Neuropathy – sciatic nerve; Sciatic nerve dysfunction
Definition of 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.
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.
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.
Because sciatica is a symptom of another medical condition, the underlying cause should be identified and treated.
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 or sensation. Nerve pain may be severe and persist for a prolonged period of time.
Linda J. Vorvick, MD, Medical Director, MEDEX Northwest Division of Physician Assistant Studies, University of Washington, School of Medicine; and C. Benjamin Ma, MD, Assistant Professor, Chief, Sports Medicine and Shoulder Service, UCSF Dept of Orthopaedic Surgery. Also reviewed by David Zieve, MD, MHA, Medical Director, A.D.A.M., Inc. – 7/10/2009