Oral pharmacotherapy for the movement disorders of cerebral palsy

Principles of Medical and Surgical Treatment of Cerebral Palsy

Cerebral palsy is the most common cause of childhood motor disability, affecting 2 to 3/1000 children worldwide. Clinical abnormalities in tone, posture, and movement are the result of brain dysgenesis or injury early in life, and impairment varies in type, distribution, and in severity. The underlying brain disorder may also lead to other associated neurologic and systemic impairments. Variability in functional impairments, which can change during development, necessitates an individualized treatment plan. Treatment options are primarily symptomatic and directed toward optimizing independence, function, and/or ease of care-while limiting side effects. New promising disease-preventing and modifying treatments are emerging.

Use of trihexyphenidyl in children with cerebral palsy

A paucity of information exists regarding medications to treat dystonia in children with cerebral palsy. This study sought to review the benefits and tolerability of trihexyphenidyl in children with cerebral palsy, treated for dystonia or sialorrhea or both in a pediatric tertiary care hospital, through a retrospective chart review. In total, 101 patients (61 boys and 40 girls) were evaluated. The mean age at drug initiation was 7 years and 10 months (range, 1-18 years). The mean initial dose was 0.095 mg/kg/day. The dose was increased by 10-20% no sooner than every 2 weeks. The mean maximum dose reached was 0.55 mg/kg/day. Ninety-three patients (91%) tolerated the medication well, with a mean duration of treatment of 3 years and 7 months. Side effects occurred in 69% of subjects, the majority in patients aged ≥7 years, and soon after treatment initiation. Sixty-four percent continued the treatment at study end. Ninety-seven patients reported benefits, including reduction of dystonia in upper (59.4%) and lower (37.6%) extremities, sialorrhea (60.4%), and speech issues (24.7%). The majority of patients tolerated trihexyphenidyl well on a schedule of gradual dose increases, and almost all demonstrated improvements in dystonia or sialorrhea or both.

Continuous intrathecal baclofen infusion for intractable spastic cerebral palsy--is it worth it?

This Practice Point commentary discusses a recent paper by Hoving et al., who compared the cost-effectiveness of continuous intrathecal baclofen infusion (CIBI) with that of 'standard care' in children with cerebral palsy whose abnormal muscle tone was interfering with function and/or quality of life. The current management of severe spasticity and dystonia in cerebral palsy consists of oral medications, botulinum toxin, selective dorsal rhizotomy, orthopedic surgery, and/or CIBI. CIBI is the treatment of choice for patients whose severely abnormal tone is interfering with their care, comfort, and/or quality of life. The added cost of care associated with the use of CIBI for 1 year is nearly twice that of standard care. However, on the basis of their cost-effectiveness analysis, which took into consideration the improvement in quality of life, Hoving et al. concluded that the added expense is cost-effective. Although this prospective study lasted for only 1 year and included only 15 patients, the conclusions are similar to those based on previously published results.

Prospective open-label clinical trial of trihexyphenidyl in children with secondary dystonia due to cerebral palsy

Although trihexyphenidyl is used clinically to treat both primary and secondary dystonia in children, limited evidence exists to support its effectiveness, particularly in dystonia secondary to disorders such as cerebral palsy. A prospective, open-label, multicenter pilot trial of high-dose trihexyphenidyl was conducted in 23 children aged 4 to 15 years with cerebral palsy judged to have secondary dystonia impairing function in the dominant upper extremity. All children were given trihexyphenidyl at increasing doses over a 9-week period up to a maximum of 0.75 mg/kg/d. Trihexyphenidyl was subsequently tapered off over the next 5 weeks. Objective motor assessments were performed at baseline, 9 weeks, and 15 weeks. The primary outcome measure was the Melbourne Assessment of Unilateral Upper Limb Function, tested in the dominant arm. Tolerability and safety were monitored closely throughout the trial. Of the 31 children who agreed to participate in the study, 5 failed to meet entry criteria and 3 withdrew due to nonserious adverse events (chorea, drug rash, and hyperactivity). Three children required a dosage reduction because of nonserious adverse events but continued to participate. The 23 children who completed the study showed a significant improvement in arm function at 15 weeks (P = .045) but not at 9 weeks (P = .985). Post hoc analysis showed that a subgroup (n = 10) with hyperkinetic dystonia (excess involuntary movements) worsened at 9 weeks (P = .04) but subsequently returned to baseline following taper of the medicine. The authors conclude that scientific evidence for the clinical use of trihexyphenidyl in cerebral palsy remains equivocal. Trihexyphenidyl may be a safe and effective for treatment for arm dystonia in some children with cerebral palsy if given sufficient time to respond to the medication. Post hoc analyses based on the type of movement disorder suggested that children with hyperkinetic forms of dystonia may worsen. A larger, randomized prospective trial stratified by the presence or absence of hyperkinetic movements is needed to confirm these results.

