Spinal disc herniation is an
injury
An injury is any physiological damage to living tissue caused by immediate physical stress. An injury can occur intentionally or unintentionally and may be caused by blunt trauma, penetrating trauma, burning, toxic exposure, asphyxiation, o ...
to the cushioning and
connective tissue
Connective tissue is one of the four primary types of animal tissue, along with epithelial tissue, muscle tissue, and nervous tissue. It develops from the mesenchyme derived from the mesoderm the middle embryonic germ layer. Connective tiss ...
between
vertebrae
The spinal column, a defining synapomorphy shared by nearly all vertebrates,Hagfish are believed to have secondarily lost their spinal column is a moderately flexible series of vertebrae (singular vertebra), each constituting a characteristic i ...
, usually caused by excessive
strain
Strain may refer to:
Science and technology
* Strain (biology), variants of plants, viruses or bacteria; or an inbred animal used for experimental purposes
* Strain (chemistry), a chemical stress of a molecule
* Strain (injury), an injury to a mu ...
or trauma to the
spine. It may result in
back pain
Back pain is pain felt in the back. It may be classified as neck pain (cervical), middle back pain (thoracic), lower back pain (lumbar) or coccydynia (tailbone or sacral pain) based on the segment affected. The lumbar area is the most common area ...
, pain or sensation in different parts of the body, and physical
disability
Disability is the experience of any condition that makes it more difficult for a person to do certain activities or have equitable access within a given society. Disabilities may be Cognitive disability, cognitive, Developmental disability, dev ...
. The most conclusive diagnostic tool for disc
hernia
A hernia is the abnormal exit of tissue or an organ (anatomy), organ, such as the bowel, through the wall of the cavity in which it normally resides. Various types of hernias can occur, most commonly involving the abdomen, and specifically the gr ...
tion is
MRI
Magnetic resonance imaging (MRI) is a medical imaging technique used in radiology to form pictures of the anatomy and the physiological processes of the body. MRI scanners use strong magnetic fields, magnetic field gradients, and radio waves ...
, and treatment may range from painkillers to surgery. Protection from disc herniation is best provided by
core
Core or cores may refer to:
Science and technology
* Core (anatomy), everything except the appendages
* Core (manufacturing), used in casting and molding
* Core (optical fiber), the signal-carrying portion of an optical fiber
* Core, the centra ...
strength and an awareness of body mechanics including
posture
Posture or posturing may refer to:
Medicine
* Human position
** Abnormal posturing, in neurotrauma
** Spinal posture
** List of human positions
* Posturography Posturography is the technique used to quantify postural control in upright stance in ...
.
When a tear in the outer, fibrous ring of an
intervertebral disc
An intervertebral disc (or intervertebral fibrocartilage) lies between adjacent vertebrae in the vertebral column. Each disc forms a fibrocartilaginous joint (a symphysis), to allow slight movement of the vertebrae, to act as a ligament to hold t ...
allows the soft, central portion to bulge out beyond the damaged outer rings, the disc is said to be herniated.
Disc herniation is frequently associated with age-related degeneration of the outer ring, known as the ''
annulus fibrosus'', but is normally triggered by trauma or straining by lifting or twisting. Tears are almost always
posterolateral (on the back sides) owing to relative narrowness of the
posterior longitudinal ligament
The posterior longitudinal ligament is a ligament connecting the posterior surfaces of the vertebral bodies of all of the vertebrae. It weakly prevents hyperflexion of the vertebral column. It also prevents posterior spinal disc herniation, altho ...
relative to the
anterior longitudinal ligament
The anterior longitudinal ligament is a ligament that runs down the anterior surface of the spine. It traverses all of the vertebral bodies and intervertebral discs on their ventral side. It may be partially cut to treat certain abnormal curvatur ...
. A tear in the disc ring may result in the release of chemicals causing
inflammation
Inflammation (from la, wikt:en:inflammatio#Latin, inflammatio) is part of the complex biological response of body tissues to harmful stimuli, such as pathogens, damaged cells, or Irritation, irritants, and is a protective response involving im ...
, which can result in severe pain even in the absence of
nerve root A nerve root (Latin: ''radix nervi'') is the initial segment of a nerve leaving the central nervous system. Nerve roots can be classified as:
*cranial nerves, Cranial nerve roots: the initial or proximal segment of one of the twelve pairs of crania ...
compression.
Disc herniation is normally a further development of a previously existing
disc protrusion, 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 central portion 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 surgery.
The condition may be referred to as a ''slipped disc'', but this term is not accurate as the spinal discs are firmly attached between the vertebrae and cannot "slip" out of place.
Signs and symptoms
Typically, symptoms are experienced on one side of the body only.
Symptoms of a herniated disc can vary depending on the location of the herniation and the types of soft tissue involved. They can range from little or no pain, if the disc is the only tissue injured, to severe and unrelenting
neck pain
Neck pain, also known as cervicalgia, is a common problem, with two-thirds of the population having neck pain at some point in their lives.
Neck pain, although felt in the neck, can be caused by numerous other spinal problems. Neck pain may arise ...
or
low back pain
Low back pain (LBP) or lumbago is a common disorder involving the muscles, nerves, and bones of the back, in between the lower edge of the ribs and the lower fold of the buttocks. Pain can vary from a dull constant ache to a sudden sharp feel ...
that radiates into regions served by nerve roots which have been irritated or impinged by the herniated material. Often, herniated discs are not diagnosed immediately, as patients present with undefined pains in the thighs, knees, or feet.
Symptoms may include sensory changes such as numbness, tingling,
paresthesia
Paresthesia is an abnormal sensation of the skin (tingling, pricking, chilling, burning, numbness) with no apparent physical cause. Paresthesia may be transient or chronic, and may have any of dozens of possible underlying causes. Paresthesias ar ...
