USE OF INTRATHECAL BACLOFEN IN THE TREATMENT OF PATIENTS WITH DYSTONIA

Background: Continuous infusion of intrathecal (IT) baclofen is a high ly effective standard therapy for severe spasticity of spinal origin. By contrast, there is limited clinical experience regarding the use of IT baclofen in treating patients with dystonia, and little is known r egarding the indications for treatment, efficacy, and safety of IT bac lofen in this disorder. Objective: To study retrospectively the effect s of IT baclofen in treating 25 patients with severe segmental or gene ralized dystonia. Setting: Neurological Institute, Columbia-Presbyteri an Medical Center, New York, NY. Patients: Twenty-five patients with s evere segmental or generalized dystonia that was refractory to oral me dications underwent IT baclofen test dosing. In addition to dystonia, 17 patients had spasticity or painful spasms. Thirteen of 25 patients responded to the test doses of IT baclofen, according to unblinded neu rological assessments that included the patient's subjective report; a ll 13 underwent implantation of a pump for continuous IT baclofen infu sion. Results: In contrast to reports of patients with spasticity of s pinal origin, those with dystonia in the present series had a lower re sponse rate to bolus IT baclofen doses and a smaller degree of clinica l improvement. For 10 of the 13 responders to the test doses of IT bac lofen, dystonia rating scale scores of videotaped examinations by blin ded observers detected no significant change (P<.07) in severity of dy stonia. Retrospective data from 11 of 13 patients with implantable pum ps, followed up for a mean interval of 21 months after pump insertion, showed continuing efficacy in 6 individuals (55%), based on a determi nation of patient satisfaction; however, only 3 patients (27%) reporte d a sustained improvement in functional capacity. Five (38%) of the 13 patients with implantable pumps experienced severe complications that required hospitalization. Conclusions: Despite recent reports that ha ve described the benefit in small numbers of patients with dystonia, w e concluded that the role of IT baclofen in treating severe dystonia r emains uncertain. Intrathecal baclofen may be more effective when dyst onia is associated with spasticity or pain. In the present series, we detected no significant difference in the response to IT baclofen in p atients with or without spasticity or pain, perhaps owing to the small sample size.