Only 10% of patients have significant pain at 6 weeks to consider surgery.
Herniated portion of the disk partially or completely regresses in two thirds of patients by six months.
Spinal disc herniation
Also known as a slipped disc.
Refers to a tear in the outer, fibrous ring of an intervertebral disc allowing the soft, central portion to bulge out beyond the damaged outer rings.
Usually due to age-related degeneration of the outer ring, known as the anulus fibrosus, although trauma, lifting injuries, or straining have been implicated.
Tears occur almost always postero-laterally owing to the presence of the posterior longitudinal ligament in the spinal canal.
Tears may result in the release of chemicals causing inflammation, which may directly cause severe pain even in the absence of nerve root compression.
Disc herniations are normally a progressive development of a previously existing disc protrusion.
Disc protrusion is a condition in which the outermost layers of the anulus fibrosus are still intact, but can bulge when the disc is under pressure.
In disc protrusion in contrast to a herniation, none of the central portion escapes beyond the outer layers.
Most minor herniations heal within several weeks.
Anti-inflammatory agents for pain associated with disc herniation, protrusion, bulge, or disc tear are generally effective.
Severe herniations may require surgery.
Symptoms of a herniated disc vary depending on the location of the herniation.
Symptoms vary by the types of soft tissue that become involved.
Symptoms can range from little or no pain if the disc is the only tissue injured.
Symptoms may be severe and will radiate into the regions served by affected nerve roots that are irritated or impinged by the herniated material.
Often not diagnosed immediately, as patients have undefined pains in the thighs, knees, or feet.
Symptoms may include sensory changes such as numbness, tingling, paresthesia
Symptoms may include motor changes such as muscular weakness, paralysis and altered reflexes.
Lumbar herniated discs may experience sciatica due to irritation of one of the nerve roots of the sciatic nerve.
Pain from a herniated disc is usually continuous or at least is continuous in a specific position of the body, but it is possible to have a herniated disc without any pain or symptoms.
If an extruded nucleus pulposus doesn’t press on soft tissues or nerves, it may not cause any symptoms, and study of the cervical spine in symptom-free volunteers has found focal disc protrusions in 50% of participants.
A prolapsed disc in the lumbar spine can cause radiating nerve pain. usually felt in the lower extremities or groin area.
Radiating nerve pain caused by a herniated disc can also cause bowel and bladder incontinence.
Typically, symptoms are experienced only on one side of the body.
In very large prolapses pressing on the nerves within the spinal column or the cauda equina, both sides of the body may be affected,.
Compression of the cauda equina, the cauda equina syndrome, can cause nerve damage or paralysis, resulting in loss of bowel and bladder control as well as sexual dysfunction.
Experts suggest degeneration of the intervertebral disc as the major cause of spinal disc herniation and cite trauma as a low cause.
Disc degeneration occurs with aging.
As degeneration occurs the contents of the disc, the nucleus pulposus and anulus fibrosus, are exposed to altered loads.
With degeneration, the nucleus becomes fibrous and stiff and less able to bear load.
The load is transf2242ing to the anulus leads to the development of fissures.
If the fissure reaches the periphery of the anulus, nuclear material can pass through as a disc herniation.
Disc herniations can result from general wear and tear.
Herniations can also result from the lifting heavy loads.
Athletes, are prone to disc herniations as well., often the result of sudden blunt impacts, abrupt bending or torsional movements of, the lower back.
When the spine is straight, as during 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 while lying down to over 300 psi when lifting with a rounded back.
Herniation of the contents of the disc into the spinal canal often occurs when the anterior side of the disc is compressed while sitting or bending forward, and the nucleus pulposus gets pressed against the tightly stretched and thinned membraned anulus fibrosus on the posterior side of the disc.
As the membrane thinning from stretching and increased internal pressure 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, producing pain and other symptoms.
Several genes are associated with intervertebral disc degeneration: type I collagen, type IX collagen, vitamin D receptor, aggrecan, asporin, MMP3, interleukin-1 and interleukin-6 polymorphisms.
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.
Many minor disc herniations heal on their own with conservative treatment, occasionally they require surgery for correction.
Surgery removes pressure or reduces mechanical compression on a neural element, either at the spinal cord, or a nerve root.
Back pain, is due to nerve compression, and to chemical inflammation.
The inflammatory mediator of this pain is tumor necrosis factor-alpha (TNF), and is released not only by the herniated disc, but also in cases of disc tear by facet joints, and in spinal stenosis.
TNF may also contribute to disc degeneration.
The majority of spinal disc herniation cases occur in the lumbar region .
95% of spinal disc herniations occur in L4-L5 or L5-S1).
The second most common site of spinal disc herniations occur the cervical region (C5-C6, C6-C7).
The thoracic region accounts for only 0.15% to 4.0% of cases of spinal herniations.
Herniations usually occur posterolaterally, where the anulus fibrosus is relatively thin and is not reinforced by the posterior or anterior longitudinal ligaments.
In the cervical spinal cord a posterolateral herniation between two vertebrae may impinge on the nerve as it exits the spinal canal between those two vertebrae on that side, so that a right posterolateral herniation of the disc between vertebrae C5 and C6 will impinge on the right C6 spinal nerve.
