RESUMO
BACKGROUND: The locations of cortex controlling motor, sensory, or language functions can change in adult humans under some circumstances, such as expanding tumours, trauma or continuous focal seizures. It is not clear what other circumstances might result in changes in cortical functional maps. METHODS: The results of extraoperative cortical mappings of motor, sensory, and language functions were compared in two epilepsy patients who underwent cortical resections on two separate occasions and who did not have brain tumours. RESULTS: It was found that the locations of motor functions could differ between the first and second procedures, but the locations of language functions were quite similar. The changes were not necessarily in or adjacent to epileptogenic regions or adjacent to resection boundaries. CONCLUSIONS: These findings support previous evidence indicating that cortical functional representations can change over time in humans, and suggest that these changes cannot be explained solely by lesion effects.
Assuntos
Mapeamento Encefálico , Córtex Cerebral/fisiopatologia , Epilepsia/cirurgia , Idioma , Atividade Motora/fisiologia , Regeneração Nervosa/fisiologia , Plasticidade Neuronal/fisiologia , Complicações Pós-Operatórias/fisiopatologia , Adulto , Córtex Cerebral/cirurgia , Dominância Cerebral/fisiologia , Estimulação Elétrica , Eletroencefalografia , Epilepsia/fisiopatologia , Feminino , Lobo Frontal/fisiopatologia , Lobo Frontal/cirurgia , Humanos , Processamento de Imagem Assistida por Computador , Imageamento Tridimensional , Imageamento por Ressonância Magnética , Rede Nervosa/fisiopatologia , Reoperação , Sensação/fisiologia , Lobo Temporal/fisiopatologia , Lobo Temporal/cirurgia , Tomografia Computadorizada por Raios XRESUMO
Subdural grid electrodes are implanted routinely for the pre-surgical work up of epilepsy. While different approaches are available, many centers, including ours, visualize electrode locations by co-registering pre-operative 3-D MR images with post-implantation 3-D CT images. This method allows the determination of the electrode positions in relation to the individual patient's anatomy, but does not easily allow comparison across patients. The goal of this study was to develop and validate a method for transforming electrode positions derived from 3-D CT images into standardized space. We analyzed data from twelve patients with subdurally implanted electrodes. Volumetric CT and MRI images were co-registered and then normalized into common stereotactic space. Electrode locations were verified statistically by comparing distances between the anterior commissure and a representative sampling of 8 electrode sites per patient. Results confirm the accuracy of our co-registration method for comparing electrode locations across patients.