Contrast induced spinal myoclonus after percutaneous coronary intervention

We present a case of a 77-year-old man diagnosed with contrast-induced spinal myoclonus following primary percutaneous coronary intervention. After being admitted with a diagnosis of anteroseptal myocardial infarction, he underwent primary percutaneous coronary intervention to the left anterior descending artery and was prescribed aspirin, clopidogrel, and intravenous heparin. The following day he developed non-intentional irregular jerky movements confined to the truncal area. In view of rhythmic jerking confined to muscles innervated by a restricted segment of the spinal cord, resistance to supra-spinal influences and voluntary action, and no preceding electroencephalography activity in the contralateral sensorimotor cortex, a diagnosis of spinal myoclonus was made. Spinal myoclonus is a rare entity in which myoclonic movements occur in muscles originating from few (segmental), or many adjacent spinal motor roots (propriospinal). Structural lesions are found in the majority of cases but the actual pathophysiology is still unknown. Contrast-induced spinal myoclonus is an even rarer phenomenon with few published reports. We describe postulated mechanisms and the management of this phenomenon. <Learning objective: Myoclonus is a jerky movement due to abrupt involuntary contractions involving agonist and antagonist muscles. Spinal myoclonus is a rare disorder where myoclonic movements occur in muscles originating from spinal motor roots. The cause is usually a structural lesion, but in rare cases it can be induced by contrast. A video of this rare phenomenon is available with this article and the proposed pathophysiological mechanisms and treatment are discussed.>.