In the rest of the spinal cord a symptomatic posterolateral herniation between two vertebrae will actually impinge on the nerve exiting at the next intervertebral foramen down, 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 disc herniations can affect the back of the skull, the neck, shoulder girdle, scapula, arm, and hand and most often between the fifth & sixth (C5/6) and the sixth and seventh (C6/7) cervical vertebral bodies.
The nerves of the cervical plexus and brachial plexus can be affected.
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.
Lumbar disc herniation symptoms can affect the lower back, buttocks, thigh, anal/genital region, 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 causing numbness, and tingling throughout one or both legs and even feet or even a burning feeling in the hips and legs.
A hernia in the lumbar region often compresses the nerve root exiting at the level below the disk.
Thus, a herniation of the L4/5 disc will compress the L5 nerve root.
Intradural disc herniation is a rare form of disc herniation with an incidence of 0.2-2.2%.
Diagnosis is made based on the history, symptoms, and physical examination.
Tests 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.
Discs can be torn, ripped, herniated, and degenerated, but cannot be slipped.
A positive straight leg raising test has low specificity, but high sensitivity.
A positive ipsilateral straight leg racing test in which pain results when the leg on the side of the back or leg pain is raised and is highly sensitive at 92% of patients with herniated disk.
A negative straight leg raising sign is important in helping to rule out the possibility of a lower lumbar disc herniation.
Lift the leg while the patient is sitting, reduces the sensitivity of the test.
Pain X-rays are limited in their ability to image soft tissues such as discs, muscles, and nerves, but are still used to confirm or exclude other possibilities such as tumors, infections, fractures, etc.
X-ray can still play a relatively inexpensive role in confirming the suspicion of the presence of a herniated disc.
Computed tomography scan can show the shape and size of the spinal canal, its contents, and the structures around it, including soft tissues.
Disc herniation can be difficult to see with a CT,
Magnetic resonance imaging (MRI) can show the spinal cord, nerve roots, and surrounding areas, as well as enlargement, degeneration, and tumors.
It shows soft tissues better than CT scans.
An MRI performed with a high magnetic field strength usually provides the most conclusive evidence for diagnosis of a disc herniation.
A myelogram is an x-ray of the spinal canal following injection of a contrast material into the surrounding cerebrospinal fluid spaces.
A myelogram can show the presence of structures that can cause pressure on the spinal cord or nerves, such as herniated discs, tumors, or bone spurs.
To avoid the injection of foreign substances, MRI scans pref2242ed for most patients. though myelograms still provide excellent outlines of space-occupying lesions, especially when combined with CT scans.
Electromyogram and Nerve conduction studies (EMG/NCS) measure the electrical impulse along nerve roots, peripheral nerves, and muscle tissue.
EMG/NCS can indicate whether there is ongoing nerve damage.
EMG/NCS can indicate 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 usually used to identify the sources of nerve dysfunction distal to the spine.
The presence and severity of myelopathy can be evaluated by means of Transcranial Magnetic Stimulation (TMS).
In the majority of cases, spinal disc herniation does not require surgery.
Initial treatment usually consists of non-steroidal anti-inflammatory pain medication.
Epidural corticosteroid injections provide a slight and questionable short-term improvement in those with sciatica but are of no long term benefit.
Complications occur in 0 to 17% of cases when performed on the neck, but most are minor.
The FDA suggests that epidural corticosteroids may result in rare but serious adverse events, including loss of vision, stroke, paralysis, and death, and has not approved corticosteroids for this use.
Lumbar disc herniation initial treatment is usually non-surgical, leaving surgery as a last resort.
Analgesics are often prescribed as the first attempt to alleviate the acute pain and allow the patient to begin exercising and stretching.
Physical therapy to improve mechanical factors and educate about proper body mechanics.
Physical therapy measures of traction, electrical stimulation, massage may be helpful.
Non-steroidal anti-inflammatory drugs (NSAIDs) may reduce pain.
Weight control should be employed.
Spinal manipulation is more effective than placebo for the treatment of acute lumbar disc herniation and acute sciatica, but there is little evidence for treating chronic lumbar symptoms.
Spinal manipulation is likely to be safe when used by appropriately trained clinicians.
Spinal manipulation is contraindicated for disc herniations or progressive neurological deficits.
Surgery may be useful with a herniated disc causing pain radiating into the leg, significant leg weakness, bladder problems, or loss of bowel control.
Discectomy can bring relief sooner than nonsurgical treatments.
Discectomy or microdiscectomy have better outcomes at one year but not at four to ten years.
The presence of cauda equina is considered a medical emergency requiring immediate attention and possibly surgical decompression.
For failed medical without a neurological deficit, there is limited evidence to support some aspects of surgical practice.
Disc herniation can occur in any disc.
The two most common herniations are lumbar disc herniation and cervical disc herniation.
The former is the most common, causing lower back pain and often leg pain as well, in which case it is commonly ref2242ed to as sciatica.
Lumbar disc herniation occurs 15 times more often than cervical 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 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 have no discs and and do not have an risk of disc herniations.
Disc herniations occur when a person is in their thirties or forties when the nucleus pulposus is still a gelatin-like substance.
As the nucleus pulposus dries out the risk of herniation is greatly reduced.
After age 50 or 60, osteoarthritic degeneration or spinal stenosis are more likely causes of low back pain or leg pain.