Fig. 2

DSI tractography of pyramidal tracts (PTs) and pre to post-operation motor function changes. a Illustration of PT tractography result: deficit of all the PT fibers was classified as “damaged”; continuous PTs with a deficit in most of the fibers were classified as “atrophied”; while the PTs within the lesioned hemisphere that were symmetric with the healthy hemisphere PTs were classified as “robust PTs.” b Patient 1–5 with broken PTs within lesioned hemisphere exhibited mild paralysis with muscle strength pre-operatively but remained stable postoperatively. Patients 6–9 with atrophied PTs exhibited paralysis with muscle strength pre-operatively and suffered mild deterioration postoperatively. Patient 10 exhibited symmetric and robust PTs between hemispheres, with contra-lateral innervation confirmed by intracranial stimulation. This patient received multilobar lesioned resection and remained stable with muscle strength postoperatively. c Three patients with damaged PTs in the lesioned hemisphere had “no grasping ability” pre-operatively. Two of the patients with damaged PTs in the lesioned hemisphere were able to grasp pre-operatively. These patients’ postoperative hand grasping functions were stable compared with preoperative hand function. Four patients with atrophied PTs in the lesioned hemisphere could not grasp after the operation. Two of these patients who could grasp preoperatively lost their grasping ability postoperatively. The patient with robust symmetric PTs received multilobar lesion resection and remained stable in motor function after the operation. Abbreviation: PT (pyramidal tract), pre-OP (pre-operative), post-OP (post-operative)