Accumulation of oedema fluid in deep white matter after cerebral cold injury.

The distribution of oedema fluid was examined in cats subjected to a cryogenic cortical injury. The lesion was made in the parietal cortex, and the animals were sacrificed 6 hr after the injury. The serum concentration of 125I bovine serum albumin was kept constant over the 6 hr period by a programmed infusion. Autoradiograms were made from the coronal sections through the lesion and were used to quantify densitometrically the regional content of extravasated serum albumin. After autoradiographic exposure, the section was stained with luxol-fast blue (LFB), and the degree of LFB discoloration was quantified. The maximal accumulation of extravasated serum albumin was observed in the deeper white matter under the subcortical white matter and not in the subcortical white matter of the lesion. The degree of oedema indicated by LFB discoloration showed a similar distribution pattern. This indicates that the compliance of the white matter in vasogenic oedema is regionally different. This difference of regional compliance seems to depend on the structural characteristics of each region such as the type of the fibers and the orientation of the fibers.