Chronic Fatigue Syndrome• Chronic fatigue syndrome (CFS) (referred to as myalgic encephalomyelitis in the United Kingdom and Canada) is characterized by 6 months or more of severe, debilitating fatigue, often accompanied by myalgia, headaches, pharyngitis, low-grade fever, cognitive complaints, gastrointestinal symptoms, and tender lymph nodes.
Infectious etiology?????• The search continues for an infectious cause of chronic fatigue because of the high percentage of patients who report abrupt onset after a severe flu-like illness.
ICD-10• The disorder is classified in the 10th revision of International Statistical Classification of Diseases and Related Health Problems (ICD- 10) as an ill-defined condition of unknown etiology under the heading “Malaise and Fatigue” and is subdivided into asthenia and unspecified disability.
Epidemiology• Incidence- 0.007 percent to 2.8 percent in the general adult population.• The illness is observed primarily in young adults (ages 20 to 40).• Women are at least twice as likely as men to be affected.• The symptoms often coexist with other illnesses, such as fibromyalgia, irritable bowel syndrome, and temporomandibular joint disorder.
Etiology• The cause is unknown.• Viral infection- Ebstein-Barr virus implicated- not conclusive.• Reports have shown of disruption in the hypothalamic-pituitary-axis (HPA) with mild hypocortisolism.• Chronic fatigue syndrome may be familial. In one study, the correlation within twin pairs for monozygotic twins was more than 2.5 times greater than the correlation for dizygotic twins. Further studies are needed, however.
Diagnosis and Clinical Features• Because chronic fatigue syndrome has no pathognomonic features, diagnosis is difficult. • Although chronic fatigue is the most common complaint, most patients have many other symptoms.• The physical examination is also an unreliable source of diagnostic certainty. Some patients had neurally mediated hypotension. Hence tilt-table test should be done.
Differential Diagnosis• Chronic fatigue must be differentiated from endocrine disorders (e.g., hypothyroidism), neurological disorders (e.g., multiple sclerosis [MS]), infectious disorders (e.g., acquired immune deficiency syndrome [AIDS], infectious mononucleosis), and psychiatric disorders (e.g., depressive disorders).• Up to 80 percent of patients with chronic fatigue syndrome meet the diagnostic criteria for major depression.
Course and Prognosis• Spontaneous recovery is rare in patients with chronic fatigue syndrome, but improvement does occur. • Patients with the best prognosis have had no previous or concurrent psychiatric illness, are able to maintain social contacts, and continue to work, even at reduced levels.
Treatment• It is mainly supportive.• A few patients have shown a lessening of fatigue with the antiviral drug amantadine (Symmetrel).• Symptomatic treatment (e.g., analgesics for arthralgias and muscular pain).• Several studies have reported a positive effect from graded exercise therapy (GET).
When does psychiatric treatment comes in?• Patients must be encouraged to continue their daily activities and to resist their fatigue as much as possible. A reduced workload is far better than absence from work.• Psychiatric treatment is desirable, especially when depression is present.• Cognitive-behavioral therapy is especially useful.
Pharmacology• Pharmacological agents, especially antidepressants with nonsedating qualities, such as bupropion (Wellbutrin), may be helpful. Nefazodone (Serzone) was reported to decrease pain and improve sleep and memory in some patients.• Analeptics (e.g., amphetamine or methylphenidate [Ritalin]) may help reduce fatigue.
Neurasthenia• Also called “nervous exhaustion”.• Introduced in the 1860s by the American neuropsychiatrist George Miller Beard, who applied it to a condition characterized by chronic fatigue and disability.• This disorder is a prime example of cultural differences influencing the classification and manifestations of diseases.
Epidemiology• A World Health Organization (WHO) study found an incidence of about 2 percent, which increased to 6 percent when depressive symptoms were present.
Etiology• According to Beard, the cause of neurasthenia was “nervous exhaustion,” which referred to depletion of the “stored nutrient” in the nerve cell (neuron). This depletion resulted from stress, such as overwork.• Freud agreed with Beard that stress was involved, but Freud thought that neurasthenia was produced by a disturbance in sexual functioning (one of the neuroses), specifically the inadequate discharge of sexual energy that occurred when masturbation replaced normal intercourse.
Differential Diagnosis• Neurasthenia must be distinguished from anxiety disorders, depressive disorder, and the somatoform disorders.• Hallmarks of neurasthenia are a patients emphasis on fatigability and weakness and concern about lowered mental and physical efficiency (in contrast to the somatoform disorders, in which bodily complaints and preoccupation with physical disease dominate the picture).• Chronic fatigue syndrome must also be considered.
Course and Prognosis• Untreated, the disorder is usually chronic, and patients may become incapacitated by one or more symptoms so that all areas of functioning become impaired.• With treatment, the prognosis should be favorable; but the long-term prognosis is unknown.
Treatment• The key concept in the current treatment of neurasthenia is clinicians understanding that a patients symptoms are not imaginary.• Medical workup should be done.• Reassurance that medications (analgesics, laxative, etc) + Psychotherapeutic intervantion will be useful.• Identification of stressors and coping mechanisms.
Psychopharmacological Agents• Serotonergic agents (e.g., fluoxetine)• Other antidepressants- nefazodone and mirtazapine (Remeron)• Benzodiazepines• Similarly, small doses of analeptics, such as amphetamine or methylphenidate, may help to treat chronic fatigue and anhedonia.