Neurological symptoms of systemic lupus erythematosus (SLE) are not uncommon. These symptoms include:
- Brain fog
- Sensory problems (such as challenges with eyesight, hearing, or smell)
Lupus causes these symptoms because of inflammation damage to the heart, lungs, and circulatory system. Damage to these organs interferes with the flow of oxygen and nutrients to the sensitive tissues of the brain and nervous system.
Other organ systems can impact the nervous system too. The cells and structures of the nervous system itself can come under attack. In both instances, the nervous system becomes compromised and neuropsychiatric symptoms occur.
One of these symptoms is fatigue. Fatigue is a state of extreme tiredness where energy levels are low. In this state of malaise, small tasks like getting out of bed, showering, and walking feel as though they take more effort.
Fatigue can be measured using a self-assessed fatigue scale, and is a well-known symptom of lupus and other autoimmune diseases.
Fatigue has many different causes making it difficult to medically diagnose. One of the better-known mechanisms is neurological. In autoimmune diseases like MS, which directly attack the nervous system, you can actually see fatigue in action on a brain scan. Impulses take a less efficient or roundabout route to travel from the brain to the body. Every action takes more energy to transmit and activate, and this adds up. Inflammation may cause nerve signals to lose efficiency in lupus, too.
How are Fatigue and Neurological Symptoms Related?
An article in the Lancet goes deeper into the connection between neurological symptoms and fatigue:
“Chronic fatigue is a typical symptom of neurological diseases, and is most disabling in multiple sclerosis, postpoliomyelitis, poststroke, and in chronic fatigue syndrome.”
The article goes on to describe how various parts of the nervous system may be involved in propagating feelings of fatigue. Possibly linked elements include the central nervous system, the parts of the brain related to the senses and perception, and the neuromuscular junctions (where the nervous system interacts with the muscles).
The neuromuscular junction theory is particularly interesting. It speculates that more energy is required to activate and control the muscles, which may cause both muscles and nerves to become tired faster.
Structure and Metabolism
Structure and metabolism changes caused by lupus and lupus-related inflammation might be a key cause of fatigue in lupus and similar diseases. They cause changes in cell behavior or disruptions to the way that the cells work leading to fatigue. Specific altered areas include:
- The energy-producers of the cell
- Inflammation can disrupt the organelles – little organs – in the cell. Nerve cells (axons and ganglia) and muscle cells need a lot of energy, and may be more affected by a mitochondria issue.
- The signaling molecules that allow nervous system cells to communicate and coordinate with each other
- Improper communication between nervous system cells may cause fatigue along with other symptoms of lupus. These are also effected by exercise.
- Direct nervous system or circulatory system damage from immune system attacks
- This can cause damage to the circuits that the neurons use to communicate with each other as well as other organs in the body. The communication becomes less efficient, and thus requires more energy.
- All of the above
With inflammation disrupting mitochondria and neurotransmitters, and physical damage making an already difficult situation worse. Studies of prevalence of neurological symptoms and fatigue in patients with SLE have shown a link between the presence of neurological symptoms and both reported symptoms of fatigue and fatigue severity.
The exact mechanisms will depend on the symptoms of each individual person’s lupus. And, they may not be the only factors in play.
Different Types of Fatigue in Lupus
Aside from structural or metabolic changes that affect the nervous system and its supporting systems, there are a few other factors in lupus fatigue. Each has its own symptoms, mechanisms of action, and treatment.
Insomnia, Sleep, and Fatigue
Insomnia, narcolepsy and other sleep issues are a common symptom that many Lupus Warriors struggle with daily (or nightly). You can read more about them here. These issues have many causes, including:
- Dietary issues
- Hormone levels
- Kidney or gastrointestinal issues
- Temperature sensitivity
- Medication side effects
All sleep-related symptoms have one thing in common, however: they all influence energy levels and brain and body function. Sleep-related problems can contribute to fatigue, which can in turn affect sleep cycles and energy levels further. In essence, fatigue and sleep problems contribute to each other.
Taking care of sleep symptoms can help with fatigue. You can find a few tips for how to go about doing that, here.
Motor neuron damage directly affects the ability of the muscles to respond to commands from the brain. However, a group of sensory nerves called “Proprioceptors” might also affect how much effort it takes to move or act.
Proprioception (also known as kinesthesia or orientation) is our sense of where our body is in our environment. It is a sense that we do not often think about. Still, it is important for movement and, if it is impaired, it makes moving around much clumsier and more difficult (if not dangerous).
Proprioception, just like other senses (such as touch, taste, smell, and sight) uses sensory neurons to provide feedback to the brain about the location of the limbs and the body. These neurons can be damaged or interfered with by lupus. Even slight damage could make movement require more energy to maintain coordination of the limbs and body. This increase in energy need leads to physical and mental fatigue.
Dopamine and Fatigue in Lupus
Dopamine is a major neurotransmitter, responsible for regulating many different processes throughout the body. These processes include, but are not limited to:
- Mood regulation
- Nausea and appetite
- Cognition (including concentration and motivation)
- Movement (as a neurotransmitter involved in communicating between motor neurons)
- Circulatory system and kidney function
- Immune system regulation
Many of these dopamine-requiring functions are heavily related to lupus symptoms and to fatigue alike. One of the possible explanations of fatigue, the “dopamine imbalance theory,” is that inflammation may affect dopamine levels in the body. This could be by interfering with the production of dopamine in the brain. Or the ability of the neurons to sense dopamine.
Changes in dopamine levels would send all of these systems out of whack, causing or contributing to fatigue. Some support for this theory is that treatment with antidepressants or medications that affect dopamine can help with fatigue.
Treating Neurological Fatigue
Most treatments for neurological fatigue target the tiredness aspect, using stimulants to create a feeling of increased energy. Modafinil mofetil, a “wakefulness-promoting” medication, is one such medication that has been tested for treating nervous system-related fatigue.
In a 2018 study, researchers found little evidence of effectiveness against fatigue, and several study participants experienced adverse symptoms (though it is unclear whether these were from Modafinil or from their disease). Other studies also did not support its use, but Modafinil is still under consideration.
As suggested by the research, stimulants may not be the most effective way to treat fatigue. Medications that treat issues in the heart (or circulatory system), reduce inflammation, block pain, or improve kidney function may be able to help with fatigue.
Physical Therapy and Treatments
Physical therapy aimed at increasing the sensitivity of proprioceptive neurons (or motor neurons) is another potential treatment strategy. Through strengthening exercises, movement becomes less energy-intensive and the body is able to overcome damage within the system more easily. This reduce fatigue overall.
If you are experiencing fatigue and neurological symptoms, these treatments are worth considering. Lifestyle changes such as increased exercise and healthy diets have also proven useful, along with mindfulness training and other strategies. Talk to your lupus treatment team about the possibilities.
And know, you aren’t alone in experiencing fatigue and other symptoms of lupus.
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