A distinctive episodic syndrome of headaches. The most common cluster headache pattern, acute cluster headache, is characterized by one to three short attacks of pain each day around the eyes, clustered over a stretch of 1 to 2 months, and followed by a pain-free period that averages 1 year. The other main pattern of cluster headache, chronic or episodic cluster headache, is characterized by the absence of sustained periods of remission, with pain occurring out of the blue or emerging several years after an episodic pattern. Cluster headache is different and distinct from migraine, although the underlying mechanisms are similar. For example, propranolol is effective in treating migraine but not in treating cluster headache, whereas lithium is beneficial for cluster headache but not migraine. Also known as ciliary neuralgia, erythroprosopalgia, histamine cephalgia, migrainous neuralgia, Raeder syndrome, sphenopalatine neuralgia, and vidian neuralgia.
Cigar: A small roll of tobacco leaf for smoking. The word “cigar,” from the Spanish “cigarro,” first appeared in English in 1730. In 1998, a National Cancer Institute report outlined cause-and-effect connections between cigar smoking and disease, including cancer of the mouth and lungs, heart disease and emphysema, and stressed the danger of secondhand cigar […]
CIC: Completely-in-the-canal (the ear canal). See: Completely-in-the-canal hearing aid. See also: Hearing aid.
- Ci (Curie)
Ci (Curie): Ci is the abbreviation for a Curie, a unit of radioactivity. (Specifically, the quantity of any radioactive nuclide in which the number of disintegrations per second is 3.7 X 10 to the 10th). Named for Marie and Pierre Curie who did pioneering research in radioactivity, distinguished alpha, beta, and gamma radiation, discovered polonium […]
CMG2: Capillary morphogenesis gene 2, a transmembrane protein that is induced during capillary morphogenesis (the development of capillaries). Mutations in CMG2 cause infantile systemic hyalinosis and juvenile hyaline fibromatosis.
- CMV (cytomegalovirus)
CMV (cytomegalovirus): A virus that infects 50-85% of adults in the US by age 40 and is also the virus most frequently transmitted to a child before birth. Persons with symptoms have a mononucleosis-like syndrome with prolonged fever and mild hepatitis. Once a person becomes infected, the virus remains alive and usually dormant within that […]