[Motor evoked potentials during embolization of arteriovenous malformations for the detection of ischemic...

Motor evoked potentials (MEP) recorded from the distal extremity muscles in response to transcranial magnetoelectrical stimulation were analyzed in a total of 10 patients during embolization of arteriovenous malformations (AVM) localized in frontal and parietal lobe (N = 5), in the temporal lobe (N = 2), in the the brain stem (N = 1), in the medulla oblongata (N = 1), and in the cerebellum (N = 1). The objective of this study was to clarify whether MEP allow reliable detection of ischemic complications during these procedures. Stable potentials as observed in 8 of 10 patients coincided in every case with an uneventful neurological outcome. Temporary significant prolongation of the central motor conduction time (CMCT) was observed in 2 patients. Both patients demonstrated a transient hemiparesis after the procedure, probably caused by ischemia. Our results clearly indicate that MEP are able to detect ischemic events during embolization of AVMs. Therefore, the use of MEP as a monitor of pyramidal function during endovascular therapeutic procedures seems to be promising.