Validation of a care and comfort hypertonicity questionnaire

The lack of evidence regarding functional and quality of life benefits resulting from tone reduction with intrathecal baclofen (ITB) infusion treatment relates to the lack of validated and responsive measures. We integrated our scale/questionnaire, developed from chart review, with the non-validated Caregiver Questionnaire (CQ) to yield a final document, the Care and Comfort Hypertonicity Questionnaire (CCHQ). Convergent validity was achieved by administering the CCHQ to 47 patients with spastic/dystonic cerebral palsy (CP) who were being evaluated for tone management. The population studied included 18 females and 29 males (mean age 10y [SD 4y 10mo]; range 3y 1mo-21y 1mo). Twenty-five patients were subsequently referred for botulinum toxin (BTX-A) injections (mean Gross Motor Function Classification System [GMFCS] 3.2); 11 patients were referred for ITB (mean GMFCS 4.4); four were referred for orthopedic surgery (mean GMFCS 3.3); 3 were referred for selective dorsal rhizotomy (mean GMFCS 2.7); one was recommended for oral baclofen (GMFCS 5); and three were recommended for no treatment (mean GMFCS 3.7). Blinded to the score, those with the highest scores (severe hypertonicity) were recommended for ITB; those with the lowest scores were recommended for BTX-A injections. Responsiveness of the CCHQ was established by administering the questionnaire to patients who already had an implanted ITB pump. The children with the largest dose increase demonstrated a statistically significant improvement in the CCHQ score. This scale can be used to document the efficacy of treating severe hypertonicity both in clinical and research protocols.

Approach to the rehabilitation of spasticity and neuromuscular disorders in children

The management of children and adults with upper motor neuron disorder is complex and multifaceted. This article reviews new information and potential treatment. As part of the upper motor neuron syndrome (UMNS), spasticity may occur in cerebral palsy, congenital brain malformation, head injury, or other etiologies. Within the UMNS the most recognizable clinical concern is the frequent abnormality of tone, which may have a significant functional impact. Tone reduction is not itself a goal, but is performed for the functional benefits it may allow. New approaches to treatment and management of hypertonia recently have become available. There are many other associated features of the UMNS that affect patient functioning. Ones that frequently occur are abnormalities of speech and other areas of oral motor control. A new area of intervention combines the use of botulinum toxin and ultrasonography to address the common problem of slalorrhea, which is a potential medical issue and a substantial social barrier in affected patients. This article also reviews new information and potential treatment for neuromuscular disorders.

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.

A forward look at therapy for pediatric movement disorders

The mainstay of current therapy for pediatric movement disorders is oral symptomatic medication, unless a reversible etiology can be found. However, this approach is apt to pale in comparison with innovative strategies on the clinical forefront. Classical pharmacotherapy is restricted by the blood-brain barrier, which prevents access to the brain of potentially therapeutic molecules. Recent developments in molecular biotechnology include antibody-mediated drug release, feedback-responsive delivery systems, carrier-mediated transport, microspheres composed of polymers and liposomes, permeabilizers, and selective delivery to localized sites and vectors. Neuroprotective strategies for delivering neurotrophic factors and antiapoptotic and antioxidant molecules in neurodegenerative disorders are currently under study in clinical trials. Stem cell transplantation has great potential for tissue engineering and also as a carrier for gene therapy, although its use raises complex societal issues. These approaches, together with a plethora of transgenic knockout animal models of neurodegenerative disorders, offer real promise for a previously untreatable group of movement disorders.

