Intrathecal baclofen for intractable cerebral spasticity: a prospective placebo-controlled, double-blind study.

OBJECTIVE: To conduct a placebo-controlled prospective study of the effectiveness of intrathecal bolus injections and continuous administration of baclofen on functional parameters in patients with severe spasticity of cerebral origin. To compare this functional evaluation with spasticity scores in different muscle groups.

METHODS: In 11 patients with spasticity of cerebral origin (mainly cerebral palsy), double-blind scoring of spasticity (Ashworth scale score and visual analog score), spasms, pain, and functional abilities was performed during tests with bolus injections including a placebo control. Eight patients were considered good responders and received a subcutaneous device for intrathecal drug delivery. Six of these patients were followed up for 2 years, during which they underwent the same scoring procedures as after their bolus injections. These patients were subjected to a blinded dose reduction test.

RESULTS: There was a noticeable placebo effect on spasticity scores during tests with bolus injections. Eight patients demonstrated a significant beneficial effect of intrathecal bolus injections compared with this placebo effect. Functional improvements were noted in most patients. During continuous infusion, Ashworth scale scores were less favorable but still significantly lower than at baseline. Subjective evaluation (visual analog scores) remained positive, functional improvements were maintained, and patient comfort was invariably and significantly improved.

CONCLUSION: Intrathecal administration of baclofen is a safe and effective treatment for spasticity of cerebral origin. Functional improvement was demonstrated. The presence of a placebo effect on the spasticity scores suggests the need for double-blind screening in each patient.