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Similarities and Differences Between Fibromyalgia and Gulf War Syndrome
Gulf War syndrome (GWS), fibromyalgia, chronic fatigue syndrome, and multiple chemical sensitivities syndrome occur commonly in the same groups of people and they have overlapping symptoms. Due to their similarities, some researchers think these syndromes, and perhaps also irritable bowel syndrome, may be subsets of the same condition.
Symptoms include longstanding (more than three to six months) of chronic widespread muscle or joint pain, extreme fatigue, trouble sleeping, headaches and problems with memory and thinking. People with these syndromes are also more likely to suffer from anxiety, depression or post-traumatic stress disorder (PTSD).
Diagnosis may depend on the most prominent symptom present (fatigue in chronic fatigue syndrome or pain in fibromyalgia) and which medical specialist diagnoses it (a rheumatologist is more likely to diagnose fibromyalgia). If not the same condition, there may be a similar underlying mechanism.
The cause of these syndromes remains unknown but all are now thought to involve dysfunction of central pain processing, leading to increased sensitivity to touch and other stimuli. A number of genes involved in pain and touch sensitivity have been linked to these conditions, indicating there may be a genetic predisposition. All seem to affect women more than men; however, it seems there is usually some trigger, such as an illness, exposure to a noxious chemical or a stressful event.
What Is GWS?
Within a year of returning home, many of the personnel — approximately 30 percent — involved in the Gulf War began experiencing a range of symptoms that were difficult to explain and varied between individuals.
Many researchers have tried to identify the cause of GWS and explain the symptoms. Current evidence suggests the strongest association with the combined heavy use of pesticides and insect repellants, pyridostigmine bromide use, and nerve gas exposure. Not all individuals exposed developed GWS and genetic predisposition appears to play a significant role.
Gulf War syndrome, like fibromyalgia and chronic fatigue syndrome, often displays no visible marks of illness. The sometimes vague symptoms may be overlooked or dismissed by doctors. Diagnosis is based on individuals meeting a set of criteria based on self-reporting of symptoms and excluding other causes.
GWS is diagnosed when veterans have one or more symptoms from two of three categories for at least six months, which cannot be explained by some other illness. The categories are:
- Muscle or joint pain. Joint pain, joint stiffness, muscle pain.
- Problems with mood or thinking. Feeling depressed or anxious, trouble sleeping, difficulty remembering or concentrating, trouble with recalling words when talking.
Other symptoms associated with GWS include: headaches, skin rashes, indigestion, diarrhea and breathing issues. A wide range of symptoms, affecting many body systems, has been reported.
An increased incidence of brain tumors and amyotrophic lateral sclerosis (ALS), has been reported in Gulf War veterans. It is likely there are number of illnesses that contribute to the variety of symptoms they experience.
For example, there is evidence some individuals with predominately nervous system symptoms may be suffering from the delayed effects of organophosphate (pesticide) nerve toxicity and some respiratory issues may be due to infection. These other illnesses may be different to the classic GWS that is similar to fibromyalgia and chronic fatigue syndrome. Certainly, brain tumors and ALS are not common to fibromyalgia and will likely have a different cause.
How Similar Are GWS and Fibromyalgia?
Fibromyalgia is characterized by chronic widespread pain and tenderness, problems sleeping, fatigue, and problems with concentration and memory. It is diagnosed using two scales, the widespread pain index (WPI) and the symptom severity (SS) scale.
The WPI assesses pain experienced when touching 19 different areas on the body. The SS scale has two parts. Part one measures the severity of: fatigue, waking unrefreshed, and problems with thinking and remembering. Part two tallies the number of other symptoms experienced into a few, moderate and many.
These other symptoms may include fibromyalgia and skin rashes, muscle weakness, diarrhea, constipation, vomiting, loss of appetite, headache, dizziness, insomnia, numbness in legs, depression, nervousness, abdominal pain, chest pain, blurred vision, fever, dry mouth, itching, sun sensitivity, hives, wheezing, shortness of breath, ringing in the ears, heartburn, changes in taste, mouth ulcers, seizures, dry eyes, problems with hearing, hair loss (hair loss and rheumatoid arthritis also go hand-in-hand, which can add to diagnosis difficulties), easy bruising, painful urination and bladder spasms.
Fibromyalgia is diagnosed when a person receives a WPI of seven or higher and a SS score of five or more or a WPI of three to six and a SS score of nine or more. The symptoms must be present at a similar level for more than three months and there must be no other illness that would explain the symptoms.
People with GWS are more likely to be diagnosed with fibromyalgia, chronic fatigue syndrome and irritable bowel syndrome. Both GWS and fibromyalgia have the key diagnostic criteria in common: fatigue, muscle pain, sleeping issues and thinking issues.
Many sufferers also present with a wide range of symptoms affecting many other parts of the body. The symptoms greatly overlap and it is not clear whether or not they are part of the same illness other than that veterans were involved in the Gulf War. However, GWS is not exactly the same as fibromyalgia.
People with GWS do not have to experience muscle or joint pain. Where fatigue or sleeping difficulties are more common, they might fit the criteria for chronic fatigue syndrome more closely. It seems that there may be some common link between these syndromes and science is just beginning to look into what that might be.