Nucleus Pulposus Herniation – Causes, Symptoms, Treatment

Nucleus pulposus herniation is the most common cause of sciatic pain and one of the most common indications for spine surgery worldwide. This condition presents as a displacement of the nucleus pulposus beyond the intervertebral disc space.

Nucleus pulposus herniation results from a failure in the annulus fibrosis integrity, making the content of the nucleus to protrude into the neural canal, the intervertebral foramen (foraminal) or lateral to the foramen (extraforaminal). Nucleus pulposus protrusion is the less severe scenario of disc herniation, due to partial rupture of the annulus fibrosis when the annulus structure becomes completely disrupted the nucleus content may extrude outside the disc space and in some cases a fragment of nucleus pulposus may migrate (sequestration).

The disc anatomy consists of two main structures, the nucleus pulposus (NP) and the annulus fibrosus (AF).

Anatomy

The nucleus pulposus is composed of water, type II collagen, chondrocyte-like cells, and proteoglycans. This unique composite allows the NP to be elastic, flexible under stress forces and to absorb compression. Disc herniation is a consequence of degenerative changes in the annulus; those changes are age-related adaptive modifications in the disc structure that encompass desiccation, fissures, disc narrowing, mucinous degeneration, intradiscal gas (vacuum), osteophytes, inflammatory changes, and subchondral sclerosis. Annulus fissures predispose to a weakness, which allows disc material to bulge or migrate outside the annulus margins.

The composition of the AF is mainly concentric layers of collagen type I fibers, forming a fibrous tissue with helical disposition surrounding the NP, this structure is denser in the anterior part and is attached to the vertebral body by Sharpey fibers.

Another way to differentiate protrusion from extrusion is related to the shape of the displaced material. A protrusion is when the greatest distance between the limits of the disc material outside the disc space is less than the distance between the limits of the base of that disc material outside the disc space. The base is the width of disc material at the outer margin of the disc space. Extrusion is present when, in at least one plane, the distance between the limits of the disc material beyond the disc space exceeds the distance between the limits of the base of the disc material beyond the disc space.

Another type of disc herniation is when disc material migrates in craniocaudal direction through a gap between the endplate and the disc making a space within the vertebral body (intravertebral disc herniation) better know as Schmorl nodes.

The integrity of the annulus fibrosus has to be compromised to develop a nucleus pulposus herniation. The loss of annulus fibrosus integrity may be present in different forms, such as radial, transverse, or concentric fissures. These types of fissures are observable in the early stages of disc degeneration. One important kind of annulus fissure can be observed in T2-weighted MRI and is called high-intensity zone (HIZ), this changes denote the presence of liquid within an annular fissure and correlates with acute disc annular tear or fissure.

Causes of Nucleus Pulposus Herniation

  • Disc herniation and disc degeneration – are associated terms, being nucleus pulposus herniation a possible evolution from a degenerative disc. Disc degeneration is usually associated with the loss of proteoglycans. Multiple factors influence the degenerative process such as genetic, mechanical, and behavioral.
  • Mechanical load – is important in maintaining a healthy IVD by generating signals to cells that regulate proper matrix homeostasis. On the other hand, prolonged exposure to hypo- or hyper-loading correlates with disc degeneration induction.
  • Repetitive trauma – such as poor posture, poor ergonomics, or repetitive heavy work can lead to disc degeneration and a bulging disc. These long term injuries are often also associated with poor muscle strength, obesity, and other factors such as smoking.
  • An Injury caused – by sudden forces or load on the disc such as a car accident or an awkward heavy lift. This sudden increase in pressure on the disc can cause damage and tears to the annulus that causes a bulging disc.
  • Spinal Degeneration – While some degeneration is a normal part of the aging process, poor spinal function and posture will dramatically speed up disc degeneration with a bulging disc.
  • People who have led a sedentary lifestyle or those who smoke – increase the chances for bulging discs.
  • Continuous strain on the disc from injury or heavy lifting – and strain can wear them down throughout the years.
  • Weakened back muscles – can accelerate the process and may lead to a sudden herniation of the weakened disc. Although bulging discs occur over time, herniated discs may occur quickly by trauma.
  • Bad posture – including improper body positioning during sleep, sitting, standing, or exercise are all risk factors that may contribute to the development of a bulging disc.
  • Obesity
  • High contact sports or activities – are also risk factors.
  • Runners who fail to use shoes that provide orthopedic support – may also develop bulging discs.
  • Activities that place stress and strain on the spine – can lead to the weakening of the discs.

