Sciatica

What it is

Sciatica is a clinical syndrome with many causes, and the word is often used to describe the pain of lumbar radiculopathy: the sciatic nerve is irritated or compressed, and the compression is at the root.

Causes and risk

• Disc herniation, the most common cause.
• Spinal stenosis.
• Tumor.

How it presents

The pain is severe and usually unilateral, involving the buttocks, and it is worse when sitting. It goes from the low back to the buttocks and the back of the thigh, with pain and numbness in the affected leg. When the cause is a herniated disc the pain shoots down the leg like lightning with cough and hip flexion. The straight leg raise elicits the pain. Impaired plantar flexion points to L4 and impaired dorsiflexion to L5.