SCIATICA

Sciatica

Sciatica refers to pain, weakness, numbness, or tingling in the leg. It is caused by injury to or compression of the sciatic nerve. Sciatica is a symptom of another medical problem, not a medical condition on its own.

Causes, incidence, and risk factors

Sciatica occurs when there is pressure or damage to the sciatic nerve. This nerve starts in the spine and runs down the back of each leg. This nerve controls the muscles of the back of the knee and lower leg and provides sensation to the back of the thigh, part of the lower leg, and the sole of the foot.

Common causes of sciatica include:

  • Piriformis syndrome (a pain disorder involving the narrow piriformis muscle in the buttocks)
  • Slipped disk
  • Degenerative disk disease
  • Spinal stenosis
  • Pelvic injury or fracture
  • Tumors

Symptoms

Sciatica pain can vary widely. It may feel like a mild tingling, dull ache, or a burning sensation. In some cases, the pain is severe enough to make a person unable to move.

The pain most often occurs on one side. Some people have sharp pain in one part of the leg or hip and numbness in other parts. The sensations may also be felt on the back of the calf or on the sole of the foot. The affected leg may feel weak.

The pain often starts slowly. Sciatica pain may get worse:

  • After standing or sitting
  • At night
  • When sneezing, coughing, or laughing
  • When bending backwards or walking more than a few yards, especially if caused by spinal stenosis

Signs and tests

Sciatica might be revealed by a neuromuscular examination of the legs by a physician. There may be weakness of knee bending or foot movement, or difficulty bending the foot inward or down. Reflexes may be abnormal, with weak or absent ankle-jerk reflex. Pain down the leg can be reproduced by lifting the leg straight up off the examining table.

Tests are guided by the suspected cause of the dysfunction, as suggested by the history, symptoms, and pattern of symptom development. They may include various blood tests, x-rays, MRIs, or other tests and procedures.

Expectations (prognosis)

If the cause of the sciatic nerve dysfunction can be identified and successfully treated, full recovery is possible. The extent of disability varies from no disability to partial or complete loss of movement or sensation. Nerve pain may be severe and persist for a prolonged period of time.

Complications

  • Partial or complete loss of leg movement
  • Partial or complete loss of sensation in the leg
  • Recurrent or unnoticed injury to the leg
  • Side effects of medications
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