• Clinical science

Complete spinal cord injury


Complete spinal cord injury is the complete sensory and motor loss below the site of spinal cord injury following acute or chronic destruction, compression, or ischemia of the spinal cord. Initially, this may present as spinal shock, which is an acute physiological loss or depression of spinal cord function. It presents as a flaccid areflexic paralysis below the level of the injury with autonomic features (e.g., hypotension and bradycardia). After some days to weeks the spinal shock wears off and a complete spinal cord injury may remain. It presents with spastic paresis, hyperreflexia, and continued sensory loss. Acute stabilization, a thorough neurological examination, and imaging is required for adequate diagnosis. Treatment involves acute care (e.g., analgesia, urinary catheterization) and definitive treatment (bracing or surgery). Symptomatic treatment, assistant devices, and physical therapy can improve mobility and quality of daily life. Less than five percent of cases fully recover after complete spinal cord injury.

Spinal shock

  • Definition: : acute physiological loss or depression of spinal cord function ; (loss of all sensorimotor functions below the level of injury) that lasts several hours to weeks following a spinal cord injury
  • Etiology: Traumatic spinal cord injury
  • Pathophysiology
    • Damaged neurons
    • → loss of intracellular potassium into the extracellular space
    • → hyperpolarized neurons
    • → poor axonal transmission and transient physiologic reflex depression
  • Clinical features
    • Flaccid areflexic paralysis
      • Paraplegia or tetraplegia, if cervical cord is involved (in ∼ 50% of cases in the US)
      • Sensory disturbances: analgesia and anesthesia
      • Areflexia: absence of the proprioceptive and polysynaptic reflexes (e.g., abdominal reflex)
      • Loss of bladder control: urine retention, bladder distention, and dribbling incontinence
      • Loss of bowel control: paralytic ileus
      • Impaired breathing
    • Hypotension and bradycardia
    • Absent bulbocavernosus reflex → incontinence
    • Male patients might develop priapism
    • After 48–72 hours: spasticity, hyperreflexia, and clonus
  • Diagnostics and treatment: see evaluation and diagnosis of spinal cord injury
  • Prognosis
    • Usually reversible, it is difficult to predict the outcome and remaining disabilities in this acute phase.
    • Poor, if transition to complete spinal cord injury occurs
    • Better, if transition to incomplete spinal cord syndrome occurs

If a spinal injury is suspected (trauma to the neck or back), the affected patient should be moved with extreme care to avoid further damage to the spine!


Complete spinal cord injury


  • Complete bilateral loss of sensation or motor function below a spinal cord injury lesion.


  • ∼ 25% of annual spinal cord injuries in the US



  • Acute or chronic spinal cord injury (e.g., fracture, dislocation, or penetrating injury)
  • → destruction (e.g., trauma), compression (e.g., hematoma), or ischemia (e.g., injured spinal arteries) of spinal cord
  • → incomplete or complete spinal cord injury

Clinical features

  • Symptoms of complete spinal cord injury occur 6-8 weeks after spinal shock has worn off.
  • Spared sensory levels above lesion
  • Reduced sensation next to caudal level
  • Bilaterally absent sensory and motor function below the lesion (including lowest sacral segments S4–S5)

Evaluation and diagnosis of spinal cord injuries

  • Stabilize patient
    • ABCDE approach (airway, breathing, circulation, disability, and exposure) in the field
    • Stabilize spine
      • Log-rolling of patient
      • Backboard for transfer
      • Rigid cervical collar
  • Neurological exam:
  • Imaging
    • Complete spinal imaging (cervical, thoracic, lumbar): plain x-rays or CT, if available
      • CT is superior than MRI for imaging fractures of the vertebrae
    • MRI: can provide further information on extent of ligamentous/disc injuries, spinal cord pathology, or epidural hematoma

Management of spinal cord injuries


  • Early mortality: 4–20%
  • < 5% chance of recovery
  • In complete thoracic and lumbar injury, up to ∼ 8% of patients can still walk with the assistance of special devices.
  • Leading causes of death are pneumonia, pulmonary embolism, and suicide.
  • Prevention: Avoid risk-taking behavior (e.g., diving head first into shallow water or drunk diving) and implement safety precautions in high-risk occupations

In acute spinal cord injury (spinal shock), flaccid paralysis and a complete absence of reflexes occur below the injury. A change in symptoms occurs after a period of 6–8 weeks and includes spastic paralysis, recurrence of proprioceptive reflexes as hyperreflexia, and the presence of pathological reflexes (e.g., plantar reflex)!