Introduction

Neurofatigue, or brain fatigue, is a chronic and extreme fatigue that makes it difficult or impossible for someone with a brain disorder to perform daily activities.

It is not the same as just physical fatigue, although it can significantly impact physical functioning.

This fatigue has physical, cognitive, and emotional components. Neurofatigue can be a daily reality.

It's important to realize that the brain normally consumes 20% of the body's total energy. In people with brain injuries, this is much more.

There are several causes for this.

One of them is that the brain tries to create more connections to bypass the affected (dead) brain area.

A second cause is that neurological disorders are associated with inflammatory responses in the brain.

This is called neuroinflammation. It can cause increased energy consumption in the body, including in the brain.

Fatigue due to neurological disorders is a common problem that is often underestimated.

It affects 36-77% of people who have suffered a stroke, traumatic brain injury, Long COVID, MS, Parkinson's, Alzheimer's, or another brain disease. For people with a brain tumor, this figure rises to 99%.

Fatigue fatigue fatigue, that is what people with brain injury often experience.

Everything takes effort. The energy for the whole day is often consumed completely within two hours. There are many brain injury victims who have insomnia on top of this all. Another group of brain injury survivors have an increased need for sleep. But the similarity is FATIGUE.

Mental fatigue is different from physical fatigue.
We can all understand what people mean when they're talking about physical fatigue. Feeling tired after exercising, taking a brisk walk, doing housework, or after strenuous activity etc.

But mental fatigue can be harder to explain. It is because the brain uses its informational processing abilities, either by concentrating intensely like when you learn something new or solve a complex problem, or by doing something for a long time like watching TV extensively.

Healthy people can feel mentally tired. Usually that feeling occurs at the end of a full and active day or after a long session of intense concentration, like studying for an exam. Oftentimes people notice their mental fatigue when they've become sensitive to sound. Noise from the radio becomes too distracting or an alarm going off gives them a headache. They may feel like they need to have things quiet for a while to recharge.

For brain injury victims that is many times worse. The mental energy has already been exhausted after a short time. They use more parts of the brain, because the dead area must be passed by, in the communication between brain cells.

More brain activity in brain injury patients

Scientists discovered that the brain of a brain injured person works harder and uses more brain cells to process information more nerve activity is shown.

More brain areas are involved in performing normal activities than before the brain injury. That difference can be seen with PET scans. Parts of the brain that normally show little activity while performing a specific action now become actively involved in the brain's functioning after the injury.

This requires many extra bypasses and consumes more energy to complete. Therefore, the reaction time of a brain injured person is often a bit slower and it requires more energy to reach the same point. It can make someone really tired.

The definition of fatigue in the scientific literature: "the sense of a reduction in the capacity for physical and / or mental labor, caused by an imbalance in the presence, the use and / or recovery of energy that is needed to perform activities" Aaronson et al (1999)

To have brain injury is like being a top athlete. It deserves respect.

Fatigue management

Fatigue management is the starting point towards recovery. In order to manage fatigue, a person first needs to accept that they don't not have the same physical and mental stamina that they had before the accident.

Signals that the battery is running low

At some point during the day a brain injured person may get noticable signals that their battery is running low.

Signs of fatigue can be a drawn, a tense look, a pale or greyish pallor, glazed eyes, irritability and, ironically, too much activity. (the person may become restless, more distracted or more talkative and make an increased number of mistakes.)

For example, he notices that he is tired, makes more mistakes or loses concentration. These are all signs that let you know that the bottom of the battery is in sight. It's time to take a rest so that the battery can charge again.

Signals That It's Time to Rest

Pay attention to bodily signals

Do you get headaches, do you feel dizzy or feel a tension in neck and shoulders? Is the pace going down or do you make more mistakes than usual?

Check in with your thoughts and feelings

Are you feeling cranky or irritated? Have you lost interest in something you normally enjoy? Do you have feelings of hopelessness or thoughts that say "I can't take it anymore?" or "I can't do this?"

These are signs that you need to stop what you're doing and rest.

When your battery is low it can be very hard to determine if you're experiencing these signals. So, it can be helpful to ask a family member or friend if they notice any of these signs in your behavior.

Sleeping disorders

Many brain injured persons suffer from sleeping disorders as well.

It can be hard to distinguish between fatigue that comes from a damaged battery and the fatigue that comes from a sleep disorder.

Read the factsheet about sleeping issues on synapse.org.au.

