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​Research round-up: faulty pain receptors and more

May 18, 2017

Each month, Action for M.E. volunteer and Pharmacist Emily Beardall explains some of the recently published research studies on M.E.

Please note this is not an exhaustive list – we have selected to highlight the studies that we think are most likely to resonate with the daily lives of those affected by the condition. We will also report separately on further studies of significance, as and when they are published.

You can search online directory PubMed for most studies about M.E. published in peer-reviewed journals.

The following studies were published online between 22 March and 21 April 2017. In each case, we have used the same name for the illness as the researchers publishing the paper.

Faulty pain receptors

A study presented at the 2016 CMRC conference by Jessica Van Oosterwijck has now been published in the journal Pain Physician. In healthy people, the brain suppresses pain during and after exercise but previous studies have found that this happens to a lesser extent in people with M.E./CFS, possibly explaining why post-exertional malaise leads to muscle pain.

This study examined the link between the autonomic nervous system, which regulates automatic body functions (eg. blood pressure), and faulty pain suppression. It found that blood pressure remains raised for longer in the M.E./CFS patients after exercise, suggesting that the blood pressure receptors and parasympathetic branch of the autonomic nervous system are involved.

What can cerebrospinal fluid tell us?

Cerebrospinal fluid surrounds the brain and spinal cord, acting as a cushion, providing physical and immunological protection, and removing waste products. A study published in the Journal of the Neurological Sciences compared the cerebrospinal fluid of three groups: people with both CFS and a psychiatric diagnosis, people with CFS, and a healthy group. There were marked differences between all the people with CFS compared with healthy controls, and CFS patients with mental illness didn’t differ from those with CFS alone. The authors conclude that their results show CFS is not caused or perpetuated by having a psychiatric diagnosis.

Published in the journal Translational Psychiatry, a different study compared the cerebrospinal fluid of people whose M.E./CFS began with an infection (typical) and those whose illness began without a distinct trigger but in the presence of other serious conditions (atypical). Both sets of patients had levels of cytokines which were very different from the healthy controls, but in the typical M.E./CFS patients these were higher and then dipped after three years of having the illness. In those with atypical M.E./CFS, there were a different set of cytokines involved, which continued and even increased after three years. The authors suggest different pathways may be involved in developing typical and atypical M.E./CFS, and that atypical patients may have a genetic predisposition to atypical M.E./CFS along with other serious immune and neurological illnesses, such as multiple sclerosis, as their illness progresses.

Reporting on M.E./CFS in the media

Using 214 print articles from national, regional, and local newspapers, a study of the language used in US media coverage of M.E./CFS since 1987 has been published in the journal Chronic Illness. It concludes that the mixed messages for the public about the illness are potentially harmful for patients and research funding.

Each article was coded according to how they referred to the cause of the illness, comorbidities (ie. separate conditions occuring at the same time), diagnostic criteria, the name of the illness and treatments mentioned.

The name “CFS” appeared in 94% of the articles, “chronic fatigue” in 3% and the remainder used M.E./CFS, M.E. or CFIDS, although the term “myalgic encephalomyelitis” was used additionally in 12.6% of the articles.

Around two thirds of the articles referred to the illness as having a physical cause, which the authors said was much more than they had expected. A fifth mentioned both physical and psychological causes.

Of the articles which mentioned comorbid conditions, the most common was depression, which appeared in just over a fifth. Fibromyalgia was mentioned in around 10%, and the remainder mentioned allergies, anxiety and chemical sensitivity.

Just under half mentioned treatments, the most to least common being alternative and holistic treatments (eg. nutrient therapy and meditation), antidepressants, antiviral treatments, CBT, GET, counselling and pacing.

As for the headlines of the articles, around a fifth were found to contain what the authors termed stigmatising or trivialising language, such as chronic fatigue, fatigue, Yuppie Flu and tired.