Exacerbation of spinal cord injury due to static compression occurring early after onset.

Object. The authors used a rat model to assess spinal cord compression following an incomplete spinal cord injury (SCI). Methods. Incomplete SCI was created in the thoracic spinal cord in a novel application of a rodent spinal cord compression model. A moderate impaction force was applied instantaneously to the spinal cord and was followed by 0 seconds. 10 seconds, 30 seconds. or 5 minutes of continued compression (termed "dwell"). The different groups were assessed by behavioral testing with the Basso, Beattie, Bresnahan locomotor rating scale, and with histological injury quantification and morphometrical analysis. Results. Compression alter the SCI resulted in worsened Basso, Beattie, Bresnahan scale scores; however, the duration of compression was not significant. Compression did not significantly affect the percentage of spared total tissue, percent spared total white matter, or percent spared total gray matter. Percent spared tissue at the epicenter of injury was statistically worsened by compression but not in a time-dependent manner. Conclusions. The authors' results suggest that spinal cord compression after the initial injury is an additional mechanism by which SCI worsens, and that the mechanism of this injury occurs rapidly. These data, however, do not support duration of compression as a significant variable. (DOI: 10.3171/2009.5.SPINE08588)