The use of botulinum toxin for the treatment of muscle spasticity in the first 2 years of life

Effect of combined rehabilitation program with botulinum toxin type A injections on gross motor function scores in children with spastic cerebral palsy

[Purpose] To examine whether combining botulinum toxin type A with physiotherapy is better than botulinum toxin type A alone in reducing muscle tone and improving gross motor function in spastic diplegia. [Subjects and Methods] Forty-six ambulatory children with spastic diplegia (age: 25–154 months) were recruited. Patients were assigned to Groups 1 (n=18) and 2 (n=28). After baseline assessment, all children received botulinum toxin type A injections (6 units/kg) into the lower limb muscles. A second botulinum toxin type A injection was given 6 months later. The ankles were placed in plaster casts for 2 weeks after the first injection and an orthosis was prescribed after cast removal. Group 2 received 2 weeks of intensive physiotherapy. The gross motor function scores for the 2 groups were recorded at baseline, 4, 6, and 52 weeks. [Results] The improvement in gross motor function scores was significant for Group 2 and non-significant for Group 1. After 4, 6, and 52 weeks, Groups 1 and 2 showed 2.6% and 6.3% improvement, 4.8% and 12% improvement, and 5.5% and 19.4% improvement, respectively. [Conclusion] The addition of a 2-week physiotherapy programme after the initial botulinum toxin type A injections produced significantly greater improvements in gross motor function scores.

Botulinum toxin injection causes hyper-reflexia and increased muscle stiffness of the triceps surae muscle in the rat

Botulinum toxin is used with the intention of diminishing spasticity and reducing the risk of development of contractures. Here, we investigated changes in muscle stiffness caused by reflex activity or elastic muscle properties following botulinum toxin injection in the triceps surae muscle in rats. Forty-four rats received injection of botulinum toxin in the left triceps surae muscle. Control measurements were performed on the noninjected contralateral side in all rats. Acute experiments were performed, 1, 2, 4, and 8 wk following injection. The triceps surae muscle was dissected free, and the Achilles tendon was cut and attached to a muscle puller. The resistance of the muscle to stretches of different amplitudes and velocities was systematically investigated. Reflex-mediated torque was normalized to the maximal muscle force evoked by supramaximal stimulation of the tibial nerve. Botulinum toxin injection caused severe atrophy of the triceps surae muscle at all time points. The force generated by stretch reflex activity was also strongly diminished but not to the same extent as the maximal muscle force at 2 and 4 wk, signifying a relative reflex hyperexcitability. Passive muscle stiffness was unaltered at 1 wk but increased at 2, 4, and 8 wk (P < 0.01). These data demonstrate that botulinum toxin causes a relative increase in reflex stiffness, which is likely caused by compensatory neuroplastic changes. The stiffness of elastic elements in the muscles also increased. The data are not consistent with the ideas that botulinum toxin is an efficient antispastic medication or that it may prevent development of contractures.

Best clinical practice in botulinum toxin treatment for children with cerebral palsy

Botulinum toxin A (BoNT-A) is considered a safe and effective therapy for children with cerebral palsy (CP), especially in the hands of experienced injectors and for the majority of children. Recently, some risks have been noted for children with Gross Motor Classification Scale (GMFCS) of IV and the risks are substantial for level V. Recommendations for treatment with BoNT-A have been published since 1993, with continuous optimisation and development of new treatment concepts. This leads to modifications in the clinical decision making process, indications, injection techniques, assessments, and evaluations. This article summarises the state of the art of BoNT-A treatment in children with CP, based mainly on the literature and expert opinions by an international paediatric orthopaedic user group. BoNT-A is an important part of multimodal management, to support motor development and improve function when the targeted management of spasticity in specific muscle groups is clinically indicated. Individualised assessment and treatment are essential, and should be part of an integrated approach chosen to support the achievement of motor milestones. To this end, goals should be set for both the long term and for each injection cycle. The correct choice of target muscles is also important; not all spastic muscles need to be injected. A more focused approach needs to be established to improve function and motor development, and to prevent adverse compensations and contractures. Furthermore, the timeline of BoNT-A treatment extends from infancy to adulthood, and treatment should take into account the change in indications with age.

Rationale for using botulinum toxin A as an adjunct to upper limb rehabilitation in children with cerebral palsy

Cerebral palsy describes a group of disorders of movement and posture that result from disturbances in the developing brain. Although the brain lesion is nonprogressive, the secondary physical symptoms change with time and growth. If left untreated, symptoms may result in the development of physical impairment and impede independent performance of daily tasks. Intramuscular injection of botulinum neurotoxin A is a relatively safe and effective adjunct to upper limb therapy. Botulinum neurotoxin A primarily aims to reduce muscle overactivity, thereby reducing the development of increased muscle stiffness that can lead to permanent changes. With a specific focus on the physiological action of botulinum neurotoxin A, this article describes the secondary symptoms of cerebral palsy and their different contributions. To highlight research directions and future implications for clinical practice, this article also documents the recent scientific evidence for upper limb botulinum neurotoxin A and proposes a preventive clinical model that aims to mitigate the effects of increasing upper limb impairment.

Optimal management for people with severe spasticity

Spasticity is characterized by velocity-dependent increase in tonic stretch reflexes and tendon jerks. Many people affected by spasticity receive late treatment, or no treatment, which greatly reduces the potential to regain full motor control and restore function. There is much to consider before determining treatment for people with spasticity. Treatment of pediatric patients increases the complexity, because of the substantial difference between adult and pediatric spasticity. Proper patient evaluation, utilization of scales and measures, and obtaining patient and caregiver history is vital in determining optimal spasticity treatment. Further, taking into consideration the limitations and desires of individuals serve as a guide to best management. We have grouped contributing factors into the IDAHO Criteria to elucidate a multidisciplinary approach, which considers a person's complete field of experience. This model is applied to goal setting, and recognizes the importance of a spasticity management team, comprising the treatment subject, his/her family, the environment, and a supportive, well-informed medical staff. The criteria take into account the complexity associated with diagnosing and treating spasticity, with the ultimate goal of improved function.