Neuromuscular blockade in the management of cerebral palsy

Spasticity evaluation and management tools

Spasticity is a complex and often disabling symptom for patients with upper motor neuron syndromes. Although spasticity arises from neurological disease, it often cascades into muscle and soft tissue changes, which may exacerbate symptoms and further hamper function. Effective management therefore hinges on early recognition and treatment. To this end, the definition of spasticity has expanded over time to more accurately reflect the spectrum of symptoms experienced by persons with this disorder. Once identified, clinical and research quantitative assessments of spasticity are hindered by the uniqueness of presentations both for individuals and for specific neurological diagnoses. Objective measures in isolation often fail to reflect the complex functional impact of spasticity. Multiple tools exist to quantitatively or qualitatively assess the severity of spasticity, including clinician and patient-reported measures as well as electrodiagnostic, mechanical, and ultrasound measures. A combination of objective and patient-reported outcomes is likely required to better reflect the burden of spasticity symptoms in an individual. Therapeutic options exist for the treatment of spasticity along a broad spectrum from nonpharmacologic to interventional procedures. Treatment strategies may include exercise, physical agent modalities, oral medications, injections, pumps, and surgery. Optimal spasticity management most often requires a multimodal approach, combining pharmacological management with interventions that match the functional needs, goals, and preferences of the patient. Physicians and other healthcare providers who manage spasticity must be familiarized with the full array of spasticity interventions and must frequently reassess results of treatment to ensure the patient's goals of treatment are met.

A consensus statement on the use of botulinum toxin in pediatric patients

Botulinum toxin has been used in medicine for the past 30 years. However, there continues to be controversy about the appropriate uses and dosing, especially in the pediatric population. A panel of nine pediatric physiatrists from different regions and previous training programs in the United States were nominated based on institutional reputation and botulinum toxin (BoNT) experience. Based on a review of the current literature, the goal was to provide the rationale for recommendations on the administration of BoNT in the pediatric population. The goal was not only to review safety, dosing, and injection techniques but also to develop a consensus on the appropriate uses in the pediatric population. In addition to upper and lower limb spasticity, the consensus also provides recommendations for congenital muscular torticollis, cervical dystonia, sialorrhea, and brachial plexus palsies.

Botulinum Toxin in the Management of Children with Cerebral Palsy

During the past 25 years, botulinum toxin type A (BoNT-A) has become the most widely used medical intervention in children with cerebral palsy. In this review we consider the gaps in our knowledge in the use of BoNT-A and reasons why muscle morphology and function in children with cerebral palsy are impaired. We review limitations in our knowledge regarding the mechanisms underlying the development of contractures and the difficulty in preventing them. It is clear from this review that injection of BoNT-A in the large muscles of both the upper and lower limbs of children with cerebral palsy will result in a predictable decrease in muscle activity, which is usually reported as a reduction in spasticity, for between 3 and 6 months. These changes are noted by the use of clinical tools such as the Modified Ashworth Scale and the Modified Tardieu Scale. Decreased muscle over-activity usually results in improved range of motion in distal joints. Injection of the gastrocnemius muscle for toe-walking in a child with hemiplegia or diplegia usually has the effect of increasing the passive range of dorsiflexion at the ankle. In our review, we found that this may result in a measurable improvement in gait by the use of observational gait scales or gait analysis, in some children. However, improvements in gait function are not always achieved and are small in magnitude and short lived. We found that some of the differences in outcomes in clinical trials may relate to the use of adjunctive interventions such as serial casting, orthoses, night splints and intensive therapy. We note that the majority of clinical trials of the use of BoNT-A in children with cerebral palsy have focussed on a single injection cycle and this is insufficient to understand the balance between benefit and harm. Most outcomes were reported in terms of changes in muscle tone and there were fewer studies with robust methodology that reported improvements in function. Changes in the domains of activities and participation have rarely been reported in studies to date. There were no clinical reviews to date that consider the findings of studies in human volunteers and in experimental animals and their relevance to clinical protocols. In this review we found that studies in human volunteers and in experimental animals show muscle atrophy after an injection of BoNT-A for at least 12 months. Muscle atrophy was accompanied by loss of contractile elements in muscle and replacement with fat and connective tissue. It is not currently known if these changes, mediated at a molecular level, are reversible. We conclude that there is a need to revise clinical protocols by using BoNT-A more thoughtfully, less frequently and with greatly enhanced monitoring of the effects on injected muscle for both short-term and long-term benefits and harms.

