New approach for graded compression spinal cord injuries in Rhesus macaque: method feasibility and preliminary observations

Background Current models of spinal cord injury (SCI) have been ineffective for translational research. Primate blunt SCI, which more closely resembles human injury, could be a promising model to fill this gap. Methods Graded compression SCI was produced by inflating at T9 an epidural balloon as a function of spinal canal dimensions in a non‐uniform group of monkeys. Results Sham injury and cord compression by canal invasion of 50–75% produced minimal morpho‐functional alterations, if at all. Canal invasion of 90–100% resulted in proportional functional deficits. Unexpectedly, these animals showed spontaneous gradual recovery over a 12‐week period achieving quadruped walking, although with persistent absence of foot grasping reflex. Histopathology revealed predominance of central cord damage that correlated with functional status. Conclusions Our preliminary results suggest that this model could potentially be a useful addition to translational work, but requires further validation by including animals with permanent injuries and expansion of replicates.