SCIWORA Syndrome (Spinal Cord Injury without Radiologic Abnormality)

Basics

Also called spinal cord injury without radiographic evidence of trauma (SCIWORET), spinal cord injury without CT evidence of trauma (SCIWOCTET), or spinal cord injury without neuroimaging abnormality (SCIWONA)

Description

  • SCIWORA occurs after trauma; it is an acute spinal cord injury (SCI) and nerve root trauma resulting in transient or permanent sensory, motor, or combined sensorimotor deficits.
  • Neural injuries occur without a fracture or misalignment visible on imaging (x-ray, CT).
  • SCIWORA has a broad presentation, from minor neurologic symptoms to complete quadriplegia.

Epidemiology

Incidence

  • Variable: reported to be 19–34% of pediatric SCIs (1)
  • Occurs in all populations—90% in pediatric patients (1)
  • Bimodal: affects children <8 years old and adults >60 years old; rarely occurs between 16 and 36 years (2)
  • There is no association between Chiari malformation type 1 and SCIWORA.

Etiology and Pathophysiology

  • Trauma (3)
    • Motor vehicle collision (MVC) (most common cause); either unrestrained passengers, pedestrians, or bicyclists struck by motor vehicles
    • Sports-related injury
    • Significant fall
    • Child abuse
  • Mechanism
    • Traumatic neural (edema, hematomyelia, cord disruption) and extraneural (disc injury or ligament disruption) injury occurs after (2,4):
      • Hyperextension
      • Hyperflexion
      • Longitudinal distraction
      • Ischemic damage
      • Secondary injury from inflammatory response to tissue damage
  • Age: Pediatric patients have a higher incidence of SCIWORA than adults due to anatomic differences and increased mobility and flexibility (1,5).
    • Horizontally oriented facet joints permit more translational motion in the coronal (AP) plane.
    • Anterior wedging of vertebral bodies
    • Ligament and joint capsule elasticity permits increased intersegmental movement and disc protrusion.
    • In patients age <8 years, head size-to-trunk ratio is disproportionately large.
    • Weaker nuchal musculature
    • Uncovertebral joints are absent.
    • Pseudosubluxation of C2–C3
  • Location
    • Cervical: upper > lower
    • Thoracic: protected and splinted by ribs preventing forced flexion and extension
    • Lumbar: rare and usually fatal (1)

Risk Factors

  • History of trauma
  • Age <8 years
  • Male: female
    • Adult; 4.5:1 (3), children; 2:1 (3)
  • Improper seatbelt wear

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