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

ABSTRACT

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.