Showing papers on "Inferior longitudinal fasciculus published in 2006"

Restored Activation of Primary Motor Area from Motor Reorganization and Improved Motor Function after Brain Tumor Resection

Abstract: BACKGROUND AND PURPOSE: Reorganization of brain function may result in preservation of motor function in patients with brain tumors. The goal of the present study was to investigate whether function of the primary motor area (M1) was restored and whether motor function improved after brain tumor resection. METHODS: Five patients with metastatic brain tumors located within or near M1 underwent awake surgery with intraoperative cortical mapping and continuous task monitoring. Preoperative and postoperative functional MR imaging (fMRI) was performed during hand clenching, and diffusion tensor imaging (DTI) was performed in 1 case to further characterize the area activated in fMRI. RESULTS: Preoperative fMRI performed during hand clenching demonstrated reorganization of motor function. In patients with severe paresis (cases 3, 4, and 5), clenching of the affected hand induced a large blood oxygen level–dependent response in the right hemisphere, mainly in the anterior temporal lobe, despite the location site of the tumor. Postoperative fMRI during hand clenching demonstrated activation of the contralateral M1. Furthermore, in case 5, DTI detected tracts, possibly the inferior longitudinal fasciculus, arising from anterior temporal activated area as well as tracts connecting the premotor and M1 activated area. This patient demonstrated mirror movement of the hand during the course of motor function recovery. CONCLUSIONS: Tumor resection resulted in restoration of M1 function and improved motor function in patients with preoperative reorganization of M1 function. Furthermore, the preoperative reorganization of motor function in cases with severe paresis may be related to changes in the right hemisphere, including the temporal lobe.

Visualizing white matter fiber structure in human brain using diffusion tensor imaging

Abstract: Objective To visualize the matter fibers of human brain by diffusion tensor MR imaging, and to investigate the consistency between the imaging and anatomic descriptions. Methods Twenty healthy volunteers were examined by MRI and single shot echo-planar diffusion tensor imaging (b=0, 500 s/mm~2), post processing were made in SIEMENS Leonardo workstation using SIEMENS Standar 12 dirs software to reconstruct the white matter fibers. Results Visualizing the white matter fibers of human brain such as, corticospinal tract, corticobulbar tract, corpus callosum, cingulum, superior longitudinal fasciculus, inferior longitudinal fasciculus, superior fronto-occipital fasciculus, inferior fronto-occipital fasciculus, uncinate fasciculus. Each fiber need selecting appreciative regions of interest (ROI) and FA threshold, angle threshold, step length and number of sampling in a voxel size. The images shown on diffusion tensor tractography was well consistent with the anatomic features. Conclusion The white matter of human brain could be visualized by diffusion tensor imaging in vitro, with the imaging features being well consistent with anatomic descriptions. Diffusion tensor imaging is a reliable method to study the white matter fibers of human brain.

ORIGINAL RESEARCH Restored Activation of Primary Motor Area from Motor Reorganization and Improved Motor Function after Brain Tumor Resection

Abstract: BACKGROUND AND PURPOSE: Reorganization of brain function may result in preservation of motor function in patients with brain tumors. The goal of the present study was to investigate whether function of the primary motor area (M1) was restored and whether motor function improved after brain tumor resection. METHODS: Five patients with metastatic brain tumors located within or near M1 underwent awake surgery with intraoperative cortical mapping and continuous task monitoring. Preoperative and postoperative functional MR imaging (fMRI) was performed during hand clenching, and diffusion tensor imaging (DTI) was performed in 1 case to further characterize the area activated in fMRI. RESULTS: Preoperative fMRI performed during hand clenching demonstrated reorganization of motor function. In patients with severe paresis (cases 3, 4, and 5), clenching of the affected hand induced a large blood oxygen level–dependent response in the right hemisphere, mainly in the anterior temporal lobe, despite the location site of the tumor. Postoperative fMRI during hand clenching demonstrated activation of the contralateral M1. Furthermore, in case 5, DTI detected tracts, possibly the inferior longitudinal fasciculus, arising from anterior temporal activated area as well as tracts connecting the premotor and M1 activated area. This patient demonstrated mirror movement of the hand during the course of motor function recovery. CONCLUSIONS: Tumor resection resulted in restoration of M1 function and improved motor function in patients with preoperative reorganization of M1 function. Furthermore, the preoperative reorganization of motor function in cases with severe paresis may be related to changes in the right hemisphere, including the temporal lobe.