Stable improvement in hand muscle strength in incomplete spinal cord injury patients by long-term paired associative stimulation—a case series study

This study investigates the potential of paired associative stimulation (PAS) to improve hand function in patients with spinal cord injury (SCI). PAS involves combining transcranial magnetic stimulation (TMS) with peripheral nerve stimulation (PNS). The 'high-PAS' protocol used in this study combines high-intensity TMS with high-frequency PNS. The goal is to induce neuroplastic changes in spared corticospinal connections, potentially leading to restored motor function. Four patients with chronic, incomplete SCI received high-PAS multiple times a week until their hand muscle strength stopped improving. The study found that strength increased in both the stimulated and non-stimulated hands and that the achieved strength level was maintained for at least 6 months after stimulation.

• 1
  Muscle strength increased in both the stimulated and non-stimulated hands of patients with incomplete SCI after high-PAS treatment.
• 2
  The increase in muscle strength, particularly in muscles innervated by stimulated nerves, averaged 24.5% from pre- to post-stimulation conditions.
• 3
  High motor point integrity testing scores (indicating a low extent of lower motor neuron damage) correlated positively with good MRC outcomes of the stimulated hand after high-PAS.