-IBIS-1.5.0-
tx
musculoskeletal system
sciatica
diagnoses

definition and etiology

definition:
A specific entity with many causes. Involves inflammation of the great sciatic nerve and presents as acute or chronic pain down the back of the leg originating in the buttock and extending to the foot.

etiology:
• Pressure can originate in the nerve roots as in discopathy or facet syndrome, or can be caused by the gluteal muscles or piriformis tightening over the nerve.
• Gluteal muscle spasm is often secondary to sacroiliac joint dysfunction (SI dysfunction is in turn secondary to short leg syndrome, sacroiliac sprain, lumbar sprain/strain causing tightening of the entire low back musculature etc.)
• A rule of thumb to use in its investigation is to remember that nerves are usually irritated by pressure or stretch. A common scenario is that the sacroiliac joint becomes subluxated (from many causes) and the gluteus medius muscles gradually spasm to protect the joint which the body perceives as injured. The splinting spasms produce pressure on the sciatic nerve as it exits the pelvis causing irritation. Additionally, in a common anatomical variant, the sciatic nerve may pass through the piriformis muscle, which if in spasm, pressures the nerve.
• Sciatica is rarely a result of frank trauma although stretch of the nerve can result from an injury to the leg, or vertebral trauma.
• Practitioners of Chinese medicine have often noted that sciatica along the lateral thigh is often associated with a history of gallbladder problems since that is the path of the associated acupuncture channel.

signs and symptoms

• burning along the tract of the sciatic nerve, usually in the buttocks and extending downward in the posterior leg
• spasm of the gluteal or piriformis muscles
• burning pain increased by direct pressure to the nerve
• straight leg raise causes worsening of sciatic nerve irritation
• knee may buckle upon loading as long-standing pain causes weakening

course and prognosis

Onset is usually gradual as the nerve becomes inflamed. Treat the cause. Sciatica is rarely a primary diagnosis. (Ice often brings immediate temporary relief.)
Sciatica usually causes splinting spasm of other muscles and may cause favoring of the opposite leg. The practitioner must work to make the person comfortable while seeking the underlying cause.

differential diagnosis

• other nerve irritation in the gluteal region
• short leg syndrome
• cauda equina syndrome
• referred pain from lesion in the pelvis
• spinal segmental lesion
• sacroiliac joint dysfunction
• gluteal strain
• cauda equina syndrome
• discopathy (protrusion or prolapse)
• fracture, infection, or tumor involving the low back or pelvis
• spondylolisthesis: (congenital fracture of the pars interarticularis and forward slippage of the body of the vertebrae)


footnotes