Sub-pial infiltration of blood products following experimental subarachnoid haemorrhage.

The authors studied the trans-pial penetration of blood products into the cerebral cortex of cats within the first hour following subarachnoid hemorrhage (SAH). Twenty-two animals were subjected to SAH by cisternal injection of blood, and 13 were used as controls. The brains were fixed in situ and the histological sections were examined under the fluorescence microscope. The cerebral parenchyma of the control animals displayed a homogeneous greenish autofluorescence. In the animals with SAH, the subarachnoid blood showed a yellow autofluorescence that also penetrated into the superficial cortex. The possible clinical implications of the observation are discussed.