What is Chronic Fatigue Syndrome?

Chronic fatigue syndrome (CFS) is an emerging illness characterized by debilitating fatigue (experienced as exhaustion and extremely poor stamina), neurological problems, and a variety of flu-like symptoms. The illness is also known as chronic fatigue immune dysfunction syndrome (CFIDS), and outside of the USA is usually known as myalgic encephalomyelitis (ME). In the past the syndrome has been known as chronic Epstein-Barr virus (CEBV).

The core symptoms include excessive fatigue, general pain, mental fogginess, and often gastro-intestinal problems. Many other symptoms will also be present, however they will typically be different among different patients. These include: fatigue following stressful activities; headaches; sore throat; sleep disorder; abnormal temperature; and others.

The degree of severity can differ widely among patients, and will also vary over time for the same patient. Severity can vary between getting unusually fatigued following stressful events, to being totally bedridden and completely disabled. The symptoms will tend to wax and wane over time. This variation, in addition to the fact that the cause of the disease is not yet known, makes this illness difficult to diagnose.

For a slight majority of patients, the illness begins suddenly as though one had come down with the flu. Except that this "flu" doesn't seem to completely go away. For many other patients, the onset appears gradually over a long period of time.

In many cases, a high-stress event seems to "trigger" the illness. There are many cases in which CFS appears to have begun with a severe head injury, for example. But since such events seem to have no apparent logical connection to the illness that follows, many have speculated that the CFS was latent in people beforehand in these cases, and that the stress of trauma merely triggered the stress-hypersensitivity aspect of the illness. Some have further speculated that other stressful factors in our environment, be they microbes or pollution, may also prompt this illness to bloom.

The illness varies greatly in its duration. A few recover after a year or two. More often, those who recover are more likely to do so from 3 to 6 years after onset. Others may recover after a decade or more. Yet for some, the illness seems to simply persist.

CFS often occurs in cycles. It can be frustrating to obtain some relief, but then not know whether you have recovered or if you are merely between cycles.

What Causes CFS?

The cause of the illness is not yet known. Current theories are looking at the possibilities of neuroendocrine dysfunction, viruses, environmental toxins, genetic predisposition, or a combination of these. For a time it was thought that Epstein-Barr Virus (EBV), the cause of mononucleosis, might cause CFS but recent research has discounted this idea. The illness seems to prompt a chronic immune reaction in the body, however it is not clear that this is in response to any actual infection -- this may only be a dysfunction of the immune system itself.

A recent concept promulgated by Prof. Mark Demitrack is that CFS is a generalized condition which may have any of several causes (in the same way that the condition called high blood pressure is not caused by any one single factor). It *is* known that stressors, physical or emotional, seems to make CFS worse.

Some current research continues to investigate possible viral causes including HHV-6, other herpes viruses, enteroviruses, and retroviruses. Additionally, co-factors (such as genetic predisposition, stress, environment, gender, age, and prior illness) appear to play an important role in the development and course of the illness.

Many medical observers have noted that CFS seems often to be "triggered" by some stressful event, but in all likelihood the condition was latent beforehand. Some people will appear to get CFS following a viral infection, or a head injury, or surgery, excessive use of antibiotics, or some other traumatic event. Yet it's unlikely that these events on their own could be a primary cause.

Is CFS contagious?

Since the cause of the illness is not known, the question of contagion is not known. Many studies suggest that there is no correlation between CFS and casual or intimate contact. On the other hand, there are infrequent but occasional reports of cluster outbreaks of CFS. How that can happen, while at the same time in other instances intimate family members do not pass on the disease, remains one of the mysteries of this illness.

Is CFS genetic?

Several studies suggest that there may be a genetic component to CFS. This is not surprising since CFS seems to involve immune dysfunction to some degree, and immune-related illnesses often have a genetic component. The evidence on this point is not clear. And the fact that there seem to be cluster outbreaks of this illness seems to argue against genetics as being the sole factor.

Is CFS a "Real" Disease?

At this early point, many practicing clinicians remain unconvinced that CFS is a genuine illness, although it is slowly increasing in acceptance. The reluctance is due in part to the facts that (1) no specific cause has yet been found, (2) there is no observable marker that doctors can use to specifically identify the illness, and (3) most doctors are not yet familiar with the peer-reviewed research which does tend to legitimize this disease.

Emerging illnesses such as CFS typically go through a period of many years before they are accepted by the medical community, and during that interim time patients who have these new, unproven illnesses are all too often dismissed as being "psychiatric cases". This has been the experience with CFS as well.

But many top-level researchers are showing that this is a distinct, organic illness.

Who gets CFS?

Few studies address this question. Several show that 70 to 80 percent of CFS patients are women, although some researchers say that these are normal figures for any immune-related illness. Some studies indicate that CFS is less common among lower income people and minorities, but critics point out that the average CFS patient sees so very many doctors before they can get a diagnosis, that only those with great access to medical care get counted in such studies, thus giving a bias with regards to income and race.