Symptoms of Nucleus Pulposus Herniation

If a Nucleus Pulposus Herniation has not yet reached the stage of herniation, a patient may have little to no pain involved. A bulging disc may have no pain at all because it has not reached a certain severity level, and this can make it difficult to identify the bulging disc symptoms before the condition becomes more severe.

Most commonly, Nucleus Pulposus Herniation creates pressure points on nearby nerves which create a variety of sensations. Evidence of a bulging disc may range from mild tingling and numbness to moderate or severe pain, depending on the severity. In most cases, when a bulging disc has reached this stage it is near or at herniation.

  • Tingling or pain in the fingers, hands, arms, neck or shoulders – This could indicate a bulging disc in the cervical area.
  • Pain in the feet, thighs, lower spine and buttocks – This is the most common symptom and could indicate an issue in the lumbar region.
  • Difficulty walking or feeling of impairment while lifting or holding things.
  • Loss of Bladder or Bowel Function – There are some bulging disc cases where professional care is essential. In some cases, such as when you lose bowel or bladder control, it is deemed an emergency, and you may require immediate surgery. These bulges usually are very significant and affect your nerve control involving your bladder or bowels. You should go straight to your nearest emergency department in these instances.
  • Weakness in your limb muscles – is a significant concern. If you experience arm, hand, leg or foot weakness, please seek prompt medical assessment.
  • The reduced or altered sensation – is your next priority. Mild disc bulges can reduce your ability to feel things touching you, e.g. numbness or pins and needles. If you experience any of the above symptoms, you should seek professional assistance.
  • Referred Pain – Pain in your limbs, e.g. legs (sciatica) or arms (brachialgia) is usually a more significant injury than when experiencing only spinal pain. We recommend that you seek the professional advice of your trusted spinal care practitioner.
  • Spinal Pain – Interestingly, if you are only experiencing spinal pain, bulging discs are generally mild injuries and the most likely to rehabilitate quickly. Please adhere to low disc pressure postures and exercise accordingly. If in doubt, please seek professional advice.
  • Intermittent or continuous back pain. This may be made worse by movement, coughing, sneezing, or standing for long periods of time.
  • Spasm of the back muscles
  • Sciatica. Pain that starts near the back or buttock and travels down the leg to the calf or into the foot.
  • Muscle weakness in the legs
  • Numbness in the leg or foot
  • Decreased reflexes at the knee or ankle
  • Changes in bladder or bowel function

Associate clinical feature is

Approximate area of “saddle anesthesia” seen from behind (yellow highlight)

These symptoms require immediate medical evaluation as they may be a sign of a potentially life-threatening condition.

Diagnosis of Nucleus Pulposus Herniation

History

Proper understanding of anatomical zones and vertebral levels is essential to interpret the clinical manifestations secondary to a disc herniation. Wiltse proposed these anatomical zones, based on the following landmarks: medial border of the articular facet, lateral, upper and medial borders of the pedicles, coronal and sagittal planes at the center of the disc. On the axial plane, these landmarks determine the central zone, the subarticular zone (lateral recess), foraminal, and extraforaminal zones. On the sagittal plane, the levels are termed as follows: The supra pedicular level, the pedicular level, the infrapedicular level, and the disc level. The correct knowledge of anatomy and the relationship between nerve roots and disc herniation allows the proper understanding of common clinical findings associated with this problem.

