Fig. 1

a-g The AVM occupied the right percentral knob in patient 4. Left hand movement elicited the SA, SPL in the ipsilesional hemisphere and AMA, SPL in the contralesional hemisphere (in green). Two aberrant fiber tracts were tracked using the motor activation areas as the ROI (in yellow). One derived from ipsilesional SPL, and the other one derived from controlesional AMA. h Postoperative CT scan shows surgical field hemorrhage and surrounding edema. i and j Intraoperative electrical stimulation results showed that the positive stimulation sites were found at cortex (i) and subcortex levels (j) just behind the lesion