Spinal Disc Herniation
A spinal disc herniation (prolapsus disci intervertebralis) is a medical condition affecting the spine due to trauma, lifting injuries, or idiopathic (unknown) causes, 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 beyond the damaged outer rings. 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.
Disc herniations are 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. In contrast to a herniation, none of the nucleus pulposus escapes beyond the outer layers.
Most minor herniations heal within several weeks. Anti-inflammatory treatments for pain associated with disc herniation, protrusion, bulge, or disc tear are generally effective. Severe herniations may not heal of their own accord and may require surgical intervention.
The condition is widely referred to as a slipped disc, but this term is not medically accurate as the spinal discs are fixed in position between the vertebrae and cannot "slip".
Terminology
Normal situation and spinal disc herniation in cervical vertebrae.
Some of the terms commonly used to describe the condition include herniated disc, prolapsed disc, ruptured disc and slipped disc. Other phenomena that are closely related include disc protrusion, pinched nerves, sciatica, disc disease, disc degeneration, degenerative disc disease, and black disc.
The popular term slipped disc is a misnomer, as the intervertebral discs are tightly sandwiched between two vertebrae to which they are attached, and cannot actually "slip", or even get out of place. The disc is actually grown together with the adjacent vertebrae and can be squeezed, stretched and twisted, all in small degrees. It can also be torn, ripped, herniated, and degenerated, but it cannot "slip". Some authors consider that the term "slipped disc" is harmful, as it leads to an incorrect idea of what has occurred and thus of the likely outcome. However, during growth, one vertebral body can slip relative to an adjacent vertebral body. This congenital deformity is called spondylolisthesis
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. Patients with L3 or L5 herniated disc (usually affecting the knee and leg) also have a high chance of experiencing decreased sexual performance ( erectile dysfunction ) due to the tissue involved with the penile muscle tissue. If the extruded nucleus pulposus material doesn't press on the p tissues or muscles, patients may not experience any reduced sexual function symptoms. 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 suggests 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, both sides of the body may be affected, 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. This disorder is called cauda equina syndrome.
Cause
Disc herniations can result from general wear and tear, such as when performing jobs that require constant sitting and squatting. However, herniations often result from jobs that require lifting. Traumatic 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).[citation needed]
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.[citation needed]
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.
Location
The majority of spinal disc herniation cases occur in lumbar region (95% in L4-L5 or L5-S1). The second most common site is the cervical region (C5-C6, C6-C7). The thoracic region accounts for only 0.15% to 4.0% of cases.
Herniations usually occur posterolaterally, where the annulus fibrosis is relatively thin and is not reinforced by the posterior or anterior longitudinal ligament in the cervical spinal cord, a symptomatic posterolateral herniation between two vertebrae will impinge on the nerve which exits the spinal canal between those two vertebrae on that side. So for example, a right posterolateral herniation of the disc between vertebrae C5 and C6 will impinge on the right C6 spinal nerve. The rest of the spinal cord, however, is oriented differently, so a symptomatic posterolateral herniation between two vertebrae will actually impinge on the nerve exiting at the next intervertebral foramen down.So for example, a herniation of the disc between the L5 and S1 vertebrae will impinge on the S1 spinal nerve, which exits between the S1 and S2 vertebrae.
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.
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
Physical examination
Main article: Straight leg raise
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 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.
Treatment
In the majority of cases, spinal disc herniation doesn't require surgery, and a study on sciatica, which can be caused by spinal disc herniation, found that "after 12 weeks, 73% of patients showed reasonable to major improvement without surgery." The study, however, did not determine the number of individuals in the group that had sciatica caused by disc herniation.
Initial treatment usually consists of non-steroidal anti-inflammatory pain medication (NSAIDs), but the long-term use of NSAIDs for patients with persistent back pain is complicated by their possible cardiovascular and gastrointestinal toxicity. An alternative often employed is the injection of cortisone into the spine adjacent to the suspected pain generator, a technique known as “epidural steroid injection”.Epidural steroid injections "may result in some improvement in radicular lumbosacral pain when assessed between 2 and 6 weeks following the injection, compared to control treatments. Complications resulting from poor technique are rare.
Ancillary approaches, such as rehabilitation, physical therapy, anti-depressants, and, in particular, graduated exercise programs, may all be useful adjuncts to anti-inflammatory approaches.
