Effect of Timing of Decompression on Neurological Outcome Following Spinal Cord Injury (SCI)

Optimal timing of decompression of the spinal cord (SC) following SCI with concomitant spinal stenosis (SS) remains controversial. Some surgeons recommend emergent decompression and others believe that timing of decompression has no effect on long–term outcome.

To answer this question we asked two critical questions:

1) what constitutes a significant spinal stenosis following SCI, and

2) what is the optimal timing of decompression following SCI + concomitant spinal stenosis?

In an earlier experiment, we performed a T1O laminectomy in Sprague–Dawley rats and inserted different sized spacers at the level of moderate SCI (25 gm–cm created using a NYU impactor). Narrowing of the spinal canal by a 35% sized spacer was the greatest degree of spinal stenosis that consistently showed neurological improvement (p less than 0.05). In this experiment, 42 Sprague–Dawley rats underwent a TI 0 laminectomy, a moderate SCI, and insertion of a 35% spacer which was left in the epidural space for 2, 6, 24, or 72 hours, then removed. All rats were evaluated weekly for 6 weeks using the BBB locomotor score. Neurological outcome was significantly greater the earlier that decompression was performed. BBB scores for rats in which decompression was performed at 2 hours were greater than at 6 hours, greater than at 24 hours, and greater than at 72 hours (p less than 0.05). If extrapolated clinically, the greater the degree of spinal stenosis existing following a spinal cord injury, the poorer the neurological outcome. Furthermore, neurological outcomes improve the earlier the spinal cord can be decompressed.