Intrathecal Baclofen for Dystonia and Related Motor Disorders

Abstract

In clinical practice, oral baclofen has long been regarded as a drug of choice for spasticity of spinal origin (1,2,2a). Baclofen has also been considered to be an effective agent for treating dystonia (3,4). However, treatment of dystonia using oral baclofen is often limited due to adverse effects, such as nausea and sedation. Intrathecal catheter systems enable higher concentrations of baclofen to reach the spinal cord than can be safely obtained through purely oral administration of baclofen (5). A subcutaneous reservoir, implanted in the abdominal wall, delivers baclofen directly to the subarachnoid space by a thin catheter. In the treatment of spasticity of spinal origin, this technique has proved to be a safe and effective therapy. Intrathecal delivery enables as much as four times the concentration of baclofen to accumulate at the spinal cord using 1% of the standard oral dosage, thus limiting systemic adverse effects. Because oral baclofen reduces dystonia, clinical investigators considered that Intrathecal baclofen (ITB) might benefit dystonia patients, especially for individuals unable to tolerate high oral doses of baclofen.