By: Cindya Y. Umaña, SPT
A herniated disc most commonly occurs in the lumbar spine, but can also occur at the cervical spine level. A disc bulge or protrusion occurs when the annulus fibrosus of the intervertebral disc remains intact, but the increased pressure of the nucleous pulposus protruding from the disk causes compression of any surrounding spinal nerves. A true disk herniation occurs when the annulus fiber ruptures and the nucleous pulposus leaks out from the center of the disc. The nucleous pulposus can cause irritation to the spinal nerves and initiate an inflammatory response. The nucleous pulposus is the gel-like substance of the inner intervertebral disk which primary function is shock absorption. Age is a factor for an increased chance of a herniated disc due to the elasticity and water content of nucleus pulposus decreasing with age.1
There are 7 cervical vertebrae which are separated by discs, which act as shock absorbers preventing the vertebrae from rubbing together. The annulus fibrosus is the outer ring of the disk that has fibers that attach between each vertebral body. The nucleous pulposus is the gel-like substance of the inner intervertebral disk which primary function is shock absorption. At every cervical level, a pair of spinal nerves exits from the spinal cord to branch to the entire body to relay sensory and motor information from the body to the brain.2
Cervical Spine and Intervetebral disc Anatomy Video
The levels that are most commonly affected with dics herniations are C5-C6, C6-C7, and C4-C5. The level of C7-T1 is rarely seen to be affected with herniation. When there is a herniation, the nerve that is affected is the one exiting at that level. For example, a disc herniation at level C6-C7 would affect the C7 nerve root.3
A cervical disc herniation with the following affected nerve root can present signs and symptoms in following manner:3
C4 - C5 (C5 nerve root) -weakness in the deltoid muscle and shoulder pain.
C5 - C6 (C6 nerve root) - weakness in the biceps and wrist extensor muscles. Numbness and tingling along with pain can radiate to the thumb side of the hand.
C6 - C7 (C7 nerve root) - weakness in the triceps and the finger extensor muscles. Numbness and tingling along with pain can radiate down the triceps and into the middle finger.
C7 - T1 (C8 nerve root) - weakness with handgrip. Numbness and tingling and pain can radiate down the arm to the little finger side of hand.
IV. Incidence/ Prevalence:
A herniated disc of the cervical spine can be detected by magnetic resonance imaging (MRI) in 10% of asymptomatic individuals aged younger than 40 years and 5% of those older than 40 years.4
Also, degenerative disc disease (DDD) may be observed with an MRI in 25% of asymptomatic individuals aged less than 40 years and 60% of those aged more than 40 years.4 The true source of neck pain or radiating pain may not always be coming from the herniated disc seen with diagnostic imaging. However, 51% of adults experience neck and/or arm pain at some time in their life.4
V. Clinical Presentation
Symptoms of a herniated disc may include some or all of the following:5
• Dull or sharp pain in the neck or between the shoulder blades, which can be intensified by certain positions or after certain movements.
• Cervical radiculopathy: Pain that radiates down the arm to the hand or fingers.
• Numbness or tingling in the shoulder or down the arm to fingers.
• Weakness in both arms and legs and gait abnormalities.
VI. Potential Etiologies:
Four stages of a herniated disc:1
1. Disc Degeneration: chemical changes associated with aging causes discs to weaken, but without a herniation.
2. Prolapse: the position of the disc changes so that there is protrusion of the nucleus propulsus with some slight impingement into the spinal canal.
3. Extrusion: the nucleus pulposus breaks through the annulus fibrosus, but remains within the disc.
4. Sequestration: the nucleus pulposus breaks through the annulus fibrosus and lies outside the disc in the spinal canal.
