P.082 Neural Reorganization Following Compression of the Motor Cortex: An fMRI and DTI Case Report

Background: Functional magnetic resonance imaging (fMRI) and diffusion tensor imaging (DTI) are noninvasive and reliable tools for mapping eloquent cortex and white matter tracks prior to brain surgery. In this case, fMRI and DTI were used to inform the surgical approach in the resection of a deep cavernous malformation near the right lentiform nucleus. Post-surgery, the patient developed a fluid collection in the frontal cortex that applied pressure to M1, which led to reorganization of the motor cortex. Methods: The tasks included finger tapping, arm rubbing, and lip licking. All fMRI analyses were performed using BrainVoyager. Tensors were tracked from 20-direction diffusion MR images using DSIStudio. Results: An fMRI scan one-month pre-surgery revealed activation in M1 for the three tasks. A six-month follow-up scan revealed motor activation had been displaced by the fluid collection. A ten-month follow-up scan revealed that activation had shifted from its original location to more lateral and anterior regions. DTI revealed atrophy in the tracts through the insula, but increase in tracts through the lentiform nucleus. Conclusions: The results provide evidence that components of motor processing subserved by M1 can be taken over by adjacent regions, and that the rapid onset of pressure can lead to reorganization in a relatively short time period.