Efficacy and safety of serial injections of botulinum toxin A in children with spastic cerebral palsy

BACKGROUND

Botulinum toxin A (BTX-A) has been successfully used as a treatment for children with spastic cerebral palsy; however, the effect of BTX-A on reducing spasticity only lasts a few months, thus serial injections are required. The present study was to evaluate the efficacy and safety of serial injections of BTX-A in children with spastic cerebral palsy.

METHODS

Fifty-two pediatric patients with spastic cerebral palsy, 2-12 years of age (mean age, 4.79 ± 2.70), were retrospectively analyzed. Muscle tone was assessed with the Modified Ashworth Scale, and gait was assessed with the Physician Rating Scale. Assessments were undertaken at baseline, 3 months, and 6 months after serial injections of BTX-A.

RESULTS

The beneficial effects of BTX-A occurred 1 week after the injection, whereas the adverse side-effects appeared within 1 week and lasted <2 weeks. BTX-A significantly improved muscle tone and gait 3 and 6 months after its serial injections compared to baseline (P <0.05).

CONCLUSIONS

Serial injections of BTX-A are effective and safe for children with spastic cerebral palsy. The sideeffects of serial injections of BTX-A are mild and selflimited.

The effects of phenol neurolysis of the obturator nerve on the distribution of buttock-seat interface pressure in spinal cord injury patients with hip adductor spasticity

OBJECTIVES

Hip adductor spasticity may adversely effect shear-force and pressure distribution on the buttocks, where ulcerations most frequently appear in patients with spinal cord injury (SCI). Phenol neurolysis of the obturator nerve (ON) is commonly used to manage hip adductor spasticity. This study aimed to determine the effects on the distribution of buttock-seat interface pressure (BSIP) in a group of SCI patients with adductor spasticity that underwent ON blockade with phenol.

METHODS

We reviewed the records of SCI patients that were admitted to our clinic between January 2009 and December 2009. BSIP values (obtained with an X-sensor 48) and hip adductor spasticity levels of SCI patients with hip adductor spasticity that underwent ON blockade with phenol were collected. BSIP distributions of the patients were divided into two portions: first one is the BSIP distribution at the pressure ≤37 mm Hg, and the second one is at the pressure >37 mm Hg.

RESULTS

The study included 20 SCI patients (19 males and 1 female), with a mean age of 42.85±13.24 years. Although the percentage of BSIP distribution at ≤37 mm Hg range increased significantly (P<0.001), after ON neurolysis, BSIP distribution at >37 mm Hg range decreased significantly (P<0.001). In addition, mean hip adductor spasticity decreased significantly after ON neurolysis (P<0.001).

CONCLUSION

Phenol neurolysis of the ON is a promising treatment for the management of hip adductor spasticity in SCI patients and also has positive effects on BSIP, which has a crucial function in the development of pressure ulcers.

A dose-response relationship research on botulinum toxin type A local intramuscular injections of lower extremity spasticity in children with cerebral palsy

OBJECTIVES

To observe the dose-response relationship of intramuscular injections of botulinum toxin A (BTX-A) in the spastic cerebral palsy.

METHODS

One hundred fifty cases (age between 2 and 12 years) were randomly divided into three groups. The patients were injected with different dose of BTX-A. The movement function was evaluated with modified Ashworth scale (MAS) and physician's rating scale (PRS) at entry and 1 month after injection. The analyses were conducted with one-way analysis of variance and chi (2) test.

RESULTS

The evaluation of MAS and PRS revealed a significant increase of movement function. No statistically significant differences of the side effects among three groups could be demonstrated.

CONCLUSIONS

The study suggested that the movement function was more significantly improved with relatively higher dose of BTX-A, which was safe and effective.

A comparison of the effect of doxorubicin and phenol on the skeletal muscle. May doxorubicin be a new alternative treatment agent for spasticity?

