Preliminary Application Of Intraoperative MRI And Functional Neuronavigation Combined With Direct Electrical Stimulation In Rolandic Glioma Surgery

Objective: To investigate and summarize the experiences of the application ofiMRI(intraoperative MRI) and functional neuronavigation combined with directelectrical stimulation in the surgery of rolandic glioma. Methods: In the first part, westudied how to choose optimal threshold to reconstruct the primary motor cortex underpathological condition based on Bold-fMRI data.12patients with rolandic lesions inour hospital were included in our study, The image post-processing were performed bySPM (Statistical Parametric Mapping). we use three different threshold (FDR (FalseDiscover Rate) corrected p<0.05, uncorrected p<0.001and uncorrected p<0.0001) toreconstruct the primary motor cortex respectively. The results of the three thresholdswere assessed. In the second part, the experiences of application of iMRI and functionalneuronavigation combined with direct electrical stimulation in rolandic glioma surgerywere summarized in17patients prospectively. Results：In the first part, the primarymotor cortex reconstructed by three thresholds had the same location according to thecoordinate system，all the results reconstructed using threshold P<0.001are larger thanFDR p<0.05, meanwhile, all the results reconstructed using threshold P<0.0001aresmaller than or similar to FDR p<0.05. The correspondence between P<0.0001andFDR p<0.05are obviously higher than P<0.001and FDR p<0.05. In the second part, thetumors were totally resected when the first iMRI scan in4patients（29.41%）, then wecontinued surgery in9patients，in the end, resection were total in10patients（58.82%）.The application of iMRI improve EOR (extent of resection) from76.04%±29.88%to91.86%±12.57%(P=0.014). The total resection rate increased greatly in the groups ofthe distance between tumor margin and reconstructed pyramidal tract based on DTI scanmore than5mm(P=0.036). Only1patient（5.9%）had motor impairment3months later.The results of Bold-fMRI and direct electrical stimulation were in agreement in13 patients (81.75%). Focal epileptic seizures were provoked in2patients, the seizureswere rapidly resolved after local administration of40C Ringer’s solution, no relatedlong-term complication was observed. Conclusion：The first part: the result of primarymotor cortecx reconstructed using threshold p<0.0001has false positive rate less than0.05，which is more reliable and suitable for clinical application. Using thresholdp<0.001can caused higher false positive rate，which should be used with caution. Thesecond part:1, iMRI can improve total resection rate obviously in the rolandic gliomasurgery;2, The relationship between eloquent area and tumor can be assessed based onBold-fMRI and DTI scan, it is a important factor whether the distance between tumormargin and reconstructed pyramidal tract less or more than5mm to affect total resectionrate;3,The accuracy of neuronavigation based on Bold-fMRI could be affected by usingthreshold p<0.001or tumor’s mass effect；4; There are two indications to use directelectrical stimulation in rolandic glioma surgery: a, The accuracy of neuronavigationbased on Bold-fMRI was doubted；b, tumor located in the primary motor cortex.