Pathomechanism of brain oedema in experimental intracerebral mass haemorrhage.

The prognosis of intracerebral haemorrhage is extremely poor when arterial hypertension is present. We investigated elastance of the brain tissue and brain hydraulic conductivity in normotensive (MAP approximately 110 mmHg) and hypertensive (MAP approximately 170 mmHg/angiotensin infusion) cats following a stereotactically produced intracerebral haemorrhage. For 12 hours after the onset of haemorrhage we registered the course of ICP, subsequently the water content of cortex, white matter and basal ganglia as well as the interstitial concentration of serum proteins in the corresponding regions were determined (Evans-Blue, immunofluorescence). Hypertension was associated with a slight increase in ICP and tissue water content but with a 3 fold more elevated content of interstitial serum proteins. Immunofluorescence analysis showed the oedema in the hypertensive group to be vasogenic in nature and in the normotensive cats to originate from the haematoma itself. The generally poor outcome of intracerebral mass haemorrhage in hypertensive subjects could be ascribed to the nature of the concomitant brain oedema, as described in this study.