, and motor changes such as muscular weakness, paralysis, and affection of
reflex
In biology, a reflex, or reflex action, is an involuntary, unplanned sequence or action and nearly instantaneous response to a stimulus.
Reflexes are found with varying levels of complexity in organisms with a nervous system. A reflex occurs ...
es. If the herniated disc is in the lumbar region, the patient may also experience
sciatica
Sciatica is pain going down the leg from the lower back. This pain may go down the back, outside, or front of the leg. Onset is often sudden following activities like heavy lifting, though gradual onset may also occur. The pain is often described ...
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 continuous in a specific
position of the body.
It is possible to have a herniated disc without pain or noticeable symptoms if the extruded ''nucleus pulposus'' material doesn't press on soft tissues or nerves. A small-sample study examining the cervical spine in symptom-free volunteers found
focal disc protrusions in 50% of participants, suggesting that a considerable part of the population might have focal herniated discs in their cervical region that do not cause noticeable symptoms.
A herniated disc in the lumbar spine may cause radiating nerve pain in the lower extremities or groin area and may sometimes be associated with bowel or bladder incontinence.
Typically, symptoms are experienced only on one side of the body, but if a herniation is very large and presses on the nerves on both sides within the spinal column or the ''
cauda equina
The cauda equina () is a bundle of spinal nerves and spinal nerve rootlets, consisting of the second through fifth lumbar nerve pairs, the first through fifth sacral nerve pairs, and the coccygeal nerve, all of which arise from the lumbar enlarg ...
'', both sides of the body may be affected, often with serious consequences. Compression of the ''cauda equina'' can cause permanent nerve damage or paralysis which can result in loss of bowel and bladder control and sexual dysfunction. This disorder is called
cauda equina syndrome
Cauda equina syndrome (CES) is a condition that occurs when the bundle of nerves below the end of the spinal cord known as the cauda equina is damaged. Signs and symptoms include low back pain, pain that radiates down the leg, numbness around ...
. Other complications include
chronic pain
Chronic pain is classified as pain that lasts longer than three to six months. In medicine, the distinction between Acute (medicine), acute and Chronic condition, chronic pain is sometimes determined by the amount of time since onset. Two commonly ...
.
Cause
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 (lying down) to over (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 fibrosus'') on the posterior side (back side) of the disc. The combination of membrane-thinning from stretching and increased internal pressure () can result 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, which may produce intense and potentially disabling pain and other symptoms.
Some authors favour degeneration of the intervertebral disc as the major cause of spinal disc herniation and cite trauma as a minor cause.
Disc degeneration occurs both in
degenerative disc disease
Degenerative disc disease (DDD) is a medical condition typically brought on by the normal aging process in which there are anatomic changes and possibly a loss of function of one or more intervertebral discs of the spine. DDD can take place with ...
and aging.
With degeneration, the disc components – the ''nucleus pulposus'' and ''annulus fibrosus'' – become exposed to altered loads. Specifically, the nucleus becomes fibrous and stiff and less able to bear load. Excess load is transferred to the ''annulus'', which may then develop fissures as a result. If the fissures reach the periphery of the ''annulus'', the nuclear material can pass through as a disc herniation.
Mutations in several genes have been implicated in intervertebral disc degeneration. Probable candidate genes include
type I collagen
Type I collagen is the most abundant collagen of the human body. It forms large, eosinophilic fibers known as collagen fibers.
It is present in scar tissue, the end product when tissue heals by repair, as well as tendons, ligaments, the endomy ...
(sp1 site),
type IX collagen,
vitamin D receptor
The vitamin D receptor (VDR also known as the calcitriol receptor) is a member of the nuclear receptor family of transcription factors. Calcitriol (the active form of vitamin D, 1,25-(OH)2vitamin D3) binds to VDR, which then forms a heterodim ...
,
aggrecan,
asporin
Asporin is a protein that in humans is encoded by the ''ASPN'' gene.
Function
ASPN belongs to a family of leucine-rich repeat (LRR) proteins associated with the cartilage matrix. The name asporin reflects the unique aspartate-rich N terminus a ...
,
MMP3
Stromelysin-1 also known as matrix metalloproteinase-3 (MMP-3) is an enzyme that in humans is encoded by the ''MMP3'' gene. The MMP3 gene is part of a cluster of MMP genes which localize to chromosome 11q22.3. MMP-3 has an estimated molecular wei ...
,
interleukin-1
The Interleukin-1 family (IL-1 family) is a group of 11 cytokines that plays a central role in the regulation of immune and inflammatory responses to infections or sterile insults.
Discovery
Discovery of these cytokines began with studies on t ...
, and
interleukin-6
Interleukin 6 (IL-6) is an interleukin that acts as both a pro-inflammatory cytokine and an anti-inflammatory myokine. In humans, it is encoded by the ''IL6'' gene.
In addition, osteoblasts secrete IL-6 to stimulate osteoclast formation. Smoo ...
polymorphisms.
Mutation in genes – such as
MMP2
72 kDa type IV collagenase also known as matrix metalloproteinase-2 (MMP-2) and gelatinase A is an enzyme that in humans is encoded by the ''MMP2'' gene. The ''MMP2'' gene is located on chromosome 16 at position 12.2.
Function
Proteins of the ...
and
THBS2
Thrombospondin-2 is a protein that in humans is encoded by the ''THBS2'' gene.
The protein encoded by this gene belongs to the thrombospondin family. It is a disulfide-linked homotrimeric glycoprotein that mediates cell-to-cell and cell-to-matrix ...
– that encode for proteins and enzymes involved in the regulation of the extracellular matrix has been shown to contribute to lumbar disc herniation.
Disc herniations can result from general wear and tear, such as weightlifting training,
constant sitting or squatting, driving, or a sedentary lifestyle. Herniations can also result from the lifting of heavy loads.
