Sciatica is a set of symptoms including pain that may be caused by general compression or irritation of one of five spinal nerve roots that give rise to sciatic nerve or by compression or irritation of the left or right or both sciatic nerves. The pain of sciatica is typically felt from the low back (lumbar area) to behind the thigh and radiating down below the knee. Apart from pain, which is sometimes severe, there may be numbness, muscular weakness, pins and needles or stinging and difficulty in moving and controlling the leg. Normally, the symptoms are only felt on one side of the body.
Sciatica is generally caused by the compression of lumbar nerves L4 or L5 or sacral nerves S1, S2, or S3, or by compression of the sciatic nerve itself. 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.
• SPINAL DISC HERNIATION
One of the possible causes of sciatica is a spinal disc herniation pressing on one of the sciatic nerve roots. A spinal disc herniation (prolapsus disci intervertebralis), informally and misleadingly called a \"slipped disc\", is a medical condition affecting the spine, in which a tear in the outer, fibrous ring (annulus fibrosus) of an intervertebral disc allows the soft, central portion to bulge out.
The spinal discs are composed of a tough spongiform ring of cartilage with a more malleable center. The discs separate the vertebrae, allowing room for the nerve roots to suitably exit through the spaces between the L4, L5, and sacral vertebrae. The discs cushion the spine from compressive forces, but are weak to pressure applied during rotational movements. That is why a person who bends to one side, at a bad angle to pick something up,is more likely herniate a spinal disc than a person jumping from a ladder and landing on his or her feet.
Herniation of a disc occurs when the nucleus pulposis of the disc bulges outwards, breaking the ring of fibers or the annulus fibrosus, forces its way into the spinal canal, and compresses a nerve root against the lamina or pedicle of a vertebra, thus causing sciatica. This may cause inflammation and swelling of surrounding tissue which may cause further compression of the nerve root in the confined space in the spinal canal.
Sciatica can be caused by tumours imposed on the spinal cord or the nerve roots. Severe back pain extending to the hips and feet, loss of bladder or bowel control, or muscle weakness, may result from spinal tumours. Trauma to the spine may also lead to sciatica.
• SPINAL STENOSIS
Compression of spinal cord may cause lumbar spinal stenosis, Lumbar spinal stenosis (LSS) is a medical condition in which the spinal canal narrows and presses the spinal cord and nerves at the level of the lumbar vertebra. This is due to the common occurrence of spinal degeneration that occurs with aging. It can also be caused by spinal disc herniation, osteoporosis or a tumor.
A course of conservative treatment including \"activity modification, medications, physical therapy, home exercise therapy, and spinal injections\" is suggested for the treatment of Spinal Stenosis.
• PIRIFORMIS SYNDROME
In 15% of the total population, the sciatic nerve runs through the piriformis muscle rather than beneath it. Piriformis syndrome is a neuromuscular disorder that occurs when the sciatic nerve is compressed or otherwise irritated by the piriformis muscle causing pain, tingling and numbness in the buttocks and along the path of the sciatic nerve descending down the lower thigh and into the leg.
It has been referred to as \"wallet sciatica\" since a wallet carried in a rear hip pocket will compress the muscles of the buttocks and sciatic nerve when the bearer sits down. Piriformis syndrome may be a cause of sciatica when the nerve root is normal.
Sciatica pain may 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 experience 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 initiates slowly and gradually and 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.
The most applied diagnostic test is the straight leg rising test, or Lasègue's sign, which is considered positive, "if pain in the sciatic distribution is reproduced between 30 and 70 degrees passive flexion of the straight leg.
If no improvement in symptoms has occurred in six weeks or red flags are present, imaging is appropriate. Imaging may include either CT or MRI. MR neurography has been shown to diagnose 95% of severe sciatica patients.
Because sciatica is a set of symptoms of another medical condition, the underlying cause should be identified and treated. In some cases, no treatment is required and recovery occurs on its own.
When the cause of sciatica is due to a prolapsed or lumbar disc herniation 90% of disc prolapses resolve with no interference.
Although medications are commonly prescribed for the treatment of sciatica, there is no good evidence from clinical trials to guide the use of analgesics to relieve pain and disability.
Elective surgery is the main option for unilateral sciatica and focuses on removal of the underlying cause by removing disk herniation and eventually part of the disc. Spinal manipulation is effective for the treatment of acute sciatica, however, only low level evidence was found to support spinal manipulation for the treatment of chronic sciatica.
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.
The Sciatic pain may complicate into
• 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
Prevention varies depending on the cause of the nerve damage. Avoid prolonged sitting or lying with pressure on the back.
Doctor Of Pharmacy
University Of Lahore