Shift of pyramidal tract during craniotomy and its countermeasures

Objective To study the pyramidal tract shift craniotomy and its countermeasures. Methods Seventy-four patients with frontal,temporal or insular lobe mass lesions were enrolled in the study.Preoperative and intra-operative diffusion tensor images（DTI） were obtained.The iPlan 2.6（Brain Laboratory,Feldkirchen,Germany） was used for reconstruction of the pyramidal tract and assessment of its shifting. Results Forward shifting,backward shifting,and no shifting of the pyramidal tract were found in 25,45 and 4 patients,respectively,while outward shifting,inward shifting,and no shifting of the pyramidal tract were found in 32,38 and 4 patients,respectively. Conclusion Pyramidal tract shift is common during craniotomy with its direction and distance unpredictable.Only by intra-operative updated real-time MRI navigation,can the shifting be prevented.