Intracranial haemorrhage induced at arterial pressure in the rat: Part 1: Description of technique, ICP changes and neuropathological findings

Intracranial haemorrhage was produced in the caudate nucleus or the lateral ventricle of Sprague Dawley Rats by connecting a stereotactically inserted cannula to the femoral artery. Two types of lesion resulted from this type of arterial-pressure haemorrhage: Contained intracerebral haemorrhage (ICH) and Uncontained haemorrhage. When the haemorrhage was uncontained, a large and transient rise in intracranial pressure (ICP) (to 65mmHg mean) was accompanied by a fall in cerebral perfusion pressure. By contrast, with contained intracerebral haemorrhage, the rise in ICP was smaller (to 18mmHg mean) and neuropathological evidence of ischaemic brain damage was found in areas surrounding the clot. This observation suggests that with ICH there may be a local reduction in flow in tissue immediately surrounding the haematoma

Intracranial haemorrhage induced at arterial pressure in the rat: Part 2: Short term changes in local cerebral blood flow measured by autoradiography

The regional distribution of blood flow following intracranial haemorrhage at arterial pressure was measured with the 14 C-iodoantipyrine autoradiographic technique in Sprague Dawley Rats. With uncontained haemorrhage, there was a bilateral reduction in cerebral blood flow, associated with a fall in cerebral perfusion pressure. With contained intracerebral haemorrhage there was a profound ipsilateral reduction in flow in the hemisphere adjacent to the haematoma. This study, indicates that extensive cerebral ischaemia occurs immediately after an intracerebral haemorrhage, and that this may be the result of compression of the microcirculation