Disability from multiple sclerosis may be caused by more than loss of spinal nerve fibres, new research shows.
This could mean the use of MRI scans to predict disability from MS may not be as reliable as thought.
The research questions the belief that, in MS, loss of spinal axons, or nerve fibres, is the key factor in levels of chronic disability.
This has led to the wide use of MRI to measure the cross-sectional area of the spinal cord in order to predict disability. But researchers from Queen Mary University of London have now sampled spinal cords of 13 people with MS and 5 healthy controls. They found that spinal cord cross-sectional area is not a good predictor of axonal loss.
Results of the research “Axonal loss in the multiple sclerosis spinal cord revisited” were published in Brain Pathology on May 7.
Lead researcher Klaus Schmierer said: “The lack of association between axonal loss and spinal cord cross-sectional area significantly changes our understanding of chronic disability in MS.
Disability imbalance between MS and spinal cord trauma
“The nature of the spinal cord needs to be appreciated as a highly organised and largely autonomous network . We need to identify other factors over and above axonal loss. Factors that determine the collapse of the spinal cord network and lead to the functional deficits seen in MS.
“In spinal cord trauma, people with less than 10% of axons, may still be able to have lower limb movement. But MS patients with up to 40% of their axons retained are almost invariably wheelchair-bound, as shown in our study. So, there is clearly something happening here which we’ve yet to understand.”
Finding other factors causing the chronic disability seen in MS, it could help identify targets for new treatments.
The team’s preliminary results indicate the loss of synaptic connections in the spinal cords of people with MS is substantial. It is possible that further research could determine is this is the missing link that is driving disability.
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50shadesofsun.com is the personal website of Ian Franks, who has enjoyed a successful career as a journalist, from reporter to editor, in the print media. During that career he gained a Journalist of the Year award in his native UK. Diagnosed with MS in 2002, he continued to work until mobility problems made him retire early in late 2006. He now lives in the south of Spain. Besides MS, Ian is also able to write about both epilepsy and cardiovascular matters from a patient’s perspective. Besides that, he is a keen advocate on mobility and accessibility issues.