Spine trauma

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

Classification

ASIA Classification

Motor Function:

Motor fnx is ✓ at five levels in UE & LE (20 stations) on scale from 0-5. The scale is as follows:

• 0: No movement
• 1: Muscle twitch, but no movement
• 2: Movement, but not against gravity
• 3: Movement against gravity, but not against resistance
• 4: Movement against resistance, but weaker than normal
• 5: Normal strength

The max total score for motor fnx (adding up scores from left & right sides) is 100.

Sensory Function:

Sensory fnx is ✓ for light touch and pinprick (sharp/dull discrimination) in 28 different dermatomes (56 stations), on a scale from 0-2:

• 0: Absent (no sensation)
• 1: Impaired (some sensation)
• 2: Normal (full sensation)

The max total score for each sensory modality (light touch or pinprick, adding up scores from left & right sides) is 112.

Frankel/ASIA impairment scale

Grade	Degree of Impairment	Definition
A	Complete	No sensory or motor function is preserved in sacral segments S4-5.
B	Incomplete	Sensory, but not motor, function is preserved below the neurological level and extends through sacral segments S4-5.
C	Incomplete	Sensory and motor functions are preserved below the neurological level. Most key muscles below the neurological level have a muscle grade of <3.
D	Incomplete	Sensory and motor functions are preserved below the neurological level. Most key muscles below the neurological level have a muscle grade of ≥3.
E	Normal	Sensory and motor functions are normal.