What Is Multiple Sclerosis Cognitive Dysfunction?

If you're forgetful or unfocused lately, it's might be your MS

Woman looking tired sitting on sofa
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Approximately half of all people with multiple sclerosis (MS) will have some sort of cognitive dysfunction as a result of the disease. In the beginning, the signs of cognitive dysfunction might be so subtle that you don't notice them or attribute them to other things, such as aging or being tired.

People with MS are more likely to struggle with certain brain functions more than others, including memory, attention and concentration, information processing, executive functions such as planning and prioritizing, visual perception, and word-finding, according to the National Multiple Sclerosis Society.


The good news: Generally, your other brain functions, such as your intellect, long-term memory, conversational skill, and reading comprehension, won't be affected by MS. Let's take a closer look at what MS cognitive dysfunction looks and feels like, and how to cope with it. 

What Does It Feel Like?

While cognitive dysfunction feels different for everyone and can change daily, many people with MS can identify with part or all of the following descriptions of MS-related cognitive problems:

  • Short-term memory deficits: The most common form of cognitive dysfunction in MS, this usually manifests in things like forgetting whose number you just dialed, going to the pantry and not knowing what you went there for (even though you just looked at your recipe), or being unable to remember if you took your pills or not. You may also find yourself repeating a sentence or part of a story to someone that you just told it to, not aware that you had already said it.
  • Problems with abstract conceptualization: Put simply, this is difficulty with figuring things out in the “abstract” in a way that is going to lead to a desired outcome. It means that people get easily overwhelmed if something is too complex, as it is hard to organize thoughts and tasks, to apply lessons learned from multiple past experiences, and to be “flexible” enough in their thinking to come up with alternate solutions if a problem arises. This can negatively impact judgment.
  • Attention difficulties: This can manifest as being easily distracted or simply unable to keep your mind on a task. You may find that you are unable to multitask or that even minor ambient noise, like the television or music, can make it virtually impossible to concentrate on things like reading or performing sequential tasks, such as those involved in cooking.
  • Slower speed of information processing: This includes all the aforementioned symptoms, and it also means that the brain simply cannot take in and prioritize all of the information coming at you at once. You might have trouble processing language (spoken or written), sensory information (visual, sounds, smells, touch), spatial information (such as the kind involved in navigation while driving), or more abstract things such as social cues and reading people’s emotions.

What Causes It?

Cognitive dysfunction tends to be worse in people with progressive forms of MS than in people with relapsing-remitting MS. In general, people with progressive MS seem to be more severely affected (however, even people with very little disability can experience some degree of cognitive dysfunction). People with more pronounced cognitive dysfunction tend to have:

  • More T1-Weighted Lesions: T1-weighted lesions in MS are areas that appear dark on MRI scans . These are also called “black holes” and indicate that there has been destruction of nerve fibers called axons, not just demyelination.
  • Atrophy of Corpus Callosum: This means that the bundle of nerve fibers that connect the right and left hemispheres of the brain has shrunk, due to destruction of nerve cells.

However, cognitive problems can also be made worse temporarily by other symptoms of MS, such as:

  • Depression: An extremely common symptom of MS, depression seems to impact cognitive function, especially in the areas of memory, attention and ability to concentrate. People who are depressed also often exhibit problems making good decisions, communicating and maintaining relationships with others, and with overall complex functioning, such as that required to make quick decisions and cope with complicated problems in everyday life.
  • Fatigue: The most common symptom of MS, fatigue is experienced by an estimated 85 to 95 percent of people with MS, and often considered the most debilitating. The crushing fatigue felt by people with MS can have a huge impact on how well we perform cognitively.
  • Heat Intolerance: MS-related heat intolerance can make all symptoms of MS worse, including cognitive dysfunction.

How Severe Can It Get?

Cognitive problems in people with MS can become severe enough to make it difficult to work in a profession that requires speedy or complex problem-solving. Most people, however, can develop coping techniques that keep cognitive symptoms from interfering with daily life too much.

