Hypertensive cerebral hemorrhage. Demonstration of the source of bleeding.

Abstract

There have been many studies of hypertensive cerebral hemorrhage and the associated microvascular abnormalities. The actual primary site of bleeding has probably never been identified. In the present study, a 2- × l-cm hypertensive thalamic hemorrhage was studied in its entirety using continuous 8-μm-thick serial sections and stained with Mallory's phosphotungstic acid hematoxylin stain. The site of bleeding was focal rupture of a thin-walled elongated aneurysmal dilatation of a small artery normally 180 μm in diameter. The dilatation was 5-mm long and 600 μm in diameter. At the proximal end of the dilatation, the feeding artery showed a typical hypertensive lipohyalinotic lesion. There was only 1 site of bleeding. It was concluded that the aneurysmal dilatation was a preformed intracerebral saccular aneurysm of unusual shape and size. Rupture occurred during the period of hypertension induced by the infusion of pitressin. The presence of the lipohyalinotic lesion is considered a coincidence. This is probably the first demonstration of the primary site of arterial rupture in a hypertensive hemorrhage. The source of bleeding in hypertensive intracerebral hemorrhage has been studied over the years by many pathologists beginning with Charcot and Bouchard in 1868 (1). The most thorough investigations were by Matuoka in 1939 and 1952 (2, 3). It is probably correct to say, however, that despite the many studies of hypertensive brain hemorrhage, the actual primary site of bleeding has never been demonstrated. One of the main obstacles is the blood clot itself, which when fixed in formalin preparatory to making microscopic studies, becomes hardened to a degree that precludes a methodical microscopic study of the artery or arteries suspected of harboring the bleeding site. Another complicating factor is the development of secondary hemorrhages, “bleeding globes,” as a result of the mass effect of the main hemorrhage stretching and disrupting the surrounding …