Spinal disc herniation

Spinal disc herniation, also called disc extrusion, refers to when the nucleus pulposus extrudes out of the disc through a tear in the annulus fibrosus, which compresses spinal nerves or spinal cord.

Spinal disc protrusion, also called disc prolapse, refers to a similar situation where the intervertebral disc protrudes onto spinal nerves or the spinal cord but the nucleus has not broken through the annulus. The protruding disc may still compress nerves.

Spinal disc sequestration is similar to herniation but part of the nucleus pulposus has torn off and has been left as a fragment.

Compression of spinal nerves or spinal cord can cause sciatica, cauda equina syndrome, or conus medullaris syndrome.

Clinical features

The most common symptom is sciatia (pain in the distribution of one of the below mentioned spinal nerves), but it can also cause loss of muscle function or paraesthesia.

• L4
  • Motor: Tibialis anterior muscle
  • Reflex: Patellar reflex
  • Sensory: Medial part of feet
• L5
  • Motor: Extensor hallucis longus muscle
  • Reflex: Ankle reflex
  • Sensory: Middle part of feet
• S1
  • Motor: Peroneus muscle
  • Reflex: Achilles reflex
  • Sensory: Lateral part of feet

Diagnosis and evaluation

• Physical examination
• Straight leg-raise test (Lasegue test)
• MRI
  • Gold standard

Treatment

• Most cases are self-limiting, healing itself
• Conservative
  • Physiotherapy
  • Local heat
  • NSAIDs
• Herniectomy or discectomy
  • If conservative treatment fails or in case of cauda equina syndrome