What symptoms are used to diagnose CFS?

In addition to the official researchers' definition discussed below, patients and experienced clinicians have noticed symptom patterns that seem prominent in CFS. These include the observations that cognitive dysfunction often increases over time (over several years), and that brain scans often show that blood flow to the brain is decreased. CFS is defined somewhat differently by various medical groups in different countries. The 1994 research definition published by the U.S. Centers for Disease Control and Prevention recommends a step-wise approach for identifying CFS cases. The first step is to clinically evaluate the presence of chronic fatigue, i.e. "self-reported persistent or relapsing fatigue lasting 6 or more consecutive months".

Conditions that explain chronic fatigue should exclude a diagnosis of CFS. These are:

"any active medical condition that may explain the presence of chronic fatigue ..." - any previous condition which might explain fatigue and which has not documentably come to an end; - "any past or current diagnosis of a major depressive disorder with psychotic or melancholic features; bipolar affective disorders; schizophrenia of any subtype; delusional disorders of any subtype; dementias of any subtype; anorexia nervosa; or bulimia"; - substance abuse within 2 years prior to onset; - severe obesity.

The following should not exclude a diagnosis of chronic fatigue:

conditions which cannot be confirmed by lab tests, "including fibromyalgia, anxiety disorders, somatoform disorders, nonpsychotic or nonmelancholic depression, neurasthenia, and multiple chemical sensitivity disorder"; - any condition which might produce chronic fatigue but which is being sufficiently treated; - any condition which might produce chronic fatigue but whose treatment has already been completed; - any finding which on its own is not sufficient to strongly suggest one of the exclusionary conditions.

After the above criteria are met, the following core criteria for CFS are applied: "A case of the chronic fatigue syndrome is defined by the presence of the following:

1) clinically evaluated, unexplained persistent or relapsing chronic fatigue that is of new or definite onset (has not been lifelong); is not the result of ongoing exertion; is not substantially alleviated by rest; and results in substantial reduction in previous levels of occupational, educational, social or personal activities; and
2) the concurrent occurrence of four or more of the following symptoms, all of which must have persisted or recurred during 6 or more consecutive months of illness and must not have predated the fatigue:

- self-reported impairment in short term memory or concentration severe enough to cause substantial reduction in previous levels of occupational, educational, social or personal activities;
- sore throat;
- tender cervical or axillary lymph nodes;
- muscle pain;
- multi-joint pain without joint swelling or redness;
- headaches of a new type, pattern or severity;
- unrefreshing sleep;
- and post exertional malaise lasting more than 24 hours."

The journal citation for the CDC definition article is: Keiji Fukuda, Stephen Straus, Ian Hickie, Michael Sharpe, James Dobbins, Anthony Komaroff, and the International CFS Study Group. "The Chronic Fatigue Syndrome: A Comprehensive Approach to Its Definition and Study". Ann Intern Med. 1994;121:953-959.

What are Specific Treatments are Available for CFS?

Many treatments are available. Most seem to be of limited usefulness, however different patients will respond differently and in some instances there is good response. An FAQ on treatments is being developed, and more detail about these issues will be discussed there. Please see the subsections immediately below for a discussion of treatments.

Avoid stress

As odd as it may seem, typically the most beneficial program is for the patient to avoid stress and to get lots of rest. This is usually the most effective regimen, among others that might also be undertaken. Stress does not merely mean unpleasant experiences, but rather any biological stressors, physical or emotional, which prompt a protective reaction in the body and which may alter physiologic equilibrium ("homeostasis"). Failure to avoid stress often leads to short-term and long-term set-backs which may be serious. Many patients believe that if they had done more to avoid stress in the early phases of the illness, they would not have become nearly so disabled later on. The correlation between stress and the progress of this illness appears to be strong.

Medications

Treatments tend to address the symptoms, since the underlying mechanism of the disease is not really understood. Medications which are helpful are often those which have immune-modulating characteristics. CFS patients are unusually sensitive to drugs and they usually must take doses that are 1/4 or less than standard doses. Some drugs will be a big help to some patients and little or no help to others. And drugs that seem to work for a while may stop being effective later.

According to studies presented at the October 1994 CFS medical conference, widely used treatments included: SSRIs ("selective serotonin re-uptake inhibitors" such as Zoloft, Paxil and Prozac) used to address fatigue, cognitive dysfunction and depression; low dose TCAs ("tricyclic anti-depressants" such as doxepin and amitriptyline) for sleep disorder, and muscle and joint pain; and NSAIDs ("non-steroidal anti-inflammatory drugs" such as ibuprofen and naproxen) for headache, and muscle and joint pain. Other treatments often prescribed are Klonopin, intra-muscular gamma globulin (IMgG), nutritional supplements (particularly anti-oxidants, B-vitamins generally and B-12 specifically), herbs, and acupuncture. Less often prescribed were chiropractic therapy, intra-muscular gamma globulin (IVgG), kutapressin, antivirals, interferon, and transfer factor.