We summarize the anatomy, motor function, sensitive distribution, and reflex of the most commons nerve roots involved in cervical and lumbosacral nucleus pulposus herniation:

Cervical

  • C5 nerve root – Exits between C4 and C5 foramina, innervates deltoids and biceps (with C6), sensory distribution: lateral arm (axillary nerve) and is assessed with biceps reflex.
  • C6 nerve root – Exits between C5 and C6 foramina, innervates biceps (with C5) and wrist extensors, sensory distribution: lateral forearm (musculocutaneous nerve), assessed with brachioradialis reflex.
  • C7 nerve root – Exits between C6 and C7 foramina, innervates triceps, wrist flexors, and finger extensors, sensory distribution: middle finger, assessed with triceps reflex.
  • C8 nerve root – Exits between C7 and T1 foramina, innervates interosseus muscles and finger flexors, sensory distribution: ring and little fingers and distal half of the forearm (ulnar side), no reflex.

Lumbosacral

  • L1 nerve root – Exits between L1 and L2 foramina, innervates iliopsoas muscle, sensory distribution: upper third thigh, assessed with the cremasteric reflex (male).
  • L2 nerve root – Exits between L2 and L3 foramina, innervates iliopsoas muscle, hip adductor, and quadriceps, sensory distribution: middle third thigh, no reflex.
  • L3 nerve root – Exits between L3 and L4 foramina, innervates iliopsoas muscle, hip adductor, and quadriceps, sensory distribution: lower third thigh, no reflex.
  • L4 nerve root – Exits between L4 and L5 foramina, innervates quadriceps and tibialis anterior, sensory distribution: anterior knee, medial side of the leg, assessed with patellar reflex.
  • L5 nerve root – Exits between L5 and S1 foramina, innervates extensor hallucis longus, extensor digitorum longus, and brevis, and gluteus medius, sensory distribution: anterior leg, lateral leg, and dorsum of the foot, no reflex.
  • S1 Nerve – back, radiating into buttock, lateral or posterior thigh, posterior calf, lateral or plantar foot; sensory loss on the posterior calf, lateral or plantar aspect of foot;  weakness on hip extension, knee flexion, plantar flexion of the foot; Achilles tendon; Medial buttock, perineal, and perianal region; weakness may be minimal, with urinary and fecal incontinence as well as sexual dysfunction.
  • S2-S4 Nerves – sacral or buttock pain radiating into the posterior aspect of the leg or the perineum; sensory deficit on the medial buttock, perineal, and perianal region; absent bulbocavernosus, anal wink reflex.

Cervical and thoracic disc herniation can also exhibit symptoms of myelopathy such as spasticity, clumsiness, wide-based gate, and weakness, on physical examination hyperreflexia is the most important sign. The Lhermitte sign is the presence of an electric shock-like sensation towards the back and lower extremities, especially by flexing the neck. Bowel and bladder dysfunction may indicate a poor prognosis.

Physical Examination

A physical exam for diagnosing disc pain may include one or more of the following tests:

  • Palpation – Palpating (feeling by hand) certain structures can help identify the pain source. For example, worsened pain when pressure is applied to the spine may indicate sensitivity caused by a damaged disc.
  • Movement tests – Tests that assess the spine’s range of motion may include bending the neck or torso forward, backward, or to the side. Additionally, if raising one leg in front of the body worsens leg pain, it can indicate a lumbar herniated disc (straight leg raise test).
  • Muscle strength – A neurological exam may be conducted to assess muscle strength and determine if a nerve root is compressed by a herniated disc. A muscle strength test may include holding the arms or legs out to the side or front of the body to check for tremors, muscle atrophy, or other abnormal movements.
  • Reflex test – Nerve root irritation can dampen reflexes in the arms or legs. A reflex test involves tapping specific areas with a reflex hammer. If there is little or no reaction, it may indicate a compressed nerve root in the spine.
  • The straight leg raise test – With the patient lying supine, the examiner slowly elevates the patient’s led at an increasing angle, while keeping the leg straight at the knee joint. The test is positive if it reproduces the patient’s typical pain and paresthesia.
  • The contralateral (crossed) straight leg raise test – As in the straight leg raise test, the patient is lying supine, and the examiner elevates the asymptomatic leg. The test is positive if the maneuver reproduces the patient’s typical pain and paresthesia. The test has a specificity higher than 90%.

