False Positive Radiographical Evidence of Pump Catheter Migration into the Spinal Cord

Abstract

Intrathecal drug delivery systems are becoming an increasingly common modality used by physicians to treat patients. Specifically, chronic spasticity secondary to multiple sclerosis (MS) may be treated with intrathecal baclofen (ITB) therapy when oral antispasmodics do not provide adequate relief. ITB therapy is effective, localizes drug delivery, and does not have the same degree of intolerable systemic effects often seen with oral and parenteral medications. As the use of intrathecal drug delivery systems has become more common, so has the incidence of adverse events. ITB administration requires the surgical implantation of indwelling catheters and a pump reservoir. Although this therapy is useful in treating spasticity, risks unique to intrathecal drug delivery systems include medication dosing errors, pump malfunction, infection, and catheter breakage or dislocation. To our knowledge intrathecal pump catheter migration into the spinal cord is a very rare complication with only 2 such complications reported. We present a case of an intrathecal baclofen pump catheter that was initially believed to have migrated into the spinal cord and the innovative use of cinefluoroscopy and digital subtraction used to identify catheter placement. Moreover, after confirmation of the catheter position within the spinal cord on magnetic resonance imaging (MRI) our team elected to perform a laminectomy, which demonstrated that the catheter was not in the spinal cord but was surrounded by arachnoid adhesions. We hope our efforts will provide the clinician insight into the common difficulties that arise and how best to troubleshoot them to serve this specific patient population and prevent potentially life-threatening complications. Key words: Intrathecal pump, intrathecal catheter, multiple sclerosis, pain medicine, spasticity, cine mode, baclofen