Chronic fatigue syndrome

Causes and Risks:
The exact cause of chronic fatigue syndrome (C.F.S.) is unknown. Some researchers suspect it may be caused by a virus, such as human herpes virus-6 (HHV-6); however, no distinct viral cause has been identified.

Recent studies have shown that chronic fatigue syndrome MAY be caused by inflammation of pathways in the nervous system; and that this inflammation MAY be some sort of immune response or autoimmune process. C.F.S. may occur when a viral illness is complicated by an inadequate (dysfunctional) immune response or by other factors (such as age, prior illness, stress , environment, or genetic disposition). C.F.S. most commonly occurs in women between 30 to 50 years of age.

The Centers for Disease Control (CDC) describes C.F.S. as a distinct disorder with specific symptoms and physical signs, based on the exclusion of other possible causes. The number of patients with C.F.S. is unknown.

Symptoms of C.F.S. appear much like symptoms of most common viral infections ( muscle aches , headache , and fatigue ). The symptoms often develop within a few hours or days and last for 6 months or more.

Symptoms:
Main symptoms:
  • fatigue or tiredness , never experienced to this extent before (new onset), lasting at least 6 months and not relieved by bed rest
  • fatigue that is severe enough to restrict activity (serous fatigue develops with less than one-half of the exertion compared to before the illness)

Other symptoms:



Signs and Tests:
Physical examination may confirm the fever , lymph node tenderness, lymph node swelling , or other symptoms. The throat may appear red without drainage or pus.

The health care provider can presume a diagnosis of chronic fatigue syndrome (or C.F.S.) only after ruling out all other known possible causes, such as:

A diagnosis of C.F.S. must include:

  • extreme, prolonged fatigue
  • absence of other causes of chronic fatigue
    • at least 6 of the other symptoms listed plus two confirming physical examination findings (or)
    • at least 8 of the other symptoms listed

There are no specific tests to confirm the diagnosis of C.F.S., though a variety of tests are usually done to exclude other possible causes of the symptoms.

There are some "typical" findings on tests that, while not specific enough to diagnose C.F.S., are seen consistently in people who are eventually diagnosed with the disorder. These include:

  • higher levels of specific white blood cells (CD4 T cells) compared to other types of white blood cells (CD8 T cells)
  • brain MRI shows swelling in the brain or destruction of part of the nerve cells ( demyelination )
  • specific white blood cells (lymphocytes) frequently show active forms of herpes virus-6 on lymphocyte cell cultures



Treatment:
There is currently no treatment that has been proven to be effective in curing C.F.S.. Instead, the symptoms are treated. Many people with C.F.S. experience depression and other psychological problems that may improve with treatment.

Some of the treatments used include:

  • antiviral drugs (such as acyclovir)
  • drugs to fight "hidden" yeast infections (such as nystatin)
  • medications to treat depression (antidepressant drugs)
  • medications to treat anxiety (antianxiety drugs)
  • medications to reduce pain, discomfort, and fever

Some medications can cause adverse reactions or side effects that are worse than the original symptoms of chronic fatigue syndrome.

Patients with C.F.S. are encouraged to maintain active social lives, and mild physical exercise may also be helpful.

Prognosis:
The outcome is usually good. A full recovery can be expected though the symptoms may linger for 6 months to a year or more.

Complications:

  • social isolation caused by fatigue
  • lifestyle restrictions (some people are so fatigued that they are essentially disabled during the course of the illness)
  • depression
  • side effects and adverse reactions related to medication treatments.



Call Your Healthcare Provider:
Call for an appointment with your health care provider if you experience persistent, severe fatigue , with or without other symptoms of this disorder. Other more serious disorders can cause similar symptoms and should be excluded.