Or read our page on CSAS.

Lack of sleep has a negative effect on our cognition, mood, energy levels and appetite. The average person needs eight hours of sleep a night or they will suffer from decreased concentration, energy and many other problems. These effects are multiplied many times by a brain injury.

Unfortunately, brain injury can often lead to a sleep disorder. The American Academy of Neurology reports that as many as 40-65% of people with mild traumatic brain injury complain of insomnia.

Sleep disorders can be hard to detect because people with brain injuries can also have a fatigue disorder. Although some may have problems with getting too much sleep, the usual type of sleep disorder is trouble sleeping at night, particularly problems with the timing or amount of sleep.

These people are very easily awakened, sometimes dozens of times a night. Sleep can be light and sufferers may find it very difficult to go back to sleep once they've been woken up despite feeling very tired.

Research suggests that a major cause is a disruption to normal releases of certain neurotransmitters in the brain which causes "sleep fragmentation".

There can be a variety of other causes which disrupts your sleep. Discomfort from a headace, neck pain, or back pain can make it hard to get to sleep. Depression is a common feature after a brain injury and survivors may find they fall asleep easily but wake up several hours before dawn, unable to sleep again. Anxiety and inability to handle stress are other problems that many people experience. Negative thoughts whirring through the mind will usually make it very hard to fall asleep.

The connection between neurofatigue and sensory overload

Brain fatigue can cause other symptoms.

It can cause problems with thinking, memory, attention and brain fog.
At some point, it simply runs out, and the patient can no longer absorb information. For example, she or he may forget what was said, become distracted, or experience double vision.

Physical complaints may then follow, as can exhaustion or burnout.
It is known that neurofatigue can be both a consequence and a cause of sensory overload. The two consequences of brain injury can reinforce each other.
Some people only have neurofatigue without sensory overload, but there are no people with sensory overload without neurofatigue.

The link between worsening physical difficulties and neurofatigue

Research in people with brain injuries shows that they often report increased visual difficulties, worsening spasticity, increased pain and sensitivity to stimuli, or balance problems due to fatigue.

Muscles may feel heavy and painful.
Using the tongue and oral muscles properly to speak clearly can become increasingly difficult. In short, neurological complaints may worsen and physical function may decline.

Acquired Brain Injury (ABI) Burnout

Acquired Brain Injury (ABI) and burnout are two different conditions, but they can influence each other. People with ABI are at risk of burnout due to intense fatigue, difficulty concentrating, and overstimulation. This is especially true if too much is demanded of them at work or in their personal lives, if they push themselves too hard, or if they don't yet recognize the signs of the brain injury.
People who strive to fight back to their previous level with all their might are at high risk of ABI burnout.
Burnout is caused by prolonged overload and stress, which can develop particularly quickly with ABI. It's important to listen to your body, set boundaries, and get enough rest.

Fight back to your previous level or regulate your energy?

Brain fatigue manifests differently for everyone.

It can manifest as irritation, tiredness, feeling overwhelmed, and frustration. Others may develop headaches or feel completely exhausted.

During periods of exhaustion, physical and cognitive symptoms can worsen. Exhaustion can sometimes last for years and, in the worst cases, never recover. It can even lead to a brain injury (ABI) burnout.

It is important that the person experiencing fatigue learns when it's too much and she or hee needs to take a step back.
That is precisely what is so difficult.

People try to keep up for a long time and/or "fight" their way back to their "previous level," sometimes against their better judgment. This can sometimes leave people on edge for a long time. This can actually prolong the recovery time after a brain injury.
Therefore, it's better not to push yourself to the limit, but to pay close attention to your own limits.
Pace your energy... alternate rest and exertion, take early rest, and spread activities throughout the day or week. This requires careful planning and a constant awareness that there's no other option. It also requires the same awareness from your partner, family members, friends, and employer.
No matter how difficult that is for everyone.

Brain fatigue can sometimes recover somewhat over time. However, it's likely a lifelong issue.

Therefore, it is important to learn to manage it.
An occupational therapist can be helpful.

Recognize that chronic fatigue can lead to other illnesses, because with constant stress, the body continuously produces stress hormones, which can also alter the nervous system. This can lead to symptoms such as stomach problems, autoimmune system changes, cardiovascular disease, changes in muscle function, sleep disturbances, depression, burnout, or anxiety disorders.

References and further information

• Synapse: managing fatigue after ABI