An Unusual Cause of Overdose after Baclofen Pump Implantation: Case Report.

Accepted, December 13, 2004. OBJECTIVE AND IMPORTANCE: 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. CLINICAL PRESENTATION: An intrathecal pump system was implanted in a 15-yearold 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. INTERVENTION: The spinal catheter was subsequently revised, and the patient made a full recovery. CONCLUSION: 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.

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