Fmri based connectivity analysis of brain plasticity in facial lesion patients

This study aims to map the connections created by the sensory stimuli applied to the hand and face regions in the brain and examine the cortical plasticity in facial lesion patients accepted as potential transplant candidates. Five patients with facial lesions and ten healthy individuals participated in the study. Functional magnetic resonance imaging recordings were taken according to the block design created by stimulating the hand and face regions. Connection maps of the right hand, left hand, right face, and left face stimuli were created to obtain general judgments resulting from the second-level analysis using only the records taken from healthy individuals. The connection maps created serve as a reference for comparison with the patient group and other studies in this field. Connectivity measurements were repeated for the facial lesion patients selected as the patient group under the same conditions. As a result of comparing the connectivity measurements with healthy individuals, the changing conditions for the facial lesion group were examined under the concept of cortical plasticity. Significant differences were found in the connectivity analysis results of facial lesion patients who were potential face transplant candidates. The number of associated voxels in the seed-to-voxel connection measurements in the lesion group was considerably reduced compared to the control group measurements. In particular, the PostCG area, which is the sensory stimulus center containing the body representation, showed a correlation with the high voxel count in the control group, while this number decreased a lot in the lesion group. It has been found that some connections do not form, change, or decrease in density and strength. The detected differences constitute essential findings for the cortical plasticity that occurs after the injury. It is thought that the results obtained will support the transplantation process and the rehabilitation process before transplantation. When the results obtained in this study are compared with the post-transplant connection analysis, the cortical plasticity in the brain due to sensory stimuli can be interpreted.