What is sciatica?
Sciatica is a type of neuropathic pain that is very common. It is not a disease or a specific diagnosis but is a symptom caused usually by compression of the sciatic nerve by a herniated disk (also known as a slipped disk) or due to spinal stenosis.
The sciatica pain is typically unilateral and radiates along the path of the sciatic nerve. The pain originates in the lower back and radiates across the hips and buttocks and down the leg. At times, it can be so severe so as to make the person immobile.
The pain is sometimes accompanied by numbness, weakness, and tingling, which can be felt on the back of the calf or on the sole of the foot.
Most cases clear up with conservative treatment within a few weeks. However, severe sciatica cases with serious weakness in the leg or bowel or bladder incontinence might need surgery.
It is a very common pain condition with as many as 40 percent of the population experiencing it at some time in their lives.
Causes
Sciatica develops due to compression of the sciatica nerve. This can happen due to various causes. They include:
- Herniated (slipped) disk is the cause of sciatica in 90% of the cases. The intervertebral disc is a cartilage that is present between the vertebrae and acts as a cushion that allows the spine to be flexible.
- Spinal stenosis is a narrowing of the spinal canal in the lower part of your back, creating pressure on the spinal cord and nerve roots, thereby compressing the nerves traveling through the lower back to the legs.
- Degenerative disc disease occurs when the intervertebral disc wears down. This causes the adjacent vertebrae to come closer causing compression of the nerves that come out from between them.
- Spondylolisthesis is a weakness or stress fracture in one of the vertebrae. It causes one of the vertebrae of the vertebral column to slip out of its position onto the vertebra below it. This causes narrowing of the intervertebral space and subsequent compression of the nerves coming out from the spinal cord through intervertebral space.
- Bone spurs, also called osteophytes, are bony overgrowths that can develop on the spine and around. When these bone spurs compress on the sciatica nerve, you develop sciatica symptoms.
- Injury to the spinal cord
Risk factors
Factors that increase your risk of developing sciatica include:
- Advancing age. As you age, certain changes take place in your spine. These are normal changes of aging and can include herniated disks and the formation of bone spurs. If severe, they can compress the spinal nerves and make you more prone to sciatica.
- Obesity. Your spine supports the weight of the body. If you are overweight or obese, the extra weight increases stress on the spine. The spine can sag under the extra pressure and this could push on the sciatic nerve.
- Certain jobs cause stress to the spine. A job that requires you to lift heavy objects repeatedly will weaken the muscles of your back and lead to sciatica. Jobs in this category include port employees, factory workers, porters, movers, and delivery people.
- Prolonged sitting. People who sit for prolonged periods may not use the right posture all the time. This can cause strain on the lower back muscles, which can weaken over time and not be able to hold the vertebrae in their position. The vertebrae can slip from their position and press on the sciatica nerve. People who drive for long periods, couch potatoes who watch TV for long, or those who work on the computers for long hours are susceptible to developing sciatica.
- Sedentary lifestyle. Sedentary behavior (chronic sitting) is probably the most common factor associated with a moderate increase in the risk of lower back pain (LBP) in adults and adolescents. If corrective measures are not taken, LBP leads to sciatica.
- Bad posture practices. Not having proper posture repeatedly when walking and more importantly when sitting, causes strain on your back muscles. Chronic strain can weaken these back muscles, which support and hold the back vertebrae in position. These vertebrae can then slip from their normal position and press on the sciatic nerve causing symptoms of sciatica.
- Uncontrolled diabetes. Diabetes is a known cause of neuropathy, which damages and weakens the nerves of the hands, legs, and feet. This can lead to the sudden onset of sciatica-like pain, numbness, and tingling.
Symptoms
The sciatic nerve is the terminal and largest branch of the sacral plexus formed from both anterior and posterior divisions of the anterior rami of spinal nerves L4 to S3.
It is the largest nerve in our body and starts from just outside the base of the spine at the lumbosacral region. It travels downwards through the top of your gluteus muscles (buttocks) and down the back of your thighs and lower legs (calves). The symptoms will therefore be felt in these areas it innervates.
Symptoms, which are essentially unilateral can include:
Sciatica pain.
Pain in the areas the sciatica nerve innervates is the typical presenting symptom. The type of pain varies in different people. It can be mild or it can be so severe as to make you immobile. It can be dull, sharpshooting, or “burning” type of pain, which can be of sudden onset or may come on gradually.
The sciatica pain originates in the spine and radiates down the back of the leg. Back pain accompanied by leg pain is the main giveaway symptom that suggests you have sciatica. The sciatica pain is usually aggravated with coughing, sneezing, bending, and when straining such as during a bowel evacuation.