Professional athlete
In professional sports, as opposed to amateur sports, participants receive payment for their performance. Professionalism in sport has come to the fore through a combination of developments. Mass media and increased leisure have brought larg ...
s, especially those playing
contact sport
Contact sports are sports that emphasize or require physical contact between players. Some sports, such as mixed martial arts, are scored on impacting an opponent, while others, including rugby football, gridiron football and Australian rules fo ...
s, such as
American football
American football (referred to simply as football in the United States and Canada), also known as gridiron, is a team sport played by two teams of eleven players on a rectangular field with goalposts at each end. The offense, the team with ...
,
Rugby
Rugby may refer to:
Sport
* Rugby football in many forms:
** Rugby league: 13 players per side
*** Masters Rugby League
*** Mod league
*** Rugby league nines
*** Rugby league sevens
*** Touch (sport)
*** Wheelchair rugby league
** Rugby union: 1 ...
,
ice hockey
Ice hockey (or simply hockey) is a team sport played on ice skates, usually on an ice skating rink with lines and markings specific to the sport. It belongs to a family of sports called hockey. In ice hockey, two opposing teams use ice hock ...
, and
wrestling
Wrestling is a series of combat sports involving grappling-type techniques such as clinch fighting, throws and takedowns, joint locks, pins and other grappling holds. Wrestling techniques have been incorporated into martial arts, combat ...
, are known to be prone to disc herniations as well as some limited contact sports that require repetitive flexion and compression such as
soccer
Association football, more commonly known as football or soccer, is a team sport played between two teams of 11 players who primarily use their feet to propel the ball around a rectangular field called a pitch. The objective of the game is ...
,
baseball
Baseball is a bat-and-ball sport played between two teams of nine players each, taking turns batting and fielding. The game occurs over the course of several plays, with each play generally beginning when a player on the fielding tea ...
,
basketball
Basketball is a team sport in which two teams, most commonly of five players each, opposing one another on a rectangular Basketball court, court, compete with the primary objective of #Shooting, shooting a basketball (ball), basketball (appr ...
, and
volleyball
Volleyball is a team sport in which two teams of six players are separated by a net. Each team tries to score points by grounding a ball on the other team's court under organized rules. It has been a part of the official program of the Summ ...
.
[he incidence of disk changes in volleyball players. The magnetic resonance findings- PubMed">] Within athletic contexts, herniation is often the result of sudden blunt impacts against, or abrupt bending or torsional movements of, the lower back.
Pathophysiology
The majority of spinal disc herniations occur in the
lumbar
In tetrapod anatomy, lumbar is an adjective that means ''of or pertaining to the abdominal segment of the torso, between the diaphragm and the sacrum.''
The lumbar region is sometimes referred to as the lower spine, or as an area of the back i ...
spine (95% at L4–L5 or L5–S1).
The second most common site is the
cervical
In anatomy, cervical is an adjective that has two meanings:
# of or pertaining to any neck.
# of or pertaining to the female cervix: i.e., the ''neck'' of the uterus.
*Commonly used medical phrases involving the neck are
**cervical collar
**cerv ...
region (C5–C6, C6–C7). The
thoracic
The thorax or chest is a part of the anatomy of humans, mammals, and other tetrapod animals located between the neck and the abdomen. In insects, crustaceans, and the extinct trilobites, the thorax is one of the three main divisions of the crea ...
region accounts for only 1–2% of cases. Herniations usually occur postero-laterally, at the points where the ''annulus fibrosus'' is relatively thin and is not reinforced by the posterior or anterior longitudinal ligament.
[ In the cervical spine, a symptomatic postero-lateral 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 postero-lateral 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 postero-lateral herniation between two vertebrae will impinge on the nerve exiting at the next intervertebral level down.][
]
Lumbar disc herniations occur in the back, most often between the fourth and fifth lumbar vertebral bodies or between the fifth and the sacrum
The sacrum (plural: ''sacra'' or ''sacrums''), in human anatomy, is a large, triangular bone at the base of the spine that forms by the fusing of the sacral vertebrae (S1S5) between ages 18 and 30.
The sacrum situates at the upper, back part ...
. Here, symptoms can be felt in the lower back, buttocks
The buttocks (singular: buttock) are two rounded portions of the exterior anatomy of most mammals, located on the posterior of the pelvic region. In humans, the buttocks are located between the lower back and the perineum. They are composed ...
, thigh
In human anatomy, the thigh is the area between the hip ( pelvis) and the knee. Anatomically, it is part of the lower limb.
The single bone in the thigh is called the femur. This bone is very thick and strong (due to the high proportion of ...
, anal/genital region (via the perineal nerve
The perineal nerve is a nerve of the pelvis. It arises from the pudendal nerve in the pudendal canal. It gives superficial branches to the skin, and a deep branch to muscles. It supplies the skin and muscles of the perineum. Its latency is test ...
), and may radiate into the foot and/or toe
Toes are the digits (fingers) of the foot of a tetrapod. Animal species such as cats that walk on their toes are described as being ''digitigrade''. Humans, and other animals that walk on the soles of their feet, are described as being ''plan ...
. The sciatic nerve is the most commonly affected nerve, causing symptoms of sciatica
Sciatica is pain going down the leg from the lower back. This pain may go down the back, outside, or front of the leg. Onset is often sudden following activities like heavy lifting, though gradual onset may also occur. The pain is often described ...
. The femoral nerve
The femoral nerve is a nerve in the thigh that supplies skin on the upper thigh and inner leg, and the muscles that extend the knee.
Structure
The femoral nerve is the major nerve supplying the anterior compartment of the thigh. It is the largest ...
can also be affected and cause the patient to experience a numb, tingling feeling throughout one or both legs and even feet or a burning feeling in the hips and legs. A herniation in the lumbar region often compresses the nerve root exiting at the level below the disc. Thus, a herniation of the L4–5 disc compresses the L5 nerve root, only if the herniation is posterolateral.
