Evaluation of combined use of transcranial and direct cortical motor evoked potential monitoring during unruptured XXXX surgery.

@entity1 @entity135 @entity66 @entity1269 @entity439 @entity432 @entity121 @entity438
The feasibility and reliability of combined use of transcranial and direct cortical motor evoked potential (MEP) monitoring during unruptured @entity439 surgery were evaluated. Forty-eight @entity1 with unruptured @entity438 underwent @entity135 clipping accompanied by @entity121 monitoring. MEPs were elicited successfully by transcranial electrical stimulation in all @entity1 . Direct cortical stimulation elicited MEPs in 44 @entity1 . Reduction in MEP amplitude to less than 50% of baseline was considered significant. No postoperative motor paresis occurred in 39 @entity1 in whom transcranial and direct MEPs remained unchanged. Four @entity1 in whom direct MEPs could not be recorded had no intraoperative @entity66 . Four of the other 5 @entity1 manifested significant transient direct MEP changes without transcranial MEP changes. The transient MEP changes were observed in 3 @entity1 during temporary clipping of the parent artery and in one @entity1 with inadequate clipping of an @entity438 , and were considered due to insufficiency of blood flow. Decrease or disappearance of direct MEP waves recovered immediately after re-application of the clip and release of the temporary clip. Direct MEP waves disappeared and did not recover until the end of microsurgical procedures in one @entity1 , although transcranial MEP amplitude remained at less than 50% of baseline. She developed @entity1269 postoperatively, which recovered within 6 hours. The duration of @entity432 in @entity1 with direct MEP changes was significantly longer than that in @entity1 without (p < 0.05). Direct MEP was sensitive in detecting ischemic stress to descending motor pathways during @entity439 surgery. Transcranial MEPs could be elicited in @entity1 in whom direct MEPs could not be obtained, and during periods such as craniotomy or after dural closure, in which direct MEPs could not be recorded. These findings suggest that combined transcranial and direct cortical MEP recording may improve the feasibility and reliability of MEP monitoring during unruptured @entity439 surgery.
