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Fall 2002

CFIDS and Overlapping Disorders: Variations on a Theme?
By Katrina Berne, PhD

Many chronic disorders share common features, including symptoms and abnormalities. Studies of illnesses such as chronic fatigue and immune dysfunction syndrome (CFIDS), fibromyalgia (FM) and irritable bowel syndrome (IBS) show that several chronic disorders often occur in the same patient. Since these illnesses are compartmentalized and labeled, each is studied as a discrete disorder. But as common factors become more apparent, the boundaries between illnesses tend to blur.

Because of the number of overlapping symptoms and characteristics, there is speculation that many chronic conditions are either related or are different manifestations of the same illness, perhaps caused by similar factors. Muhammad Yunus, MD, considers CFIDS, FM, Gulf war illness, multiple chemical sensitivity disorder and others to be part of a greater grouping that he calls “central sensitivity syndrome,” or CSS.

A group of overlapping disorders is presented below. Numerous others have been excluded due to space constraints. The illnesses profiled here overlap in terms of symptoms; complexity; poorly understood pathophysiology; variability among cases; increased prevalence in women; possible involvement of infectious agents; dysfunction of the immune and central nervous systems; known or suspected autoimmune component; and dismissal or lack of “real” illness status unless a marker or test has been identified.

Their relationships to one another remain unclear. Similarities of symptoms and multiple dysregulations suggest a common mechanism in several conditions, possibly hypothalamic-pituitary-adrenal (HPA) axis dysfunction. The HPA axis controls the release of hormones in response to stressors; in CFIDS, the axis may be disrupted because of abnormalities in the central nervous and immune systems. The mechanisms of the HPA axis are complex and delicate, and minor variations in dysfunction might account for similarities among these disorders.

Fibromyalgia
About 75 percent of people diagnosed with CFIDS meet the criteria for FM. Fifty-eight percent of females with FM, and 80 percent of males with FM, meet CFIDS criteria. Symptoms of both illnesses include pain, gastrointestinal problems, cognitive difficulties, sleep disturbance and neurological problems such as lightheadedness, fainting and dizziness.

People with both conditions typically show normal results on routine lab tests. Both illnesses are most common in women in their middle years. Strenuous activity can trigger relapses, the illnesses wax and wane and secondary psychological problems such as depression, anxiety and mood swings are common for people with both diseases.

There are also a number of physiological similarities. For instance, abnormalities in the central nervous system, such as low levels of brain transmitters serotonin and norepinephrine, are common to both illnesses. Immune system abnormalities are often similar, and include decreased function of natural killer cells, increased antibody (cytokine) levels and disturbances in hormone secretion and function.

Differences between two conditions have been noted. Fatigue is more common in CFIDS, while people with FM have tender points and “trigger” points that cause pain. Substance P, a brain chemical associated with pain signal transmission, is elevated in FM but more often normal in CFIDS. And abnormal versions of the blood-based protein RNaseL are common in CFIDS but much less prevalent in FM cases.

The scientific community cannot yet give us a definitive answer to the question of the relationship between CFS and FM for many reasons. Diagnostic criteria vary among studies, making it difficult to compare results. No objective tests exist to measure such symptoms as fatigue. And large-scale comparative studies have not been funded.

Whether it is the same illness, subtypes of one illness, or different illnesses, the bottom line is the same: More funding and larger, better-designed studies are needed.

Inflammatory Bowel Disease (IBD) and IBS
Gastrointestinal symptoms are common in people with CFIDS and FM. IBD is a serious, chronic condition, often accompanied by arthritis-like pain and occurring in a waxing-and-waning pattern that significantly impacts one’s lifestyle. Two serious types of IBD are Crohn’s disease, a severe inflammation of a part of the gastrointestinal (GI) tract, and ulcerative colitis, an inflammatory process of the large intestine. Crohn’s is characterized by abdominal pain, diarrhea, fever and weight loss, sometimes with serious complications. Symptoms of ulcerative colitis include abdominal cramps, blood and mucus in the stool and increased urgency to defecate. Attacks may be severe and sudden, with the possibility of severe complications.

IBS is more common than IBD in people with CFIDS. It is a function of bowel function rather than structure, and is estimated to affect 20 percent of adults in the Western world. A distressing disorder that greatly affects one’s quality of life, IBS was once dismissed as a mild, psychogenic disorder of gut motility. It is now regarded as the result of brain-gut dysfunction with dysregulation of the autonomic nervous system. This autonomic dysfunction may account for the presence of IBS in both CFIDS and FM.

Gulf war illness            
The U.S. government has alternately acknowledged and denied the existence of a group of symptoms experienced by at least 100,000 of the 700,000 U.S. troops deployed to the Persian Gulf in 1990. Although no case definition for Gulf war illness (GWI) exists, its symptoms strongly resemble those of CFIDS, FM and rheumatoid arthritis. More than half of GWI patients meet criteria for CFIDS.

