Does Age of MS Onset Impact on Cognition?

Research Summary: Long-term Cognitive Outcomes in Patients With Pediatric-Onset vs Adult-Onset Multiple Sclerosis

Ask people living with multiple sclerosis what their worst symptom is and they will probably answer either fatigue or ‘cog fog’.  ‘Cog fog’ is a commonly used term in the MS community that refers to cognition problems.  These cognitive issues have been shown to have a huge impact in many areas.  It is a leading cause of being unable to maintain employment, lessens people’s ability to interact socially and results in an overall decreased quality of life.

It was thought that these cognitive problems were just a result of decreased neurologic ability, that is, that it was just a side-effect of having had MS for a long time.  However, this may not be the full picture, with more recent studies showing that it can actually be one of the first symptoms to appear.  Considering all of this, any research that helps us get closer to understanding this problem and allow for the potential to specifically treat it, is very exciting.  Today, we are feature one such project….

Who?

The study was primarily performed by researchers from the Karolinska Institute in Sweden, with help from collaborators in Canada.

Where?

The study was published in JAMA Neurology in June, 2019.  The abstract can be found here.

What?

The study aimed to see whether or not there were differences in the long-term cognitive outcomes for people who had an  onset of multiple sclerosis as children (less than 18 years of age) compared to those with their onset as adults (over 18 years old).

How?

The study used the large Swedish MS Registry and included 5,704 participants, almost all of whom had relapsing-remitting MS.  Of these participants, 300 had an onset of MS before the age of 18.

FINDING #1:  Cognitive problems are experienced by many people living with multiple sclerosis.  In this cohort, almost 71% of people in the childhood-onset group, and almost 60% in the adult-onset group, were found to have reduced ability to process information, a sign of cognitive issues.

FINDING #2: At 30 years of age, there was no observable difference in the cognitive function between the two groups.

FINDING #3:  The ability of people with childhood-onset multiple sclerosis to complete this cognitive test declined quicker than those with adulthood-onset.  It was found that this result was independent of age, the treatment being taken or how long they had had MS.

FINDING #4:  The researchers also found that this result may have important implications for maintaining employment.  They found that people with childhood-onset MS reached a cognitive test score that represents a stage of “employed, but work challenged” by 34 years of age, whereas those with adult-onset MS didn’t reach this point until an average age of 50.

THOUGHT #1:  This study shows that we need to place a large focus on the cognitive issues experienced by people living with multiple sclerosis.  It also shows that, in particular, people whose initial clinical symptoms of multiple sclerosis are experienced earlier in life may need to be more closely monitored for changes in cognitive function and helped to deal with the problems that these issues can cause in many facets of life.

THOUGHT #2:  Further studies will now be required to see if we can understand what is happening to cause the differences observed in this study.  By working out what leads to quicker cognitive decline in people with their initial onset of multiple sclerosis during childhood, we may be able to find specific targets for treating it.  

THOUGHT #3:  This further highlights the importance that registries can play in multiple sclerosis research.  By having large amounts of long-term clinical data, scientists are now capable of finding answers to questions that had previously been impossible to determine.

Read more of our research summaries here.