Cheyne-Stokes respiration (CSR) [John Cheyne; William Stokes, Irish physician, 1804–1878; L, respirare to breathe] , an abnormal pattern of respiration, characterized by alternating periods of apnea and deep, rapid breathing. The respiratory cycle begins with slow, shallow breaths that gradually become abnormally rapid and deep. Breathing gradually becomes slower and shallower and is followed by 10 to 20 seconds of apnea before the cycle is repeated. Each episode may last from 45 seconds to 3 minutes. Underlying CSR is a complex alteration in the functioning of the respiratory center in the brain, caused by dysfunction of the diencephalon or by bilateral hemispheric lesions. The respiratory center may have a reduced sensitivity to the concentrations of blood gases, as is seen in cerebrovascular disease, in tumors of the brainstem, and in severe head injury. CSR may be triggered by changes in blood chemical processes, especially in elderly patients with degenerative arterial disease or respiratory diseases, such as bronchopneumonia. In an otherwise healthy person, CSR may be caused by hyperventilation, exposure to high altitudes, or an overdose of a narcotic or hypnotic drug. CSR occurs more frequently during sleep. Also called agonal respiration, periodic breathing. Compare Biot’s respiration.
