What is the treatment for disc protrusion causing compression of the thecal sac and spinal cord?

Treatment for Disc Protrusion Causing Compression of the Thecal Sac and Spinal Cord

Emergency surgical decompression should be performed within 24 hours of neurological deficit onset in patients with disc protrusion causing compression of the thecal sac and spinal cord to improve long-term neurological recovery. 1

Diagnostic Approach

Initial Imaging

1. MRI of the spine (without IV contrast) is the preferred initial study for evaluating thecal sac and spinal cord compression 1

   • Provides superior soft-tissue contrast
   • Accurately depicts soft-tissue pathology
   • Assesses vertebral marrow and spinal canal patency
   • Can identify disc protrusion, extent of compression, and associated edema

2. CT spine without IV contrast can be used if MRI is contraindicated 1

   • 50% thecal sac effacement on CT predicts significant spinal stenosis
   • Less than 50% thecal sac effacement reliably excludes cauda equina impingement

3. CT myelography may be useful for surgical planning when MRI is contraindicated 1

   • Assesses patency of the spinal canal/thecal sac
   • Evaluates subarticular recesses and neural foramen

Clinical Assessment

• Evaluate for neurological deficits:
  • Motor weakness
  • Sensory disturbances
  • Bowel/bladder dysfunction
  • Radicular pain
  • Myelopathic signs (hyperreflexia, spasticity, Babinski sign)

Treatment Algorithm

1. Emergent Management

• Corticosteroids: Administer high-dose dexamethasone if significant neurological deficit is present 1
  • Helps reduce cord edema and inflammation
  • Should be initiated before radiographic confirmation if clinical suspicion is high
  • Can be tapered based on neurological symptoms

2. Surgical Management

• Emergency surgical decompression within 24 hours of neurological deficit onset 1

  • Strongly recommended for improving long-term neurological recovery
  • Particularly important for patients with:
    • Progressive neurological deficits
    • Spinal instability
    • Significant sequestered paraspinal abscess
    • Spinal cord or nerve root compression

• Surgical approach depends on location and characteristics of disc protrusion:

  • For central thoracic disc protrusions: Anterolateral transthoracic approach provides direct access without disturbing the spinal cord 2
  • For lumbar disc protrusions: Open lumbar discectomy for removal of extruded disc material 3
  • For cases with spinal instability: Decompression with fusion may be necessary 1

3. Conservative Management

• Reserved for cases without significant neurological deficits or when surgery is contraindicated
• Components include:
  • Pain management
  • Physical therapy
  • Activity modification
  • External bracing for immobilization 1

Special Considerations

Thoracic Disc Protrusions

• Symptomatic thoracic disc herniations requiring surgery are rare (1-2% of all discectomies) 1
• Often calcified (20-65%) and sometimes intradural (5-10%) 1
• Posterior surgical approach is not suitable due to risk of cord manipulation 2
• Anterolateral approach is preferred for central thoracic disc protrusions 2

Lumbar Disc Protrusions

• More common than thoracic disc protrusions
• May present with cauda equina syndrome requiring urgent intervention 1
• Surgical approach depends on location and extent of protrusion

Follow-up Care

• Regular neurological assessments
• Rehabilitation with physical therapy
• Periodic surgical consultation during the course of medical treatment 1
• Follow-up MRI to assess decompression and recovery

Pitfalls and Caveats

1. Delayed diagnosis and treatment can lead to permanent neurological damage
2. Misinterpretation of imaging findings - CT may underestimate soft tissue compression
3. Inadequate surgical decompression - Incomplete removal of disc material can lead to persistent symptoms
4. Overlooking spinal instability - May require fusion in addition to decompression
5. Steroid complications - High-dose steroids can cause significant side effects including GI bleeding and perforation 1

The evidence strongly supports early surgical intervention for disc protrusion causing compression of the thecal sac and spinal cord, particularly when neurological deficits are present, to maximize chances of neurological recovery and prevent permanent damage.