Investigations

The investigation of lumbar disc prolapse should include:

• lumbar MRI:
  • the definitive investigation if the facility is available
    
    
• plain X-rays:
  • of limited benefit in the investigation of lumbar disc disease
  • may reveal loss of a disc space or spondylolisthesis
  • it is more important in excluding other causes, e.g. metastatic bony changes
    
    
• radiculography:
  • may show a filling defect in the theca on an AP or lateral view
  • may show obliteration or displacement of the nerve root sleeve
    
    
• spinal CT:
  • may detect small, laterally-placed protrusions which may be missed on radiculography
  • shows hypertrophied facet joints and the diameter of the spinal cord
    
    
• electromyography:
  • denervation in the muscles supplied by the affected roots may be shown
  • a low specificity test