Treatment of attention-deficit disorder, cerebral palsy, and mental retardation in epilepsy

Epilepsy in childhood is often associated with other neurologic disorders, including attention-deficit/hyperactivity disorder, cerebral palsy, and mental retardation. A single pathologic process may explain both epilepsy and these associated disorders. However, in some cases, distinct etiologies may be present. Recognition of these problems is essential, as is individualized treatment. Proper classroom placement; behavior modification, speech, occupational, and physical therapies; pharmacological agents; and even surgical procedures have a role in the management of these comorbid disorders. Diagnostic criteria and therapeutic modalities used in these syndromes will be discussed.

Age-dependent effects of trihexyphenidyl in extrapyramidal cerebral palsy

Trihexyphenidyl (Artane) is a centrally active muscarinic antagonist commonly used to treat patients with generalized dystonia. In a retrospective survey of 22 consecutive children with extrapyramidal cerebral palsy, we evaluated trihexyphenidyl on upper extremity and lower extremity function, expressive language, and drooling. Functional changes were assessed using a parental questionnaire (rating scale 1-5: from 1 = little or no change to 5 = tremendous change, with scores in either a positive or negative direction). Improvements of +4 or +5 were reported in eight children for upper extremity function, in eight children for verbal expressive language, in five for drooling, and in none for lower extremity function. Using bivariate linear regression modeling to investigate variables associated with treatment effects, there was a significant inverse relationship between age at initiation of medication and therapeutic response. Furthermore, beneficial responses were specific to upper-extremity function and expressive language. These results suggest that younger children are more likely to respond to trihexyphenidyl and that primary functional benefits include improved fine motor abilities and expressive language. A prospective masked study with a standardized clinical instrument is needed to confirm these findings.

Clinical considerations in cerebral palsy and spasticity

The ultimate goal for management of patients with cerebral palsy is to help them grow up to become as independent as possible, learn to make their own choices in life, and pursue their own dreams. Optimal mobility is crucial to achieving independence and is also necessary for better health and quality of life in these patients. This article discusses the treatment of spasticity in cerebral palsy, addresses tone management issues in relationship to mobility and physical fitness, and introduces the reader to a comprehensive approach to the management of patients with cerebral palsy.

Cerebral Palsy

The neurorehabilitation program for cerebral palsy changes over time. During the first 2 years of life, an infant stimulation program with an emphasis on more than just improving motor deficits is emphasized. The importance of involvement of a knowledgeable therapist cannot be overemphasized. Realistic expectations must be articulated firmly. Rather then cautiously attempting to correct a dysfunction that cannot be corrected, the therapist should help the patient develop compensation techniques; the severity of the disability frequently militates against the development of "normal" motor control. Educating the parents about cerebral palsy, showing how positioning can be an effective way of helping the child be mobile, and encouraging parent-child interaction are aspects of an infant stimulation program. The therapist should serve as a coach to the parents, who implement much of the actual treatment on a daily basis at home. From 2 to 5 years of age, rapid growth occurs, and muscle tone will either develop or worsen--the latter leading not only to the development of contracture but also to a decrease in mobility. In developing a program to control this muscle tone, the most important question to be answered is, Can I improve the patient's function and decrease the patient's disability by altering muscle tone? It is not uncommon for the real problem preventing the patient from performing certain functions to be lack of motor control or lack of sensation and not the abnormal muscle tone. Between 5 and 10 years of age, the child begins to approach adult height. At this time, definitive orthopedic intervention can be considered; as already noted, contracture development occurs as a result of abnormal muscle tone in combination with growth. Finally, as the child approaches the teen years, issues of sitting and hygiene are important considerations, especially in the nonambulatory patient. The problem of pain secondary to spasticity or dystonia must be addressed.

Anaesthesia and pain management in cerebral palsy

Cerebral palsy is the result of an injury to the developing brain during the antenatal, perinatal or postnatal period. Clinical manifestations relate to the area affected. Some of the conditions associated with cerebral palsy require surgical intervention. Problems during the peri-operative period may include hypothermia, nausea and vomiting and muscle spasm. Peri-operative seizure control, respiratory function and gastro-oesophageal reflux also require consideration. Intellectual disability is common and, in those affected, may range from mild to severe. These children should be handled with sensitivity as communication disorders and sensory deficits may mask mild or normal intellect. They should be accompanied by their carers at induction and in the recovery room as they usually know how best to communicate with them. Postoperative pain management and the prevention of muscle spasm is important and some of the drugs used in the management of spasm such as baclofen and botulinum toxin are discussed. Epidural analgesia is particularly valuable when major orthopaedic procedures are performed.