Real, debilitating dementia as a symptom of MS is very rare, occurring in less than 5 percent of patients, and these people are usually very severely affected by other MS symptoms. In contrast to other types of dementia, such as that caused by stroke or Alzheimer's disease, the following problems are not usually associated with MS-related cognitive dysfunction:

  • : The inability to understand the speech of other people and/or express oneself verbally. While people with multiple sclerosis (MS) often have trouble finding words or communicating, this is more often dysphasia, a symptom of MS that is not as severe as aphasia.
  • Agnosia: Difficulty recognizing familiar things, such as shapes, sounds, objects, people, and smells.

Coping with MS Cognitive Dysfunction

Just like many other MS symptoms, cognitive problems will probably be worse at certain times. Other times, you may feel like your old self. See if there is a pattern to this (you may want to keep a symptom log or at least jot down notes for a couple of days). As much as possible, plan critical tasks for those times when you feel your sharpest. Also, notice if certain things make your cognitive problems worse – music, sounds from the television, encounters with certain people, even different kinds of lighting can have profound effects on cognition. When possible, adapt your environment and situation to make things better for you.

Fight the urge to be hard on yourself or get too frustrated when something “slips through the cracks” and you are late to an appointment or forget to return a phone call promptly. If you think about it, pretty much everything we do involves many, many steps, requiring: use of long-term and short-term memory, monitoring and adapting to the reactions of others, simultaneously performing many related and unrelated tasks – all while often fighting fatigue or a number of other symptoms that we might have.

Try an experiment for yourself: Take a child grocery shopping, cook dinner while talking on the phone, or observe yourself getting ready for a meeting. Look at how many things have to happen to get from Point A to Point B and marvel that anyone gets anything accomplished! 

In addition, cognitive symptoms often intensify when your stress levels rise, not unlike most other MS symptoms. Becoming familiar with your cognitive symptoms, and when they tend to strike, can help alert you to when you may be feeling overtaxed and need to slow down. 

The Multiple Sclerosis Foundation has a very helpful list of tips for living with cognitive dysfunction (at the bottom of the page). 

A Few Words On My Own Experience 

Cognitive dysfunction as a symptom of MS may be the one that makes me the saddest. I can get angry at the “MS hug” and frustrated with trembling hands, but being mad at how my own brain and though patterns are misfiring is a little too complicated. It is also the symptom that is the hardest to talk about with people without MS, as it often comes across as a lame-sounding apology for being “ditzy” or is met with people mentioning how forgetful they have also become since they had children or turned a certain age.

The first manifestation of cognitive dysfunction that I developed was a gradual fear of driving. At first, I would feel anxious that I would forget directions and be so preoccupied with getting lost that I would be stressed out when I went anywhere. Then I noticed that driving along even very familiar routes was becoming increasingly scary – I would be afraid to change lanes, nervous that I was going to run red lights, distracted by too many cars, frightened of big trucks and uneasy if the lighting was too bright, too dark, too dappled. As I had not yet been diagnosed with MS, I just told myself that I was being silly and kept pushing it, until the anxiety started really limiting my activities.

Since my diagnosis, I have noticed many more cognitive symptoms. Conversations are sometimes hard to keep up with and I often find myself making a point out of context. I know that I repeat myself a lot and have a habit of not finishing sentences. When I am writing, I fight the urge to steer away from certain words that I seem to have forgotten how to spell.

I've made several adaptations when it comes to driving: I haven't driven on the highway in many years, and I prefer to drive alone, so that I can focus 100% of my attention on the road and what I am doing. But on good days, I still try to make small neighborhood trips during quiet traffic times. Aside from driving, I have noticed that I sometimes want to avoid conversation so people don't pick up on any of my cognition problems. But because I want to stay engaged and social, I make a serious effort to chat with people. I figure no one will be seriously injured (unlike driving) if it takes me a couple of minutes to find the word that I am looking for or I tell a story for the second time in five minutes.


Olek, MJ. Comorbid problems associated with multiple sclerosis in adults. UpToDate. Last updated May 22, 2008.

National Multiple Sclerosis Society, Cognitive Changes. 

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