WHAT IS SCIATICA PAIN?
Sciatic nerves, the longest nerves in the body, extend from one side of the pelvis through the hip and buttock and right down the leg. Many muscles in the lower legs and parts with a feeling in the thighs, legs and feet are controlled by the sciatic nerves. Sciatica is thus, a sense pain, weakness or tingling in the lower extremities of the body. The origin of sciatica is from the sciatic nerves and that is why the name.
Sciatic nerves run along both legs right up to the feet. They originate from the spinal cord in the lower back and each sciatic nerve branches at the knee into the tibial and peroneal nerves. These nerves run from one side of the pelvis through the hip and buttocks and down the back of the leg. These two nerves control many of the muscles in the lower legs, as well as sensation in parts of the thighs, legs and feet.
Sciatica pain starts from lower and radiates along one or both of the sciatic nerves. Sciatica pain affects the back, buttock or leg(s). General symptoms of sciatica are tingling, numbness or muscle weakness that could be mild initially and progress to severe, excruciating and incapacitating. Sciatica pain is more sever when the patient sits, sneezes or coughs. Sciatica can be of 2 types:
- Unilateral (affecting one side of the lower body).
- Bilateral (affecting both sides).
People between the ages of 30 and 50 are generally affected by sciatica. Most of the patients up to (80 to 90 percent) with sciatica get better after some time and are not required to undergo surgery.
WHAT CAUSES SCIATICA?
Sciatica is caused by a problem somewhere in the lower body creating a compression or injury to the spinal nerve roots merging to form a sciatic nerve. A disc herniated or extending out of the spinal vertebra is the primary cause of sciatica.
Sciatica results from damage to the peripheral nervous system or peripheral neuropathy. Nervous system is central (which consists of the brain and spinal cord or peripheral (nerves outside the central nervous system). Peripheral nerves are the communications network that transmits information between the central nervous system and other parts of the body.
AMEND THE NOTING ON DIAGRAM TO READ
Nerves run throughout the body connecting the brain through the spinal cord to muscles, body parts, skin, blood vessels and organs. Nerve damage to any nerve in any part of the body is called neuropathy.
Central Nervous System- brain and Spinal Cord ( head and neck are )
Peripheral Nervous System – legs and arms nerves.
Some causes of sciatica could be:
- Injury to the buttocks.
- Prolonged external pressure on the nerve.
- Pressure on the nerve from nearby muscular tissue.
- Pressure on the nerve in an area where it passes through a narrowed structure.
- Arthritis in the back.
Inter Vertebral Disc Rupture
Sciatic nerves originate from the lower spine (lumbar) and may be disturbed due to and pressure on the nerve. This compression known as radiculopathy is generally the result of an inter vertebral disc prolapse in the lower spine region.
Other Causes of Sciatica
Some other causes for pressure on the sciatic nerve and sciatica pain could be:
Lumbar Spine Narrowing- One or more areas in the spine canal in the lower lumbar region may be affected by stenosis or narrowing. This narrowing puts pressure on the spinal cord itself or on the roots of the nerves originating from the spinal cord in the area. This pressure initiated irritation of the nerves causes sciatica.
Due to various reasons like age or abuse, a vertebra slips slightly forward over another vertebra. This displacement of the bone creates pressure on the sciatic nerve at the point where it leaves the spine.
The growth of the fetus can create pressure against one or both of the mother’s sciatic nerves causing sciatica.
A muscle known as the piriformis muscle directly above the sciatic nerve. Due to prolonged sitting, an accident and injury from a fall or jump this muscle becomes tight or spasms, putting pressure on the sciatic nerve. Runners and walkers are most often affected by this condition. This is called Piriformis syndrome.
Growth of Tumor in Spine
A tumor-like growth can occur anywhere in the spinal cord region. The tumor can be in the
- Spinal Cord.
- Within the membranes covering the spinal cord.
- In the space between the spinal cord and the vertebrae. These tumors can create undue pressure on the spinal cord itself or the nerve roots.
- Severe back ache.
- Pain in the hip, leg or foot.
- Muscle weakness.
- Loss of sensation.
- Difficulty in walking.
- Loss of bladder or bowel function.
