Posted by Alex
Chronic fatigue syndrome (CFS) is characterized by at least 6 months of exceptional fatigue, with several associated chronic symptoms. Chronic diseases that would exclude the diagnosis of CFS include untreated hypothyroidism, sleep apnea, chronic active hepatitis, any psychotic disorder, dementia, anorexia nervosa or bulimia nervosa, recent substance abuse, and severe obesity. Bipolar affective disorder excludes a diagnosis of CFS, but nonpsychotic unipolar major depression or anxiety disorders do not. As so defined, patients with CFS represent a small fraction (1 to 3%) of all patients seeking medical care for the complaint of chronic fatigue.
Patients with CFS may be of any age, of either sex, and from all walks of life; the typical patient is a 35-year-old white woman. The onset is often sudden, frequently after an acute “viral” syndrome. In unusual cases, CFS follows in the wake not of a nondescript “flulike” illness but of a well-defined acute infectious illness, including acute infectious mononucleosis and Lyme disease (despite adequate antibacterial therapy and the resolution of Lyme disease-specific symptoms).
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Posted by Alex
Myasthenia gravis occurs at all ages, sometimes in association with a thymic tumor or thyrotoxicosis, as well as in rheumatoid arthritis and lupus erythematosus. It is commonest in young women with HLA-DR3; if thymoma is associated, older men are more commonly affected.
Onset is usually insidious, but the disorder is sometimes unmasked by a coincidental infection that leads to exacerbation of symptoms. Exacerbations may also occur before the menstrual period and during or shortly after pregnancy. Symptoms are due to a variable degree of block of neuromuscular transmission caused by autoantibodies binding to acetylcholine receptors; these are found in most patients with the disease and have a primary role in reducing the number of functioning acetylcholine receptors. Additionally, cellular immune activity against the receptor is found. Clinically, this leads to weakness; initially powerful movements fatigue readily. The external ocular muscles and certain other cranial muscles, including the masticatory, facial, and pharyngeal muscles, are especially likely to be affected, and the respiratory and limb muscles may also be involved.
Clinical Findings
A. Symptoms and Signs: Patients present with ptosis, diplopia, difficulty in chewing or swallowing, respiratory difficulties, limb weakness, or some combination of these problems. Read the rest of this entry »