Pre-Surgical Mapping of Paediatric Motor Function and Structure Using Magnetoencephalography (MEG) and Diffusion Tensor Imaging (DTI)

Donald Mabbott¹, Nadia Scantlebury¹, Conrad Rockel¹, Elysa Widjaja¹, William Gaetz¹

We investigated the clinical efficacy of using concurrent MEG-DTI methods to delineate the functional motor pathways of children seen for pre-surgical evaluation. Cortico-spinal tracts (CST) were delineated using functional and anatomical seeds in patients presenting with space-occupying lesions. Functionally-seeded tracts were more sensitive to changes in tissue micro-structure than those seeded anatomically. A significant increase in the FA, ADC and parallel diffusivity of motor-seeded, but not anatomically-seeded, CST was evident in patients relative to controls. Using motor-activated seeds to launch tracts, we characterized the displacement of CST in patients presenting with centrally-located tumors, demonstrating the validity of this technique.