Motor cortex changes in spinal cord injury: a TMS study

Using paired pulse transcranial magnetic stimulation (TMS) paradigms, we studied cortical excitability in a patient with spinal cord lesion. During posterior tibial nerve stimulation, the contextual flexion of hand fingers contralateral to the stimulated lower limb had suggested a change in motor cortex excitability. Results showed a decrease in the activity of motor cortex inhibitory circuits. This could suggest that in spinal cord injury, just as in stroke and peripheral deafferentation, a disinhibition of latent synapses within the motor cortex and the rewriting of a new motor map can occur.