Sciatica refers to a back pain caused due to an irritation with the sciatic nerve, which is a large nerve that originates in the spinal cord in the lower back region and extends down the back of each leg. Sciatica pain is usually felt from the lower back through the thighs to below the knee.
Causes and Risk Factors of Sciatica
The causes of sciatica are:
- Herniated or slipped disc: Injuries or weakness can cause the soft, inner portion of the discs in the vertebrae to protrude through the outer ring. This compresses one of your spinal nerves which causes pain and numbness along the affected nerve.
- Spondylolisthesis: In this condition, one of the lower vertebrae slips forward onto the bone directly below it, which again strains the sciatic nerve.
- Spinal Stenosis: The natural wear and tear of the vertebrae may lead to a narrowing of the spinal canal, which puts pressure on the roots of the sciatic nerve.
- Radiculopathy: This condition is characterized by a pinched nerve in the spine, which occurs due to changes in the adjacent bones and cartilage from the wear and tear, or from injury. This again puts pressure on the roots of the sciatic nerve.
- Spinal Tumours: Sciatica may also be a result of tumours inside the spinal cord or along the sciatic nerve.
- Piriformis Syndrome: This is more common in women. In this condition, a muscle called the piriformis, which runs directly over the sciatic nerve, goes into spasm. This in turn puts pressure on the sciatic nerve.
- Sacroiliitis: This condition describes any inflammation in the sacroiliac joints, where the lower spine connects to the pelvis. It causes pain in the lower back and one or both the legs.
The risk factors for Sciatica are:
- Age: Sciatica usually occurs in people aged between 30 to 50 years.
- Obesity: Excessive weight can strain your spinal cord, which can trigger sciatica.
- Genetics: In some cases, inherited spine abnormalities can also cause sciatica.
- Occupation: Jobs that require lifting heavy loads, twisting the back, sitting for prolonged periods and a sedentary lifestyle are more likely to result in sciatica.
- Diabetes: This affects the way your body uses blood sugar and increases the risk for nerve damage.
Symptoms of Sciatica:
The common symptoms of sciatica include:
- Constant pain, originating in the lower back and along the back of the thigh to the lower leg, mostly In only one side of the body, but rarely in both sides.
- Weakness, difficulty in moving the affected leg, and a feeling of numbness
- Pain that worsens when sitting down or standing, but subsides a bit when lying down or walking
- Sharp pain along the sciatic nerve
- Knee and hip pain
- Difficulty in bowel movement
- Worsening pain when coughing, sneezing, laughing and/or during bowel movement
Diagnosis of Sciatica
In order to diagnose a condition of sciatica, the doctor generally performs physical and neurological exams, and will also conduct some imaging tests. Together, these will provide a complete picture as to the extent and severity of the sciatic nerve pain to the doctor.
Before conducting the physical exam, the spine specialist may ask several questions regarding the current symptoms and to ascertain the basic outline of the condition. These questions may pertain to the location and severity of the pain, its duration, recent activities of the person, any remedies or medications that the patient may have taken, and whether they had any effect on the pain.
During the physical exam, the doctor may observe your current physical condition and range of motion and the curvature and alignment of your spine. In the neurological exam, the doctor will test your reflexes, muscle strength etc.
In order to confirm the diagnosis and ascertain the cause of sciatica, the doctor will perform some imaging tests, including X-rays, MRIs, CT scans etc.
An X-ray may reveal an overgrowth of bone in the spine that may be pressing on the sciatic nerve. Your doctor may order a Magnetic Resonance Imaging (MRI) test if your condition is suspected to have been caused by herniated disc or spinal stenosis. This test will provide detailed and high-clarity images of the bone and tissues in the affected region. An Electromyography (EMG) test can help confirm the compression of the sciatic nerve caused due to a herniated disc or spinal stenosis by measuring the electrical impulses produced by the nerves and the responses of your muscles.
Treatment of Sciatica
Treatment options for sciatica depend on the cause and include addressing the underlying issue and physical therapy. There are some conservative treatment options that patients can use in order to get relief and help regain mobility. These include:
- Strength-building exercises focusing on the core muscles of the body
- Stretching exercises to improve flexibility and relieve the pressure in the lower spine. Stretching the hamstrings, which are muscles located at the back of the thighs, can help loosen them and reduce the stress on the lower back. Walking and other aerobic exercises should also be performed for general body fitness.
- Physical therapy to help regain motion
- Heat packs and cold pads to induce a numbing sensation and reduce inflammation. Usually the heat and ice packs are applied for about 20 minutes and repeated every two hours.
- Non-steroidal, anti-inflammatory drugs such as ibuprofen can reduce the inflammation, which is usually the cause of pain. Other medications include muscle relaxants and anti-depressants, which help by reducing the perception of pain in the brain.
- Cortisone medications, either given orally or in form of epidural injections
Some alternative treatments for sciatica have also been shown to provide effective pain relief
- Chiropractic manipulation: This focuses on providing better spinal column alignment, and is performed by trained and licensed chiropractors and osteopathic physicians.
- Massage Therapy: These have been found to have many benefits such as improved blood supply, muscle relaxation, release of endorphins, which are the body’s natural pain-killers, etc.
- Acupuncture: This focuses on maintaining the well-being through the open flow of energy, by inserting thin needles into the skin near the affected region.
In cases of chronic sciatica, where there is no relief from the pain even after all treatment options have been exhausted, surgery is the final resort. The two main surgical options for sciatica are diskectomy and laminectomy.
- Diskectomy: In this procedure, the goal is to remove whatever is pressing on the sciatic nerve, be it a herniated disc, bone spur etc. The patient is given general anesthesia for this procedure, and will be able to go home on the same day of the operation.
- Laminectomy: During this procedure, the doctor removes the lamina, which is the part of the ring of bone covering the spinal cord. The patient is given general anesthesia before the start of the operation, and is generally released from the hospital on the same day.