A new study is claiming that neurological decline in patients with multiple sclerosis (MS) may not be as inevitable as previously thought.
The study, “A longitudinal study of cognitive function in multiple sclerosis: is decline inevitable?,” was published in the Journal of Neurology.
For many years, statistics have implied that some kind of cognitive impairment affects more than half of all MS patients, including memory loss or problems with processing information. Once a patient starts showing signs of cognitive decline, it is often assumed symptoms will essentially get worse as MS progresses.
However, researchers in Greece found new evidence and are challenging this long-held belief.
Investigators reviewed data from 59 patients — 14 with the clinically isolated syndrome and 45 with relapsing-remitting MS — and closely observed their cognitive decline over a ten-year period. Using the Brief Repeatable Battery of Neuropsychological Tests, cognitive impairment was measured. The report also looked into factors that revealed roughly a 10% increase in measures of overall cognitive impairment over the course of a decade in the MS group analyzed — from 42% at baseline to 52.5% at follow-up.
Cognitive discrepancies at 10 years were not linked to with the number of relapses in the intervening time, nor with disability (as measured by the Expanded Disability Status Scale) at any time point, according to the report.
However, investigators noted these overall results masked unique patterns seen when data were assessed individually.
“Looking at the individual patient performance at baseline and follow-up in all five cognitive domains investigated, one can discern several cases who have failed in fewer domains at follow-up compared to baseline, or who have failed at different domains at follow-up compared to baseline,” the researchers wrote in the report.
“Cognitive impairment at baseline does not by default lead to progressive decline. Although the overall proportion of cases with cognitive impairment increases over time, there are several patients who improve over the years in specific cognitive domains, while they may or may not decline in other domains,” the researchers wrote in the report.
“This ‘bouncing-back’ of cognitive function in impaired-at-baseline patients is an intriguing phenomenon that may reflect the [damage] compensation capabilities of the brain in ΜS patients,” they added in the conclusion of the report.
They also pointed to other correlatives, like anxiety, depression and high levels of stress which has been shown to negatively affect cognitive function in those with MS. Further research is needed to validate these results and clarify the underlying mechanisms, the researchers wrote.
Additionally, they emphasized that future studies should cast a broader, more diverse net regarding MS patient test groups, and suggested shorter testing times like at two and five years, as well as 10 — would enable a more detailed assessment of decline.
“But overall, “this study suggests a more fluid picture for the evolution of cognitive function in a subgroup of MS patients, and contradicts the concept of an inevitable, progressively evolving ‘dementia,’” the team wrote in conclusion.