Lab Test

  • A medical history – in which you answer questions about your health, symptoms, and activity.
  • Erythrocyte sedimentation rate and C-reactive protein – are inflammatory markers, and they are requested if suspicious for a chronic inflammatory condition or infectious cause as the etiology. A complete blood count is useful when suspecting infection or malignancy.
  • A physical exam to assess your strength – reflexes, sensation, stability, alignment, and motion. You may also need blood tests.
  • Laboratory testing – may include white blood cell (WBC) count, erythrocyte sedimentation rate (ESR), and C-reactive protein (CRP).
  • Elevated ESR – could indicate infection, malignancy, chronic disease, inflammation, trauma, or tissue ischemia.
  • Elevated CRP – levels are associated with infection.

Imaging

  • X-rays – X-ray is the initial workup study when there is a strong suspicion of a specific cause of cervical or back pain (fracture, infection, tumor) or in the presence of red flags (fever, age more than 50, recent trauma, pain at night or rest, unexplained weight loss, progressive motor or sensory deficit, saddle anesthesia, history of cancer or osteoporosis, failure to improve after six weeks of conservative treatment). Anteroposterior and lateral x-ray is helpful to assess fracture, bony deformity, decreased intervertebral height, osteophytes, spondylolisthesis, and facet joint osteoarthritis.
  • Magnetic Resonance Imaging (MRI) scan – MRI is the recommended diagnostic imaging in cases of severe or progressive neurologic deficits, suspicion of an underlying condition such as infection, fracture, cauda equina syndrome, spinal cord compression. In cases of radiculopathy, most of the cases improve with conservative treatment and MRI is indicated in those cases with significant pain or neurologic deficits.
  • A myelogram – is a specialized X-ray where dye is injected into the spinal canal through a spinal tap. An X-ray fluoroscope then records the images formed by the dye. The dye used in a myelogram shows up white on the X-ray, allowing the doctor to view the spinal cord and canal, a bulging disc in detail. Myelograms can show a nerve being pinched and a bulging disc by a herniated disc, bony overgrowth, spinal cord tumors, and abscesses. A CT scan may follow this test.
  • Computed Tomography (CT) scan – is a noninvasive test that uses an X-ray beam and a computer to make 2-dimensional images of your spine. It may or may not be performed with a dye (contrast agent) injected into your bloodstream. This test is especially useful for confirming which bulging disc is damaged. CT scan is not usually requested in nucleus pulposus herniation. However, it can be helpful in some cases when there is a suspicion of calcified disc herniation (thoracic disc herniation has a 30 to 70% rate of calcification) which is more challenging especially when surgery is a consideration.
  • Electromyography (EMG) & Nerve Conduction Studies (NCS) – EMG tests measure the electrical activity of your muscles. Small needles are placed in your muscles, and the results are recorded on a special machine. NCS is similar, but it measures how well your nerves pass an electrical signal from one end of the nerve to another. These tests can detect nerve damage and muscle weakness and a bulging disc.
  • Discogram – A discogram may be recommended to confirm which bulging disc is painful if surgical treatment is considered. In this test, the radiographic dye is injected into the disc to recreate disc pain from the dye’s added pressure.

In the presence of low back pain without symptoms of radiculopathy, there is no need to request studies as most of the patients improve in a couple of weeks, a 4-week follow-up is a usual timeframe.

Treatment

Therapeutic management of nucleus pulposus herniation encompasses conservative and surgical treatment. Conservative treatment is the main strategy due to the natural history of nucleus pulposus herniation, with good response to pain treatment or nerve root steroid injection as well as some cases of spontaneous regression.

