By Jennifer Pisarek
This is the summary of a paper published by a researcher from the Departments of Mechanical Engineering and Orthopaedics, ICORD researchers, and a researcher from the Combined Neurosurgical and Orthopaedic Spine Program. Original article: Jones et al. (2012). Gross morphological changes of the spinal cord immediately after surgical decompression in a large animal model of traumatic spinal cord injury. Spine, 37(15), 890-899. DOI: 10.1097/BRS.0b013e3182553d1d. http://www.ncbi.nlm.nih.gov/pubmed/22433504
A primary procedure in the treatment of spinal cord injury caused by physical trauma is reducing or removing any pressure on the spinal cord from broken or injured bones of the spinal column. During surgery, pressure on the spinal cord is relieved, with the intent of restoring blood flow to the area. However, post-surgery imaging regularly shows that the spinal cord itself becomes swollen and fills the “subarachnoid” space between two of the spinal cord’s protective membranes. This can cause similar restrictions to blood flow.
This study measures the changes in the spinal cord and subarachnoid space diameter. Ultrasound imaging of changes to the injury site was examined after the alleviation of spinal cord pressure in moderate and high severity injuries.
What was the most important finding?
The results demonstrated a contrast between the moderate and high severity groups. In the moderate severity group, the spinal cord swelled within ten minutes, though the swelling did resolve before the end of the procedure. The deformation was gradual and did not obstruct the subarachnoid space. The high severity group, however, exhibited considerable swelling immediately after the procedure, obstructing the subarachnoid space.
These results establish that the swelling response is dependent on the severity of the injury, and that early intervention will be needed to reduce cord swelling after severe spinal cord injury.
What are some things we need to consider?
An important consideration is that this study was investigated in an animal model, and therefore may provide different results in humans. It is also quite challenging to model spinal cord injury realistically, given that the mechanisms are often unknown and the timing can vary considerably.
What does this mean for people with SCI?
This study demonstrates the benefits of early surgical alleviation of pressure in the spinal cord after SCI, especially when an injury is severe. It is important to prevent blood vessels from becoming restricted, maintaining sufficient oxygen to avoid any damage to the surrounding tissues.