Summary of the temporal pattern of blood–brain barrier (BBB) disruption after spinal cord injury, relative to the expression of MMPs. Note the prominent leakage that occurs immediately after the injury, which likely reflects direct damage to the neurovascular unit (NVU). This is followed by a second phase of permeability, which peaks by about 2–3 d postinjury, with a reduction in permeability thereafter, corresponding to the angiogenic phase. The mechanism(s) driving extended permeability beyond about a month has yet to be identified