Non-Surgical

  • Spine-Specialized physical therapy – typically includes a combination of stretching, strengthening, and aerobic exercise to provide better stability and support for the spine.
  • Massage therapy – can help reduce muscle tension and muscle spasms, which may add to back or neck pain. Muscle tension is especially common around an unstable spinal segment where a disc is unable to provide the necessary support
  • Ice & Moist Heat Application – Ice application where the ice is wrapped in a towel or an ice pack for about 20 minutes to the affected region, thrice a day, helps in relieving the symptoms of a disc bulge. Heat application in the later stages of treatment also provides the same benefit.
  • Hot Bath –  Taking a hot bath or shower also helps in dulling the pain from a disc bulge. Epsom salts or essential oils can be added to a hot bath. They will help in soothing the inflamed region.
  • Traction – traction is the best essential treatment for bulging discs, pinched nerve, radiating pain management. It can be done in a manual and dynamic way to relieves pain in bulging discs.
  • Massage therapy – may give short-term pain relief, but not functional improvement, for those with acute lower back pain. It may also give short-term pain relief and functional improvement for those with long-term (chronic) and sub-acute lower back pain, but this benefit does not appear to be sustained after 6 months of treatment. There does not appear to be any serious adverse effects associated with massage.
  • Acupuncture – may provide some relief for back pain. However, further research with stronger evidence needs to be done.
  • Spinal manipulation – is a widely-used method of treating back pain, although there is no evidence of long-term benefits.
  • Back school –  is an intervention that consists of both education and physical exercises. A 2016 Cochrane review found the evidence concerning back school to be very low quality and was not able to make generalizations as to whether the back school is effective or not.
  • Patient education – on proper body mechanics (to help decrease the chance of worsening pain or damage to the disk)
  • Physical therapy – which may include ultrasound, massage, conditioning, and exercise. The goal of physical therapy is to help you return to full activity as soon as possible and prevent re-injury. Physical therapists can instruct you on proper posture, lifting, and walking techniques, and they’ll work with you to strengthen your lower back, leg, and stomach muscles. They’ll also encourage you to stretch and increase the flexibility of your spine and legs. Exercise and strengthening exercises are key elements to your treatment and should become part of your life-long fitness.
  • Over the Door Traction – This is a very effective treatment for a disc bulge. It helps in relieving muscle spasms and pain. Typically a 5 to 10-pound weight is used and it is important that patients do this under medical guidance.
  • Weight control – By keto diet or maintaining or changing the food habit to reduce the weight not any movement during the time of acute pain.
  • Use of a lumbosacral back support
  • Typically – conservative therapy is the first line of treatment to manage lumbar disk disease. Approach for Treating and Reversing a Disc Bulge about half of the disc bulges heal within six months and only about 10% of the disc bulges require surgery. So, the good news is that conservative treatment for a disc bulge helps in treating as well as reversing the disc bulges.
  • Eat Nutritiously During Your Recovery – All bones and tissues in the body need certain nutrients in order to heal properly and in a timely manner. Eating a nutritious and balanced diet that includes lots of minerals and vitamins are proven to help heal back pain of all types. Therefore focus on eating lots of fresh produce (fruits and veggies), whole grains, lean meats, and fish to give your body the building blocks needed to properly healing PLID. In addition, drink plenty of purified water, milk, and other dairy-based beverages to augment what you eat.
    • In bulging disc needs ample minerals (calcium, phosphorus, magnesium, boron) and protein to become strong and healthy again.
    • Excellent sources of minerals/protein include dairy products, tofu, beans, broccoli, nuts and seeds, sardines and salmon.
    • Important vitamins that are needed for bone healing include vitamin C (needed to make collagen), vitamin D (crucial for mineral absorption), and vitamin K (binds calcium to bones and triggers collagen formation).
    • Conversely, don’t consume food or drink that is known to impair bone/tissue healing, such as alcoholic beverages, sodas, most fast food items and foods made with lots of refined sugars and preservatives.

