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Reversible spastic paraparesis induced by high-dose intravenous methadone
P L Manfredi1, G R Gonzales, R Payne
1Department of Neurosurgery, Memorial Sloan-Kettering Cancer Center, New York, NY 10021, USA. manfredp@mskcc.org
Abstract:
High doses of parenteral opioids can cause multifocal myoclonus and seizures. Spasticity has been reported in patients receiving intraspinal opioids. In this article, we describe a patient who developed reversible spastic paraparesis with prominent extensor spasms in the legs while receiving an infusion of intravenous methadone at 100 mg/hr. We discuss clinical presentation and possible pathophysiologic mechanisms of opioid side effects on the somatic motor system.
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