Principles of Ambulatory Medicine, 7th Edition

Chapter 70

Neck Pain

Carlos A. Bagley

Ira M. Garonzik

Frederick A. Lenz

Neck pain is a common problem. Nearly 50% of people older than 50 years experience neck pain at some time. Because of the many structures in the neck that can cause pain when diseased, as well as the multiple sources of referred pain, patients who complain of new or persistent neck pain should be systematically evaluated. This chapter provides a review of the skeletal structures of the neck, the method of evaluation for complaints of neck pain, a description of common problems and their treatment, and guidance for referral of selected patients with neck pain to a physiatrist or a spine specialist.

Anatomy of the Neck and Sources of Pain

The cervical spine consists of seven vertebral bodies connected by facet joints, interspinous ligaments, and anterior and posterior longitudinal ligaments (Fig. 70.1). These ligaments provide stability when the neck is flexed and extended. The vertebral bodies are joined by intervertebral disks composed of a gel-like material (the nucleus pulposus) that absorbs increased pressure applied to the spine. The nucleus pulposus is contained within an annulus fibrosus, a fibrous structure ringing the outer margin of the disk. Beginning approximately the fourth decade of life, both the nucleus pulposus and the annulus fibrosus undergo progressive degeneration, seen microscopically as a loss of the fibrous pattern and the collagen alignment. As a result, the ability of the disk to absorb shocks is reduced. Facet joints are found between vertebral elements posteriorly, one on each side of the spine; they are apophyseal (projecting) joints with a synovium-lined capsule and are aligned in an axial plane. It is within these small joints in the posterior spine that osteoarthritis, a breakdown of the articular cartilage within the joints, can occur. The intervertebral neural foramina, located on either side of the vertebral bodies, are the canals through which the nerve roots emerge from the spinal canal. The spinal canal and the

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foramina can be encroached on by a bulging intervertebral disk or an osseous proliferation (bony spur) originating in a vertebral body, by a facet joint, or from the bony margin of a neural foramen (Fig. 70.1). When the encroachment involves a nerve root, pain in the distribution of that root (radicular pain) may occur. The facet joint capsules and the intervertebral disk are innervated by fine nerves that have simple nerve endings (1). When these nerve endings are stimulated by degenerative disease within the disk or joint capsules, the patient may experience pain, which is referred to the posterior aspect of the neck at any level. The pain felt in the neck may not be at the cervical level from which the nerve is arising. In addition, irritation of the nerves can cause pain to be referred to the interscapular area, superiorly and laterally over the shoulders. Spasm of any of the many muscles of the neck region is another common source of pain.

Evaluation of the Patient

History

The date of onset of the patient's symptoms and any associated trauma should be ascertained. Often, knowledge of the specific activity the patient was performing at the onset of pain is helpful in establishing potential causes of the pain. Prolonged extension of the neck, as occurs in people doing overhead work, is a common occupational activity that can give rise to pain in the cervical region. Another common occupational cause of neck pain is prolonged sitting with the neck flexed in one position. This occurs commonly in computer operators or typists. The sustained position causes spasm of the neck muscles, which results in pain. Also, patients may sustain minor twisting injuries or trauma to the neck but do not experience neck pain within the first 24 hours, after which pain may begin to appear and progress. Reproduction or exacerbation of pain by neck motion is helpful in localizing the problem to the cervical spine rather than to a referred source (Table 70.1). It is important to know whether the pain is felt outside the neck as well, such as in the head, posteriorly between the scapulae, about the shoulder, down the arm, or in the hand. The patient should be asked about decreased sensation in the arms or hands and, if possible, to specify which fingers are involved. If the pain and numbness are felt in a dermatome distribution (see dermatome map inChapter 86), this indicates possible nerve compression (Table 70.2).

Muscle weakness in the shoulder, arm, and hand should be elicited to help identify potential nerve compression. Pain associated with motion of the shoulder is not characteristic of cervical spine disease and suggests that the problem is within the shoulder joint (see Chapter 69). Symptoms such as dizziness, visual changes, and ataxia brought on by neck motion (usually rotation) usually are not caused by nerve root compression or degenerative disk disease, but they may be found when bony spurs

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encroach on the vertebral foramina and compress the vertebral arteries. These rare symptoms usually occur when the neck is in a certain position, and they usually are of short duration.

Constitutional signs and symptoms, such as weight loss and fever associated with severe neck pain and hypersensitivity, should raise the concern for an underlying spinal infection or malignancy. Patients with a history of cancer and new-onset neck pain should undergo a workup for metastatic spine disease.

