What is the difference between cord compression injury and spinal cord injury?

Differences Between Cord Compression Injury and Spinal Cord Injury

Cord compression injury is a specific type of spinal cord injury characterized by external pressure on the spinal cord, while spinal cord injury is a broader term encompassing any damage to the spinal cord, including direct trauma, compression, transection, or ischemia. 1

Key Distinctions

Definition and Mechanism

• Spinal Cord Injury (SCI):

  • Broad term for any damage to the spinal cord
  • Can result from direct trauma, vascular events, inflammation, or compression
  • May involve complete or partial transection, contusion, or ischemia 2

• Cord Compression Injury:

  • Specific subtype of SCI where external pressure compresses the spinal cord
  • Pressure can be acute (sudden) or chronic (developing over time)
  • Common causes include fractures, dislocations, herniated discs, hematomas, tumors, and degenerative changes 2, 1

Etiology

• Cord Compression Causes:

  • Traumatic: Fractures, malalignment, epidural hematomas 2
  • Degenerative: Spondylotic myelopathy, ossification of posterior longitudinal ligament 1
  • Neoplastic: Metastatic epidural spinal cord compression (MESCC) 1
  • Vascular: Epidural hematomas 2

• Other SCI Causes (non-compressive):

  • Direct cord transection
  • Contusion without ongoing compression
  • Spinal cord infarction (ischemic injury) 1
  • Penetrating trauma

Clinical Presentation

• Cord Compression:

  • May present with gradual neurological deterioration
  • Often includes localized pain at compression level
  • Can have varying degrees of neurological deficit based on compression severity 1
  • May be reversible if compression is relieved promptly 3

• Other SCI Types:

  • Often present with immediate, severe neurological deficits
  • May not have associated pain
  • Deficits typically correspond to level and completeness of injury 4
  • Primary injury may be irreversible even with prompt intervention

Imaging Findings

• Cord Compression:

  • MRI shows external pressure on the cord with or without signal changes within the cord
  • Measurable parameters include maximal spinal cord compression (MSCC) and extent of cord compression (ECC) 3, 5
  • May show cord swelling adjacent to compression site 3

• Other SCI:

  • MRI may show intramedullary hemorrhage, edema, or transection without external compression
  • Important findings include lesion length and presence of hemorrhage 4

Treatment Approach

• Cord Compression:

  • Primary goal is decompression to relieve pressure on the cord
  • Surgical decompression within 24 hours improves outcomes 1
  • May involve removing bone fragments, herniated discs, tumors, or hematomas 2

• Other SCI:

  • Focus on preventing secondary injury (neuroprotection)
  • Surgical stabilization may be needed without decompression
  • Management of systemic complications 1

Prognosis

• Cord Compression:

  • Better potential for recovery if compression is relieved promptly
  • Degree of recovery related to compression severity and duration 3, 5
  • Baseline measures of cord swelling predict neurological recovery 3

• Other SCI:

  • Prognosis heavily dependent on initial injury completeness 4
  • Complete injuries have limited recovery potential
  • Recovery plateau typically reached by 12-18 months post-injury 4

Clinical Implications

Diagnostic Approach

• For Suspected Cord Compression:

  • MRI is the gold standard for evaluation 1
  • CT is excellent for identifying fractures but limited in detecting cord injury 2
  • MRI should be performed emergently when compression is suspected 1

• For All SCI:

  • Complete neurological examination to determine level and completeness
  • MRI to characterize injury type, extent, and presence of compression 2

Treatment Priorities

• For Cord Compression:

  • Immediate corticosteroids upon clinical suspicion 1
  • Early surgical decompression (within 24 hours) for optimal outcomes 1
  • Type of decompression depends on location and cause of compression

• For All SCI:

  • Spinal immobilization to prevent further injury
  • Management of systemic complications
  • Rehabilitation focused on maximizing functional recovery

Animal Models and Research

Animal models of compression SCI often use methods like clip compression, balloon compression, or weight drop to simulate clinical scenarios 6. These models help researchers understand the pathophysiology and potential treatments for compression injuries, though they may not fully represent the complexity of human injuries.

Common Pitfalls in Management

• Failing to recognize cord compression as a surgical emergency requiring prompt intervention
• Overlooking compression in patients with minimal or subtle neurological deficits
• Not considering the entire spine when evaluating for compression, as multiple levels may be affected
• Delaying MRI in patients with suspected compression, which can worsen outcomes
• Focusing only on bony injury without adequate assessment of soft tissue and cord status