Spinal Cord Injury Notes (Adult II)

Spinal Cord Injury

• caused by trauma or damage to the spinal cord

• can be temporary or permanent

What are the 4 common causes of Spinal Cord Injury?

Motor Vehicle Accidents (MVC’s), Falls, Violence, and Sports Injuries

Spinal Cord Injury occurs in which 2 phases?

• Primary

  • initial physical disruption of the spinal cord

  • direct physical trauma to the spinal cord d/t blunt or penetrating trauma

    •  trauma → spinal cord compression by bone displacement, blood supply disruption, distraction from pulling

    • penetrating trauma → gunshot and stab wounds can cause tearing and transection

• Secondary

  • ongoing progressive damage that occurs after primary injury

  • begins a few mins after injury and lasts for months

  • results in ischemia, hypoxia, hemorrhage, edema, inflammation → cell death (apoptosis), demyelination, disruption of BBB

Edema is a result of the inflammatory response in secondary injury, why might it be harmful?

• limited space for tissue expansion → compression of spinal cord

• extends above and below injury, increasing ischemic damage

• permanent damage may occur w/ in 24 hrs

What is important about apoptosis in secondary injury?

• continues for weeks

• contributes to post-injury demyelination

What does the inflammatory response in secondary injury focus on?

• clearing up the initial cellular debris without damaging normal tissue

• resulting in a central non-neural core of connective tissue (glial scar)

  • restricts the cells in spinal cord from migration and regeneration

  • leading to irreversible nerve damage and permanent neurologic deficit

Spinal Shock

• may occur shortly after acute SCI

• characterized by loss of deep tendon and sphincter reflexes, loss of sensation, and flaccid paralysis below the level of injury

• lasts days to weeks

• masks post-injury neurologic function

Neurogenic Shock

• can occur in cervical or high thoracic injury (T6 or higher)

• occurs when PNS acts alone b/c the SNS isn’t working

• causes peripheral vasodilation, venous pooling, and decreased CO

• Manifestations:

  • hypotension (<90 mmHg), bradycardia, and temperature dysregulation

    • hypotension can lead to poor perfusion and O2 to the spinal cord and worsen spinal cord ischemia

• persists for as long as 5 weeks after injury

How is spinal cord injury classified?

by mechanism of injury, level of injury, and degree of injury

What are the mechanisms of injury?

• flexion, flexion-rotation, hyperextension, vertical compression, extension-rotation, and lateral flexion

  • flexion rotation is most unstable → ligaments that stabilize the spine are torn → severe neurologic deficits

What are the levels of injury?

• may be Cervical (7), thoracic (12), lumbar (5), or sacral (5), coccyx (4)

• tetraplegia and paraplegia

Tetraplegia

• aka quadriplegia

• injury from C1 to T1

• paralysis of all 4 extremities

paraplegia

• paralysis and loss of sensation in the legs

• injury below T2

What are the degrees of injury?

• Complete

  • total loss of sensory and motor function below the level of injury

• Incomplete

  • mixed loss of voluntary motor activity and sensation and leaves some tracts intact

What are the 5 major syndromes associated with incomplete injuries?

central cord syndrome, anterior cord syndrome, Brown-Séquard syndrome, cauda equina syndrome, and conus medullaris syndrome

anterior cord syndrome

• damage to anterior spinal artery

• acute compression of anterior part of spinal cord → compromised BF

• common with flexion injury

• manifestations:

  • motor paralysis and loss of pain/temp sensation below level of injury

  • posterior cord tracts not injured (sensations of touch, position, vibration, and motion remain intact)

Brown-Séquard Syndrome

• damage to half of the spinal cord

• results from penetrating injury to spinal cord (gun shot, stab wound)

• manifestations:

  • contralateral (opposite side of injury): loss of pain/temp sensation below level of injury

  • Ipsilateral (same side as injury): loss of motor function, light touch, pressure, position, and vibratory sense

Cauda Equina Syndrome

• damage to cauda equina (lumbar and sacral nerve roots)

• Manifestations:

  • asymmetric distal weakness, patchy sensation in lower extremities

  • may cause flaccid paralysis of lower extremities

  • complete loss of sensation b/t legs and over buttocks, inner thighs, and back of legs (saddle area)

  • Areflexic (flaccid, loose) bladder and bowel

  • Severe, radicular, asymmetric pain

Central Cord Syndrome

• damage to central spinal cord

• occurs most often in cervical cord region/older adults

• hyperextension injury in people with degenerative disease

• manifestations:

  • motor weakness and altered sensation present in upper extremities

  • lower extremities not usually affected

  • burning pain in upper extremities

Conus Medullaris Syndrome

• damage to lowest part of spinal cord

• motor function in legs may be preserved, weak, or flaccid

• decrease in or loss of sensation in perineal area

• areflexic bowel and bladder

• impotence (inability to erect)

What SCI are associated with the respiratory manifestations of SCI?

• cervical injuries above C3 → total loss of respiratory muscle function

  • these patients have respiratory arrest within minutes of injury if not intubated

• high cervical injury (C3-5) → respiratory insufficiency due to loss of phrenic nerve intervention to the diaphragm and decreased chest and abdominal wall strength

• cervical and thoracic injuries →

  • paralysis of abdominal muscles/intercostal muscles.

  • patient cannot cough effectively to remove secretions → aspiration, atelectasis, and pneumonia

• keep an arterial saturation above 92%

what SCI are associated with the cardiovascular manifestations of SCI?

• any cord injury above T6 → SNS dysfunction

• may result in bradycardia, peripheral vasodilation, and hypotension (neurogenic shock)

  • peripheral vasodilation → Widened blood vessels hold more blood, making circulating volume seem lower (relative hypovolemia) → reduces venous return to heart → decreased CO → hypotension

What SCI’s are associated with the urinary manifestations of SCI?

• occurs in most patients

• neurogenic bladder

  • may have no reflex detrusor contractions (flaccid, hypotonic) → overdistention

  • hyperactive reflex detrusor contractions (spastic) → seen above T12 leading to incontinence

  • lack of coordination b/t detrusor contraction and urethral relaxation (dyssynergia) → reflux of urine into kidneys (could lead to stone formation, hydronephrosis, pyelonephritis, renal failure)