| How It Begins |
| Who Gets It |
| The Diagnosis |
| How Many People Have It? |
| Historical Perspective |
| The CFS Case Definition |
| How to Manage and Cope With the Disease |
| Conclusion |
| The early hallmark of the illness is a pronounced fatigue that comes on suddenly and is relentless or relapsing, causing debilitating tiredness or easy exhaustion in someone who has no apparent reason for feeling this way... |
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Email AlertsJoin our email group to receive updated information on this topic. We all get tired; most of us at times have felt depressed. But the enigma known as chronic fatigue syndrome (CFS) is not the ups and downs we experience in everyday life,or even the temporary persistence of suchfeelings in response to exceptional physical oremotional stress. The early hallmark of theillness is a pronounced fatigue that comes onsuddenly and is relentless or relapsing, causingdebilitating tiredness or easy exhaustion insomeone who has no apparent reason for feelingthis way. Unlike the mind fog of a serioushangover, to which CFS has been compared, theprofound weakness of CFS does not go away with afew good nights of sleep but instead slyly stealsa person's vigor over months and sometimes years.
People diagnosed withCFS often describe its onset as sudden butnot alarming because many of the syndrome'ssymptoms--headache, tender lymph nodes,fatigue and weakness, muscle and joint aches,inability to concentrate--mimic those of theflu. But whereas flu symptoms usually go awayin a few weeks, CFS symptoms either persistor recur frequently for more than six months. For many people, CFSbegins after an acute infection such as acold, bronchitis, hepatitis, or an intestinalbug. For some, it follows a bout ofmononucleosis, the "kissingdisease" that temporarily saps theenergy of teenagers and young adults. Inothers, CFS develops more gradually, with noclear triggering event. Often a patientreports that the illness emerged during aperiod of high stress.
Contrary to the popularstereotype, CFS is not a new "yuppieflu." Similar syndromes, known bydifferent names, date back to the late 1800s.The modern stereotype arose because those whosought help for and stimulated scientificinterest in CFS in the early 1980s weremainly well-educated, affluent women in theirthirties and forties. Since then, physicianshave seen the syndrome in people of all ages,races, and socioeconomic classes from severalcountries around the world. Still, CFS is diagnosedtwo to four times more often in females thanin males, which may be the result ofbiological, psychological, and socialinfluences. For example, a real genderdifference may exist in CFS, similar todiseases such as lupus and multiple sclerosisthat affect more women than men. Or, womenmay be more likely than men to consultdoctors about CFS-like symptoms. Also, somemembers of the medical community and thepublic remain unaware or skeptical of thesyndrome. An increasingly diverse patientpopulation will likely emerge as morephysicians recognize CFS as a legitimatedisorder.
Diagnosing CFS isdifficult because it shares symptoms withmany other diseases. When evaluatingpatients, physicians must first rule outdiseases that look similar, such as multiplesclerosis and lupus in which diagnosticsymptoms can take years to develop. Infollow-up visits, physicians need to be alertto any new cues or symptoms that mightindicate a diagnosis other than CFS. After rigorouslyexcluding people with other diseases,however, a large group of people withsymptoms associated with debilitating fatigueremain. If they meet other criteria as well,these people can be considered to have CFS(see The CFS Case Definition).
Note: For the latest CFS prevalence data, please consultthe Centers for Disease Control and Prevention Web site. The lack of a clinicalor laboratory marker for CFS has muddledefforts to determine how many people theillness affects. NIAID and the Centers forDisease Control and Prevention (CDC) fundprevalence studies. Based on the first threeyears of an ongoing surveillance study infour U.S. cities, the CDC estimates theminimum prevalence rate of CFS in the UnitedStates is 4 to 10 cases per 100,000 adults 18years of age or older (although children canhave CFS, too.) This estimate, however,relies on cases referred to CDC study sitesby primary physicians, a method that canresult in either an underestimate oroverestimate of actual cases.
Clinical portraits ofdiseases similar to CFS have been reportedunder different medical guises for more thana century. In the l860s, Dr. George Beardnamed the syndrome neurasthenia, believing itto be a neurosis characterized by weaknessand fatigue. Succeeding generations havefavored but not proved differentexplanations--iron-poor blood (anemia), lowblood sugar (hypoglycemia), environmentalallergy, or a bodywide yeast infection(candidiasis)--for this baffling malaise. In the mid-1980s, theillness became labeled "chronicEBV" when laboratory clues ledscientists to speculate that this cluster ofsymptoms might be caused by the Epstein-Barrvirus (EBV). But new evidence casts doubt onthe theory that EBV could be the sole agentcausing CFS. Elevated levels of EBVantibodies have now been found in somehealthy people as well as in some people withCFS. Likewise, some people who lack EBVantibodies, and who thus have never beeninfected with the virus, can display CFSsymptoms.
