Sciatica is the name for any kind of pain, mostly in the leg, due to compression or irritation the roots of the sciatic nerve. The sciatic nerve runs from within the pelvis all the way through the buttock and down to the back of the knee where it splits into the tibial and peroneal nerves, making it one of the longest nerves in the body.
Sciatica pain is often used inaccurately to describe pain in the leg for any reason, however sciatica pains are very specific and usually caused by a specific and identifiable problem. Most leg pain is not sciatica pain. Good information can be found at sciatica Emedicine.
Sciatica Pain Symptoms
True sciatica is a form of nerve root irritation, also called radicular (root) pain or irritation. This is a better term to use because similar nerve root irritations can occur in other parts of the body and these cannot be called sciatica. Sciatic pain is found in two main age groups, the younger adult and the older adult. The causes of the problem are different in the two groups.
Sciatica is severe leg pain which goes down the leg in a particular area, usually a clearly defined narrow strip of skin. There is no vagueness about the feeling. It is often sharp, shooting or surging in nature and worse below the knee and in the foot. It can be disabling and severe enough to badly disturb sleep. The sufferer may be forced to lie down as the pain is too severe to stand or sit.
Typical sciatica symptoms include pain in the leg, numbness and tingling, weakness of one of the muscle groups and loss of reflexes, although the last two indicate a more profound effect on the sciatic nerve of the compression and irritation.
How Common is Sciatica?
Sciatica is uncommon, much less common than back pain. In a large study Heliovaara reported the incidence of back pain over a lifetime to be 77% in men and 74% in women (people over 30), leg pain to be 35% and 45% respectively, and true sciatica only 5.3% in men and 3.7% in women. sciatica does occur in pregnancy and is usually due to the same causes as in non-pregnant people - see sciatica pregnancy.
What Causes Sciatica?
The cause of this type of pain is usually put down to ‘nerve trapping’ or more technically, to nerve root compression. However, experiments on nerves have shown that compression does not cause pain activity in a nerve, rather pins and needles and numbness. However sciatica is known to be caused by disc prolapses or bony narrowings, unlike back pain causes which are often unclear.
However, when previously damaged nerve roots are squeezed or pulled, or nerve roots are stimulated electronically, then the normal sciatic type pain is produced. This is the typical sciatica symptom of specific shooting pain in a narrow band which distinguishes this sort of pain from the aching, more vague referred pain which is much more common.
The most common cause of radicular pain is disc herniation, but it is becoming clear that this causes pain by other means than just compression. Some people can have disc herniation causing nerve compression on MRI scanning but do not have any symptoms, while others have recovered from sciatica but still show compression on an MRI scan.
There is some evidence that inflammation has a part to play in this kind of pain. The central goo in the discs, the nucleus pulposus, may cause some form of chemical irritation of the nerve root.
This causes a series of changes: increased blood flow and swelling of the root which causes a block to conduction (messages cannot get through properly). Areas of the nerve can lose their blood supply, and eventually parts of the nerves can become fibrotic, i.e. scarred.
While this explanation does explain why nerve conduction should be affected, i.e. why muscle power and feeling may be altered, it does not explain why the pain occurs. This part of the sciatica puzzle is not yet complete.
The Types of Sciatica
Sciatica can be divided into acute sciatica, the sudden onset severe pain which lasts six weeks or not much longer and chronic sciatica which lasts more than six weeks and often much longer or becomes a long term problem.
Treatment of Sciatica
Most people with sciatica recover without any specific medical treatment. Unlike what is recommended for low back pain, in sciatica treatment there may be a role for up to two weeks bed rest in someone with severe sciatica. As with back pain treatment, initial management is self care and medication with activity reduction.
Rest should only be undertaken if the pain is so severe that being upright or sitting is only possible for very short periods, or activity badly worsens the pain. In these cases forcing oneself to keep going may not help the healing process. Even in these cases the person should still get up and about for short times as able.
There is no evidence that more than two weeks bed rest is helpful and it may become counterproductive if prolonged. Regular medication should be taken as advised by a medical practitioner.
As soon as the pain begins to settle the sufferer should increase the amount of activity he or she is doing by specific planned amounts every day. Pushing to get a job done or spending too long in one position may result in a worsening. Slow steady progress should be aimed for. Recovery may take a long period.
Other sciatica treatments include physiotherapy and the physio will assess you for pain levels, pain distribution, muscle power, feeling in the legs, reflexes and the state of the low back. A sciatica cure is not realistic in the short term and the physio will give advice, exercises for sciatica and perhaps mobilisation techiques to provide pain relief from sciatica. Sciatica stretches may not be recommended as they stretch the sciatic nerve too much and may worsen the pain.
Surgery for Sciatica Relief
If the sciatic pain is exceptionally severe or the sciatica persists for longer than expected then a spinal surgical opinion may be sought. Discectomy or microdiscectomy can be performed to remove the disc prolapse with the minimum tissue and disc damage, with high frequency of good pain relief. Long term studies have indicated that similar results are obtained by having surgery and by not having surgery over two years follow up, so the decision to operate may relate to the severity of the person's pain or if it is affecting muscle power.
The Outlook for Relief of Sciatica
Most episodes of sciatica settle down and the person goes back to normal, with repeat episodes being rare. However, if your pain and disability is very severe, gets worse with time or you have other problems such as unwellness, loss of weight or bladder and bowel symptoms, consult your doctor right away.
Other Nerve Root Pains
Compression and irritation of the nerve roots can occur at any nerve level although it is very much more common in the low lumbar levels. Neck pain and shoulder pain can be due to a cervical nerve root lesion and upper back pain and middle back pain could have nerve root involvement if the pain is very severe and follows the nerve tracks, even mimicking kidney pain in the flanks.