Enhanced motor cortex excitability after spinal cord injury

Transcranial magnetic stimulation (TMS) is a non-invasive technique to study the brain, especially the motor cortex and its pathways. TMS can help researchers understand how the brain's inhibitory and facilitatory mechanisms work, particularly in conditions like spinal cord injury (SCI). Studies using TMS on individuals with incomplete SCI have shown that the brain's ability to inhibit motor activity might be reduced. This suggests that the balance between excitation and inhibition in the motor cortex is altered after a spinal cord injury. Researchers use various TMS techniques like measuring motor evoked potentials (MEPs) and short-interval intracortical inhibition (SICI) to assess these changes. These measurements provide insights into how the brain reorganizes itself after SCI and how motor function might be affected.

• 1
  Motor cortex excitability is increased after spinal cord injury, as indicated by TMS studies. This suggests the brain attempts to compensate for impaired motor function.
• 2
  Short-interval intracortical inhibition (SICI) is reduced after incomplete SCI, indicating altered inhibitory mechanisms in the motor cortex.
• 3
  The pattern of I-wave facilitation is significantly different in SCI patients, suggesting altered GABAergic inhibition in the motor cortex.