In the development of secondary changes of brain damage caused by injury, tumour and hypoxia of different origin with unconsciousness also the activity of the metalloproteinase matrix (MMP) may participate. Their activation occurs first in the vascular wall which they damage and it may be assumed that MMP potentiate thus secondary changes in the sense of interfering with the haematoencephalic barrier with development of vasogenic cerebral oedema. In the cells of the vascular wall and in glial elements already after two days MMP-2 and MMP-9 activity was proved. While in focal injuries the findings were in particular at the site of contusion foci, in prolonged hypoxia for various reasons these changes were diffuse.

        Key words: metalloproteinase matrix - cerebral hypoxia - secondary cerebral changes