#ECTRIMS2021 – Brain Lesions Help Predict Long-term Disability
Editor’s note: The Multiple Sclerosis News Today team is providing in-depth coverage of the virtual 37th Congress of the European Committee for Treatment and Research in Multiple Sclerosis (ECTRIMS), Oct. 13–15. Go here to see the latest stories from the conference.
Assessing lesions in the cortex — a brain region involved in cognitive function and the control of motor activities — can help predict the long-term risk of cognitive impairment and disability progression among people with multiple sclerosis (MS).
That’s according to new data shared by researchers from the University of Verona, in Italy, in a pair of presentations at the 37th Congress of the European Committee for Treatment and Research in Multiple Sclerosis (ECTRIMS), taking place virtually Oct. 13–15.
Brain lesions — areas of damage and inflammation visible on MRI scans — are characteristic of MS, but researchers are still working to understand exactly what information can be reliably inferred from the identification of different types.
In an oral presentation, “Cortical lesions at diagnosis predict cognitive impairment in multiple sclerosis: a 20-year follow-up study,” researchers showed that measuring lesions in the cortex — called cortical lesions or CLs — at diagnosis could predict the long-term risk of cognitive impairment.
“Cortical lesions reflect brain damage since the early stages of disease are … associated with clinical disability, and responsible for disease progression. However, prognostic data about the role of early cortical lesions with reference to long-term cognitive impairment are still missing,” said Stefano Ziccardi, PhD, a researcher at the University of Verona, who presented the data.
The team assessed data on 170 MS patients, who were followed for over 19 years, on average. At diagnosis, 41% of patients had no cortical lesions, 19% had one or two CLs, and 40% of patients had three or more CLs. By the end of follow-up, half of the patients met the criteria for cognitive impairment: 25% for mild cognitive impairment, and another 25% for severe impairment.
Statistical analyses demonstrated that patients who eventually developed severe cognitive impairment had substantially more lesions, on average, when they were diagnosed.
“Cognitively impaired patients show a significantly higher number of cortical lesions at diagnosis, with reference to cognitively normal patients,” Ziccardi said. Similarly, patients with severe impairment tended to have more CLs at diagnosis than those with mild impairment, he noted.
Specifically, analyses showed that patients with three or more CLs at diagnosis were approximately 3.7 times more likely to be cognitively impaired later on, and about 3.3 times more likely to be severely impaired, than patients without CLs at diagnosis.
Of note, among the 68 patients with three or more CLs at diagnosis, more than two-thirds (69%) were cognitively impaired by the end of follow-up, with 41% meeting criteria for severe impairment. By contrast, among patients with zero CLs at diagnosis, just 38% were cognitively impaired by the end of follow-up, and most impairment was mild (26%).
“We can therefore conclude that the number of cortical lesions at MS diagnosis accurately discriminates between the presence or the absence of cognitive impairment after two decades of MS,” Ziccardi said.
As such, CLs “should be considered as a predictive marker of long-term cognitive impairment” in MS, Ziccardi added, noting that testing for CLs may make it easier to identify, and manage, cognitive impairment that develops later on.
In a separate poster at ECTRIMS, the researchers presented the results of a similar analysis conducted to assess the relationship between CLs and risk of disability progression and conversion to secondary progressive MS (SPMS). That poster was titled “Cortical lesions at diagnosis predict conversion to secondary progressive multiple sclerosis and accumulation of disability: a 20-year follow-up study.”
This analysis included 152 patients with relapsing-remitting MS (RRMS) at diagnosis. Among them, 47 had clinically isolated syndrome (CIS) and eight had primary progressive disease. In terms of CLs at diagnosis, 102 patients had no CLs, 49 had one to three, and 57 had four or more.
Of note, after about 17 years of follow-up, 39 patients originally diagnosed with RRMS or CIS had developed SPMS. The vast majority of these patients — 84.6% — had three or more CLs at diagnosis. By contrast, most patients who did not develop SPMS had fewer CLs, with 61.9% having none.
Statistical analyses also showed that patients with three or more CLs at diagnosis were significantly more likely to reach a score of 6.0 on the Expanded Disability Status Scale (EDSS) by the end of follow-up. At this level of disability, patients require an aid to walk about 100 meters (roughly 325 feet).
The researchers concluded, as reported in the poster, that assessing CLs at diagnosis “might represent a good prognostic marker of evolution towards the SPMS phase and one of the best surrogate early marker of disability accumulation.”