Tag: neuromuscular strain

Chronic fatigue syndrome flare-ups caused by straining muscles and nerves

A recent study conducted by researchers at the University of Alabama at Birmingham and Johns Hopkins University School of Medicine published in PLOS ONE shows that symptoms of chronic fatigue syndrome, a complex and disabling multisystem disorder, can be provoked by imposing a mild to moderate strain to the muscles and nerves.

Eighty individuals, 60 with CFS and 20 without CFS, reported their levels of fatigue, body pain, lightheadedness, concentration difficulties and headache every five minutes while undergoing 15 minutes of either a passive supine straight leg raise — the raising and holding up of one of an individual’s legs while they lie on their back on an exam table — or a sham leg raise that did not cause strain.

Participants were contacted 24 hours later and again reported their symptoms. Compared to those with CFS who underwent the sham leg raise, individuals with CFS who underwent the passive leg raise that actually strained their muscles and nerves reported significantly increased body pain and concentration difficulties during the procedure. After 24 hours, these same individuals who underwent the true strain also reported greater symptom intensity for lightheadedness and the overall combined score for symptoms. The individuals with CFS who underwent the true strain also reported more symptoms during, and 24 hours after, the true strain compared to individuals without CFS.

“These findings have practical implications for understanding why exercise and the activities of daily living might be capable of provoking CFS symptoms,” said Kevin Fontaine, Ph.D., professor and chair of the UAB School of Public Health Department of Health Behavior and a co-author of the paper. “If simply holding up the leg of someone with CFS to a degree that produces a mild to moderate strain is capable of provoking their symptoms, prolonged or excessive muscle strain beyond the usual range of motion that occurs during daily activities might also produce symptom flares.”

As Peter Rowe, M.D., lead author and director of Johns Hopkins Children’s Center Chronic Fatigue Clinic, noted in the article, “The lengthwise strain applied to the nerves and muscles of the lower limb is capable of increasing symptom intensity in individuals with CFS for up to 24 hours, indicating that increased mechanical sensitivity may be a contributor to the provocation of symptoms in this disorder.”

Rowe and Fontaine, and their physical therapist collaborator Rick Violand, intend to extend this work to further understand the effects that strains to the muscles and nerves have on CFS, as well as whether specific physical therapy methods could be used to improve neuromuscular function to reduce symptoms.

Journal Reference: Peter C. Rowe, Kevin R. Fontaine, Megan Lauver, Samantha E. Jasion, Colleen L. Marden, Malini Moni, Carol B. Thompson, Richard L. Violand. Neuromuscular Strain Increases Symptom Intensity in Chronic Fatigue Syndrome. PLOS ONE, 2016; 11 (7): e0159386 DOI: 10.1371/journal.pone.0159386

 

Source: University of Alabama at Birmingham. “Chronic fatigue syndrome flare-ups caused by straining muscles and nerves.” ScienceDaily. ScienceDaily, 18 July 2016. https://www.sciencedaily.com/releases/2016/07/160718194125.htm

 

Neuromuscular Strain Increases Symptom Intensity in Chronic Fatigue Syndrome

Abstract:

Chronic fatigue syndrome (CFS) is a complex, multisystem disorder that can be disabling. CFS symptoms can be provoked by increased physical or cognitive activity, and by orthostatic stress. In preliminary work, we noted that CFS symptoms also could be provoked by application of longitudinal neural and soft tissue strain to the limbs and spine of affected individuals.

In this study we measured the responses to a straight leg raise neuromuscular strain maneuver in individuals with CFS and healthy controls. We randomly assigned 60 individuals with CFS and 20 healthy controls to either a 15 minute period of passive supine straight leg raise (true neuromuscular strain) or a sham straight leg raise. The primary outcome measure was the symptom intensity difference between the scores during and 24 hours after the study maneuver compared to baseline.

Fatigue, body pain, lightheadedness, concentration difficulties, and headache scores were measured individually on a 0-10 scale, and summed to create a composite symptom score. Compared to individuals with CFS in the sham strain group, those with CFS in the true strain group reported significantly increased body pain (P = 0.04) and concentration difficulties (P = 0.02) as well as increased composite symptom scores (all P = 0.03) during the maneuver.

After 24 hours, the symptom intensity differences were significantly greater for the CFS true strain group for the individual symptom of lightheadedness (P = 0.001) and for the composite symptom score (P = 0.005). During and 24 hours after the exposure to the true strain maneuver, those with CFS had significantly higher individual and composite symptom intensity changes compared to the healthy controls.

We conclude that a longitudinal strain applied to the nerves and soft tissues of the lower limb is capable of increasing symptom intensity in individuals with CFS for up to 24 hours. These findings support our preliminary observations that increased mechanical sensitivity may be a contributor to the provocation of symptoms in this disorder.

 

Source: Rowe PC, Fontaine KR, Lauver M, Jasion SE, Marden CL, Moni M, Thompson CB, Violand RL. Neuromuscular Strain Increases Symptom Intensity in Chronic Fatigue Syndrome. PLoS One. 2016 Jul 18;11(7):e0159386. doi: 10.1371/journal.pone.0159386. ECollection 2016. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4948885/ (Full article)

 

Neuromuscular strain as a contributor to cognitive and other symptoms in chronic fatigue syndrome: hypothesis and conceptual model

Abstract:

Individuals with chronic fatigue syndrome (CFS) have heightened sensitivity and increased symptoms following various physiologic challenges, such as orthostatic stress, physical exercise, and cognitive challenges. Similar heightened sensitivity to the same stressors in fibromyalgia (FM) has led investigators to propose that these findings reflect a state of central sensitivity.

A large body of evidence supports the concept of central sensitivity in FM. A more modest literature provides partial support for this model in CFS, particularly with regard to pain. Nonetheless, fatigue and cognitive dysfunction have not been explained by the central sensitivity data thus far.

Peripheral factors have attracted attention recently as contributors to central sensitivity. Work by Brieg, Sunderland, and others has emphasized the ability of the nervous system to undergo accommodative changes in length in response to the range of limb and trunk movements carried out during daily activity. If that ability to elongate is impaired-due to movement restrictions in tissues adjacent to nerves, or due to swelling or adhesions within the nerve itself-the result is an increase in mechanical tension within the nerve. This adverse neural tension, also termed neurodynamic dysfunction, is thought to contribute to pain and other symptoms through a variety of mechanisms. These include mechanical sensitization and altered nociceptive signaling, altered proprioception, adverse patterns of muscle recruitment and force of muscle contraction, reduced intra-neural blood flow, and release of inflammatory neuropeptides. Because it is not possible to differentiate completely between adverse neural tension and strain in muscles, fascia, and other soft tissues, we use the more general term “neuromuscular strain.”

In our clinical work, we have found that neuromuscular restrictions are common in CFS, and that many symptoms of CFS can be reproduced by selectively adding neuromuscular strain during the examination. In this paper we submit that neuromuscular strain is a previously unappreciated peripheral source of sensitizing input to the nervous system, and that it contributes to the pathogenesis of CFS symptoms, including cognitive dysfunction.

 

Source: Rowe PC, Fontaine KR, Violand RL. Neuromuscular strain as a contributor to cognitive and other symptoms in chronic fatigue syndrome: hypothesis and conceptual model. Front Physiol. 2013 May 16;4:115. doi: 10.3389/fphys.2013.00115. eCollection 2013.  https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3655286/ (Full article)