Embolization of a spinal arteriovenous malformation: Correlation between motor evoked potentials and angiographic findings: Technical case report

OBJECTIVE AND IMPORTANCE: Endovascular procedures for the treatment of spin al arteriovenous malformations place the spinal cord at risk of ischemia. T his report illustrates the usefulness of motor evoked potentials (MEPs) in detecting functional changes within the spinal cord motor pathways during e mbolization of a spinal arteriovenous malformation under general anesthesia . CLINICAL PRESENTATION: A 28-year-old man presented with a history of progre ssive lower extremity numbness and weakness followed by bladder dysfunction . Magnetic resonance imaging and angiography disclosed a T11-T12 spinal art eriovenous malformation. INTERVENTION: During the endovascular procedure, before injection of partic les, the disappearance of MEPs from the tibialis anterior muscle led to pro mpt angiographic reevaluation, which disclosed the arrest of spinal blood f low secondary to radiculomedullary artery occlusion by the catheter. Emboli zation and catheter withdrawal were followed by temporary recovery of spina l blood flow and MEPs. A second arrest of spinal cord blood flow, caused by severe vasospasm of the feeding radiculomedullary artery, was documented b y a control angiogram, and its functional relevance was revealed by a secon d disappearance of MEPs. The therapeutic effect of papaverine infusion and induced moderate hypertension was confirmed angiographically by complete re opacification of the anterior spinal artery and confirmed neurophysiologica lly by the complete recovery of MEPs. At the end of the procedure, no addit ional neurological deficits were noted. CONCLUSION: During spinal cord embolization, MEPs may play a critical role in early detection of spinal cord dysfunction by aiding in the prevention o f damage to the spinal cord as well as by predicting the clinical outcome.