Table 18.1 Nomenclature of bone tumors

Chronic fatigue syndrome

BASIC INFORMATION
There has probably been more controversy over the existence and cause of CFS than any other ‘functional’ syndrome in recent years. This is reflected in its uncertain classification as neurasthenia in the psychiatric classification and myalgic encephalomyelitis (ME) under neurological diseases. There is now good evidence for the independent existence of this syndrome, although the diagnosis is made clinically and by exclusion of other fatiguing disorders. Its prevalence is 0.5% in the UK, but it is found world-wide, while varying in prevalence.
The symptom of abnormal fatigue occurs in 10-20%. It occurs most commonly in women between the ages of 20 and 50 years, particularly in ethnic minority groups in the UK. The cardinal symptom is chronic fatigue made worse by minimal exertion. The fatigue is usually both physical and mental, associated most commonly with poor concentration, impaired registration of memory, alteration in sleep pattern (either insomnia or hypersomnia), and muscular pain. Mood disorders are present in a large minority of patients, and can cause problems in diagnosis because of the large overlap in symptoms. These mood disorders may be secondary, independent (co-morbid), or primary (with a misdiagnosis of CFS).

DEFINITION
Chronic fatigue syndrome (CFS) is characterized by four or more of the following symptoms, present concurrently for at least 5-6 months: Impaired memory or concentration, Sore throat, Tender cervical or axillary, lymph nodes, Muscle pain, Multijoint pain, New headaches, Unrefreshing sleep and Postexertion malaise.

SYNONYMS
Yuppie flu
CFS
Chronic Epstein-Barr syndrome
CLINICAL FEATURES
The clinical manifestations are very nonspecific, variable, and include chronic fatigue, sleep disorders, states of diffuse pain, and fever. The possible causes which are being discussed include chronic infections, immune dysfunctions, muscle diseases, neurobiological dysfunctions, or psychogenic disorders. Various viral diseases (Epstein−Barr virus, cytomegalovirus, enteroviruses), have been ruled out as possible causes.
EPIDEMIOLOGY & DEMOGRAPHICS
PREVALENCE IN USA: 120 to 400 cases/100,000 persons
PREDOMINANT AGE: Young adulthood and middle age
PREDOMINANT SEX: Female > male
PHYSICAL FINDINGS & CLINICAL PRESENTATION
• There are no physical findings specific for CFS.
• The physical examination may be useful to identify fibromyalgia and other rheumatologic conditions that may coexist with CFS.
ETIOLOGY
• The etiology of CFS is unknown.
• Many experts suspect that a viral illness may trigger certain immune responses leading to the various symptoms. Most patients often report the onset of their symptoms with a flulike illness.
• Initial reports indicated a possible role of Epstein-Barr virus, but subsequent studies disproved this theory.
DIAGNOSIS
DIFFERENTIAL DIAGNOSIS
• Psychosocial depression, dysthymia, anxiety-related disorders, and other psychiatric diseases
• Infectious diseases (SBE, Lyme disease, fungal diseases, mononucleosis, HIV, chronic hepatitis B or C, TB, chronic parasitic infections)
• Autoimmune diseases: SLE, myasthenia gravis, multiple sclerosis, thyroiditis, RA
• Endocrine abnormalities: hypothyroidism, hypopituitarism, adrenal insufficiency, Cushing’s syndrome, diabetes mellitus, hyperparathyroidism, pregnancy, reactive hypoglycemia
• Occult malignant disease
• Substance abuse

• Systemic disorders: chronic renal failure, COPD, cardiovascular disease, anemia, electrolyte abnormalities, liver disease
• Other: inadequate rest, sleep apnea, narcolepsy, fibromyalgia, sarcoidosis, medications, toxic agent exposure, Wegener’s granulomatosis
WORKUP
Because CFS is a clinical diagnosis and the symptoms are generally subjective, the history and physical examination are essential for excluding other causes of fatigue. A detailed mental status examination is necessary. Abnormalities should be further evaluated with appropriate psychiatric, psychologic, or neurologic examination.
LABORATORY TESTS
• No specific laboratory tests exist for diagnosing CFS. Initial laboratory tests are useful to exclude other conditions that may mimic or may be associated with CFS.
1. Screening laboratory tests: CBC, ESR, ALT, total protein, albumin, globulin, alkaline phosphatase, calcium, phosphorus, glucose, BUN, creatinine, electrolytes, TSH, and urinalysis are useful.
2. Serologic tests for Epstein-Barr virus, Candida albicans, human herpesvirus 6, and other studies for immune cellular abnormalities are not useful; these tests are expensive and generally not recommended.
• Other tests may be indicated depending on the history and physical examination (e.g., ANA, RF in patients presenting with joint complaints or abnormalities on physical examination, lyme titer in areas where lyme disease is endemic).
IMAGING STUDIES
Generally not recommended unless history and physical examination indicate specific abnormalities (e.g., chest x-ray examination in any patient suspected of TB or sarcoidosis)
TREATMENT
NONPHARMACOLOGIC THERAPY
• Education and counseling help to develop realistic goals and expectations.
• Support groups (see below) are useful.
• Patients should be reassured that the illness is not fatal and that most patients improve over time.
• An initially supervised exercise program to preserve and increase strength is beneficial for most patients and can improve symptoms.
ACUTE GENERAL Rx
Therapy is generally palliative. The following medications may be helpful:
• Antidepressants: The choice of antidepressant varies with the desired side effects. Patients with difficulty sleeping or fibromyalgia-like symptoms may benefit from low-dose tricyclics (doxepin 10 mg hs or amitriptyline 25 mg qhs). When sedation is not desirable, low-dose SSRIs (paroxetine 20 mg qd) often help alleviate fatigue and associated symptoms.
• NSAIDs can be used to relieve muscle and joint pain and headaches.
• Fludrocortisone as monotherapy for neurally mediated hypotension is no more efficacious than placebo.
• Low-dose hydrocortisone therapy provides a few benefits in quality of life; however, it is associated with frequent side effects and is not recommended.
“Alternative” medications (herbs, multivitamins, nutritional supplements) are very popular with many CFS patients but are generally not very helpful.
CHRONIC Rx
Psychiatric referral and treatment are helpful in coping with the disease in the majority of patients.
DISPOSITION
Moderate to complete recovery at 1 year occurs in 20% to 65% of patients with CFS.