Reorganization in the primary motor cortex after spinal cord injury - A functional Magnetic Resonance (fMRI) study

Activation maps in the primary motor cortex (M1) were investigated in three patients with complete spinal cord injury (SCI) at level TH3, TH7 and TH9 and in one patient with an incomplete spinal cord injury at level L1 during right elbow (4 patients), right thumb (4 patients), bilateral lip (2 patients) and right foot (3 patients during imagined, 1 patient during executed) movements using functional Magnetic Resonance Imaging (fMRI). Compared to controls fMRI activation maps of patients with complete paraplegia showed a cranial displacement of the activation maxima in the contralateral primary motor cortex during elbow movement of 13.3mm, whereas the maxima of thumb and lip movements were not altered. The patient with an incomplete spinal cord injury revealed no displacement of elbow activation maxima. The reorganization is likely to occur on the cortical and not on the spinal level.