weeks, 1, 2, and 3 months after treatment. No statistically significant differences were found in age, gender, number of the spastic lower limbs, affected side, as well as clinical assessments (PROM, MAS, CSS, GMFM and WV) before treatment between the 2 groups (P > 0.05). All the children showed a reduction of spasticity (PROM, MAS and CSS) after 2 weeks, 1, 2, and 3 months of treatment (P < 0.05). When compared with the baseline findings, the improvement of standing and walking (GMFM), walking velocity were statistically significant after 2 weeks, 1, 2, and 3 months of treatment (P < 0.05). Furthermore, the differences of PROM, MAS and CSS between the 2 groups at 2 weeks, 1, 2, and 3 months examination were also statistically significant (after 3 months of treatment: t(PROM) = 6.48, t(MAS) = 9.74, t(CSS) = 9.59; P < 0.05). The difference in GMFM between the 2 groups was statistically significant (t(1M) = 2.20, t(2M) = 3.26, t(3M) = 4.13; P < 0.05) at 1, 2, and 3 months after treatment. The difference of WV between the 2 groups was statistically significant (t(2M) = 2.12, t(3M) = 2.57; P < 0.05) at 2 and 3 months after treatment. BTX-A injection guided by electrical stimulation in combination with physiotherapy was more effective than physiotherapy alone in terms of reducing spasticity and improving functional performance in standing, walking, walking pattern and velocity on spasticity in ankle plantar flexors of ambulant children with CP.