Sciatica is a medical condition characterized by pain going down the leg from the lower back. This pain may go down the back, outside, or front of the leg. Typically, symptoms are only on one side of the body. Certain causes, however, may result in pain on both sides.
Lower back pain is sometimes but not always present. Weakness or numbness may occur in various parts of the affected leg and foot Causes
1- Spinal disc herniation
2- Spinal stenosis
4- Piriformis syndrome
1:- Spinal disc herniation
Spinal disc herniation pressing on one of the lumbar or sacral nerve roots is the most frequent cause of sciatica, being present in about 90% of cases.
Sciatica caused by pressure from a disc herniation and swelling of surrounding tissue can spontaneously subside if the tear in the disc heals and the pulposus extrusion and inflammation cease.
2:- Spinal stenosis
Other compressive spinal causes include lumbar spinal stenosis, a condition in which the spinal canal (the spaces the spinal cord runs through) narrows and compresses the spinal cord, cauda equina, or sciatic nerve roots. This narrowing can be caused by bone spurs,
spondylolisthesis, inflammation, or a herniated disc, which decreases available space for the spinal cord, thus pinching and irritating nerves from the spinal cord that travel to the sciatic nerves.
Sciatica may also occur during pregnancy as a result of the weight of the fetus pressing on the sciatic nerve during sitting or during leg spasms. While most cases do not directly harm the fetus or the mother, indirect harm may come from the numbing effect on the legs, which can cause loss of balance and falls. There is no standard treatment for pregnancy- induced sciatica.
4:- Piriformis syndrome
Piriformis syndrome is a controversial condition that, depending on the analysis, varies from a “very rare” cause to contributing to up to 8% of low back or buttock pain. In 17% of the population, the sciatic nerve runs through the piriformis muscle rather than beneath it. When the muscle shortens or spasms due to trauma or overuse, it is posited that this causes compression of the sciatic nerve.It has colloquially been referred to as “wallet sciatica” since a wallet carried in a rear hip pocket compresses the buttock muscles and sciatic nerve when the bearer sits down. Piriformis syndrome causes sciatica when the nerve root itself remains normal and no herniation of a spinal disc is apparent.
Sciatica can also be caused by tumors impinging 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 tumors or cauda equina syndrome. Trauma to the spine, such as from a car accident, may also lead to sciatica.
Straight Leg test sometimes used to help diagnose a lumbar herniated disc
Sciatica is typically diagnosed by physical examination, and the history of the symptoms.
Generally if a person reports the typical radiating pain in one leg as well as one or more neurological indications of nerve root tension or neurological deficit, sciatica can be diagnosed.
The most applied diagnostic test is the straight leg raise to produce Lasègue’s sign, which is considered positive if pain in the distribution of the sciatic nerve is reproduced with passive flexion of the straight leg between 30 and 70 degrees. While this test is positive in about 90% of people with sciatica, approximately 75% of people with a positive test do not have sciatica.
Imaging tests such as computerised tomography or magnetic resonance imagingcan help with the diagnosis of lumbar disc herniation. The utility of MR neurography in the diagnoses of piriformis syndrome is controversial.
common Sciatica Symptoms Usually, sciatica affects only one side of the lower body and the pain radiates from the lower back to the back of the thigh and down the leg.
See Types of Sciatic Nerve Pain
Some combination of the following symptoms is most common:
Constant pain in only one side of the buttock or leg, but rarely in both sides
Pain that originates in the low back or buttock and continues along the path of the sciatic nerve—down the back of the thigh and into the lower leg and foot
Pain that feels better when patients lie down or are walking, but worsens when standing or sitting Pain typically described as sharp or searing, rather than dull
A “pins-and-needles” sensation, numbness or weakness, or a prickling sensation down the leg in some cases Weakness or numbness when moving the leg or foot
Severe or shooting pain in one leg, making it difficult to stand up or walk
Pain and other symptoms in the toes, depending on where the sciatic nerve is affected Lower back pain that, if experienced at all, is not as severe as leg pain
Symptoms may intensify during sudden movements, such as a sneeze or cough, or when changing positions, such as when moving from a sitting position to standing up.
Sciatica Symptoms for Each Nerve Root
All five nerves bundle together to form the sciatic nerve, and then branch out again within the leg to deliver motor and sensory functions to specific destinations in the leg and foot.There are two nerve roots that exit the lumbar spine (L4 and L5) and three that exit the sacral segment (S1, S2, and S3).
Sciatica symptoms vary based on where the compressed nerve root is located. For example:
L4 nerve root sciatica symptoms usually affect the thigh. Patients may feel weakness in straightening the leg, and may have a diminished knee-jerk reflex.
L5 nerve root sciatica symptoms may extend to the big toe and ankle (called foot drop).
Patients may feel pain or numbness on top of the foot, particularly on the “web” of skin between the big toe and second toe. S1 nerve root sciatica affects the outer part of the foot, which may radiate to the little toe or toes. Patients may experience weakness when raising the heel off the ground or trying to stand on their tiptoes. The ankle-jerk reflex may also be reduced.
Since more than one nerve root may be compressed, patients may experience a combination of the above symptoms.
Sciatica Symptoms Needing Immediate Medical Attention Symptoms that continue to get worse rather than improve, which may indicate possible nerve damage, especially if the progressive symptoms are neurological (such as leg weakness).Rarely, sciatica symptoms that worsen quickly may require immediate surgery. The following symptoms indicate a need for immediate medical care:
Symptoms that occur in both legs (called bilateral sciatica)—or that cause bladder or bowel incontinence or dysfunction or altered sensation in the genital area or “saddle area”—may indicate cauda equina syndrome. Cauda equina syndrome is an acute compression of one or several nerve roots that occurs relatively rarely (in approximately 2% of herniated lumbar disc cases) and can cause paralysis.7
Sciatica that occurs after an accident or trauma, or if it develops in tandem with other troubling symptoms like fever or loss of appetite, is also cause for prompt medical evaluation. Patients should seek medical attention right away if they feel there is cause for concern.