Researchers develop understanding of MS pathological processes

Researchers have further developed their understanding of the pathological processes underlying multiple sclerosis (MS) in two related papers published in the Journal of Neurology, Neurosurgery and Psychiatry and Brain.

MS is a disease in which the protective covering surrounding the nerves of the central nervous system is damaged and the nerve cells and fibres lost. The underlying cause for this remains unknown. Magnetic resonance imaging (MRI) can reveal MS lesions on the brain or spinal cord and more subtle changes in parts of the brain that do not appear to contain lesions.

In work published in the Journal of Neurology, Neurosurgery and Psychiatry, Dr Declan Chard and his team set out to examine where lesions in or near the cortex (the brain’s outer layer of neural tissue) originated and used MRI to determine how individual MS lesions evolved over time. The team found that lesions involving grey matter very rarely developed from white matter and instead that it was much more usual for lesions to form in grey matter and then spread into the adjacent white matter.

In the work reported in the Brain paper, Dr Chard and his team looked at white matter, exploring whether, as with grey matter, MS pathology is greater near the surface of the brain. Using magnetisation transfer imaging the team discovered that abnormalities in lesions and normal-appearing white matter were greatest next to ventricles (chambers in the centre of the brain that hold the cerebrospinal fluid) and decreased with distance from them. While there are several potential explanations for this finding, the team suggest that this too may be consistent with the possibility of external factors influencing MS brain changes.

BRC supported Dr Chard said: “MS has long been thought of as mainly being a white matter disease, but there is now very good evidence that grey matter is also substantially affected, particularly the grey matter close to the surface of the brain. This and other work has raised the distinct possibility that factors external to the brain may affect MS pathology within it.”

Such studies may have significant implications for MS treatments, as those currently available may not reach tissues and fluid surrounding the brain, yet they may play a significant role in MS disease progression.

To read Magnetization transfer ratio measures in normal-appearing white matter show periventricular gradient abnormalities in multiple sclerosis in Brain click here.

To read A longitudinal study of cortical grey matter lesion subtypes in relapse-onset multiple sclerosis in the Journal of Neurology, Neurosurgery and Psychiatry click here.