Breathing patterns were recorded by impedance pneumograph or pneumotachograph and capnograph in 227 patients in a neurosurgical unit; most had recent head injury, intracranial tumor, or ruptured aneurysms. The site of brain damage was determined from clinical investigation or autopsy, and the outcome three months later was classified. Abnormal patterns were recorded at some time in 60% of patients. Periodic breathing, irregular breathing, and tachypnea were equally common. All patients with a lesion in the medulla had abnormal patterns; medullary and pontine lesions were frequently associated with irregular breathing. Only gross irregularity of breathing was of localizing value in these acutely brain damaged patients, by contrast with previous reports of other associations in more chronic neurological disorders. Tachypnea (frequency >25/min) and hyperventilation (arterial carbon dioxide pressure <30 mm Hg) were associated with a poor prognosis when they were combined.
J. Brian North, Sheila Jennett. Abnormal Breathing Patterns Associated With Acute Brain Damage. Arch Neurol. 1974;31(5):338–344. doi:10.1001/archneur.1974.00490410086010