Tailored keyhole surgery for basal ganglia cavernous malformation with preoperative three-dimensional pyramidal tracts assessment and intraoperative electrophysiological monitoring

Background: Accurately mapping the pyramidal tracts preoperatively and intraoperatively is the primary concern when operating on cavernous malformations (CMS) in the basal ganglia. We have conducted new methods for preoperative planning and have tailored lesion resection to prevent the damage of pyramidal tracts. Patients and methods: Eleven patients harboring cavernous malformations in basal ganglia were treated surgically from April 2008 to January 2015. Surgical planning was based on three-dimensional diffusion tensor pyramidal tractography and Virtual Reality system. Intraoperative detecting of pyramidal tracts with subcortical stimulation mapping and motor evoked potential monitoring were performed. The extent of resection and postoperative neurological function were assessed in each case. Results: Total removal of the cavernous malformations were achieved in each case. Four of the total eleven cases presented temporary neurological deficits, including one occurrence of hemiparesis and three occurrences of hemianesthesia. No permanent neurological deficit was developed in this series of cases. Conclusion: Three-dimensional diffusion tensor pyramidal tractography is quite helpful for preoperative planning of basal ganglia cavernous malformations, especially in choosing a suitable surgical approach. Intraoperative detection of pyramidal tracts with subcortical stimulation mapping and motor evoked potential monitoring play important roles in preventing damage to pyramidal tracts during lesion resection.