The many faces of fatigue

-

 

Photo by Inset Agency on Unsplash


When I started my research into fatigue, I was surprised by the complexity of fatigue and it took me a while to get to grips with the many ways it is defined. We use the one word 'fatigue' to describe a range of experiences and symptoms. When I talk to therapists and people with brain injury who live with fatigue, they identify different types of fatigue: mental (cognitive), physical, and emotional fatigue. In my current research project,  the need to label fatigue as one type or another is important because people associate different types of fatigue with different types of activity. Some researchers write about exertion fatigue and chronic fatigue, others about fatigue and fatigability, state or trait fatigue (Tseng e al, 2010, Kluger et al, 2011, Wylie & Flashman , 2018).

Kluger argues that we need to separate the perception of feeling fatigued from the concept of fatigability when considering neurological conditions. Fatigability describes a decremental decline in performance as the person tires.  An example of this might be how a person gets slower as they climb flights of stairs or where they make more mistakes when concentrating on a task for a long time. It makes sense to most of us that feeling fatigued relates to fatigability, but this doesn't seem to be the case for mental fatigue (or it hasn't yet been shown to be related in research studies)(Beaulieu-Bonneau and Ouellet, 2017; Ashman et al., 2008).  We don't yet have a reliable and objective measure of mental fatigue and this is probably why researchers can't find a relationship between how people with brain injury perform on a mental task and mental fatigue. 

Wylie and Flashman (2017) propose that fatigue can be separated into trait fatigue (the tendency to be fatigued) or state fatigue ( how fatigued I feel at this very moment). Wylie argues that state fatigue relates more closely to our behaviour than trait fatigue. We decide whether to continue or to stop based on how we feel in the moment. The difference between trait and state fatigue are seen in fatigue questionnaires and visual or numeric rating scale. Questions such as "because of my fatigue over the last 4 weeks I have been...." tap into trait fatigue, whereas "How fatigued are you at the moment.." captures state fatigue.  

Does it matter that there is a difference between how people experience fatigue and what they think when they reflect back on their experience? Does understanding fatigue as it happens enrich fatigue our clinical assessment of fatigue. I argue that it does matter, particularly when trying to understand fatigue triggers and guide people on using strategies such as pacing and prioritising and to support behaviour change. But there is no conclusive evidence at the moment. There is a theory that in-the-moment experiences are processed differently to our explanations of what happened (see Two Minds Theory (google.com) and this might explain the gap between what people report in the moment and what they report when reflecting back. But whether this gap is meaningful when it comes to managing fatigue is simply not known, yet.


References

Kluger, B. M., Krupp, L. B. and Enoka, R. M. (2013) 'Fatigue and fatigability in neurologic illnesses Proposal for a unified taxonomy', Neurology, 80(4), pp. 409-416. doi: 10.1212/WNL.0b013e31827f07be.Tseng, B., et al. (2010) 'Exertion fatigue and chronic fatigue are two distinct constructs in people post-stroke', Stroke (00392499), 41(12), pp. 2908-2912. doi: 10.1161/STROKEAHA.110.596064.

Wylie, G. R. and Flashman, L. A. (2017) 'Understanding the interplay between mild traumatic brain injury and cognitive fatigue: models and treatments', Concussion, 2(4). doi: 10.2217/cnc-2017-0003.

 



. 












Comments

Post a Comment

Popular posts from this blog

Mechanisms of fatigue

-
Image
  Unraveling the Mystery of Post-Brain Injury Fatigue  " Over 100 year of research on fatigue and we are not closer to understanding it"  (De Luca, 2005). Have you ever wondered why fatigue after a brain injury feels so different from regular tiredness? It's like comparing a gentle breeze to a hurricane – they're both wind, but the intensity and impact are worlds apart. Let's dive into this fascinating topic and explore why post-brain injury fatigue is such a complex beast. The Multifaceted Nature of Fatigue Imagine your brain as a bustling city. After an injury, it's like some of the roads are closed, traffic lights are malfunctioning, and there's construction everywhere. Everything takes more effort, from simple tasks to complex problem-solving. This is where the complexity of post-brain injury fatigue comes into play. It's not just about feeling tired. It's a intricate web of factors: Physical changes in the brain Emotional state Coping mechanis...
Read more

The Overwhelming Complexity of Modern Life: A Reflection on Brain Injury and Fatigue

-
Image
  ‘The fatigue is not only real, it is absolutely legitimate’: why are so many of us so tired right now? | Australian lifestyle | The Guardian   I saw this article today and it resonated with me; the feeling of so many things to deal with, too many complex issues that I just can't fix, not enough time, not enough emotional and cognitive bandwidth. I feel tired and weary and wonder whether its just me, is this part of getting older? Or is this  feeling of exhaustion and weariness a response to modern life and our rapidly evolving digital landscape? The Parallels with Brain Injury I think back to the people I met through public engagement and involvement in research, those living with brain injury. I particularly recall one young women talking about the sense that time is moving faster for her than other people. She is going as fast as she can and everyone wonders why she is so slow.  Mental Slowness After a brain injury, survivors often experience slower information p...
Read more

Je suis fatigué

-
Image
The etymology of fatigue: "1660s, "that which causes weariness," from French fatigue "weariness," from fatiguer "to tire" (15c.), from Latin fatigare "to weary, to tire out," originally "to cause to break down," from pre-Latin adjective *fati-agos "driving to the point of breakdown," https://www.etymonline.com/word/fatigue When I started my studies a few years ago, I was talking to people with brain injuries at a local support group about the word " fatigue". People commented that it wasn't a word they used much before their brain injury. In everyday life, we talk about being tired, sometimes exhausted, but less often fatigued. One man explained how in his culture, older people would never admit to being tired, they would either say nothing or say they were ill. Admitting to tiredness was generally seen as a sign of weakness. This conversation triggered several questions for me. Has our understanding of ...
Read more