Since spasticity is still an unsolved problem for orthopaedic surgeons, different chemical agents are tried before surgery. Phenol is a chemical agent which has been used for spasticity treatment for a long time. Doxorubicin is an antitumoral agent that has recently been used for chemomyectomy. The intramuscular effects of phenol and two different dose of doxorubicin were compared in that experimental study. In the first group 0.5 mg/0.5 cm3 doxorubicin, in the second group 1 mg/0.5 doxorubicin and in the third group 5% aqueous solution of fenol/0.5 injection were applied into left quadriceps muscle of rats. Degeneration areas were wider in the high dose doxorubicin group (29.9%; 8.5-61), in comparison with the low dose doxorubicin group (6.4%; 3.1-12) and phenol group (4%; 0-14) after 6 weeks. Differences in degeneration area among three groups were statistically significant (P<0.001). The difference was significant between the high dose doxorubicin group and the phenol group (P=0.001) and also between the high dose doxorubicin group and the low dose doxorubicin group (P<0.001). The results of this study suggested that doxorubicin could provide an alternative treatment modality for neuromuscular disease causing spasticity and it has a dose-dependent effect. Further studies are needed for long-term comparison and clinical use of doxorubicin for spasticity treatment.

The use of botulinum toxin in pediatric disorders

Botulinum toxins have an exciting and important role in treating the child with hypertonia. The guidelines presented in this article are those that have been published representing the safe use of botulinum toxins in children. Experience and a decade of research have provided the framework for using botulinum toxins in decreasing deformity and promoting function. In children, a window of opportunity exists with botulinum toxin that allows improved motor control and elongation of shortened muscles. Although 3 to 4 months in an adult life is short, for a child it is a relatively greater proportion of their life experience and may be long enough for skill development. The improvement noted in function after botulinum toxin use is facilitated by comprehensive rehabilitation. The pediatric physiatrist has a unique role in the management of children with cerebral palsy and other conditions with hypertonia. Their knowledge and training reflect an understanding of anatomy and development that allows accurate evaluation of specific functional problems in children related to hypertonia. The pediatric physiatrist has experience in localization of muscles by EMG, nerve stimulation, and surface anatomy. Although many other physicians inject botulinum toxins, goal-directed management is the cornerstone to the physiatrist's thinking and treatment plan. Orthopedic surgery ultimately may be the intervention of choice if persistent contracture or progression of contractures occurs. Working in collaboration with an orthopedist identifies the timing of optimal surgical intervention for alignment. For persistent and severe hypertonia, the treatment team includes a neurosurgeon. All options for spasticity, such as selective posterior rhizotomy and intrathecal baclofen, should be considered. Re-evaluation of the child after selective dorsal rhizotomy or intrathecal baclofen is appropriate and should be discussed with therapists for focal intervention. Communication between members of the team and the family is desirable and frequently is one of the major contributions of the pediatric physiatrist. For children with focal hypertonia, botulinum toxins offer a dramatic but temporary repeatable change that affects rehabilitation. Research rapidly has captured the positive effect of the toxins on impairment and functional limitations. Not to be overlooked are outcomes related to quality of life. The long-term use of botulinum toxins and the role the toxins play throughout the life span of the person with a childhood hypertonic disorder are yet to be determined.

Pharmacologic management of the spastic and dystonic upper limb in children with cerebral palsy

Spasticity or dystonia of the upper limb in children with CP commonly is seen as part of a more involved clinical picture. Each can cause functional problems in and can interfere with the quality of life of children with CP. Pharmacologic manipulation of the spasticity and dystonia requires a patient and ordered approach. Treatment often is performed using an open trial method, with medications introduced slowly but often being limited in their usefulness by significant side effects. Despite multiple medications being available for spasticity and dystonia management, few of the oral treatments have been assessed systematically in children with CP. Specific evaluation of the use of enteral medications in upper limb management is even rarer.

Idiopathic foot dystonia treated with intramuscular phenol injection

We describe a patient who developed involuntary, painless, dystonic contraction of the left foot on walking. The patient had been treated with botulinum toxin A without benefit. Examination showed that walking brought on a spasmodic twisting of the left foot, with extension and eversion of the ankle. The patient underwent an intramuscular phenol injection, which abolished the foot dystonia. This case suggests that intramuscular phenol treatment may be an alternative for patients where botulinum toxin was unable to relieve the dystonias.