MS researchers pulling double duty

A team of British researchers have discovered an imaging correlation for cognitive decline in young multiple sclerosis (MS) patients—and developed a large-scale workflow for MS imaging on the side, according to an article published in NeuroImage: Clinical.

Multiple sclerosis (MS) is a disease in which the sheaths of nerve cells in the central nervous system deteriorate over time, disrupting the ability of nerve cells to communicate with another. The sheaths, made out of a material called myelin, are a fatty layer that electrically insulates the cells. A lack of insulation means electrical signals can’t pass between cells—causing a wide range of visual, motor or sensory deficiencies.

The root cause is unclear and there’s no cure, but treatment has shown to be moderately effective in restoring function after flare-ups. Treatments vary depending on disease phenotype, indicating the need for a reliable measure of disease progression.

Brain-volume MRI offers an in vivo measure of MS progress, as brain volume in MS patients decreases by 0.7 to 1 percent per year—three times as fast as the general population. While the traditional school of thought assigns much of this loss to white matter atrophy, recent studies have shown that grey matter may be the culprit.

“There is a growing body of evidence to suggest that grey matter degeneration is prevalent in MS and may be a stronger predictor of clinical decline than white matter measures,” the authors wrote.

The findings from this study were two-fold: an effective imaging workflow for larger MS studies and the discovery of substantial atrophy in the hippocampus of younger MS patients.

“A number of fully-automated [workflow] solutions are being explored, however in this workflow we opted for manual delineation of both white and grey matter lesions. Lesions were then filled to allow automated segmentation of tissues to produce accurate volume measures of tissues and structures independent of lesion burden,” the authors wrote. “We hope that this workflow will be adopted to facilitate direct comparison of future measures with those reported herein.”

In addition, the decrease in hippocampal volume may demonstrate an imaging correlation with pronounced cognitive impairment in some cases of early-onset MS. The hippocampus plays a central role in memory processing and is the chief reason for cognitive decline in Alzheimer’s and other neurological diseases.  

“The notable loss in the young-onset and relative preservation in the older-onset MS patients may be indicative of early and marked loss of neurons in hippocampal substructures, as seen in post-mortem studies, wrote the authors. “A number of studies have reported worse cognitive dysfunction in early onset MS, most clearly demonstrated in pediatric and juvenile MS."

While the authors caution that their conclusion is limited by a lack of neuropyschometric data, they are confident that the detection of hippocampal atrophy can help future research better understand the implications of brain volume loss and it’s relationship with age and cognition.