Research from Johns Hopkins University in 1995 indicate that treatment for neurally mediated hypotension may be effective for the many CFS patients who may show positive for that condition.

Role of Exercise

CFS patients will need to avoid stressful activities, and each patient's toleration for stress will be different, and can change). It is nonetheless important for patients who can exercise to do so, up to their level of toleration. But this should be done with great care, since crossing the "invisible line" of exercise intolerance for this illness may prompt a serious relapse, and may negatively affect the longer-term future course of the illness.

Dietary Changes

CFS patients appear to be alcohol intolerant. Other food products often recommended against include caffeine, sugar and nutrasweet. Since in many patients it appears that the immune system is over-active, it may be more important than usual to take nutritional supplements to replenish burnt up reserves.

Many patients have or develop food sensitivities, and in these cases relief may be found by avoiding foods that prompt problems. Patients tend to gain weight and they don't have vigorous exercise available as a counterbalance, so diet needs to be monitored with this in mind.

Secondary Problems

There can be several related problems, such as yeast, that need to be watched out for. Also, CFS has so many symptoms that it's easy to ascribe all new anomalies to this disease. But CFS patients are not exempt from getting other illnesses also, therefore it is important to regularly monitor your health and to consult with your doctor about the changes as they progress.

What is the Role of Stress and Psychology in CFS?

Preliminary research suggests that CFS may involve a brain disorder -- specifically, HPA dysfunction  -- which affects the stress response system in our bodies. CFS patients are standardly observed to be hypersensitive to stress. Stress does not merely mean unpleasant experiences, but rather any biological stressors, physical or emotional, which prompt a protective reaction in the body and which may alter the physiologic equilibrium known as "homeostasis". Stress in this physiological sense may be subtle and may not necessarily be noticed. Merely hearing loud sounds or seeing bright lights may be stressful in this context.

High-stress events sometimes seem to "trigger" the first appearance of the illness, and they will usually worsen the symptoms if the illness has already developed. Because stress is often mistakenly thought of as a purely emotional phenomenon with no physical aspect, the correlation of CFS with stress makes some people imagine that CFS must a non-physical "psychological illness". Medical studies show that stress plays an important role in several immune-mediated illnesses, and in fact a new field of research called psychoneuroimmunology has been created to study just this phenomenon.

HPA and neurotransmitter dysfunction may make CFS patients excessively irritable, and may prompt panic attacks. These behaviors might be misinterpreted, thereby reinforcing a misconception that CFS is merely a psychological condition.

Is CFS related to depression?

Many emerging illnesses, before they have gained acceptance by the medical community, have initially been discounted as being hysteria, depression, somatoform disorders, etc. One hundred years ago, polio was dismissed in just that fashion. When CFS gained notice in recent times, many of its symptoms were correlated to depression, and many un-read physicians today still believe that's what CFS is. Much recent research, notably the finding by Demitrack that cortisol levels are low in CFS patients whereas in depressed people they are high, indicates that CFS is not depression. Other noted differences are that CFS patients tend to overestimate their abilities, retain a strong interest in life, and respond poorly to exercise, whereas the opposite are typically observed in people who are depressed.

A politico-economic aspect of this issue is that health insurers have an incentive to classify patients as having temporary illnesses that can be treated cheaply and in a short time. Depression is considered to be a short-term, treatable illness.

Another issue is that CFS patients can get "secondary depression" if their lives have been disrupted because their illness has interfered with their job or their social or family life. This indirect consequence of the illness may be taken by some medical professionals as indicating a cause rather than an effect of the observed symptoms.

How Does one Live with CFS?

- Know that it's not you. It takes a lot to adjust to your new, lessened capabilities, and the adjustment is made more difficult by the expectations of you and those around you who have been long accustomed to dealing with your "normal, healthy self".

- Patients often find an equilibrium point at which they can function. As in combating any chronic illness, a positive hopeful attitude is essential.

- Be prepared for a possible lack of acceptance from some from whom you might expect support. This may be a shock, but when you cannot regularly "go bowling" with the gang, or you increasingly depend on being accommodated at home or on the job, and when you have a condition that your doctor may not certify or that other people have already heard of as "that yuppie disease", then your emotional world will become quite different.

- Find new sources of support. It will be important to create a new family-and-friends support structure. This can be done through CFS support groups, electronic networking, pen pals, and other means.

- You will need to take the time to create a new self image for yourself, to know that your new physical limitations do not limit you as a person, as a soul, no matter what other people are thinking. And take some advice from those who have traveled this difficult road before you.

Source: CFS FAQ Version: 1.37 (last revised 1997/08/02). The CFS FAQ is copyright (c) 1997 by Roger Burns on behalf of the CFS Internet Group. Permission is granted to redistribute or quote this document for non-commercial purposes provided that you include an attribution to the CFS Internet group.