Cervical disc herniation
Cervical disc herniations occur in the neck, most often between the fifth and sixth (C5–6) and the sixth and seventh (C6–7) cervical vertebral bodies. There is an increased susceptibility amongst older (60+) patients to herniations higher in the neck, especially at C3–4. Symptoms of cervical herniations may be felt in the back of the skull, the neck, shoulder girdle, scapula
The scapula (plural scapulae or scapulas), also known as the shoulder blade, is the bone that connects the humerus (upper arm bone) with the clavicle (collar bone). Like their connected bones, the scapulae are paired, with each scapula on eithe ...
, arm, and hand. The nerves of the cervical plexus and brachial plexus
The brachial plexus is a network () of nerves formed by the anterior rami of the lower four cervical nerves and first thoracic nerve ( C5, C6, C7, C8, and T1). This plexus extends from the spinal cord, through the cervicoaxillary canal in th ...
can be affected.
Intradural disc herniation
Intradural disc herniation is a rare form of disc herniation with an incidence of 0.2–2.2%. Pre-operative imaging can be helpful for diagnosis, but intra-operative findings are required for confirmation.
Inflammation
It is increasingly recognized that back pain resulting from disc herniation is not always due solely to compression of the spinal cord or nerve roots, but may also be caused by chemical inflammation. There is evidence that points to a specific inflammatory mediator in back pain: an inflammatory molecule, called tumor necrosis factor alpha
Tumor necrosis factor (TNF, cachexin, or cachectin; formerly known as tumor necrosis factor alpha or TNF-α) is an adipokine and a cytokine. TNF is a member of the TNF superfamily, which consists of various transmembrane proteins with a homolo ...
(TNF), is released not only by a herniated disc, but also in cases of disc tear (''annulus'' tear) by facet joints
Facets () are flat faces on geometric shapes. The organization of naturally occurring facets was key to early developments in crystallography, since they reflect the underlying symmetry of the crystal structure. Gemstones commonly have facets cut ...
, and in spinal stenosis
Spinal stenosis is an abnormal narrowing of the spinal canal or neural foramen that results in pressure on the spinal cord or nerve roots. Symptoms may include pain, numbness, or weakness in the arms or legs. Symptoms are typically gradual i ...
.[ In addition to causing pain and inflammation, TNF may contribute to disc degeneration.
]
Diagnosis
Terminology
Terms commonly used to describe the condition include ''herniated disc'', ''prolapsed disc'', ''ruptured disc'', and ''slipped disc''. Other conditions that are closely related include disc protrusion, radiculopathy
Radiculopathy, also commonly referred to as pinched nerve, refers to a set of conditions in which one or more nerves are affected and do not work properly (a neuropathy). Radiculopathy can result in pain (radicular pain), weakness, altered sens ...
(pinched nerve), sciatica
Sciatica is pain going down the leg from the lower back. This pain may go down the back, outside, or front of the leg. Onset is often sudden following activities like heavy lifting, though gradual onset may also occur. The pain is often described ...
, disc disease, disc degeneration, degenerative disc disease
Degenerative disc disease (DDD) is a medical condition typically brought on by the normal aging process in which there are anatomic changes and possibly a loss of function of one or more intervertebral discs of the spine. DDD can take place with ...
, and black disc (a totally degenerated spinal 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, a deformity called ]spondylolisthesis
Spondylolisthesis is the displacement of one spinal vertebra compared to another. While some medical dictionaries define spondylolisthesis specifically as the forward or anterior displacement of a vertebra over the vertebra inferior to it (or t ...
.
Spinal disc herniation is known in Latin as ''prolapsus disci intervertebralis''.
; Click images to see larger versions
File:Lumbar Disc Lesions Classification.jpg, Lumbar disc lesions, classification
File:ACDF coronal english.png, Normal situation and spinal disc herniation in cervical vertebrae
File:Herniated Disc.png, Illustration depicting herniated disc and spinal nerve compression
File:Disc prolapse.png, Nucleus herniating through tear in ''annulus'' (with MRI)[Anjankar SD, Poornima S, Raju S, Jaleel M, Bhiladvala D, Hasan Q. Degenerated intervertebral disc prolapse and its association of collagen I alpha 1 Spl gene polymorphism: A preliminary case control study of Indian population. Indian J Orthop 2015;49:589-94]
File:Disc herniation - Degeneration Prolapse Extrusion Sequestration -- Smart-Servier.jpg, Illustration showing disc degeneration, prolapse, extrusion and sequestration.
Physical examination
Diagnosis of spinal disc herniation is made by a practitioner on the basis of a patient's history and symptoms, and by physical examination
In a physical examination, medical examination, or clinical examination, a medical practitioner examines a patient for any possible medical signs or symptoms of a medical condition. It generally consists of a series of questions about the patien ...
. During an evaluation, tests may be performed to confirm or rule out other possible causes with similar symptoms – spondylolisthesis, degeneration, tumor
A neoplasm () is a type of abnormal and excessive growth of tissue. The process that occurs to form or produce a neoplasm is called neoplasia. The growth of a neoplasm is uncoordinated with that of the normal surrounding tissue, and persists ...
s, metastases
Metastasis is a pathogenic agent's spread from an initial or primary site to a different or secondary site within the host's body; the term is typically used when referring to metastasis by a cancerous tumor. The newly pathological sites, then ...
and space-occupying lesion
A lesion is any damage or abnormal change in the tissue of an organism, usually caused by disease or trauma. ''Lesion'' is derived from the Latin "injury". Lesions may occur in plants as well as animals.
Types
There is no designated classifi ...
s, for instance – as well as to evaluate the efficacy of potential treatment options.
Straight leg raise
The straight leg raise is often used as a preliminary test for possible disc herniation in the lumbar region. A variation is to lift the leg while the patient is sitting. However, this reduces the sensitivity of the test. A Cochrane review published in 2010 found that individual diagnostic tests including the straight leg raising test, absence of tendon reflexes, or muscle weakness were not very accurate when conducted in isolation.