Lumbar
Non-surgical methods of treatment are usually attempted first, leaving surgery as a last resort. Pain medications are often prescribed as the first attempt to alleviate the acute pain and allow the patient to begin exercising and stretching. There are a variety of other non-surgical methods used in attempts to relieve the condition after it has occurred, often in combination with pain killers. They are either considered indicated, contraindicated, relatively contraindicated, or inconclusive based on the safety profile of their risk-benefit ratio and on whether they may or may not help:
Surgical options
- Chemonucleolysis - dissolves the protruding disc
- IDET (a minimally invasive surgery for disc pain)
- Discectomy/Microdiscectomy - to relieve nerve compression
- Tessys method - a transforaminal endoscopic method to remove herniated discs
- Laminectomy - to relieve spinal stenosis or nerve compression
- Hemilaminectomy - to relieve spinal stenosis or nerve compression
- Lumbar fusion (lumbar fusion is only indicated for recurrent lumbar disc herniations, not primary herniations)
- Anterior cervical discectomy and fusion (for cervical disc herniation)
- Disc arthroplasty (experimental for cases of cervical disc herniation)
- Dynamic stabilization
- Artificial disc replacement, a relatively new form of surgery in the U.S. but has been in use in Europe for decades, primarily used to treat low back pain from a degenerated disc.
- Nucleoplasty
Surgical goals include relief of nerve compression, allowing the nerve to recover, as well as the relief of associated back pain and restoration of normal function.
Rehabilitation
Rehabilitation of a herniated disc varies greatly upon a patient’s condition. Major factors taken into consideration are the patient’s pain threshold and severity of injury. [Degree of injury] ranges from some minor discomfort to immense pain that causes movement restrictions *. Possible sciatica symptoms are also taken into account when discussing a patient’s discomfort.
Electrostimulation
A module of rehabilitation is electrostimulation * which is commonly used in the physical therapy field. Electrostimulation therapy includes placement of electrode pads proximal to the strained or weakened erector spinae surrounding the herniated disc.
Laser Light Therapy
[Laser light therapy] is a light utilizing module with an instrument that emits the therapeutic light directly onto the injured area.
Ultrasound Therapy
Ultrasound* is similar to laser therapy in its direct application to damaged tissues but utilizes vibrations in a crystal-containing handheld unit.
Hot/Cold Therapy
A general form of therapy is the use of ice packs and heat packs which are usually wrapped in a towel and applied directly.
Weightlifting
Weightlifting has been used in conjunction with the aforementioned therapeutic modalities. Gasiorowski’s research proves that patients who qualify for surgical procedures can alternatively select weightlifting to avoid risks of surgery. Weightlifting involves the use of multigym machines, free-weights, and barbells. As a part of this type of therapy, plyometric exercises were implemented to help correct any imbalances in the patient’s gait that resulted from disc herniation *.
Epidemiology
Stages of Spinal Disc Herniation
Disc herniation can occur in any disc in the spine, but the two most common forms are lumbar disc herniation and cervical disc herniation. The former is the most common, causing lower back pain (lumbago) and often leg pain as well, in which case it is commonly referred to as sciatica.
Lumbar disc herniation occurs 15 times more often than cervical (neck) disc herniation, and it is one of the most common causes of lower back pain. The cervical discs are affected 8% of the time and the upper-to-mid-back (thoracic) discs only 1 - 2% of the time.
The following locations have no discs and are therefore exempt from the risk of disc herniation: the upper two cervical intervertebral spaces, the sacrum, and the coccyx.
Most disc herniations occur when a person is in their thirties or forties when the nucleus pulposus is still a gelatin-like substance. With age the nucleus pulposus changes ("dries out") and the risk of herniation is greatly reduced. After age 50 or 60, osteoarthritic degeneration (spondylosis) or spinal stenosis are more likely causes of low back pain or leg pain.
- 4.8% males and 2.5% females older than 35 experience sciatica during their lifetime.
- Of all individuals, 60% to 80% experience back pain during their lifetime.
- In 14%, pain lasts more than 2 weeks.
- Generally, males have a slightly higher incidence than females.
Prevention
Because there are various causes for back injuries, prevention must be comprehensive . Back injuries are predominant in manual labor so the majority low back pain prevention methods have been applied primarily toward biomechanics Prevention must come from multiple sources such as education, proper body mechanics, and physical fitness.
Education
Education should emphasize not lifting beyond ones capabilities and giving the body a rest after strenuous effort. Over time, poor posture can cause the IVD to tear or become damaged. Striving to maintain proper posture and alignment will aid in preventing disc degradation
Exercise
Exercises that are used to enhance back strength may also be used to prevent back injuries. Back exercises include the prone press-ups, transverse abdominus bracing, and floor bridges. Abdominal bracing protects against joint and disc injury. If pain is present in the back, the stabilization muscles of the back are weak and a person needs to train the trunk musculature. Another preventative measure is to not work ourselves past fatigue. Signs of fatigue include shaking, poor coordination,muscle burning and loss of the transverse abdominal brace.Individuals who engage in power lifting place their bodies under heavy stress Barbells are common tools used in strength training.The usage of lumbarsacral support belts may restrict movement at the spine and support the back during lifting
POSTED BY ATTORNEY RENE G. GARCIA:
http://en.wikipedia.org/wiki/Herniated_disc
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