Weak Muscles of Back leads to abnormal increased curvature which causes compression of disk.
A spinal disc herniation (prolapsus disci intervertebralis), informally and misleadingly called a "slipped disc", is a medical condition affecting the spine, in which a tear in the outer, fibrous ring (annulus fibrosus) of an intervertebral disc (discus intervertebralis) allows the soft, central portion (nucleus pulposus) to bulge out. Tears are almost always postero-lateral in nature owing to the presence of the posterior longitudinal ligament in the spinal canal. This tear in the disc ring may result in the release of inflammatory chemical mediators which may directly cause severe pain, even in the absence of nerve root compression .This is the rationale for the use of anti-inflammatory treatments for pain associated with disc herniation, protrusion, bulge, or disc tear.
It is normally a further development of a previously existing disc protrusion, a condition in which the outermost layers of the annulus fibrosus are still intact, but can bulge when the disc is under pressure.
It is possible to have a herniated disc without any pain or noticeable symptoms, depending on its location. If the extruded nucleus pulposus material doesn't press on soft tissues or nerves, it may not cause any symptoms. A small-sample study examining the cervical spine in symptom-free volunteers has found focal disc protrusions in 50% of participants, which shows that a considerable part of the population can have focal herniated discs in their cervical region that do not cause noticeable symptoms.
Typically, symptoms are experienced only on one side of the body. If the prolapse is very large and presses on the spinal cord or the cauda equina in the lumbar region, affection of both sides of the body may occur, often with serious consequences. Compression of the cauda equina can cause permanent nerve damage or paralysis. The nerve damage can result in loss of bowel and bladder control as well as sexual dysfunction.
Herniation of the contents of the disc into the spinal canal often occurs when the anterior side (stomach side) of the disc is compressed while sitting or bending forward, and the contents (nucleus pulposus) get pressed against the tightly stretched and thinned membrane (annulus fibrosis) on the posterior side (back side) of the disc. The combination of membrane thinning from stretching and increased internal pressure (200 to 300 psi) results in the rupture of the confining membrane. The jelly-like contents of the disc then move into the spinal canal, pressing against the spinal nerves, thus producing intense and usually disabling pain and other symptoms.
There is also a strong genetic component. Mutation in genes coding for proteins involved in the regulation of the extracellular matrix, such as MMP2 and THBS2, has been demonstrated to contribute to lumbar disc herniation.
Thoracic
Thoracic discs are very stable and herniations in this region are quite rare. Herniation of the uppermost thoracic discs can mimic cervical disc herniations, while herniation of the other discs can mimic lumbar herniations.
Lumbar
Lumbar disc herniations occur in the lower back, most often between the fourth and fifth lumbar vertebral bodies or between the fifth and the sacrum. Symptoms can affect the lower back, buttocks, thigh, anal/genital region (via the Perineal nerve), and may radiate into the foot and/or toe. The sciatic nerve is the most commonly affected nerve, causing symptoms of sciatica. The femoral nerve can also be affected and cause the patient to experience a numb, tingling feeling throughout one or both legs and even feet or even a burning feeling in the hips and legs.
If pain due to disc herniation, protrusion, bulge, or disc tear is due to chemical radiculitis pain, then prior to surgery it may make sense to try an anti-inflammatory approach. Often this is first attempted with non-steroidal anti-inflammatory medications (NSAIDs), but the long-term use of NSAIDs for patients with persistent back pain is complicated by their possible cardiovascular and gastrointestinal toxicity; and NSAIDs have limited value to intervene in tumor necrosis factor-alpha (TNF)-mediated processes. alternative often employed is the injection of cortisone into the spine adjacent to the suspected pain generator, a technique known as “epidural steroid injection”.Although this technique began more than a decade ago for pain due to disc herniation, the efficacy of epidural steroid injections is now generally thought to be limited to short term pain relief in selected patients only.In addition, epidural steroid injections, in certain settings, may result in serious complications. Fortunately there are now emerging new methods that directly target TNF.These TNF-targeted methods represent a highly promising new approach for patients with chronic severe spinal pain, such as those with failed back surgery syndrome. Ancillary approaches, such as rehabilitation, physical therapy, anti-depressants, and, in particular, graduated exercise programs, may all be useful adjuncts to anti-inflammatory approaches.