Spinal imaging
* Projectional radiography
Projectional radiography, also known as conventional radiography, is a form of radiography and medical imaging that produces two-dimensional images by x-ray radiation. The image acquisition is generally performed by radiographers, and the images ...
(X-ray imaging). Traditional plain X-rays are limited in their ability to image soft tissues such as discs, muscles, and nerves, but they are still used to confirm or exclude other possibilities such as tumors, infections, fractures, etc. In spite of their limitations, X-rays 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.
File:L5S1 prolapsed intervertibral disc PID.jpg, Narrowed space between L5 and S1 vertebrae, indicating probable prolapsed intervertebral disc - a classic picture.
* Computed tomographyscan is the most sensitive imaging modality to examine the bony structures of the spine. CT imaging allows for the evaluation of calcified herniated discs or any pathological process that may result in bone loss or destruction. It is deficient for the visualization of nerve roots, making it unsuitable in the diagnoses of radiculopathy.
* Magnetic resonance imaging
Magnetic resonance imaging (MRI) is a medical imaging technique used in radiology to form pictures of the anatomy and the physiological processes of the body. MRI scanners use strong magnetic fields, magnetic field gradients, and radio wave ...
is the gold standard study for confirming a suspected LDH. With a diagnostic accuracy of 97%, it is the most sensitive study to visualize a herniated disc due to its significant ability in soft tissue visualization. MRI also has higher inter-observer reliability than other imaging modalities. It suggests disc herniation when it shows an increased T2-weighted signal at the posterior 10% of the disc. Degenerative disc diseases have shown a correlation with Modic type 1 changes. When evaluating for postoperative lumbar radiculopathies, the recommendation is that the MRI is performed with contrast unless otherwise contraindicated. MRI is more effective than CT in distinguishing inflammatory, malignant, or inflammatory etiologies of LDH. It is indicated relatively early in the course of evaluation (<8 weeks) when the patient presents with relative indications like significant pain, neurological motor deficits, and cauda equina syndrome. Diffusion tensor imaging is a type of MRI sequence used for detecting microstructural changes in the nerve root. It may be beneficial in understanding the changes that occur after herniated lumbar disc compresses a nerve root, and might help in differentiating the patients that need surgical intervention. In patients with a high suspicion of radiculopathy due to lumbar disc herniation, yet the MRI is equivocal or negative, nerve conduction studies are indicated. T2-weighted images allow for clear visualization of protruded disc material in the spinal canal.
File:C5-C6-herniation.jpg, MRI scan of cervical disc herniation between C5 and C6 vertebrae.
File:C6-C7-disc-herniation-cevical-mri-scan.jpg, MRI scan of cervical disc herniation between C6 and C7 vertebrae
File:L4-l5-disc-herniation.png, MRI scan of large herniation (on the right) of the disc between L4 and L5 vertebrae
File:Severe herniation of L4-L5 disc.png, A rather severe herniation of the L4–L5 disc
File:Herniated-Disc.jpg, Example of a herniated disc
Spinal disc herniation is an injury to the cushioning and connective tissue between vertebrae, usually caused by excessive strain or trauma to the spine. It may result in back pain, pain or sensation in different parts of the body, and physical ...
at L5–S1 in the lumbar spine
* Myelography
Myelography is a type of radiographic examination that uses a contrast medium to detect pathology of the spinal cord, including the location of a spinal cord injury, cysts, and tumors. Historically the procedure involved the injection of a radioc ...
. An X-ray of the spinal canal following injection of a contrast material into the surrounding cerebrospinal fluid spaces will reveal 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 spur
An exostosis, also known as bone spur, is the formation of new bone on the surface of a bone. Exostoses can cause chronic pain ranging from mild to debilitatingly severe, depending on the shape, size, and location of the lesion. It is most commonl ...
s. Because myelography involves the injection of foreign substances, MRI scans are now preferred for most patients. Myelograms still provide excellent outlines of space-occupying lesions, especially when combined with CT scanning (CT myelography). CT myelography is the imaging modality of choice to visualize herniated discs in patients with contraindications for an MRI. However, due to its invasiveness, the assistance of a trained radiologist is required. Myelography is associated with risks like post-spinal headache, meningeal infection, and radiation exposure. Recent advances with a multidetector CT scan have made the diagnostic level of it nearly equal to the MRI.
* The presence and severity of myelopathy
Myelopathy describes any neurologic deficit related to the spinal cord. The most common form of myelopathy in humans, ''Spinal cord compression, cervical spondylotic myelopathy (CSM)'', also called ''degenerative cervical myelopathy'', results fro ...
can be evaluated by means of transcranial magnetic stimulation
Transcranial magnetic stimulation (TMS) is a noninvasive form of brain stimulation in which a changing magnetic field is used to induce an electric current at a specific area of the brain through electromagnetic induction. An electric pulse gener ...
(TMS), a neurophysiological method that measures the time required for a neural impulse to cross the pyramidal tracts
The pyramidal tracts include both the corticobulbar tract and the corticospinal tract. These are aggregations of efferent nerve fibers from the upper motor neurons that travel from the cerebral cortex and terminate either in the brainstem (''cort ...
, starting from the cerebral cortex
The cerebral cortex, also known as the cerebral mantle, is the outer layer of neural tissue of the cerebrum of the brain in humans and other mammals. The cerebral cortex mostly consists of the six-layered neocortex, with just 10% consisting of ...
and ending at the anterior horn cells
The anterior grey column (also called the anterior cornu, anterior horn of spinal cord, motor horn or ventral horn) is the front column of grey matter in the spinal cord. It is one of the three grey columns. The anterior grey column contains motor ...
of the cervical, thoracic, or lumbar spinal cord. This measurement is called the ''central conduction time'' (''CCT''). TMS can aid physicians to:
:*determine if myelopathy exists
:*identify the level of the spinal cord where myelopathy is located. This is especially useful in cases where more than two lesions may be responsible for the clinical symptoms and signs, such as in patients with two or more cervical disc hernias
:*assess the progression of myelopathy with time, for example before and after cervical spine surgery
:*TMS can also help in the differential diagnosis of different causes of pyramidal tract damage.
