An unusual cause of overdose after baclofen pump implantation: case report.

Abstract

Intrathecal baclofen delivery for the treatment of spasticity has been used for almost 20 years with a great deal of success. A wide variety of complications and pitfalls have been described. This report details a novel complication involving inadvertent and initially unrecognized canalization of the subdural space with the spinal catheter, which ultimately resulted in an overdose. An intrathecal pump system was implanted in a 15-year-old girl with spasticity. This initially resulted in a lack of therapeutic effect. The diagnostic workup ultimately led to contrast administration through the pump system, which precipitated a baclofen overdose when sequestered medication in the subdural compartment was released into the intrathecal space. The spinal catheter was subsequently revised, and the patient made a full recovery. The possibility of a subdural catheter should be included in the differential diagnosis in patients who experience a lack of drug effect after pump implantation, despite increases in dosage. Close monitoring is required because of the risk of spontaneous or induced overdose, which may occur when a communication develops between the subdural and intrathecal compartments.