Amyotrophic Lateral Sclerosis (ALS) is a debilitating 
neurodegenerative and neurovascular disorder with multi-factorial 
molecular mechanisms of pathology. At the very core of B-CNS
B alterations associated with ALS are the keys to barrier immuno 
penetration by inflammatory cells into the CNS parenchyma, the 
Matrix Metallo Proteinases (MMPs). MMPs are a vastly diverse 
family of endo peptidases that possess a multitude of CNS 
functions, substrates and regulatory mechanisms. This review will 
examine the accumulated evidence describing MMPs and TIMPs 
(Tissue Inhibitors of Metallo Proteinases) and discuss the various 
CNS processes in the neurodegenerative environment that MMPs 
are implicated in including neuro and systemic inflammation, cell damage and apoptosis, as well as interactions with vascular 
growth factors. In conclusion, opposing MMP functions and their 
contribution to B-CNS-B disruption in ALS will be addressed 
with perspective into potential future studies.