Neuropathological evaluation of brain damage in a rabbit model of focal cerebral ischaemia

In the present paper we studied different methods for a qualitative and quantitative morphologic assessment of the focal brain damage in rabbits after occlusion of the middle cerebral artery with vaseline microspheres. The study of the early brain ischaemic damage (4 to 12 hours after embolisation) was performed on serial coronal cryostat sections of hemispheres frozen in liquid nitrogen and processed for NADH enzyme-histochemical method. In the ischaemic area the necrotic cells were pale or negative after enzyme-histochemical reaction, but a quantitative assessment of the ischaemic area was approximative. The Evans blue method for the identification of the region of the edema at 24 hours after embolisation showed inconstant results. A reproducible method for a quantitative assessment of the ischaemic area up to the 24th hour after embolisation was proposed by Osborne and utilised in the present experimental conditions. The volumetric assessment of the ischaemic area was obtained after delineation of brain damage areas at 8 preselected coronal levels with a computerized automatic image analyzer and by integration of areas with the distance between each level. In treated animals, the measures of the volume of cerebral infarction were accurate and reproducible, and were suitable for neurophysiologic correlations.