Single-fiber electromyography can be used to electrically stimulate single muscle fibers to determine if there is muscle weakness present. The diagnosis of MG can also be confirmed with blood work that measures the amount of blocking antibody present, but only 70% of ocular MG patients have detectable antibody levels. Additional lab and image tests for commonly associated thyroid, thymus and autoimmune diseases are also advisable. Treatment
The prognosis tends to be good for patients with MG. It is often best not to treat mild cases of MG. Management necessitates avoidance of medications that can worsen neuromuscular transmission, such as aminoglycoside antibiotics, quinolone antibiotics, beta-blockers, chloroquine, anti-arrhythmics, calcium channel blockers, some anticonvulsants and intravenous iodinated contrast should be avoided. MG is characteristically variable in course, with the frequency of diplopia and ptosis affected by environmental, emotional and physical factors such as bright sunlight, stress, viral illness, menstruation, pregnancy, etc. Spontaneous remission can occur in any patient and remain for years. In a study of the natural history of generalized MG among 168 patients (with an average follow-up of 12 years), 14% experienced complete remission. Patients with mild-to-moderate ocular myasthenia are usually treated initially with oral anticholinesterase agents, Mestinon (pyridostigmine) being the most commonly employed. There have not been any randomized clinical trials conducted with these agents, and this treatment is often unsuccessful, particularly in resolving diplopia. Immunosuppressive therapy is then started and the agent of choice is usually prednisone. In a small controlled study this drug demonstrated greater efficacy than pyridostigmine.
Radiation proctitis or radiation proctopathy is condition characterized by damage to the rectum after exposure to x-rays or other ionizing radiation as a part of radiation therapy. Radiation proctopathy may occur as acute inflammation called "acute radiation proctitis" (and the related radiation colitis) or with chronic changes characterized by radiation associated vascular ectasiae (RAVE) and chronic radiation proctopathy. Radiation proctitis most commonly occurs after pelvic radiation treatment for cancers such as cervical cancer, prostate cancer, bladder cancer, and rectal cancer. RAVE and chronic radiation proctopathy involves the lower intestine, primarily the sigmoid colon and the rectum, and was previously called chronic radiation proctitis, pelvic radiation disease and radiation enteropathy. Signs and symptoms
Acute radiation proctopathy often causes pelvic pain, diarrhea, urgency, and the urge to defecate despite having an empty colon (tenesmus). Hematochezia and fecal incontinence may occur, but are less common. Chronic radiation damage to the rectum (>3 months) may cause rectal bleeding, incontinence, or a change in bowel habits secondary. Severe cases may lead to with strictures or fistulae formation. Chronic radiation proctopathy can present at a median time of 8-12 months following radiation therapy. Histopathology
Acute radiation proctopathy occurs due to direct damage of the lining (epithelium) of the colon. Rectal biopsies of acute radiation proctopathy show superficial depletion of epithelial cells and acute inflammatory cells located in the lamina propria. By contrast, rectal biopsies of RAVE and chronic radiation proctopathy demonstrates ischemic endarteritis of the submucosal arterioles, submucosal fibrosis, and neovascularization.