Cerebral Palsy Treatment & Management: Approach …

Numerous medications, although often used off label for age and indication, may relieve the movement difficulties associated with cerebral palsy. These drugs target spasticity, dystonia, myoclonus, chorea, and athetosis. For example, baclofen, administered either orally or intrathecally, is often used for treating spasticity in these patients.

AbobotulinumtoxinA (Dysport) is the first botulinum toxin to gain FDA approval for the treatment of lower limb spasticity in children aged 2-17 years. Approval was based on a randomized, multicenter, double-blind, placebo-controlled, international Phase III study in 235 pediatric patients (158 received abobotulinumtoxinA and 77 received placebo) aged 2 to 17 years with lower limb spasticity due to cerebral palsy causing dynamic equinus foot deformity. Patients treated with abobotulinumtoxinA showed statistically significant improvement in efficacy assessments (ie, mean change from baseline in Modified Ashworth scale [MAS] in ankle plantar flexor muscle tone and mean Physicians Global Assessment [PGA]) response to treatment score at Week 4 and Week 12.[38]

OnabotulinuimtoxinA (Botox)may reduce spasticity for 3-6 months and may be considered for off-label use in children with cerebral palsy with spasticity in the lower extremities (gastrocnemius, in particular).[1, 2, 3, 4, 5, 39] This therapy can allow for improved range of motion, reduced deformity, improved response to occupational and physical therapy, and delay in the need for surgical management of spasticity. Casting, with or without botulinum toxin type A, may be an additional option for children with an equinus deformity, although the evidence is still somewhat conflicting.[40]

The established total body dose of onabotulinumtoxinA is limited to 12 U/kg, to a maximum of 400 U per visit. (Many practices, however, have been safely using 20 U/kg, to a maximum of 600 U). Each small muscle receives 1-2 U/kg, and large muscles, 4-6 U/kg. The interval between doses should be at least 4 months in order to help prevent antibody formation, which could make subsequent botulinum toxin procedures less effective. Note that large muscles may not respond to this limiting dose, or quite often, patients need several muscles done at each visit.

Historically, phenol intramuscular neurolysis has been considered another medication option. This agent can be used for some large muscles or when several muscles are treated, but phenol therapy is more difficult to administer than other agents. Because phenol is administered using a nerve stimulator, this treatment is more painful, and anesthesia is often used when the therapy is performed. In addition, phenol can, in certain nerves, cause unpleasant sensory dysesthesias, therefore, its use is often limited to nerves with only motor innervation, such as the musculocutaneous (for decreasing arm flexion) and the obturator (for decreasing hip adduction). Phenol treatment is also used for hamstring motor point blocks (for knee flexion).

Although antiparkinsonian drugs (eg, anticholinergic and dopaminergic drugs) and antispasticity agents (eg, baclofen) have primarily been used in the management of dystonia, anticonvulsants, antidopaminergic drugs, and antidepressants have also been tried.

Anticonvulsants (including benzodiazepines such as diazepam, valproic acid, and barbiturates) have been useful in the management of myoclonus. Chorea and athetosis are often difficult to manage, although benzodiazepines, neuroleptics, and antiparkinsonian drugs (eg, levodopa) have been tried. Benzodiazepines and baclofen are commonly used to manage spasticity.

A multidisciplinary panel conducted a systematic evaluation of published evidence of efficacy and safety of pharmacologic treatments for childhood spasticity due to cerebral palsy.[41] The panel members consisted of the Quality Standards Subcommittee of the American Academy of Neurology (AAN), and the Practice Committee of the Child Neurology Society.[41]

Localized or segmental spasticity

For localized or segmental spasticity, results of the panel found botulinum toxin type A is effective treatment in the upper and lower extremities; however, conflicting evidence exists regarding functional improvement.[41] Botulinum toxin type A was found to be generally safe in children with cerebral palsy; however, the US Food and Drug Administration (FDA) investigated isolated cases of generalized weakness resulting in poor outcomes and issued a black box warning, as follows:

"Effects of all botulinum toxin products may spread from the area of injection to produce symptoms consistent with botulinum toxin effects. These symptoms may include asthenia, generalized muscle weakness, diplopia, blurred vision, ptosis, dysphagia, dysphonia, dysarthria, urinary incontinence, and breathing difficulties. These symptoms have been reported hours to weeks after injection. Swallowing and breathing difficulties can be life threatening, and death have been reported. The risk of symptoms is probably greatest in children treated for spasticity, but symptoms can also occur in adults treated for spasticity and other conditions, particularly in those patients who have underlying conditions that would predispose them to these symptoms. In unapproved uses, including spasticity in children and adults, and in approved indications, cases of spread of effect have been reported at doses comparable to those used to treat cervical dystonia and at lower doses."

Generalized spasticity

For generalized spasticity, the panel listed diazepam as probably effective and tizanidine as possibly effective, although insufficient data exist regarding motor function and side-effect profile.[41] The panel recommends diazepam for short-term use, and tizanidine may also be considered as a treatment option. Data were insufficient for use of dantrolene, oral baclofen, and intrathecal baclofen, and toxicity was frequently reported.[41]

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