Fig. 6.

Motor pathways tumor patient group stratification. Patients with tumors involving motor pathways can be stratified into 2 main groups (low-risk and high-risk) according to clinical variables and tumor features defined by imaging. The most appropriate stimulation modality for each group is indicated. The high-risk group is further subdivided into 4 subgroups according to clinical and imaging parameters and the most appropriate neurophysiological strategy to be used intraoperatively. Abbreviations: LF, low-frequency stimulation (60 Hz); HF, high-frequency stimulation; sMT, subcortical motor threshold; sLF MT, subcortical motor threshold with LF; sHF MT, subcortical motor threshold with HF. The current intensity of sMT is indicated in milliamperes.