Medications

  • Analgesics – Such as paracetamol and prescription-strength drugs that relieve pain but not inflammation.
  • Muscle Relaxants –  These medications provide relief from spinal muscle spasms.  Muscle relaxants, such as baclofen, tolperisone, eperisone, methocarbamol, carisoprodol, and cyclobenzaprine, may be prescribed to control muscle spasms.
  • Neuropathic Agents – Drugs(pregabalin & gabapentin) that address neuropathic—or nerve-related—pain. This includes burning, numbness, and tingling.
  • Opioids – Also known as narcotics, these medications are intense pain relievers that should only be used under a doctor’s careful supervision.
  • NSAIDs – Prescription-strength drugs that reduce both pain and inflammation. Pain medicines and anti-inflammatory drugs help to relieve pain and stiffness, allowing for increased mobility and exercise. There are many common over-the-counter medicines called non-steroidal anti-inflammatory drugs (NSAIDs). They include mainly or first choice etodolac, then aceclofenac, etoricoxib, ibuprofen, and naproxen.
  • Calcium & vitamin D3 – To improve bone health and healing fracture. As a general rule, men and women age 50 and older should consume 1,200 milligrams of calcium a day, and 600 international units of vitamin D a day.
  • Glucosamine & Diacerein, Chondroitin sulfate – can be used to tightening the loose tendon, cartilage, ligament, and cartilage, ligament regenerates cartilage or inhabits the further degeneration of cartilage, ligament.
  • Dietary supplement – to remove general weakness & improved health.
  • Vitamin B1, B6, and B12 – It is essential for neuropathic pain management, pernicious anemia, with vitamin b complex deficiency pain, paresthesia, numbness, itching with diabetic neuropathy pain, myalgia, etc.
  • Antidepressants – A drug that blocks pain messages from your brain and boosts the effects of endorphins (your body’s natural painkillers).
  • Corticosteroid – to healing the nerve inflammation and clotted blood in the joints. Steroids may be prescribed to reduce the swelling and inflammation of the nerves. They are taken orally (as a Medrol dose pack) in a tapering dosage over a five-day period. It has the advantage of providing almost immediate pain relief within a 24-hour period.
  • Topical Medications – These prescription-strength creams, gels, ointments, patches, and sprays help relieve pain and inflammation throughout the skin.
  • Steroid injections  The procedure is performed under x-ray fluoroscopy and involves an injection of corticosteroids and a numbing agent into the epidural space of the spine. The medicine is delivered next to the painful area to reduce the swelling and inflammation of the nerves (Fig. 3). About 50% of patients will notice relief after an epidural injection, although the results tend to be temporary. Repeat injections may be given to achieve the full effect. Duration of pain relief varies, lasting for weeks or years. Injections are done in conjunction with a physical therapy and/or home exercise program.

Surgery

  • Microdiscectomy – for a herniated disc, a minimally-invasive procedure in which the herniated portion of the disc is removed.
  • Artificial disc replacement – for degenerative disc disease and herniated discs is a minimally invasive procedure that replaces a damaged disc with a specialized implant that mimics the normal function of the disc, maintaining mobility.
  • Spinal fusion – fusion for degenerative disc disease, in which the disc space is fused together to remove motion at the spinal segment. Spinal fusion involves setting up a bone graft, as well as possible implanted instruments, to facilitate bone growth across the facet joints. Fusion occurs after the surgery.
  • Open Back Surgery – Traditionally, bulging discs are treated with an open back procedure, meaning the surgeon makes a large incision into the skin and cuts muscle and surrounding tissue to gain access to the problematic disc. This traditional surgical option is invasive, requires overnight hospitalization, general anesthesia, and requires a lengthy recovery coupled with strong pain medication.
  • Endoscopic Surgery – Fortunately, you have a second option with endoscopic spine surgery. Thanks to the advancement of surgical technology at bulged disc surgery can be performed using endoscopic procedures, meaning the surgeon makes a small incision to insert special surgical tools. During an endoscopic bulging disc operation, the surgeon uses a tiny camera to visualize and gain access to your damaged disc. This minimally invasive new approach offers shorter recovery, easier rehabilitation, and a much higher success rate than open back or neck surgery. A local anesthetic is all that is usually required.

Some patients will not benefit from conservative treatment and will require surgery to decompress the nerve involved. Classical surgical indications are motor deficit, cauda equina syndrome, and persistent pain after conservative treatment.

In cervical disc herniation, there is no evidence of effectiveness for conservative treatment compared with surgery [Level I]. Different randomized controlled trials (RTC) have compared conservative versus surgical treatment in lumbar disc herniation, observing faster pain relief and recovery in the early surgery groups, however, similar outcomes in the long term (one or two years) were found. In another trial, carefully selected patients who underwent surgery for lumbar disc herniation achieved greater improvement compared to nonoperative treated patients at eight years follow up [Level II].

References