The Effect of Botulinum Toxin Injections on Gross Motor Function for Lower Limb Spasticity in Children with Cerebral Palsy

Abstract

The aim of this study was to investigate the use of botulinum toxin type A (BoNT-A) injections and their efficacy on gross motor function for lower limb spasticity in children with spastic cerebral palsy (CP). This retrospective study included 919 injection occasions from 591 children with CP who received a lower limb BoNT-A injection between 2006 and 2016. The Gross Motor Function Measure (GMFM-88), the Modified Ashworth Scale, and the Modified Tardieu Scale were administered before and after injections. Injections were predominantly administered to children under the age of 6 years. The most common muscle injection site was the calf muscle for dynamic foot deformity. The second most commonly injected muscle was the hip adductor among 2–3 year olds and the hamstring muscle among 4–6 year olds. Distal injections were predominantly administered to high-functioning children, whereas proximal injections were typically administered to low-functioning children. Multilevel injections were mostly administered to midfunctioning children. GMFM-88 scores significantly increased post-injection for both high- and low-functioning groups. Younger age at injection and distal injection type were associated with larger improvements on the GMFM-88 at both short- and midterm follow-up. The target muscles for injection varied depending on gross motor functioning and age. Younger age at injection and distal injection type were significantly related with greater gain in gross motor function.

Causal factors affecting gross motor function in children diagnosed with cerebral palsy

“…Thus, intrathecal baclofen pump implantation, selective dorsal rhizotomy, or chemodenervation therapies aimed at spasticity reduction should not be expected to appreciably improve gross motor function. This prediction is consistent with what has been shown in outcome analyses of these treatments 10,39,40 .…”

“…Thus, intrathecal baclofen pump implantation, selective dorsal rhizotomy, or chemodenervation therapies aimed at spasticity reduction should not be expected to appreciably improve gross motor function. This prediction is consistent with what has been shown in outcome analyses of these treatments10,39,40 .The effect sizes of strength and gait quality (GDI) were both significant, suggesting that they are important mediators of function. Both variables can be improved by treatment (strengthening, physical therapy, orthopedic surgery).…”

Transcutaneous Spinal Neuromodulation Reorganizes Neural Networks in Patients with Cerebral Palsy

“…The majority of children classified as Gross Motor Function Classification Scale (GMFCS) Level I are expected to reach their motor potential between 7 and 9 years and thereafter remain stable until age 21 when they may experience functional decline due to pain, weakness, and stiffness [8,9]. Presently, all available interventions are designed to manage and minimize symptoms rather than correcting the underlying dysfunctions [10,11]. While some commonly preferred treatments such as intramuscular injection of onabotulinum-toxinA (BotoxA) reduce symptoms of spasticity, which initially may improve function, but rarely lead to significant long-term functional changes [12] and may severely limit the eventual level of recovery that theoretically is possible [13].…”

Tratamiento con toxina botulínica en niños con parálisis cerebral espástica.

“…Las inyecciones de TB a nivel del tríceps sural en niños pequeños con PC espástica se han utilizado para reducir la espasticidad transitoriamente, efecto que dura aproximadamente 6 meses, con un rango entre 4 y 12 meses (6,(16)(17)(18)(19)(20) . De esta manera se procura mejorar la marcha y postergar la necesidad de las cirugías ortopédicas hacia edades mayores, cuando el tratamiento quirúrgico es más efectivo, disminuyendo las probabilidades de que se necesiten reintervenciones quirúrgicas (6,21) .…”

“…Asimismo, los padres percibieron una mejoría de la marcha luego del 95% de los procedimientos. De acuerdo a un estudio poblacional, el grado de espasticidad del tríceps sural aumenta en la mayoría de los niños con PC hasta los 5 años y, generalmente, tiende a disminuir a partir de esa edad hasta los 15 años (20,23) . Al mismo tiempo, casi el 90% de las habilidades motoras se alcanzan a los 5 años y el desarrollo de la función motora en niños con PC es máximo en los primeros 7 años de vida (18) .…”