Greater sustained sensorimotor function recovery and neuropathic pain reduction with Cognitive Multisensory Rehabilitation compared to adaptive fitness in adults with spinal cord injury: a pilot clinical trial

Introduction: Adults with spinal cord injury (SCI) often experience reduced or lost sensation and movement, impairing the ability of the brain to locate paralyzed body parts, which, in turn, compromises sensorimotor recovery. This disruption of the internal body map of the brain, or mental body representations (MBR), also contributes to neuropathic pain in about 69% of adults with SCI. Medications for neuropathic pain are often ineffective and can cause adverse reactions. Our previous pilot clinical trial showed that Cognitive Multisensory Rehabilitation (CMR), a physical therapy that restores MBR, produced significant, lasting reductions in neuropathic pain, improved sensorimotor function, and enhanced brain function. Building on these results, we examined whether 8 weeks of CMR or adaptive fitness (1) improved sensorimotor function and reduced pain; (2) greater brain activity and connectivity related to sensorimotor function and MBR in adults with SCI. Methods: Sixteen participants (52+/-8 years old, 13+/-10 years post-SCI) were randomized to 8 weeks of CMR or adaptive fitness (45 min, 3x/week). Ten participants had neuropathic pain of 3/10 or greater. Pain and sensorimotor function were assessed at baseline, post-intervention, and 3-month follow-up using the Numeric Pain Rating Scale (NPRS), ASIA Impairment Scale (AIS), and Neuromuscular Recovery Scale (NRS). Functional MRI included resting-state and 4 tasks: imagining feeling the left leg, imagining moving the left leg, whole-body movement imagery, and a sensation task. Results: After CMR, participants improved on AIS with large effect sizes (touch: d=1.54; pinprick: d=1.83; lower limb motor function: d=1.32), while adaptive fitness had small/moderate effects (touch: d=0.49; pinprick: d=0.53; lower limb motor function: d=0.74). CMR also showed larger effect sizes for NRS (core: d=2.19; upper limb: d=0.69; lower limb: d=0.74) than fitness (core: d=0.73; upper limb: d=0.34; lower limb: d=0.00). Benefits persisted at follow-up. Highest neuropathic pain intensity reduced post-CMR and at 3-month follow-up (d=0.48; d=0.63). Pain increased slightly after fitness (n=6; d=-0.19; d=-0.41). CMR increased brain connectivity and activation during the leg imagery task. Increased activation during whole-body imagery was greater after CMR than fitness. Discussion: : NCT05167032.