Effects of timing of methylprednisolone or naloxone administration on recovery of segmental and long-tract neurological function in NASCIS 2.

Previous analyses of the National Acute Spinal Cord Injury Study (NASCIS) have not distinguished recovery of segmental function at the injury level from recovery of the long spinal tracts. Recovery at the injury level could be of considerable clinical significance, but long-tract recovery is the ultimate therapeutic goal. This analysis demonstrates that the greatest proportion of all neurological recovery and of recovery due to treatment with very high doses of methylprednisolone within 8 hours of injury occurs below the lesion. Methylprednisolone treatment administered early following injury has been found to improve recovery below the lesion in patients initially diagnosed as having complete or incomplete injuries; it also leads to greater (but still relatively small) improvement in the injury level. The analysis indicates that delayed treatment with methylprednisolone is associated with decreased neurological recovery. Naloxone administration also improved neurological function below the lesion in patients with incomplete injuries; these results support further experimental work with this drug. This observation of differential neurological response within a narrow treatment window has important implications for both experimental studies and clinical management. Early clinical management with high-dose methylprednisolone is supported by this analysis.