Other symptoms can include:
- Tingling sensation in the feet and toes
- Numbness in the leg along the nerve path
- Muscle weakness in the leg or foot
- Altered reflexes
- Urinary and/or bowel incontinence is seen in more severe cases of sciatica
Complications
Most people fully recover from sciatica. However, ignoring your severe or long-standing symptoms is a bad idea.
If left untreated, it can lead to permanent numbness or weakness in your leg. Chronic (long-term) pain is a complication that can bother you for a long time.
If the nerve is seriously damaged, you can develop a foot drop due to chronic muscle weakness. This occurs due to damage to the peroneal nerve, which is a branch of the sciatic nerve. The nerve damage causes numbness in your foot, which makes walking difficult or even impossible.
Sciatica can also potentially cause permanent nerve damage, resulting in a loss of sensory impulses, feelings, and muscular strength in the affected leg.
Sciatica can lead to loss of bowel and/or bladder function.
Diagnosis
A medical history and clinical examination, in most cases, help to diagnose sciatica. The typical presentation of pain of sciatica can almost confirm the presence of sciatica. However, to detect the cause, imaging procedures are the only diagnostic criteria.
The symptoms of mild sciatica do not bother you much and do not last longer than 4-8 weeks. Medical diagnosis procedures are not usually necessary. However, if the pain is severe and persists for more than 4-8 weeks, imaging tests are advised.
Blood tests are rarely used except to rule out diabetes and diabetic neuropathy.
Imaging procedures include anteroposterior, lateral, and oblique X-ray views of the lower back to find out if the patient has:
- Slipped disc. X-rays show a reduction in the height of the disc space or a shift in a vertebra’s position
- Degenerative disc disease. The X-rays will often show a narrowing of the spaces between the two adjacent vertebrae, which indicates the disc has become very thin or has collapsed.
- Spondylolisthesis. X-rays show a crack or stress fracture in the pars interarticularis portion of the fourth or fifth lumbar vertebra.
- Bone spurs. X-rays will show bony growths that develop in the area where a tendon attaches to a bone.
- Any spinal injury. X-rays will show vertebral growths, fractures, or degenerative changes in the spine.
The doctor may order an MRI of the lower back if you have urinary or bowel incontinence. The doctor will also order an MRI if your pain persists even after conservative treatment, lasts longer than 3 months, or recurs repeatedly, or when there is severe muscle weakness.
Home treatments for sciatica
Sciatica of mild or moderate severity often gets better within three months with conservative treatment. This involves non-invasive therapies that you can practice at home.
- Hot or Cold Compress. Spine-health explains how to give these compresses.
- If you are overweight, lose weight
- Take vitamins supplements
- Practice yoga and stretches specifically meant for back muscles.
- Maintain the right posture when sitting and walking.
- Try over-the-counter mild painkillers after consulting your doctor.
- Try weekly massage therapy to relax your back muscles
- Acupuncture to relieve the pain can be useful.
- Meditation will help to relax and handle stress.
- Avoid sitting for long periods.
Medical treatments of sciatica
Sciatica can be acute or chronic. Acute sciatica is of recent onset and last for 4 to 8 weeks. Sciatica that lasts more than 3 months or that goes away and recurs is chronic. Chronic sciatica is a long-standing condition that can cause continuing pain. It is more difficult to treat than acute sciatica, but several remedies offer relief.
Acute sciatica treatments
Most cases of acute sciatica respond well to self-care actions. These include:
- Over-the-counter painkillers such as acetaminophen, aspirin, or NSAIDs (such as ibuprofen, ketoprofen, or naproxen)
- Light-intensity exercises such as walking or light stretching
- Alternate hot or cold compression packs to reduce pain.
Chronic sciatica treatments
Treatment of chronic sciatica usually involves the use of self-care measures along with medical treatment:
- Physical therapy and exercises are typically first-line treatments for relieving sciatica symptoms. These exercises not only help to relieve pain by promoting spine movement but can also help to prevent sciatica symptoms. Exercises and stretches help to alleviate their symptoms, reduce or avoid medications and offer long-term relief during a flare-up.
- Cognitive behavioral therapy (CBT) changes the way people perceive pain. It focuses on reducing pain by modifying sensations, thinking, and nonadaptive behaviors.
- Painkillers
You may require surgery if symptoms have not responded to conservative treatments such as physical therapy, medications, and epidural steroid injections even after a period of 8 to 12 weeks.
Depending on what has caused sciatica, the orthopedic surgeon will go over the risks and benefits of surgery and suggest the best possible option.
Surgical options include:
- Lumbar laminectomy involves surgical removal of the lamina, the back portion of a spinal bone in the lower back, thereby creating more room within the spinal canal.
- Discectomy is the partial or entire surgical removal of the herniated or degenerative disk in the lower spine.