* Electromyography
Electromyography (EMG) is a technique for evaluating and recording the electrical activity produced by skeletal muscles. EMG is performed using an instrument called an electromyograph to produce a record called an electromyogram. An electromyog ...
and nerve conduction studies
A nerve conduction study (NCS) is a medical diagnostic test commonly used to evaluate the function, especially the ability of electrical conduction, of the motor and sensory nerves of the human body. These tests may be performed by medical spec ...
(EMG/NCS) measure the electrical impulses along nerve roots, peripheral nerves, and muscle tissue. Tests can indicate if there is ongoing nerve damage, if the nerves are in a state of healing from a past injury, or if there is another site of nerve compression. EMG/NCS studies are typically used to pinpoint the sources of nerve dysfunction distal
Standard anatomical terms of location are used to unambiguously describe the anatomy of animals, including humans. The terms, typically derived from Latin or Greek roots, describe something in its standard anatomical position. This position pro ...
to the spine.
Differential diagnosis
Tests may be required to distinguish
The ruling made by the judge or panel of judges must be based on the evidence at hand and the standard binding precedents covering the subject-matter (they must be ''followed'').
Definition
In law, to distinguish a case means a court decides th ...
spinal disc herniations from other conditions with similar symptoms.
* Discogenic pain
An intervertebral disc (or intervertebral fibrocartilage) lies between adjacent vertebrae in the vertebral column. Each disc forms a fibrocartilaginous joint (a symphysis), to allow slight movement of the vertebrae, to act as a ligament to hold t ...
* Mechanical pain
* Myofascial
A fascia (; plural fasciae or fascias; adjective fascial; from Latin: "band") is a band or sheet of connective tissue, primarily collagen, beneath the skin that attaches to, stabilizes, encloses, and separates muscles and other internal organs ...
pain
* Abscess
An abscess is a collection of pus that has built up within the tissue of the body. Signs and symptoms of abscesses include redness, pain, warmth, and swelling. The swelling may feel fluid-filled when pressed. The area of redness often extends b ...
* Aortic dissection
Aortic dissection (AD) occurs when an injury to the innermost layer of the aorta allows blood to flow between the layers of the aortic wall, forcing the layers apart. In most cases, this is associated with a sudden onset of severe chest or ...
* Discitis
Discitis, or diskitis, is an infection in the intervertebral disc space that affects different age groups. In adults, it can lead to severe consequences, such as sepsis or epidural abscess, but it can also spontaneously resolve, especially in ch ...
or osteomyelitis
Osteomyelitis (OM) is an infection of bone. Symptoms may include pain in a specific bone with overlying redness, fever, and weakness. The long bones of the arms and legs are most commonly involved in children e.g. the femur and humerus, while the ...
* Hematoma
A hematoma, also spelled haematoma, or blood suffusion is a localized bleeding outside of blood vessels, due to either disease or trauma including injury or surgery and may involve blood continuing to seep from broken capillary, capillaries. A he ...
* Mass lesion or malignancy
Malignancy () is the tendency of a medical condition to become progressively worse.
Malignancy is most familiar as a characterization of cancer. A ''malignant'' tumor contrasts with a non-cancerous ''benign'' tumor in that a malignancy is not s ...
* Binign tumor like neurinoma or meningeoma
* Myocardial infarction
A myocardial infarction (MI), commonly known as a heart attack, occurs when blood flow decreases or stops to the coronary artery of the heart, causing damage to the heart muscle. The most common symptom is chest pain or discomfort which may ...
* Sacroiliac joint dysfunction
The term sacroiliac joint dysfunction refers to abnormal motion in the sacroiliac joint, either too much motion or too little motion, that causes pain in this region.
Signs and symptoms
Common symptoms include lower back pain, buttocks pain, sci ...
* Spinal stenosis
Spinal stenosis is an abnormal narrowing of the spinal canal or neural foramen that results in pressure on the spinal cord or nerve roots. Symptoms may include pain, numbness, or weakness in the arms or legs. Symptoms are typically gradual i ...
* Spondylosis
Spondylosis is the degeneration of the vertebral column from any cause. In the more narrow sense it refers to spinal osteoarthritis, the age-related wear and tear of the spinal column, which is the most common cause of spondylosis. The degenera ...
or spondylolisthesis
Spondylolisthesis is the displacement of one spinal vertebra compared to another. While some medical dictionaries define spondylolisthesis specifically as the forward or anterior displacement of a vertebra over the vertebra inferior to it (or t ...
Treatment
In the majority of cases spinal disc herniation can be treated successfully conservatively, without surgical removal of the herniated material. Sciatica
Sciatica is pain going down the leg from the lower back. This pain may go down the back, outside, or front of the leg. Onset is often sudden following activities like heavy lifting, though gradual onset may also occur. The pain is often described ...
is a set of symptoms associated with disc herniation. A study on sciatica showed that about one-third of patients with sciatica recover within two weeks after presentation using conservative measures alone, and about three-quarters of patients recovered after three months of conservative treatment. However the study did not indicate the number of individuals with sciatica that had disc herniations.
Initial treatment usually consists of nonsteroidal anti-inflammatory drug
Non-steroidal anti-inflammatory drugs (NSAID) are members of a therapeutic drug class which reduces pain, decreases inflammation, decreases fever, and prevents blood clots. Side effects depend on the specific drug, its dose and duration of ...
s (NSAIDs), but long-term use of NSAIDs for people with persistent back pain is complicated by their possible cardiovascular and gastrointestinal toxicity.