A spinal disc herniation (prolapsus disci intervertebralis), informally and misleadingly called a "slipped disc", is a medical condition affecting the spine, in which a tear in the outer, fibrous ring (annulus fibrosus) of an intervertebral disc (discus intervertebralis) allows the soft, central portion (nucleus pulposus) to bulge out. Tears are almost always postero-lateral in nature owing to the presence of the posterior longitudinal ligament in the spinal canal. This tear in the disc ring may result in the release of inflammatory chemical mediators which may directly cause severe pain, even in the absence of nerve root compression .This is the rationale for the use of anti-inflammatory treatments for pain associated with disc herniation, protrusion, bulge, or disc tear.
It is normally a further development of a previously existing disc protrusion, a condition in which the outermost layers of the annulus fibrosus are still intact, but can bulge when the disc is under pressure.
Signs and symptoms
Symptoms of a herniated disc can vary depending on the location of the herniation and the types of soft tissue that become involved. They can range from little or no pain if the disc is the only tissue injured, to severe and unrelenting neck or low back pain that will radiate into the regions served by affected nerve roots that are irritated or impinged by the herniated material. Often, herniated discs are not diagnosed immediately, as the patients come with undefined pains in the thighs, knees, or feet. Other symptoms may include sensory changes such as numbness, tingling, muscular weakness, paralysis, paresthesia, and affection of reflexes. If the herniated disc is in the lumbar region the patient may also experience sciatica due to irritation of one of the nerve roots of the sciatic nerve. Unlike a pulsating pain or pain that comes and goes, which can be caused by muscle spasm, pain from a herniated disc is usually continuous or at least is continuous in a specific position of the body.It is possible to have a herniated disc without any pain or noticeable symptoms, depending on its location. If the extruded nucleus pulposus material doesn't press on soft tissues or nerves, it may not cause any symptoms. A small-sample study examining the cervical spine in symptom-free volunteers has found focal disc protrusions in 50% of participants, which shows that a considerable part of the population can have focal herniated discs in their cervical region that do not cause noticeable symptoms.
Typically, symptoms are experienced only on one side of the body. If the prolapse is very large and presses on the spinal cord or the cauda equina in the lumbar region, affection of both sides of the body may occur, often with serious consequences. Compression of the cauda equina can cause permanent nerve damage or paralysis. The nerve damage can result in loss of bowel and bladder control as well as sexual dysfunction.
Cause
Disc herniations can result from general wear and tear, such as when performing jobs that require constant sitting. However, herniations often result from jobs that require lifting. Traumatic (quick) injury to lumbar discs commonly occurs when lifting while bent at the waist, rather than lifting with the legs while the back is straight. Minor back pain and chronic back tiredness are indicators of general wear and tear that make one susceptible to herniation on the occurrence of a traumatic event, such as bending to pick up a pencil or falling. When the spine is straight, such as in standing or lying down, internal pressure is equalized on all parts of the discs. While sitting or bending to lift, internal pressure on a disc can move from 17 psi (lying down) to over 300 psi (lifting with a rounded back).Herniation of the contents of the disc into the spinal canal often occurs when the anterior side (stomach side) of the disc is compressed while sitting or bending forward, and the contents (nucleus pulposus) get pressed against the tightly stretched and thinned membrane (annulus fibrosis) on the posterior side (back side) of the disc. The combination of membrane thinning from stretching and increased internal pressure (200 to 300 psi) results in the rupture of the confining membrane. The jelly-like contents of the disc then move into the spinal canal, pressing against the spinal nerves, thus producing intense and usually disabling pain and other symptoms.
There is also a strong genetic component. Mutation in genes coding for proteins involved in the regulation of the extracellular matrix, such as MMP2 and THBS2, has been demonstrated to contribute to lumbar disc herniation.
Cervical
Cervical disc herniations occur in the neck, most often between the fifth & sixth (C5/6) and the sixth and seventh (C6/7) cervical vertebral bodies. Symptoms can affect the back of the skull, the neck, shoulder girdle, scapula, shoulder, arm, and hand. The nerves of the cervical plexus and brachial plexus can be affected.Thoracic
Thoracic discs are very stable and herniations in this region are quite rare. Herniation of the uppermost thoracic discs can mimic cervical disc herniations, while herniation of the other discs can mimic lumbar herniations.
Lumbar
Lumbar disc herniations occur in the lower back, most often between the fourth and fifth lumbar vertebral bodies or between the fifth and the sacrum. Symptoms can affect the lower back, buttocks, thigh, anal/genital region (via the Perineal nerve), and may radiate into the foot and/or toe. The sciatic nerve is the most commonly affected nerve, causing symptoms of sciatica. The femoral nerve can also be affected and cause the patient to experience a numb, tingling feeling throughout one or both legs and even feet or even a burning feeling in the hips and legs.
