Swelling is a common reaction of your body to any form of injury; remember the last time you banged your finger, or perhaps twisted your ankle? So unsurprisingly, it can happen to the spinal cord and has been reported in patients with CSM. However, it is not present in all patients and its significance is not certain. In addition to this, some studies have now described that the spinal cord can swell after surgery. The reason for this is unclear and equally what it means for patients is not clear.
On basic MRI imaging, swelling is not that easy to detect; a doctor may look for a slight enlargement of the spinal cord or some signal change. An alternative method is to inject a ‘contrast agent’ into the patient during the scan. This is a special form of dye which highlights certain processes, and can be a indicator of swelling amongst other things. We call this ‘highlighting’ enhancement.
On this basis, a group from Japan have been looking at spinal cord swelling using contrast and what it means for patients.
What did the study measure?
The team from Japan performed ‘contrast MRI’ scans on patients with CSM due to undergo and operation, before and after their surgery. They then compared what happened to patients who had enhancement and those that did not have enhancement.
What were the results?
In the study they found that those with preoperative enhancement were more likely to have developed swelling at 1 month after the operation and the swelling was more likely to persist until 1 year post operation. Those who developed swelling had poorer outcomes as assed by a scoring system called the JOA that looks at movement skills as well as sensory loss (problems with feeling).
What does this mean for those affected?
This sort of MRI imaging is not normally performed during the work up for CSM, but the potential to offer additional information into the severity of the disease and how patients are likely to respond to surgery would be helpful to doctors and sufferers alike.
It is worth noting that the injection of dye can be harmful to some people, although this is uncommon.
Therefore, for this technique to be adopted, healthcare providers are likely to need further information, such as:
- How does this change the management of patients? This study only looked at patients who were due to undergo an operation anyway, is spinal cord swelling present in other forms of CSM? Can it help decide when to perform an operation?
Of course a number of additional MRI techniques are being developed, and it is possible that the information that might be provided by this method, is superseded.
References
Ozawa et al. Spinal Cord Swelling After Surgery in Cervical Spondylotic Myelopathy: Relationship With Intramedullary Gd-DTPA Enhancement on MRI. Clin Spine Surg. 2018 May 31. doi: 10.1097/BSD.0000000000000664
Cho et al. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3229731/