It’s 2013 and we still don’t know what causes Chronic Fatigue Syndrome (CFS), an illness that affects an estimated one million individuals in the U.S. and has profound personal, societal, and medical costs. Not only do we not understand the cause of CFS, the treatments are suboptimal and the quality of life for adults with this illness can be as bad as it is for people with congestive heart failure or multiple sclerosis, according to Dr. Peter C. Rowe, a professor of Pediatrics at Johns Hopkins School of Medicine.

As Director of the Children’s Center Chronic Fatigue Clinic and an expert on CFS and fibromyalgia, Dr. Rowe recognizes the dire need for a better understanding of what causes Chronic Fatigue Syndrome and more effective treatments. Recently, he and two like-minded clinicians published an article in Frontiers in Physiology in which they propose a new theory on what causes Chronic Fatigue Syndrome and what might be done to help people heal from this devastating illness.

A new theory on what causes Chronic Fatigue Syndrome centers on “neuromuscular strain” and “central sensitivity”

Dr. Rowe’s theory on what causes Chronic Fatigue Syndrome centers on two important concepts, neither of which gets a lot of press when it comes to CFS. The two concepts are “neuromuscular strain” and “central sensitivity.” Neuromuscular strain is a term which describes an increase in tension within nerves, as well as strain in muscles, fascia, and other soft tissues. Central sensitivity refers to a state of heightened sensitivity to stressors. It is characterized by excessive sensitivity to pain and other abnormal reactions to pain, as well as the increased symptoms that CFS sufferers regularly endure after physical and mental challenges.

Dr. Rowe and the study’s other authors describe how, through a complex cascade, neuromuscular strain contributes to central sensitivity and eventually leads to the development of CFS symptoms, including not just fatigue but pain and cognitive symptoms like brain fog, poor memory, and inability to concentrate.

Here is a brief summary of their hypothesis about what causes Chronic Fatigue Syndrome:

1. Initially, injuries and activities of daily life result in neuromuscular strains and movement restrictions. According to Dr. Rowe, whether you suffer from these types of injuries and develop resulting strains and restrictions depends on many factors, including your genetic makeup, how healthy your connective tissue is, your general flexibility, your level of habitual exercise, whether your past injuries have been properly rehabilitated, and whether maladaptive activities such as overuse (like sitting in front of a computer too long with improper posture and ergonomics) are corrected.
2. Once these “neuromuscular strains” and movement restrictions occur, you can end up with swelling and adhesions in the tissue around the nerves (or within the nerves themselves) which cause an increase in mechanical tension within the nerve.  This contributes to pain and other symptoms through a variety of mechanisms. For instance, it causes altered and abnormal signaling within the nervous system leading to enhanced sensations of pain and other feelings. It can also cause the release of inflammatory compounds and can cause muscles to fire and tighten inappropriately.
3. Any new stressor, including trauma, surgery, infection, or dehydration, can then cause old restrictions within your muscles, nerves, or other soft tissues to progress or can cause the development of new restrictions, placing further tension on an already compromised neuromuscular system. Dr. Rowe and his colleagues hypothesize that this results in a vicious cycle contributing to further central sensitization, additional aggravation and irritation of nerves, blood vessels, and the stress response system, and even more CFS symptoms.
4. Further worsening the cycle and the symptoms is the fact that most of the time, the neuromuscular strains are not treated and the person with CFS tries to adapt by decreasing her movement even more.
5. The authors state that treatments such as manual physical therapy and exercise-based therapies have been found to treat the neuromuscular strains, movement restrictions, and central sensitivity. They have seen CFS patients greatly improve with these treatments.

Purposely increasing neuromuscular strain increases fatigue, cognitive dysfunction, and other CFS symptoms

Dr. Rowe and his colleagues found that when they purposely and temporarily increase neuromuscular strain in CFS patients, many symptoms, including fatigue and cognitive disturbances, are triggered and increased. In order to better understand whether neuromuscular strain and central sensitivity are at least partly responsible for what causes Chronic Fatigue Syndrome, they are currently conducting a 2-year study of 55 adolescent and young adult subjects with the illness. They will compare the prevalence and impact of neuromuscular restrictions in CFS patients to healthy controls and determine whether treating the neuromuscular restrictions leads to improvement in overall CFS symptoms.

[1] Front Physiol. 2013 May 16;4:115.