Syringomyelia

(sir-ing-go-mi-ef ’-le-ah) [ovpiy^, tube; /iveAog, marrow]. A condition characterized by the presence of cavities in the substance of the spinal cord. It is believed to be the result of faulty development either affecting the central canal, so that the latter remains in an embryonal condition, and sends a diverticulum into the posterior portion of the cord, which may become constricted off,or groups of embryonal neuroglia cells remain in the neighborhood of the central canal or in the posterior portion of the spinal cord, and in later life take on active development and form a gliomatous tumor. The degeneration of the latter then gives rise s to cavities in the cord. S. occurs usually between the ages of 20 and 30, and is characterized by progre ive atrophy of the muscles, especially of the upper extremity, by lo of the pain-sense and temperature sense, with preservation of the tactile and muscular sense (the so-called ” di ociation symptom”), and by vasomotor and trophic changes in the skin, joints, etc. 614