Fatigue after brain injury

Today I am going to talk specifically about fatigue after stroke because that is the research area that we are working in, but obviously a lot of the things that we are going to say apply across a wide range of people with different conditions. There are really two things I want to do today: I want to tell you the facts—what we do know about fatigue and actually what we do not know—and I want to talk about some of the ways that people deal with their fatigue and talk a little bit about the evidence around this.

The first thing to say is that the term "fatigue" has really become much more used in our society today than it ever was, particularly since COVID. People tend to use this term when they mean that they are very tired, not that they are fatigued. The problem for people who actually have real clinical fatigue is that sometimes there is an impression that they just do not try hard enough or cannot push through this tiredness. This is something that a lady said to us in a study: she worked in a room with other people who complained that they had fatigue, but they were always able to finish their work, whereas when she had fatigue, she had to stop and walk away. She felt that that really made her look bad and that it was not fair. It absolutely is not fair because fatigue is different than being tired.

This is the definition that we use for fatigue after stroke, and let's be honest, it is a bit clumpy, but it basically covers the fact that this is something that is really overwhelming and that it affects not just people physically, but the way they think and their emotions. I am going to go to a definition that I often use with my own patients, which really says three things about having fatigue: one, that it is chronic and people do not just say fatigue, but they use words such as "exhausted" and "wiped out"; secondly, it is not related to what they have just done—frankly, if you have just run a marathon, you could well be very tired, but for many people with fatigue, they feel as if they have not done very much and they have this overwhelming need just to stop; and finally, that it often is not relieved just by resting. Those are the main characteristics of what we are talking about in clinical fatigue.

In terms of stroke, fatigue is one of the most distressing things that people have. We have known about this for a very long time, but it is really only in recent years that we have decided this is something we really need to be tackling. We have also known for quite a long time that people report this is a problem for them, but they do not know how to manage it. Finally, just in recent years, fatigue has been set as a priority area in stroke rehabilitation; if you think of our top ten things, fatigue is number four. We recognize that we need to do an awful lot more around this area.

It is a huge area, but I am just going to tell you a few facts. Is it true or false that the incidence of fatigue after stroke is about 50%? The answer is that we largely disagree on the numbers. Some studies say about a quarter of people have fatigue; some say 75%. The differences are because people define fatigue differently or they take the measurements at different points after the stroke. But actually, in the literature, we normally agree that about 50% of people have fatigue, which is actually quite high.

Just an important thing to say about that: fatigue is something that moves on. You do not just have it or not have it; some people will have it early, some people will have it late. It is not just static. Furthermore, fatigue is linked to increased mortality. Why mortality? What we mean is your chances of dying younger or earlier than you should. It is true, but before you panic if you have fatigue, it does not mean you are going to die young. The problem is that people who have fatigue, by and large, cannot get involved as much in their rehabilitation, and because of that, they do not tend to make the recovery that they could. They tend to have more problems looking after themselves, moving around, and just generally being fitter. It is because of those reasons that, yes, it is actually linked to mortality.

A question I often get asked is whether taking statins in particular is linked to fatigue. There are no studies that show convincingly that taking statins is linked to having fatigue. If you look at most medication packets, they say fatigue is associated with most medicines. The important message is: regardless of your condition, if you suspect a tablet that you are taking is linked to having fatigue, talk to your doctor before you just stop taking it. What we do know from a very good study done in France is that it is not specific drugs, but the number of drugs—what we call "polypharmacy"—that is much more likely to be associated with fatigue.

Is there a direct link between depression or low mood and fatigue? We know that people who are depressed often have fatigue, and we believe that people who have fatigue, because it is so overwhelming and limiting, often have low mood or depression. But here is the thing: we believe that anxiety is actually much more important than depression. When we followed people up, we found that people with the worst fatigue were very anxious. So, anxiety may be much more important here than we have known before.

