Definition: Sciatica refers to pain radiating along the path of the sciatic nerve, which runs from the lower back through the hips, buttocks, and down each leg. It is typically caused by compression or irritation of the nerve.
Epidemiology: Affects 10–40% of the population during their lifetime, with higher prevalence in middle-aged individuals (40–50 years).
Significance: While most cases resolve with conservative treatment, severe or untreated sciatica can lead to functional disability and poor quality of life.
2. Causes and Risk Factors
Causes:
Herniated disc (most common): Protrusion compressing the sciatic nerve.
Piriformis syndrome: Spasm or tightness of the piriformis muscle irritating the nerve.
Trauma or tumours: Rare causes compressing the nerve.
Risk Factors:
Sedentary lifestyle or prolonged sitting.
Heavy lifting or twisting movements.
Obesity and poor posture.
Age-related degenerative changes.
3. Pathophysiology
Compression or irritation of the sciatic nerve causes inflammation and pain along its distribution. This can result from mechanical pressure (e.g., herniated disc) or chemical irritation from inflammatory mediators.
4. Symptoms and Features
Common Symptoms:
Radiating pain along the back of the leg, often unilateral.
Numbness, tingling, or muscle weakness in the affected leg.
Worsened pain with sitting, bending, or coughing.
Red Flags (urgent evaluation required):
Saddle anaesthesia.
Loss of bowel or bladder control (cauda equina syndrome).
Severe, progressive weakness in the legs.
5. Complications
Chronic pain and disability if untreated.
Muscle weakness and atrophy in severe cases.
Permanent nerve damage in rare instances, particularly with cauda equina syndrome.
6. Diagnosis
Clinical Features: History of radiating leg pain and neurological examination to identify sensory or motor deficits.
Imaging:
MRI or CT scan: For herniated disc, spinal stenosis, or tumours.
X-ray: Useful for detecting spondylolisthesis or degenerative changes.
Electrodiagnostic Studies: Nerve conduction studies to assess the extent of nerve damage.
7. Management Overview
Goals: Relieve pain, reduce inflammation, and restore function.
Approach: Combination of lifestyle modifications, conservative therapies, medications, and advanced interventions for refractory cases.