Spinal Injury or Trauma
The lumbar or sacral nerve roots can may suffer injury / trauma leading to sciatica. This trauma could be caused by:
- Accident or fall.
- A blow to the spine.
- Fractures of the pelvis.
- Accidental nerve damage due to injections to the buttocks, surgery or other medical treatments.
- Gunshot wounds.
- Miscellaneous injury or trauma to the buttocks or thighs.
Sciatic nerve tumor or injury
Sciatic nerve itself may be affected by an injury / trauma or a tumor / abnormal growth. These are very rare situations and lead to sciatica.
A blockage in the peripheral arteries may affect the blood supply to the limbs and sciatic nerve and cause sciatic pain.
Arthritis in the backbone may also cause sciatica pain.
Improper posture, seating and anatomical irregularities such as scoliosis- a sideways bending of the spine, may lead to impingement of a sciatic nerve.
Sometime the exact cause of sciatica may be difficult to identify. Any problem of the bones, joints and muscles especially in the lumbar and peripheral region may cause sciatica.
WHAT IS A HERNIATED OR RUPTURED INTERVERTEBRAL DISC?
The inter-vertebral discs in the spine are cartilage pads placed in between each vertebra and act as cushions. The discs contain a jelly like substance covered by a tough fibrous coating. An injury, sickness or ill effects of aging can cause a rupture of the disc. As a result the inner jelly like substance oozes outwards and creates pressure on the nerve. The disc may also be affected when the back gets strained or compressed. Duse to this an inter-vertebral disc may bulge or rupture, depriving the vertebrae of the “shock absorbers” they need. The coating of the disc rupture and the inner jelly-like substance protrudes out into the space containing the spinal cord and nerve root, resulting in pain.
In more serious cases, disc material may compress the bundle of lumbar and sacral nerve roots at the end of the spinal cord, known as the cauda equina. This condition is called cauda equina syndrome, and it may cause permanent neurological damage if left untreated.
This pressure causes excruciating pain in the leg or back. The disc rupture in the lower back may even result in numbness, weakness or tingling in the buttock, leg or foot.
WHAT ARE THE RISK FACTORS FOR SCIATICA?
Sciatica may be attributed to any of the causes but people falling in certain categories are likely to have higher risk of suffering from sciatica. The factors increasing the chances of sciatica pain include:
- OLD AGE
Advancing age is the major cause for adverse effects on the bones. These could result in herniated inter vertebral discs. Such changes occur anytime from the age of as early as 30 years in some people. The risk keeps increasing with age and is most likely in age group of 40-50 years. Spinal stenosis- another leading cause of sciatica- usually occurs in people over 50 years of age.
- OCCUPATIONAL FATIGUE
Occupations where people have to place their body – spine / back- under physical stress continuously for long hours are at increased risk for sciatica. These could be where an individual has to twist his back, carry heavy loads or drive for hours at a time.
- SEDENTARY LIFESTYLE
A sedentary lifestyle results in weakened back muscles, obesity with overload and reduced muscular support to the spine. This can cause spinal injury or herniated discs due to sudden movement. Those involved in jobs requiring sitting for long periods of time or who live sedentary lifestyles with no exercise are more vulnerable to sciatica. Prolonged sitting or lying with pressure on the buttocks is particularly likely to trigger symptoms. In certain case some typically simple forms of exercise, such as walking or jogging, may also increase the risk of sciatica. Before starting any exercise schedule it is always better to consult your doctor. In any case proper warm up is necessary before starting daily exercise.
- HEREDATARY FACTORS
Some genetic conditions are likely to make people more susceptible to sciatica pain as compared to others.
- DIABETES MELLITUS
Diabetes is the leading cause for various diseases including vascular disease and weakening of the bones. Diabetes is also known to cause nerve damage and diabetics are more likely to suffer from sciatica also.
Peripheral neuropathy, another cause of sciatica, can be the result of alcohol overuse / abuse (alcoholism). Uremia (collection of toxic waste in blood due to kidney failure) is also likely to cause sciatica.
WHAT ARE THE SYMPTOMS INDICATIVE OF SCIATICA?