Disc herniation typically occurs as a result to posterolateral annular stress.6 All discs begin to degenerate in the second decade of life. Repetitive use causes circumferential tears to form in the annulus fibrosus. Gradually, circumferential tears progress into radial tears, which progress into radial fissures.6 The disc composition and shape is deformed because of the tear running through it. There is also a loss of disc height because of annular fibrosus bulging towards the periphery. When the nucleus propulsus leaks from the center of the disc, its contents empty through the fissures and causes further degradation and thinning of the space in between each disc.6
Factors that may increase the risk of a herniated disc include: vibrational stress, heavy lifting, poor posture or biomechanics, sedentary lifestyle, and whiplash accidents or frequent acceleration/deceleration.6
VII. Diagnostic Tests:
MRI remains the imaging modality of choice to evaluate cervical herniated disc, due to its low morbidity and noninvasiveness. Also, advantages for using an MRI for diagnostics includes soft-tissue definition, cerebrospinal fluid visualization, and lack of radiation exposure to the patient.6,7
VIII. Conservative Treatment:
Nonsurgical treatment is the first intervention to treat the symptoms for a cervical disc herniation. Over 90% of people improve in about 6 weeks and return to normal activity.2
These include the following:8
- Physical therapy exercises such as gentle massage, stretching, and neck bracing or traction to decrease pain and increase flexibility.8
- Pain medications such as NSAIDs to reduce swelling and pain, muscle relaxants to calm spasm, and narcotic painkillers to alleviate severe acute pain.8
Physical therapy can also emphasize patient education on decreasing risk factors, such as modifying posture, teaching proper body mechanics, and suitable exercises for pain relief and physical function.8
IX. Surgical Treatment:
Anterior Cervical Discectomy and Fusion
Anterior cervical discectomy surgery may be recommended if non-operative measures do not work. Removing the entire damaged disc or a partially damaged disc relieves pressure on the involved nerve roots and possibly on the spinal cord.8
During the surgery, the soft tissues of the neck are separated to expose the damaged disc. The disc is removed decompressing the spinal cord or nerve roots. The space left behind by the removing the damaged disc will be filled with a bone graft, commonly taken from the patient’s hip, fusing the vertebrae together. Some surgeries use hardware, such as plates or screws, to stabilize the fused spine.8
Posterior Cervical Laminoforaminotomy
In posterior cervical laminoforaminotomy, the spine is approached from the back of the neck by a small incision made along the midline of the patient’s neck. The parts of the vertebrae and the herniated disk that are compressing the nerve root are removed. This surgery may allow a quicker recovery because it does not involve vertebral body fusion.
X. Use of Modalities
The use of modalities can be used in conjunction with medical management as conservative treatment for individuals with cervical disc herniation, as well as with post-surgically treated patients.
Cryotherapy is the therapeutic application of any substance that removes heat from the body, decreasing tissue temperature, inflammation, and muscle spasm. Adverse treatment effects that one should be aware of are: bradycardia, nerve and tissue damage, and frostbite. Methods of application that could be used in the cervical spine region include: ice pack, vaso-coolant spray, and ice massage.9
Thermotherapy is the therapeutic application of any substance to the body that adds heat to the body and results in an increase in tissue temperature, blood flow, and connective tissue extensibility. One should be cautious in preventing an adverse treatment effect, such as a burn, by monitoring the duration of treatment. Methods of application that could be used in the cervical spine region include: hydrocollator pack and heat wrap.9
Transcutaneous Electrical Nerve Stimulation (TENS) is used to modulate pain by interfering with its transmission at the spinal cord level. TENS could be used at the conventional high rate mode, low-rate mode, and burst mode to modulate pain either through gating at the spinal cord or modifying endorphin release.10
Neuromuscular electrical stimulation (NMES) is the application of an electrical current to motor nerves to produce contractions of the muscles they innervate. When using this modality, patients should perform voluntary contractions and be allowed long rest times between contractions to enhance smooth muscle contractions.10