Epidural corticosteroid injections provide a slight and questionable short-term improvement for those with sciatica, but are of no long-term benefit. Complications occur in up to 17% of cases when injections are performed on the neck, though most are minor. In 2014, the US Food and Drug Administration
The United States Food and Drug Administration (FDA or US FDA) is a federal agency of the Department of Health and Human Services. The FDA is responsible for protecting and promoting public health through the control and supervision of food ...
(FDA) suggested that the "injection of corticosteroids into the epidural space of the spine may result in rare but serious adverse events, including loss of vision, stroke, paralysis, and death", and that "the effectiveness and safety of epidural administration of corticosteroids have not been established, and FDA has not approved corticosteroids for this use".
Lumbar disc herniation
Non-surgical methods of treatment are usually attempted first. Pain medications may be prescribed to alleviate acute pain and allow the patient to begin exercising and stretching. There are a number of non-surgical methods used in attempts to relieve the condition. They are considered indicated
In medicine, an indication is a valid reason to use a certain test, medication, procedure, or surgery. There can be multiple indications to use a procedure or medication. An indication can commonly be confused with the term diagnosis. A diagnosis ...
, contraindicated
In medicine, a contraindication is a condition that serves as a reason not to take a certain medical treatment due to the harm that it would cause the patient. Contraindication is the opposite of indication, which is a reason to use a certain tre ...
, relatively contraindicated, or inconclusive, depending on the safety profile of their risk–benefit ratio
A risk–benefit ratio (or benefit-risk ratio) is the ratio of the risk of an action to its potential benefits. Risk–benefit analysis (or benefit-risk analysis) is analysis that seeks to quantify the risk and benefits and hence their ratio.
A ...
and on whether they may or may not help:
Indicated
* Education on proper body mechanics
* Physical therapy to address mechanical factors, and may include modalities to temporarily relieve pain (i.e. traction, electrical stimulation
Functional electrical stimulation (FES) is a technique that uses low-energy electrical pulses to artificially generate body movements in individuals who have been paralyzed due to injury to the central nervous system. More specifically, FES can ...
, massage
Massage is the manipulation of the body's soft tissues. Massage techniques are commonly applied with hands, fingers, elbows, knees, forearms, feet or a device. The purpose of massage is generally for the treatment of body stress or pain. In Eu ...
)
* Nonsteroidal anti-inflammatory drug
Non-steroidal anti-inflammatory drugs (NSAID) are members of a therapeutic drug class which reduces pain, decreases inflammation, decreases fever, and prevents blood clots. Side effects depend on the specific drug, its dose and duration of ...
s (NSAIDs)
* Weight control
Obesity is a medical condition, sometimes considered a disease, in which excess body fat has accumulated to such an extent that it may negatively affect health. People are classified as obese when their body mass index (BMI)—a person's w ...
* Spinal manipulation. Moderate quality evidence suggests that spinal manipulation is more effective than placebo for the treatment of acute (less than 3 months duration) lumbar disc herniation and acute sciatica. The same study also found "low to very low" evidence for its usefulness in treating chronic lumbar symptoms (more than 3 months) and "the quality of evidence for ... cervical spine-related extremity symptoms of any duration is low or very low". A 2006 review of published research states that spinal manipulation "is likely to be safe when used by appropriately-trained practitioners", and research currently suggests that spinal manipulation is safe for the treatment of disc-related pain.
Contraindicated
* Spinal manipulation is contraindicated when the etiology of the herniation is the result of a Motor Vehicle Collision (MVC)
* Spinal manipulation is contraindicated for disc herniations when there are progressive neurological deficits such as with ''cauda equina'' syndrome.[WHO guidelines on basic training and safety in chiropractic. "2.1 Absolute contraindications to spinal manipulative therapy", p. 21.]
WHO
Who or WHO may refer to:
* Who (pronoun), an interrogative or relative pronoun
* Who?, one of the Five Ws in journalism
* World Health Organization
Arts and entertainment Fictional characters
* Who, a creature in the Dr. Seuss book '' Horton He ...
* A review of non-surgical spinal decompression
Spinal decompression is the relief of pressure on the spinal cord or on one or more compressed nerve roots passing through or exiting the spinal column. Decompression of the spinal neural elements is a key component in treating spinal radiculopath ...
found shortcomings in most published studies and concluded that there was only "very limited evidence in the scientific literature to support the effectiveness of non-surgical spinal decompression therapy". Its use and marketing have been very controversial.[Be Wary of Spinal Decompression Therapy with VAX-D or Similar Devices]
Stephen Barrett
Stephen Joel Barrett (; born 1933) is an American retired psychiatrist, author, co-founder of the National Council Against Health Fraud (NCAHF), and the webmaster of Quackwatch. He runs a number of websites dealing with quackery and health frau ...
Surgery
Surgery may be useful when a herniated disc is causing significant pain radiating into the leg, significant leg weakness, bladder problems, or loss of bowel control.
* Discectomy
A discectomy (also called open discectomy, if done through a 1/2 inch or larger skin opening) is the surgical removal of abnormal disc material that presses on a nerve root or the spinal cord. The procedure involves removing a portion of an int ...
(the partial removal of a disc that is causing leg pain) can provide pain relief sooner than non-surgical treatments.
* Small endoscopic discectomy (called ''nano-endoscopic discectomy'') is non-invasive and does not cause failed back syndrome
Failed back syndrome or post-laminectomy syndrome is a condition characterized by chronic pain following back surgeries. Many factors can contribute to the onset or development of FBS, including residual or recurrent spinal disc herniation, persi ...
.
* Invasive microdiscectomy
A discectomy (also called open discectomy, if done through a 1/2 inch or larger skin opening) is the surgical removal of abnormal disc material that presses on a nerve root or the spinal cord. The procedure involves removing a portion of an in ...
with a one-inch skin opening has not been shown to result in a significantly different outcome from larger-opening discectomy with respect to pain.[ It might however have less risk of infection.
