Sciatica pain

What is sciatica?

Sciatica is a lower limb pain situated on the path of the L5 or S1 root of the sciatic nerve. It is often associated with low back pain; is called sciatica. Its main cause is the herniated disc, but the lumbar osteoarthritis, trauma ... may be involved.

Sciatica is the name given to the neuralgia of the sciatic nerve. It is pain in the path of the sciatic nerve usually associated with back pain.

The sciatic nerve is a nerve that provides both the sensitivity of a part of the lower member and a portion of its movements, it is sensory and motor. It is the largest and longest nerve in the body.
It has several incipient roots of the spinal cord. Its roots go down into the spinal canal formed by the vertebrae, with other nerve roots to form "ponytail" bathed in cerebrospinal fluid.
The two main roots of the sciatic nerve are:

L5 root out between the fourth and fifth lumbar vertebrae,

S1 root out between the fifth lumbar vertebra and the first sacral vertebra.

How is the back made?

The back is composed :

- vertebrae which are the supporting elements. They are hinged together, which allows the movements of the back;

- discs between the vertebrae that consist of a core surrounded by an annulus fibrosis. They have a        role of shock absorbers;

- a spinal canal through which the spinal cord and nerve roots. Spinal cord stops at the end of the      thoracic spine and therefore, in the spinal canal, there is more than nerve roots;

- ligaments that attach to each other vertebrae;

- of muscles used to maintain or move the different floors of the back;

- of blood vessels and lymph vessels;

- nerve root from bone marrow emerging from either side of the vertebrae.

The signs of sciatica

The most common signs of sciatica are:

a lower back pain with pain in the lower limb variables depending on the affected nerve root.

If the L5 root is affected, the pain is located behind the thigh, on the outside of the knee, on the outer side of the leg, top of the foot and big toe.

If the S1 root is affected, the pain will be located behind the thigh, behind the knee, at the calf, heel, the plant and the outer edge of the foot to the last three toes;

often triggered by stress pain (when the person lifts a weight, for example);

amplified pain when sitting, coughing, sneezing and effort;

numbness and muscle weakness that may occur at certain areas of the leg and foot;

Disorder of sensitivity with presence tingling on these areas;

relief usually felt in the extended positio

Despite the pain, the appearance of the leg is normal (no swelling or discoloration).

Note: the pain of sciatica should not be confused with back pain (LBP), which remains localized in the lower back.

There are more serious, but much rarer sciatica:

the paralyzing sciatica with leg motor deficit (loss of ability to do certain leg movements);

the hyperalgesic sciatica, not relieved by the usual analgesics;

sciatica associated with cauda equina syndrome with involvement of other nerve roots and involving a loss of sensitivity of the perineum, control disorders of the urinary sphincter and / or anal and motor disorders of the lower limbs (paralysis or loss of the force).

The causes of the sciatic

The most common cause of sciatica is a herniated disc (abnormal protrusion of the intervertebral disc). The pain is due to the compression of one of the sciatic nerve roots associated with the inflammation. This phenomenon is called "disco-root conflict L4-L5 or L5-S1" according to the vertebral level reached.

However, the presence of a herniated disc is not always associated with sciatica.

For pregnant women, the cause of sciatica is usually a pinch of the disc. This pinching is due to the weight gain resulting in poor position (tilted torso forward).

Other causes are less frequent, can cause sciatica:

osteoarthritis of the lumbar vertebrae that may be responsible for a narrowing of the spinal canal or slipping of one vertebra over the vertebra below called spondylolisthesis;

trauma to the lumbar region;

infection in an element of the spine;

a tumor on the nerve route (very rare).