Sciatica pain generally begins in the lower spine and radiates down to the buttocks and into the back of the legs. Sciatica pain may be felt in one or both sides of the lower body. The pain may be like a bad leg cramp, but may be felt at any point along the nerve pathway. Sciatica is likely to follow the following patterns:
- Lower back to the knee
- Middle of the buttock to the outside of the calf, top of the foot and into the space between the last two toes
- Inside the calf to the inner ankle and sole of the foot
Sciatica pain goes from a mild ache to an excruciating sharp and burning sensation. Initially the pain may be mild and may progress over time in to an incapacitating pain. In its most severe state the pain is like an electric shock. Sciatica generally affects just one lower limb and the pain increases when sitting, coughing or sneezing.
Patients of sciatica may also experience following additional symptoms also:
- Numbness and /or weakness of the muscle along the sciatic nerve path in the leg or foot. The pain may be along part of the sciatic nerve and numbness along another part.
The sensation of feeling pins-and-needles or tingling is generally felt in the toes or part of the foot.
- Weakness of limbs
Sciatica may cause weakness of the foot or leg with an inability to move the foot or bend the knee and may also cause difficulty in walking. In its extreme form it may also cause foot drop with advanced damage of the nerve.
Sciatica also may cause loss of bladder or bowel control. This is a rare situation affecting the bundle of nerve roots -cauda equine- at the lower end of the spinal cord and is known as cauda equina syndrome. Cauda equine nerves control the sensations in the pelvic organs and lower limbs. It may also cause numbness or tingling in the groin or genital area. Cauda equine syndrome is a medical emergency and needs immediate medical care.
WHAT TESTS ARE REQUIRED FOR DIAGNOSING SCIATICA?
Sciatica pain generally may not last after the patient has had adequate rest when the symptoms were mild. In case the symptoms do not resolve within a month to six weeks or get worse, you must consult a physician for medical care. Sudden and severe pain and numbness or muscle weakness in the back or leg needs immediate attention. The appearance of other sciatica symptoms especially after an injury, or trouble in controlling bowels or bladder is also a medical emergency needing attention.
The patient will be subjected to a physical examination and past medical history will be recorded to identify specific risk factors. The doctor will pay special attention to the spine and lower limbs and may ask the patient to:
- Rising from a squatting position.
- Walking on toes or heels.
- Lying on the back and raising the legs up, one after the other.
The physical examination helps in assessment of pain. The doctor will ask for some x-ray and other imaging tests to identify the exact cause of sciatic nerve compression or to rule out other potential causes of symptoms. Following tests may be ordered:
Magnetic Resonance Imaging or MRI is one of the best non invasive tests for diagnosing most diseases. By using powerful magnetic and radio waves it produces cross-sectional images of body (back and spine- for sciatica). MRI helps in assessing inter vertebral disc prolapse or any other spinal trauma or presence of tumors.
- CAT scan
CAT scan or computed axial tomography involves recording x-ray images of the spine and back generally after injecting a contrast medium (dye) in to the spinal canal. Detailed cross sectional images are available to diagnose herniated discs, other spinal defects or tumors. The patient sometime is likely to catch an infection or have a reaction to the injected contrast medium.
Normal x-ray films help in diagnosing narrowing of the discs called spinal stenosis or shifting of the vertebra (spondylisthesis) due to old age or any other reason.
- Assessing Nerve Damage / Defects
Specific test using electrodes to check the functioning of the nerves is also undertaken. Electromyography checks for electrical impulses from & to the brain and spinal cord to nerves in the lower limbs.
Diagnosing sciatica may not be conclusive after various tests also and the physician may attempt medication to relieve the symptoms.
WHAT TREATMENT IS AVAILABLE FOR SCIATICA?
Sciatica pain in its mild form can be treated with:
- Over the counter medicines (anti inflammatory drugs).
- Avoiding activities that trigger sciatic pain.
- Cold and heat compresses on the affected area.
- Bed rest especially during a flare up.
In case the symptoms do not get relieved or the pain deteriorates professional medical care may be required. The physician may prescribe any or a combination of following treatment options:
- Cold packs Treatment
Ice wrapped in a towel or a cold pack is used on the affected area. The pack is applied for 15 to 20 minutes duration several times everyday till symptoms last. Ice should never be applied directly on the skin and a gap of at least 15 minutes should be maintained between each session. This treatment is also called Cryotherapy.
