The lesion was graded on Spetzler-Martin AVM grading system.  The nidus of this arteriovenous malformation medium sized and measured 3.2 cm in maximum dimensions (score=2) with involvement of cuneus of the occipital lobe which is an eloquent area of the brain (score=1) and superficial venous drainage into the superior sagittal sinus  (score=0). The lesion was assigned a total of grade III (2+1+0).