Matrix metalloproteinase-9 concentration in the cerebral extracellular fluid of patients during the acute phase of aneurysmal subarachnoid hemorrhage

The pro and mature forms of MMP-9 were released locally in the brain after aSAH. Pro-MMP-9 release was related to WFNS grade severity. This protease, considered as playing a critical role in endothelial basal membrane damage, may contribute to the inflammatory processes leading to arterial narrowing.