Up to two-thirds of people with multiple sclerosis (MS) eventually develop some problems with cognition. Even when such problems are mild to moderate based on objective tests, they may have an outsized impact on daily life, affecting everything from remembering appointments to managing a checking account.
If you have MS, your doctor may rely on you to mention any cognitive symptoms you’re having. Yet it’s not always easy to think accurately about how well you’re thinking. Fatigue — another common symptom of MS — can make this particularly difficult, according to a new study presented at the 2013 joint meeting of the Consortium of Multiple Sclerosis Centers and America’s Committee for Treatment and Research in Multiple Sclerosis.
The implication: When you have MS, treatments that reduce fatigue might help you gauge your own thinking more accurately. That, in turn, might make it easier to cope effectively with cognitive symptoms of MS, but not get unduly anxious about them. Fatigue-fighting options include physical and occupational therapy, stress management, sleep regulation, heat management, and certain medications.
At the meeting, I had a chance to chat with study lead author Meghan Beier, PhD, a National Multiple Sclerosis Society research fellow at the University of Washington. Here’s what she told me about her fascinating research.
Why are cognitive symptoms such an important issue for people with MS?
Meghan Beier, PhD: There are a number of reasons. About 34% to 65% of individuals with MS, depending on the study, will experience some cognitive dysfunction in their lifetime. Cognitive functioning impacts every aspect of daily living and is consistently one of the main predictors of whether an individual can remain employed.
What are some of the most common cognitive symptoms of MS?
Beier: One common symptom is a change in processing speed — how fast the brain can process information. For example, you may take longer to come up with a word in the middle of a conversation, ask people to repeat themselves a lot because you don’t catch everything they say, or need to reread information several times before it sinks in.
Another common symptom is difficulty with executive functioning — planning, organization, and initiation. For example, you may have trouble following a cooking recipe with multiple steps, need to write everything down to keep it organized, or have trouble getting going on projects.
MS may also affect complex attention or working memory — holding information in mind while trying to manipulate it or do two things at once. For example, you may have difficulty with dialing a phone number that someone just told you, talking on the phone while typing on a computer, or reading a book while trying to block out noise from the environment.
In addition, MS is associated with a distinct pattern of memory impairment. People with MS sometimes take longer to learn new information. But research shows that, once the information is learned, they are usually able to recall it again at a later time or recognize it if given a cue.
How well are people with MS able to gauge their own mental functioning?
Beier: Self-reported cognitive function is an individual’s own perception of their cognitive functioning. This has been studied in many populations, not only people with MS. Most of these studies have found that perceived cognitive dysfunction has little or no association with objective decline, as measured by neuropsychological testing.
Perceived cognitive deficits are highly associated with emotional distress, particularly depression. One study found that, with reduced depression and fatigue, people with MS were more able to accurately assess their own functioning.
In your new study, fatigue, not depression, was the strongest predictor of self-perceived cognitive problems in adults with MS. Why do you think fatigue had such a strong effect?
Beier: I don’t have a definitive answer for this question. However, I have several thoughts and hypotheses! One observation is that fatigue is multidimensional. A patient of mine described her symptoms very eloquently by saying, “I have three kinds of fatigue: cognitive fatigue, body fatigue, and feeling tired.” We may be capturing what she described as cognitive fatigue. This will need further study for a better explanation.
What are the implications of your research?
Beier: Treatment for MS needs to be holistic and targeted at all symptoms experienced by individuals with the disease, including fatigue, depression, anxiety, and stress. In addition, I think this research is important for medical providers, who often rely on patient self-report. It suggests that clinicians should also conduct objective tests of functioning or refer individuals with cognitive concerns for a neuropsychological assessment. A new screening test called the BICAMS (Brief International Cognitive Assessment for MS) was recently developed for this purpose.