Pathophysiology

Injury Phase	Time Relative to Primary Injury	Key Processes and Events
Immediate	<2 hours	Primary mechanical injury (severing of axons) Gray matter hemorrhage and ischemia Microglial activation Release of pro-inflammatory factors (IL-1β, TNFα, IL-6)
Early acute	<48 hours	Vasogenic and cytotoxic edema ROS production, lipid peroxidation Glutamate-mediated excitotoxicity Continued hemorrhage, ischemia, and necrosis Neutrophil invasion Peak BSCB permeability Early demyelination (oligodendrocyte death) Neuronal death Axonal swelling Systemic events (systemic shock, spinal shock, hypotension, hypoxia)
Subacute	<14 days	Macrophage infiltration Initiation of astroglial scar (reactive astrogliosis) BSCB repair and resolution of edema
Intermediate	<6 months	Continued formation of glial scar Cyst formation Lesion stabilization
Chronic	>6 months	Prolonged Wallerian degeneration Persistence of spared, demyelinated axons Potential structural and functional plasticity of spared spinal cord tissue

Spine trauma