SPINAL MYOCLONUS INDUCED BY AN INTRATHECAL CATHETER

We report a case of spinal myoclonus induced by the tip of an intrathe cal catheter in a 35-year-old patient with severe, adult-onset, genera lized dystonia of unknown cause, treated for 2 years using intrathecal baclofen. One month after a falling episode, the patient developed fo cal myoclonus of the right proximal leg whenever she stood up from a s eated position. The electrophysiologic recordings were compatible with spinal segmental myoclonus, originating at a focus corresponding to t he L2-S2 segments. At this site, the tip of the intrathecal catheter w as demonstrated by myelography to be in close proximity to the nerve r oots and conus medullaris. The myoclonus resolved promptly once the ca theter tip was withdrawn. We review the literature on spinal myoclonus and discuss the possible mechanisms of spinal myoclonus pertaining to the present case. This report represents an unusual complication of i ntrathecal catheter systems that, if recognized, can lead to prompt th erapeutic intervention.