The EBV work rekindledinterest in the syndrome among a small groupof medical researchers. It became apparentthat a standard CFS case description wasneeded so that scientists could more easilycompare research results. In the late 1980s, CDCconvened a group of CFS experts to tacklethis problem. Based on the best informationavailable at the time, this group publishedin the March 1988 Annals of InternalMedicine strict symptom and physicalcriteria--the first case definition--by whichscientists could evaluate CFS study patients. Not knowing the causeor a specific marker for the disease, thegroup agreed to call the illness"chronic fatigue syndrome" afterits primary symptom. "Syndrome"means a group of symptoms that occur togetherbut can result from different causes. (Today,CFS also is known in other countries asmyalgic encephalomyelitis, postviral fatiguesyndrome, and chronic fatigue and immunedysfunction syndrome.) After using thisdefinition for several years, CFS researchersrealized some criteria were vague orredundant. CDC had an international group ofCFS experts review the criteria. This led tothe first changes in the case definition,published in the same journal in December1994 (see attached article). Besides revising theCFS case criteria--which reduced the requiredminimum number of symptoms to four out of alist of eight possible symptoms--the newreport also proposes a conceptual frameworkfor studying the syndrome. This frameworkrecognizes CFS as part of a continuum ofillnesses that have fatigue as a majorsymptom. Although primarily intended forresearchers, the new guidelines should helpclinicians better diagnose CFS.
No specific treatmenthas proved effective for CFS. Scientists hopethat research will help them identify markersfor the illness. These markers would enablethem to target treatments to specificabnormalities and to objectively follow thecourse of the illness. How well differenttherapies work can then be gauged bymeasuring changes in those markers in treatedpatients. Anecdotally, physicianshave reported successes in small numbers ofpatients with various treatments includingantivirals, antidepressants, andimmunomodulators (drugs that boost the immunesystem). Few drugs have undergone rigorousclinical testing, however. NIAID researcherstested the antiviral drug acyclovir in adouble-blind, placebo-controlled trial andfound that as many CFS patients reportedfeeling better when taking a placebo as whentaking acyclovir. This outcome lessens claimsof a therapeutic role for acyclovir in CFS.Carefully controlled studies also haverevealed conflicting data regarding the valueof high-dose intravenous immunoglobulin. Because well-designedclinical trials have found that patients withfibromyalgia (an illness similar to CFS)benefit from low-dose tricyclicantidepressants, doctors often prescribethese drugs for people with CFS withgenerally positive results. Some researchersbelieve that these drugs improve the qualityof sleep. Patients also have benefitted fromother kinds of antidepressants, including thenewer serotonin reup-take inhibitors.Therapeutic doses of antidepressants oftenincrease fatigue in CFS, so doctors may haveto escalate the dosage very slowly, orprescribe the so-called more activeantidepressants. In addition, some peoplewith CFS benefit from the benzodiazepines, aclass of drugs used to treat acute anxietyand sleep problems. Patients often try morethan one drug before finding one that worksand can be tolerated. Even though no specificCFS treatments exist, symptomatic treatmentstill can be quite helpful. Nonsteroidalanti-inflammatory drugs may benefit the bodyaches or fever associated with the illness,and nonsedating antihistamines may helprelieve any prominent allergic symptoms. Learning how to managefatigue enables people with CFS to improvetheir level of functioning and quality oflife despite their symptoms. A rehabilitationmedicine specialist can evaluate individualsand teach them how to plan activities to takeadvantage of times when they usually feelbetter. The lack of any proveneffective treatment can be frustrating toboth patients and their physicians. Expertsrecommend that people with CFS try tomaintain good health by eating a balanceddiet and getting adequate rest. Physicalconditioning should be preserved byexercising regularly but without causing morefatigue. It is important that people with CFSlearn to pace themselves--physically,emotionally, and intellectually--since toomuch stress can aggravate symptoms. The course of CFSvaries from patient to patient. For mostpeople, CFS symptoms plateau early in thecourse of the illness and thereafter wax andwane. Some people get better but notcompletely. Others spontaneously recover.Emotional support and counseling can helppatients and their loved ones cope with theuncertain prognosis and ups and downs of theillness.
Several differentroutes to chronic fatigue syndrome may exist.In some people, a persistent viral infectionmay provoke CFS symptoms, and virologistscontinue to explore this possibility.Vulnerability to CFS may be associated with asubtle immune system defect. It also appearslikely, however, that CFS involvesinteractions between the immune and centralnervous systems, interactions about whichrelatively little is now known. Scientists'concerted efforts to penetrate the complexneuroimmunologic events in CFS have created achallenging new concept of the pathology ofthis and other illnesses.
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