Evaluation and Management of Spinal Cord Injury

Cervical 50%

Thoracic 35%

Lumbar 11%

Trauma accounts for more than 90% of spinal cord injuries.

Causes include:

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  motor vehicle collision (MVC).

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  fall.

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  sports injuries.

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  penetrating injuries.

Primary injury (immediate)

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  Spinal cord transection from:

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    fracture.

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    dislocation.

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    penetrating injury.

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  Spinal cord compression from:

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    epidural hematoma (EDH).

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    acute disc herniation.

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  Spinal cord infarction

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    Injury to spinal artery

Secondary injury

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  Acute phase (<48 hours)—multiple factors, including:

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    direct cellular damage.

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    hypotension.

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    hypoxia.

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    ischemia.

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    cellular edema, inflammation, and cell necrosis due to:

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      calcium influx: free calcium-dependent excitotoxicity.

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      glutamate excitotoxicity.

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      ionic imbalance.

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      ATP depletion.

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      proinflammatory cytokine release by neutrophils and lymphocytes.

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      free radical formation.

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      lipid peroxidation.

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  Subacute phase (<14 days)—mechanism includes:

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    apoptosis.

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    demyelination of surviving axons.

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    Wallerian degeneration.

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    axonal dieback.

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    matrix remodeling.

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    evolution of a glial scar around the injury site.

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  Chronic phase (6 months)

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    Formation of a cystic cavity

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    Progressive axonal dieback

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    Maturation of the glial scar

The vertebral column consists of 7 cervical vertebrae, 12 thoracic vertebrae, 5 lumbar vertebrae, 5 fused sacral vertebrae, and a variable number (3–5) of coccygeal vertebrae.

The spinal cord originates at the lower end of the medulla oblongata at the foramen magnum and ends near the L1-L2 bony level as the conus medullaris.

The cauda equina starts below the level of the conus medullaris.

The anterior spinal artery from the vertebral artery supplies the entire length of the anterior two-thirds of the spinal cord.

Two posterior spinal arteries from the vertebral artery supply the entire length of the posterior one-third of the spinal cord.

Segmental arteries to the spinal cord directly from the aorta.

Artery of Adamkiewicz

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  Branches from left posterior intercostal artery between T8-L1

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  Enters the spinal canal in the lower thoracic region but sends branches as far cephalad as T4

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  Much of the midthoracic area is a watershed area of the arterial supply and vulnerable to ischemic injury.