A new study suggests the underlying causes of the often co-existing medical conditions fibromyalgia and chronic fatigue syndrome may actually differ substantially - bucking the assumption that they are different manifestations of the same pathological processes.
Comparing symptoms experienced by patients of both illnesses it is obvious that they have much in common; in fact it is often a matter of whether pain or fatigue is more prominent that is used as the distinguishing factor. Add the fact that many patients appear to suffer from both conditions at the same time and it is easy to see why they are frequently considered to have similar causes and pathophysiologies.
Now, Dr. Benjamin Natelson, MD, head of the Pain & Fatigue Study Center at Beth Israel Medical Center in New York, has published the results of a thorough review of the best current evidence to determine if this is truly the case. Dr. Natelson is an expert in neurology and the infectious and immunological causes of pain and fatigue and is considered one of the foremost experts on fibromyalgia (FM) and chronic fatigue syndrome (ME/CFS).
The results of Dr. Natelson's review, co-authored with colleague Bhavna Abbi are published in the Quarterly Journal of Medicine and throw up some intriguing, and perhaps suprising, distinctions between FM and ME/CFS.
The two researchers write that ME/CFS and FM are both "medically unexplained syndromes that can and often do co-occur" and that as a result "...some have posited that the two are part of the same somatic syndrome-examples of symptom amplification."
They go on to say that this hypothesis if it were true means that few differences exist between FM and ME/CFS. To determine if this is the case they searched the medical literature for studies that compared the two illnesses, then analysed only those that found differences between them and reported on what these differences were.
Prohealth.com reports that Dr. Natelson breaks the identified differences down into a list of major categories:
- General (e.g., age of onset patterns)
- Hormone and neurotransmitter dynamics (e.g., regarding somatomedin/growth hormone, melatonin, cortisol, spinal fluid substance P)
- Genetic profiles, and gene expression (e.g., gene upregulation patterns after exertion)
- Mechanisms of autonomic function
- Muscle biochemistry
- Sleep disruption patterns/factors
- Comorbidities (e.g., PTSD rates)
Dr. Natelson has worked for years studying FM and ME/CFS to better understand and classify these often co-existing conditions. He is now looking for volunteers diagnosed with either syndrome to participate in several future studies to build on the insights gained in this current review.
Natelson and Abbi add: "We hope that our review encourages other groups to look for additional differences between CFS and FM."
It goes without saying that greater understanding of these illnesses will help doctors understand the best ways to manage and treat them; it is therefore essential that this type of research is undertaken as quickly and as thoroughly as possible.
Source: Abbi B and Natelson BH (2012) Is chronic fatigue syndrome the same illness as fibromyalgia: evaluating the ‘single syndrome’ hypothesis Quarterly Journal of Medicine doi: 10.1093/qjmed/hcs156