Pathophysiology
There is now recognition of the importance of “chemical radiculitis” in the generation of back pain.A primary focus of surgery is to remove “pressure” or reduce mechanical compression on a neural element: either the spinal cord, or a nerve root. But it is increasingly recognized that back pain, rather than being solely due to compression, may also be due to chemical inflammation.There is evidence that points to a specific inflammatory mediator of this pain. This inflammatory molecule, called tumor necrosis factor-alpha (TNF), is released not only by the herniated disc, but also in cases of disc tear (annular tear), by facet joints, and in spinal stenosis.In addition to causing pain and inflammation, TNF may also contribute to disc degeneration.Diagnosis
Diagnosis is made by a practitioner based on the history, symptoms, and physical examination. At some point in the evaluation, tests may be performed to confirm or rule out other causes of symptoms such as spondylolisthesis, degeneration, tumors, metastases and space-occupying lesions, as well as to evaluate the efficacy of potential treatment options.Physical examination
The Straight leg raise may be positive, as this finding has low specificity; however, it has high sensitivity. Thus the finding of a negative SLR sign is an important in helping to "rule out" the possibility of a lower lumbar disc herniation. A variation is to lift the leg while the patient is sitting.However, this reduces the sensitivity of the test.Imaging
- X-ray: Although traditional plain X-rays are limited in their ability to image soft tissues such as discs, muscles, and nerves, they are still used to confirm or exclude other possibilities such as tumors, infections, fractures, etc. In spite of these limitations, X-ray can still play a relatively inexpensive role in confirming the suspicion of the presence of a herniated disc. If a suspicion is thus strengthened, other methods may be used to provide final confirmation.
- Computed tomography scan (CT or CAT scan): A diagnostic image created after a computer reads x-rays. It can show the shape and size of the spinal canal, its contents, and the structures around it, including soft tissues. However, visual confirmation of a disc herniation can be difficult with a CT.
- Magnetic resonance imaging (MRI): A diagnostic test that produces three-dimensional images of body structures using powerful magnets and computer technology. It can show the spinal cord, nerve roots, and surrounding areas, as well as enlargement, degeneration, and tumors. It shows soft tissues even better than CAT scans. An MRI performed with a high magnetic field strength usually provides the most conclusive evidence for diagnosis of a disc herniation. T2-weighted images allow for clear visualization of protruded disc material in the spinal canal.
- Myelogram: An x-ray of the spinal canal following injection of a contrast material into the surrounding cerebrospinal fluid spaces. By revealing displacement of the contrast material, it can show the presence of structures that can cause pressure on the spinal cord or nerves, such as herniated discs, tumors, or bone spurs. Because it involves the injection of foreign substances, MRI scans are now preferred in most patients. Myelograms still provide excellent outlines of space-occupying lesions, especially when combined with CT scanning (CT myelography).
- Electromyogram and Nerve conduction studies (EMG/NCS): These tests measure the electrical impulse along nerve roots, peripheral nerves, and muscle tissue. This will indicate whether there is ongoing nerve damage, if the nerves are in a state of healing from a past injury, or whether there is another site of nerve compression. EMG/NCS studies are typically used to pinpoint the sources of nerve dysfunction distal to the spine.
Treatment
The majority of herniated discs will heal themselves in about six weeks and do not require surgery. One study found that "After 12 weeks, 73% of patients showed reasonable to major improvement without surgery."If pain due to disc herniation, protrusion, bulge, or disc tear is due to chemical radiculitis pain, then prior to surgery it may make sense to try an anti-inflammatory approach. Often this is first attempted with non-steroidal anti-inflammatory medications (NSAIDs), but the long-term use of NSAIDs for patients with persistent back pain is complicated by their possible cardiovascular and gastrointestinal toxicity; and NSAIDs have limited value to intervene in tumor necrosis factor-alpha (TNF)-mediated processes. alternative often employed is the injection of cortisone into the spine adjacent to the suspected pain generator, a technique known as “epidural steroid injection”.Although this technique began more than a decade ago for pain due to disc herniation, the efficacy of epidural steroid injections is now generally thought to be limited to short term pain relief in selected patients only.In addition, epidural steroid injections, in certain settings, may result in serious complications. Fortunately there are now emerging new methods that directly target TNF.These TNF-targeted methods represent a highly promising new approach for patients with chronic severe spinal pain, such as those with failed back surgery syndrome. Ancillary approaches, such as rehabilitation, physical therapy, anti-depressants, and, in particular, graduated exercise programs, may all be useful adjuncts to anti-inflammatory approaches.