 Limited sequences were obtained for surgical localization purposes. Susceptibility artifact is noted along the right temporal and parietal scalp where the the depth electrodes transverse the calvarium. There is a stable position of 3 distinct depth electrodes through the more anteriorly placed burr hole, the tips of which are in the anterior, mid, and posterior medial right temporal lobe. There is a focal somewhat oval area of associated T2 hyperintensity in the subcortical and deep white matter of the anterior right lateral temporal lobe as seen on 401/86. This area measures approximately 8 x 25 mm and is not present on the preoperative MRI. Additional T2 hyperintensity likely extends peripherally and posteriorly on image 401/92 although exact extent is obscured by susceptibility artifact. There is an additional linear area of T2 hypointense signal essentially parallel and just anterior to the most posterior of these 3 electrodes, which could represent an additional tract.Via the right posterior parietal burr hole, there is a single electrode inserted, with tip at the anterior mesial right temporal lobe, along the inferior aspect. This is also grossly stable in position since prior CT.There is mild right-sided dural thickening and enhancement, likely postoperative. No pathological enhancement is appreciated. There is slight prominence of extra-axial space along the right posterior parietal region towards the convexity, likely relating to minimal subdural blood products, which are hyperintense with respect to adjacent CSF on the T1 weighted images. This measures approximately 4 mm in greatest thickness, as coronal reformats are not currently available. Additional extra-axial intrinsic T1 hyperintensity is noted more caudally along the right occipital lobe, likely representing slightly older blood products, measuring 3 mm in greatest thickness. Findings of known right mesial temporal sclerosis are again suggested but not as well appreciated on this exam.The ventricles and sulci are within normal limits. The cisterns remain patent. There is no midline shift or mass effect. Normal flow-voids are demonstrated in the major intracranial vascular structures. The midline structures and craniocervical junction are within normal limits. There is partial opacification of the lateral aspect of the right frontal sinus. Scattered trace ethmoidal thickening is seen bilaterally. Multiple mucous retention cysts are seen along the posterior nasopharyngeal soft tissues
1.Stable position of multiple right-sided depth electrodes. Small area of focal oval T2 hyperintensity in the lateral right temporal lobe likely relating to an area of vasogenic edema in the area of the electrodes, with possibility of associated blood products not entirely excluded.2.Minimal right posterior parietal and occipital subdural blood products of slightly different ages, likely postoperative.3.Findings of known right mesial temporal sclerosis are suggested but not as well appreciated on this exam.