Symptoms occurring in Gulf war veterans include debilitating fatigue, post-exertional fatigue, widespread muscle and joint pain, sleep disorders, temperature dysregulation, night sweats, headaches, numbness, swelling in joints and extremities, irritability, depression, malaise and a number of neurological symptoms, including cognitive impairment, blurred vision and balance problems. Many Gulf war veterans have suffered long-term health problems, and their significant others have become ill as well.

GWI patients often show immune abnormalities similar to those in people with CFIDS. These include overreaction of cytokines and T-cells; diminished numbers of, and unusual changes in, natural killer cells; abnormal ratios of immune cells called CD4 and CD8; and reactivation of Epstein-Barr virus and human herpesvirus 6 (HHV-6).

Multiple Chemical Sensitivity Disorder
Multiple chemical sensitivity disorder (MCS), also known as environmental illness, is characterized by immediate or delayed reactions to various environmental chemicals. Toxins are everywhere in our environment. Offending chemicals are found in food additives, drugs, perfumes and other scented products, pesticides, herbicides and room deodorizers, natural gas, tobacco smoke, solvents, carpets and household furnishings. When these chemicals are inhaled, eaten or drunk, they are able to cross the blood-brain barrier, causing neurological damage.

Various studies suggest that MCS is present in 40-80 percent of people with CFIDS, and the majority of people with a primary diagnosis of MCS have concurrent CFIDS, FM, GWI and allergies. Although there is no specific test for MCS, abnormalities have been detected on immune and brain imaging tests.

Symptoms of MCS can span multiple organ systems. These symptoms include dizziness, headache or migraine, nausea and other neurological sensations, breathing difficulty, impaired concentration and memory, balance difficulties, musculoskeletal and abdominal pain, irritability, depression and anxiety.

Lyme disease
Lyme disease is a multisystem inflammatory disorder that may affect the skin, joints, heart, eyes and nervous system. It is caused by the bite of a tick infected with the spirochete Borrelia burgdorferi or related species. Lyme disease often begins with a telltale bull’s-eye-shaped rash and joint and muscle pain, although many patients are unaware of receiving a tick bite.

Antibiotic treatment is most successful in the early stages. Some patients respond well to treatment, others recover over a long period of time, and some fail to recover fully, with a lingering post-infectious syndrome or development of other serious illnesses such as Lyme arthritis.

Months to years after the initial infection, later symptoms include arthritis pain and swelling, sleep disorder, generalized achiness, stiffness, weakness, heart palpitations, headache, fever, shortness of breath and many other physical and cognitive problems. The possibility that Lyme disease is related to CFIDS has been explored, with no clear consensus. Some physicians find that patients diagnosed with CFIDS and FM actually have undiagnosed Lyme disease.

Endometriosis
Endometriosis, or overgrowth of cells from the uterine lining into the abdominal cavity, is characterized by menstrual pain, fatigue, bloating, heavy and/or irregular bleeding and bowel disturbances. Some studies indicate a statistically significant overlap with CFIDS/FM, while others do not. The two conditions may exist simultaneously but there is no known causal relationship at this point.

Depression
Depression does not cause CFIDS and is not present in all cases; however, many patients are given a psychiatric diagnosis such as depression when a physiological diagnosis is not apparent. Overlapping symptoms, presence of depressed mood in some patients, lack of a known cause or marker and simple ignorance causes confusion between CFIDS and depression.

Depressive symptoms in physically ill patients may be a result of immune activation and cytokine secretion, in addition to a psychological reaction to illness-related distress and incapacitation. Complex interactions among the immune system, the HPA axis and other neurological factors affect stress levels, emotions and vulnerability to illness. Illness, in turn, affects these body symptoms. Studies show that immune activation may precede the development of depression, with increased levels of certain cytokines.

This article was adapted from “Chronic Fatigue Syndrome, Fibromyalgia and Other Invisible Illnesses: The Comprehensive Guide” (Hunter House, 2002).

Katrina Berne, PhD, is a licensed clinical psychologist who specializes in the treatment of people with CFIDS, fibromyalgia and related disorders. She has had CFIDS since 1985.

Postpolio syndrome

Many survivors of paralytic and nonparalytic polio have developed symptoms years after the initial infection, possibly caused by damage to neurons. Symptoms of postpolio syndrome include new-onset chronic fatigue triggered or worsened by physical exertion and emotional stress; joint and muscle pain; cold intolerance; sleep disorder; cognitive impairment; headache; neck pain; muscle pain (myalgia); low-grade fever and increased sleep.

Outbreaks of “abortive” or “atypical” polio cases occurred in numerous locations. In the 1940s, an illness dubbed the “summer grippe” was characterized by abrupt onset, duration of less than a week and flu-like symptoms. These cases were typical of nonparalytic polio, caused by a mild polio virus. None of the people with summer grippe developed full-blown polio; apparently the mild polio virus conferred immunity against it.

However, even mild viruses may have damaged the central nervous system. “Potentially half of those diagnosed today with [CFIDS] may have in fact had summer grippe or undiagnosed nonparalytic polio as children in the years before the vaccine became available,” reports Richard Bruno, MD.

—Katrina Berne, PhD