Introduction

Pain and/or paresthesias in the distribution of the sciatic nerve or an associated lumbosacral nerve root.

• Sciatica is a symptom of an underlying condition and not a disease itself

Aetiology

Spinal causes:

• Herniated lumbar disc with nerve root compression (M/C cause overall, 90% cases)
  • Poor posture, trauma, strong rotational movement
• Lumbar spinal stenosis (elderly)
  • Narrowing of spinal canal (intravertebral foramen)
  • Due to:
    • Degenerative bone disorders
    • Trauma
    • Autoinflammatory conditions (rheumatoid arthritis, etc)
• Spondylolisthesis
  • Relative misalignment of one vertebra relative to another
• Lumbar/pelvic muscular spasm and/or inflammation (may impinge a lumbar or sacral nerve)
• Spinal/paraspinal mass (cause mass effect and sciatica symptoms):
  • Malignancy
  • Epidural hematoma
  • Epidural abscess

Non-spinal causes:

• Piriformis syndrome (M/C non-spinal cause)
  • Muscle inflammation/spasms causing sciatic nerve compression
• Wallet sciatica (Credit-carditis)
  • Wallets in pockets → Pressure on gluteus muscles → Pressure on sciatic nerve
• Pregnancy (vertex presses on sciatic nerve)
• Trauma to leg
• Pelvic tumours

Risk factors:

• Personal factors:
  • Age (peak 45-64 years)
  • Increasing risk with height
  • Smoking
  • Mental stress
• Occupational factors:
  • Strenuous physical activity (frequent lifting, especially while bending and twisting)
  • Driving (including vibration of whole body)

Pathoanatomy

Clinical features

• Aching and sharp leg pain following dermatomal pattern

  • Unilateral leg pain greater than low back pain

  • Pain radiating to foot/toes

  • Numbness and paraesthesia in the same distribution

  • Straight leg raising test induces more leg pain

  • Localised neurology (limited to one nerve root)

• Low backache (less severe than leg pain)

Diagnosis

Imaging

MRI:

Differential diagnosis

• Herniated lumbosacral disc
• Muscle spasm
• Nerve root impingement
• Epidural abscess
• Epidural hematoma
• Tumour
• Potts Disease (spinal tuberculosis)
• Piriformis syndrome

Management

Pain resolves on its own over time.

Lifestyle changes:

• Hot/cold formentation
• Avoidance of inciting activities or prolonged sitting/standing
• Practicing good, erect posture
• Use of proper lifting techniques
• Regular light exercises such as walking, swimming, or aquatherapy

Physiotherapy:

• Core strength exercises
• Gentle stretching of the lumbar spine and hamstrings

Medical management:

• Oral NSAIDs
• Opioid and nonopioid analgesics (if NSAIDs do not work)
• Muscle relaxants