RESPIRATORY RATE AND PATTERN DISTURBANCES IN ACUTE BRAIN-STEM INFARCTION

Respiratory rates and patterns were studied in 23 patients with acute brain stem infarction using impedance pneumography. Autopsy was obtained in 6 of 8 fatal cases. Pontine lesions were present in all patients, with coexistent infarction of the midbrain in 4 and of the medulla in 9. Respiratory rate and pattern abnormalities observed included Cheyne-Stokes respiration, Cheyne-Stokes variant pattern and tachypnea. Abnormalities of respiratory rate and pattern of varying duration were observed at some time in all patients. All patients in whom prominent Cheyne-Stokes respiration or tachypnea were observed had extensive bilateral pontine lesions involving both basal and tegmental portions. However, not all patients with large pontine infarcts had Cheyne-Stokes respiration or tachypnea. Cheyne-Stokes respiration was prominent in 4 patients (2 fatal, 2 nonfatal). Cheyne-Stokes variant pattern was present frequently in 4 patients (1 fatal, 3 nonfatal). Sustained tachypnea developed in 5 patients, 4 of whom died. In 10 patients (1 fatal, 9 nonfatal), normal respiratory rate and pattern predominated with only rare or occasional appearance of Cheyne-Stokes respiration or Cheyne-Stokes variant pattern, especially during sleep. The types of respiratory rate and pattern abnormalities in acute brain stem infarction were not specifically related to the level of lesions, but rather to the size and bilaterality of the lesions. Respiratory alkalosis was present in varying degrees in most patients with either tachypnea or prominent Cheyne-Stokes respiration.