Is fatigue likely to resolve within the first year? This is not true. People can have fatigue up to three years after their stroke, and there are a lot of studies, particularly done in Scandinavian countries, which show that people report fatigue for five, six, and even seven years after their index event. If people tell you it will resolve in a year, that may not be true.

Is all fatigue the same? We do not really know, but it seems that there are real similarities across neurological conditions such as MS, Parkinson's, and head injury, but also for conditions such as rheumatoid arthritis and even cancer. There are fewer similarities, although there is some overlap, with people who have Chronic Fatigue Syndrome and Long COVID. All of these people have fatigue, but there are some differences in how they present and perhaps in how we would manage them.

We have done several studies in Nottingham. I am not going to present all the methodologies, but I will give you some results. The results for me as a researcher and as an occupational therapist are quite shocking: how fatigue affects people day-to-day, how people have a family event and it affects their enjoyment, and how they have had to change their lifestyle. One thing we have noted is that people particularly complain about shopping—perhaps the traveling, parking, and going into a noisy environment with lights and distractions. Some people just put their shopping basket down and leave the shop. Activities where there is a lot of stimulation seem to be worse for people.

We find that people have not really talked to a professional or realized this was a "thing." Nobody mentioned it, and some people thought they were being unmotivated or lazy, or that they were going a bit mad because they did not understand what was happening. When they did talk to a doctor, they often had other priorities, such as blood pressure, spasticity, or continence. Generally, there was a feeling that people did not talk to them about having fatigue.

A lot of the time, when people do talk about fatigue, they talk about physical fatigue, but we find that people talk about "brain fog": having slow thoughts and being unable to process things well. The research says that yes, people are slower and take a while to make a decision, but there is no reason to think they make bad decisions. You are not less accurate in what you are deciding; it may just take you longer.

Some people need to practice what we call sensory deprivation—literally doing nothing. Some people need to sit in a dark room; some just need to sit somewhere really quiet. What they do not do is what other people who are resting do, which is maybe listen to music or watch something on the TV. It also affects families. Some of the carers we spoke to said they had to manage that person because if they overdid it, they would be unwell for several days. Even if someone had made a recovery in other ways, the fatigue was huge and affected their whole life.

Everyone we spoke to talked about the need to accept it. It is not something you can fight by saying, "I am going to push through this," because that usually makes it worse. It is important to talk to people and educate their family about how they are feeling, that they are not depressed, and if their fatigue is an issue, seek professional advice. Many people think about fatigue like a bank account: if you spend your money, there is nothing left. If you have used your energy for the day, you cannot just keep moving forward. You cannot spend money you have not got; you have to stop spending at that point.

There are libraries of research on fatigue, but the problem is the "camera lens" that people use. Some look at it from blood results, nutrition, psychometric testing, exercise, or brain scans. The problem is that all of this research doesn't give us very many practical things to do. We have asked clinicians what they do, and the important thing is that none of it is really well evidence-based. Most of this is because clinicians do it because that is what they were taught to do. However, people are normally advised to use "pacing"—pace yourself during the day and make sure you have rest periods—and some find it useful to keep a diary to see if there are triggers. But it is equally important to say that some people do not have these triggers, and spending time looking for them if you cannot see them may be very negative.

There is ongoing research. There are studies in Nottingham about getting people to do a bit more exercise to make them tired so that they can sleep and be more refreshed to increase activity levels. There are studies on particular drugs, cortical excitability, and mitochondria—where we keep our batteries—but none of them have shown us a clear step forward. In the meantime, talking to people about having fatigue is really, really important. We need more clinicians to tell people that fatigue is something that may happen, and talking about it with other people who have fatigue and within your family so that they understand it seems to help. We are recruiting more people with lived experience, as they have techniques of their own that we need to understand.

To conclude: managing post-stroke fatigue is common, about 50%. It is significant, not a trivial symptom. Our evidence base is weak, but there are areas that show promise. People want to talk about it so that they can share experiences and understand that they are not alone. They need to talk about their issues, including slow, confused thoughts, while understanding that it does not impair their ability to make good decisions. We need to do much better and do much more targeted research.