Biomedical subjects
Publications and source records attributed to A M MacGuire.
Popliteal cysts may be formed by the escape of a synovial effusion into one of the popliteal bursae. There is usually preexisting knee joint pathology. Presenting complaints include pain and swelling in the posterior aspect of the knee. The cyst may dissect into the calf between the muscle planes and produce pressure on draining lymphatics and veins, resulting in lower leg edema. These cysts are often mistakenly treated as deep vein thrombosis.
A patient taking excessive amounts of an ergot alkaloid for the treatment of migraine headaches developed cool, painful, swollen lower extremities with intermittent claudication and sensory changes. Symptoms subsided and pulses returned within a day of cessation of therapy. "St. Anthony's fire" may be due to stimulation of alpha-adrenergic receptors in the peripheral vasculature. Rebound headache after withdrawal of ergot alkaloids may lead to self-medication and overdosage, with subsequent risk of ergotism.