* ]Failed back syndrome
Failed back syndrome or post-laminectomy syndrome is a condition characterized by chronic pain following back surgeries. Many factors can contribute to the onset or development of FBS, including residual or recurrent spinal disc herniation, persi ...
is a significant, potentially disabling, result that can arise following invasive spine surgery to treat disc herniation. Smaller spine procedures such as ''endoscopic transforaminal lumbar discectomy'' cannot cause failed back syndrome, because no bone is removed.
* The presence of ''cauda equina'' syndrome (in which there is incontinence, weakness, and genital numbness) is considered a medical emergency requiring immediate attention and possibly surgical decompression.
When different forms of surgical treatments including (discetomy, microdiscectomy, and chemonucleolysis) were compared evidence was suggestive rather than conclusive. A Cochrane review from 2007 reported: "surgical discectomy for carefully selected patients with sciatica due to a prolapsed lumbar disc appears to provide faster relief from the acute attack than non‐surgical management. However, any positive or negative effects on the lifetime natural history of the underlying disc disease are unclear. Microdiscectomy gives broadly comparable results to standard discectomy. There is insufficient evidence on other surgical techniques to draw firm conclusions." Regarding the role of surgery for failed medical therapy in people without a significant neurological deficit, a Cochrane review
Cochrane (previously known as the Cochrane Collaboration) is a British international charitable organisation formed to organise medical research findings to facilitate evidence-based choices about health interventions involving health profes ...
concluded that "limited evidence is now available to support some aspects of surgical practice".
Following surgery, rehabilitation programmes are often implemented. There is wide variation in what these programmes entail. A Cochrane review found low- to very low-quality evidence that patients who participated in high-intensity exercise programmes had slightly less short term pain and disability compared to low-intensity exercise programmes. There was no difference between supervised and home exercise programmes.
Epidemiology
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 low back pain
Low back pain (LBP) or lumbago is a common disorder involving the muscles, nerves, and bones of the back, in between the lower edge of the ribs and the lower fold of the buttocks. Pain can vary from a dull constant ache to a sudden sharp feel ...
(lumbago) and often leg pain as well, in which case it is commonly referred to as sciatica
Sciatica is pain going down the leg from the lower back. This pain may go down the back, outside, or front of the leg. Onset is often sudden following activities like heavy lifting, though gradual onset may also occur. The pain is often described ...
. Lumbar disc herniation occurs 15 times more often than cervical (neck) disc herniation, and it is one of the most common causes of low 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
The sacrum (plural: ''sacra'' or ''sacrums''), in human anatomy, is a large, triangular bone at the base of the spine that forms by the fusing of the sacral vertebrae (S1S5) between ages 18 and 30.
The sacrum situates at the upper, back part ...
, and the coccyx
The coccyx ( : coccyges or coccyxes), commonly referred to as the tailbone, is the final segment of the vertebral column in all apes, and analogous structures in certain other mammals such as horses. In tailless primates (e.g. humans and othe ...
. 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
Spinal stenosis is an abnormal narrowing of the spinal canal or neural foramen that results in pressure on the spinal cord or nerve roots. Symptoms may include pain, numbness, or weakness in the arms or legs. Symptoms are typically gradual i ...
are more likely causes of low back pain or leg pain.
* 4.8% of males and 2.5% of 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 two weeks.
* Generally, males have a slightly higher incidence than females.
Prevention
Because there are various causes of back injuries, prevention must be comprehensive. Back injuries are predominant in manual labor
Manual labour (in Commonwealth English, manual labor in American English) or manual work is physical work done by humans, in contrast to labour by machines and working animals. It is most literally work done with the hands (the word ''manual'' ...
, so the majority of low back pain
Low back pain (LBP) or lumbago is a common disorder involving the muscles, nerves, and bones of the back, in between the lower edge of the ribs and the lower fold of the buttocks. Pain can vary from a dull constant ache to a sudden sharp feel ...
prevention methods have been applied primarily toward biomechanics
Biomechanics is the study of the structure, function and motion of the mechanical aspects of biological systems, at any level from whole organisms to organs, cells and cell organelles, using the methods of mechanics. Biomechanics is a branch of ...
. Prevention must come from multiple sources such as education, proper body mechanics, and physical fitness
Physical fitness is a state of health and well-being and, more specifically, the ability to perform aspects of Outline of sports, sports, occupations and daily activities. Physical fitness is generally achieved through proper nutrition, moderate ...
.
Education
Education should emphasize not lifting beyond one's capabilities and giving the body a rest after strenuous effort. Over time, poor posture can cause the intervertebral disc to tear or become damaged. Striving to maintain proper posture and body alignment will aid in preventing disc degradation.
Exercise
Exercises that enhance back strength may also be used to prevent back injuries
Back injuries result from damage, wear, or trauma to the bones, muscles, or other tissues of the back. Common back injuries include sprains and strains, herniated discs, and fractured vertebrae. The lumbar spine is often the site of back pain. ...
. Back exercises include the prone push-ups/press-ups, upper back extension, transverse abdominis
The transverse abdominal muscle (TVA), also known as the transverse abdominis, transversalis muscle and transversus abdominis muscle, is a muscle layer of the anterior and lateral (front and side) abdominal wall which is deep to (layered below) t ...
bracing, and floor bridges. If pain is present in the back, it can mean that the stabilization muscles of the back are weak and a person needs to train the trunk musculature. Other preventative measures are to lose weight and not to work oneself past fatigue. Signs of fatigue include shaking, poor coordination, muscle burning, and loss of the transverse abdominal brace. Heavy lifting should be done with the legs performing the work, and not the back.
Swimming is a common tool used in strength training. The usage of lumbar-sacral support belts may restrict movement at the spine and support the back during lifting.
Research
Future treatments may include stem cell therapy.
References
External links
{{Authority control
Spinal cord disorders
Bones of the vertebral column