Ultrasound is the use of heat in the form of sound waves to aid deep tissue healing, adjust inflammation, and improve transdermal drug delivery. Ultrasound is usually most effective with tissues that have high collagen content such as tendons, ligaments, joint capsules, and fascia. Pulsed modes tend to be used for acute inflammation versus a continuous mode for chronic inflammation.10
Traction is used to distract joint surfaces, reduce protrusions of nuclear discal material, stretch soft tissue, relax muscles, and mobilize joints. All these effects may reduce pain ans symptoms associated with cervical disk herniation.10 Contraindications for cervical traction includes conditions, such as, osteoporosis, infection, tumor, or cervical rheumatoid arthritis. Other conditions which may contraindicate cervical traction includes: pregnancy, cardiovascular disease, hernia, and in some cases TMJ. WIth these conditions, the forces used in traction could potentially be dangerous.1
For the treatment of Acute Inflammation, the main goals are to control pain, inflammation, and prevent aggravation of pain. The use of: TENS, cryotherapy, immobilization (such as cervical collar bracing), and low-load static traction may help in achieving the above stated goals. Contraindicated modalities include thermotherapy because it could potentially increase inflammation and pain; Also, NMES and local exercises because it may slow down the healing process of the injured area.10
For the treatment of Chronic Inflammation, the main goals are to prevent or decrease joint stiffness, control pain, increase circulation, and improve healing. These goals could be achieved with used of the following: thermotherapy, NMES, pulsed Ultrasound, and brief ice massage. The following modalities for use are contraindications: cryotherapy because it will increase stiffness and reduce range of motion of affected area, and immobilization, such as a neck collar brace, since it will restrict motion and thus, reduce circulation and overall healing.10
For the treatment of Spinal radiculopathy, the main goals are to decrease nerve root inflammation and/or compression. The modality use of Traction, either mechanical or manual could achieve the above stated goals.10 Studies have shown that in the cervical spine, there is a larger improvement in range of motion and decreased pain when patients are treated with intermittent traction of 20 pounds peak (10 seconds on, 10 seconds off, for a total of 15 minutes of treatment time) than in patients treated with 15 minutes of manual or static traction of 25 pounds. Also, a constant cervical distraction force of 30 pounds can generate a maximum vertebral separation in 7 seconds or less, and no further separation is gained by increasing the time of traction, even when held up to 60 seconds.11
For the treatment of Muscle weakness, the main goal is to increase strength. The use of NMES could achieve by increasing muscle fiber recruitment and force production. A contraindicated modality is to immobilize through a cervical brace collar because it would restrict movement and thus, increase muscular weakness and atrophy because of disuse.10
XI. Additional Web Based Resources:
1.Spine Universe Web site. Available at: http://www.spineuniverse.com/. Accessed November 23, 2010.
2. Mayfield Clinic Website. Available at: http://www.mayfieldclinic.com/. Accessed November 23, 2010.
3.Spine-health Website. Available at: http://www.spine-health.com. Accessed November 23, 2010
4. Anaka Y, Kokubun S, Sato T, et al. Cervical roots as origin of pain in the neck or scapular regions. Spine. Aug 1 2006;31(17):E568-73.
5. Shedid D, Benzel EC. Cervical spondylosis anatomy: pathophysiology and biomechanics. Neurosurgery. Jan 2007;60(1 Supp1 1):S7-13.
6. Miyazaki M, Hong SW, Yoon SH, et al. Reliability of a magnetic resonance imaging-based grading system for cervical intervertebral disc degeneration. J Spinal Disord Tech. Jun 2008;21(4):288-92.
7. Shim JH, Park CK, Lee JH, Choi JW, Lee DC, Kim DH, et al. A comparison of angled sagittal MRI and conventional MRI in the diagnosis of herniated disc and stenosis in the cervical foramen. Eur Spine J. Mar 18 2009
8. Princeton Brain and Spine Website. Available at: http://www.princetonbrainandspine.com. Accessed November 23, 2010.
9. Nadler SF, Weingard K, Kruse RJ. The Physiologic Basis and Clinical Applications of Cryotherapy and Thermotherapy for the Pain Practitioner. Pain Physician. 2004;7:395-399.
10. Cameron, MH. Physical Agents in Rehabilitation: From Research to Practice, 3rd edition. Saunders, Philadelphia, PA; 2009.
11. Cyriax JH. Textbook of Orthopaedic Medicine: Diagnosis of Soft Tissue Lesions. 8th ed. London, England: Balliere Tindall; 1982.