- Heat treatment
2 days after using cold packs heat treatment can be given to the area causing pain. Heat treatment or thermotherapy is provided through warm packs, heat lamps or heating pads. Care must be taken to prevent burn injury to the patient undergoing this treatment. The patient can be alternatively given heat and cold treatment for better effects.
- Passive Body Stretching
Doing limited passive stretching exercises is likely to benefit. It is important to prevent any jerks, bounce or twist during this.
- OTC Pain Medications
Easily available over the counter pain killer drugs like aspirin etc can be used. Even analgesic medicines help in reducing pain. Care must be taken to avoid use of steroids.
- Physical Fitness
It is important for everyone to adopt a healthy life style with regular exercise regimen. Endorphins released by the body during exercise help preventing the signals of pain to reach the brain. It also helps in fighting depression and anxiety. Strength training and stretching exercises help in preventing degenerative changes in the body. Regular exercise also helps preventing vascular disease. Consulting a physician before starting an exercise schedule is necessary.
Sciatica pain, in some cases gets aggravated and requires expert medical attention. Treatment in such cases is likely to include:
- Specific Prescription drugs.
Prescription drugs to control inflammation are given in higher dosage as compared to OTC drugs. Additional medication is prescribed to control sciatica pain:
These drugs combined with analgesics are very effective in treating nerve pain like sciatica.
- Tricyclic Antidepressants
These help in relieving pain and getting the patient sleep.
Even after the symptoms have subsided it is necessary to prevent recurrence of the pain. The main aim is to ensure posture correction, back muscle strengthening and improving flexibility. In acute cases occupational therapy may also be provided to help in learning to manage daily chores like bathing and cooking etc.
- Alternative Systems of Medicine
An individual may be advised to undergo acupressure or acupuncture therapy to relieve the sciatica symptoms.
- Steroid Therapy
Cortisone and hydrocortisone, the two anti inflammatory hormones are injected under strict supervision of a physician to treat sciatica. These hormones are used in the form of steroid (corticosteroid) medicine. Because of likely serious side effects, these are used only in very controlled and limited doses and only after other options have been ineffective.
- Pain Management Therapy
Corticosteroid is injected directly in to the sciatic nerve roots to control pain. To avoid possible side effects supervision of a physician is a must.
- Spine Surgery
In case the pain is not relieved by any other treatment and condition deteriorates, spine surgery may be required. Surgery to remove part or whole of the herniated disc may also be in cases where weakness of the limb or any such serious condition is noticed. The inter-vertebral disc or its part that is pressing on the nerve may be removed. Surgery, however, is only a short term solution and over time the pain may reappear due to degenerative changes in the bone structure.
WHAT ARE THE CHANCES OF SCIATICA PAIN SHIFTING TO THE OTHER LIMB ALSO?
Generally the pain will not shift to the other limb and is relieved by resting and use of OTC medicines. In rare cases, when the pain is due to a major spinal cord injury or trauma, the other limb may also be affected.
WHAT STEPS CAN I TAKE TO PREVENT SCIATICA?
Sciatica pain may not be always preventable. Exercises to strengthen the back muscles that support the spine can help. The steps that can be taken to reduce the chances of experiencing sciatica pain are:
- Physical Fitness
Regular exercise help in strengthening the muscles of the back and abdomen. Any weakness of these can cause injury or trauma to the spine during routine daily activities also. Exercise will help in protecting against sciatica.
- Correct posture
Always use a chair that comfortably supports the hips and does not press into the back of the thighs or knees. Use a support (a pillow or rolled towel) to support the natural curve of the lower spine. Height of the chair should be adjusted to allow the feet to rest flat on the floor. A chair with armrests is useful.
The seat in the car should help keep the knees and hips at one level. Adjust the seat to avoid over reaching for the floor pedals.
- Correct Body Movements
Do not stretch your back muscles while lifting weights without bending at the knees. Adopt a correct standing posture and use a firm mattress to sleep on. A sagging bed, very high pillow or bed that puts the back in a curved form during sleep are definitely likely to cause sciatica.