Acute Changes in Blood Pressure Following Vascular Diseases in the Brain Stem

The relationship of the type of acute change in blood pressure to the site of the brain lesion, following cerebral hemorrhage and infarction, were studied in 108 patients in whom autopsy was performed. No significant changes in blood pressure were observed in cases with lesions localized rostra] to the midbrain and in the medulla oblongata. The pressor response characteristic in primary pontine lesions, either hemorrhage or infarction, also was demonstrated in the cerebral hemorrhage with fourth ventricular and pontine extension. Blood pressure elevation was more marked with tegmental pontine lesions than when the lesion was in the basilar pons. Extension of the lesion into neighboring portions of the pons did not cause further change in blood pressure. The present results seem to suggest a positive role of the caudal brain stem, especially the pons, in the blood pressure elevation following the cerebrovascular accidents.