Physical Examination

Examination should begin with inspection of the head, neck, shoulders, and upper extremities from the front and back. Any abnormal posture, such as torticollis (wry neck) or muscle atrophy, should be noted. Next, the patient should be asked to demonstrate active range of motion of the neck, including flexion to touch the chin to the chest, extension by looking up at the ceiling, rotation to touch the chin to the shoulder on both sides, and lateral bending to touch the ear to the shoulder on both sides. Normally, the chin can be placed easily upon the anterior chest, and the neck can be extended so that the patient is looking directly above. Normally, there is almost 90 degrees of rotation of the neck to both sides. Simple hyperextension of the neck commonly exacerbates the pain caused by cervical disk degeneration. The patient should be asked to extend the neck and to maintain this position for 30 seconds to determine whether the pain is made worse. Putting direct compression on top of the head may produce or exacerbate pain in the patient with degenerative disk disease, especially if the head is compressed while the neck is extended (Spurling maneuver). Patients may report an electriclike sensation that travels down the back, arms or legs with neck flexion or extension, known as the Lhermitte sign. The posterior neck muscles are palpated for muscle spasm, which may be asymmetrical and may give the patient the appearance of torticollis. Next, the shoulder should be subjected to a

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range of motion to determine whether this action elicits pain within the shoulder itself.

Selected neurologic tests (see Chapters 86 and 92) are important in the evaluation of the patient with neck pain whenever there is any suggestion of nerve root involvement or cord compression. These tests for both the upper and lower extremities include reflex testing, muscle strength, and sensory testing. Reflex testing should include the biceps, triceps, brachioradial, quadriceps, and gastrocnemius tendons and the plantar. Muscle strength in the upper extremities should include the biceps (flexion of elbow), triceps (extension of elbow), wrist extensors and flexors, hand and finger flexors, and intrinsic muscles of the hand. Lower extremity motor examinations should include the iliopsoas, quadriceps, hamstrings, gastrocnemius, tibialis anterior, and extensor hallucis longus. A sensory examination should be performed in systemic fashion from the cranial to caudal direction. An objective sensory deficit that conforms to a dermatomal distribution is consistent with nerve root compression (see Chapters 86 and 92).

Cervical spine problems can cause cervical myelopathy. This may result from bone spur formation (spondylosis) posteriorly at the margin of an intervertebral disk, which then impinges on the spinal cord producing signs of cord compression. In addition, degenerative disease of the facet joints may result in hypertrophy and/or synovial cyst formation that also may compress the neural elements. Herniation of the nucleus pulposus of the intervertebral disk may be another source of spinal cord or nerve root compression. Clinical findings consistent with myelopathy include muscle weakness, spasticity, and increased deep tendon reflexes in the upper and lower extremities with Hoffman and/or Babinski signs. Additionally, patients may note subtle changes, such as deterioration in penmanship, difficulty with using buttons or picking up small items such as coins, and worsening gait.

Radiographic Assessment

If the history reveals severe progressive pain or an episode of recent trauma or if the neurologic examination reveals abnormalities, a complete set of cervical spine x-ray films should be obtained (2). These films should include an assessment of levels C1 through C7-T1 with oblique and open-mouth odontoid views. Plain radiographs allow for assessment of the osseous anatomy and spinal alignment and are inexpensive and widely available. These x-ray films will help in assessing the patient for fracture, subluxation, or metastatic disease. However, the correlation between clinical symptoms or signs and degenerative abnormalities on x-ray film is not good. X-ray evidence of cervical degenerative changes (spondylosis) are common and are evident in >90% of people older than 50 years (3). On the other hand, serious cervical disease may demonstrate minimal or no changes on x-ray film. When fracture or subluxation is noted on the initial films, dynamic x-ray films (flexion and extension views) aid in the assessment of the stability of the spinal column. Subluxation of >3.5 mm or of 11 degrees of angulation of the endplates in an adult is considered abnormal and a sign of spinal instability (4).

Computed tomographic (CT) is useful in the evaluation of problems of the cervical spine. CT provides excellent resolution of the bony anatomy and may provide important additional information if a fracture is suspected. Two-dimensional CT reconstructions add information regarding the sagittal and coronal alignment. Magnetic resonance imaging (MRI) is especially useful when evaluating patients suspected of having abnormalities of the soft tissue, such as metastatic cancer or a primary disk problem. CT myelography can be used to assess for neural compression when MRI is contraindicated, inadequate, or inconclusive.

Selected Syndromes Associated With Neck Pain

Many problems of the neck may result in neck pain (Table 70.3). Because the most common surgical problems—herniated cervical disk and cervical spondylosis (degenerative changes)—may have similar manifestations, they are discussed together based on the presence or absence of neurologic findings.

Pain with Neurologic Findings

Diagnosis

Patients with neurologic findings can have signs and symptoms of either nerve root or spinal cord compression (upper motor neuron syndrome, see Chapter 86). The objective signs of nerve root compression include muscle weakness, a decreased or absent deep tendon reflex, and decreased sensation in a dermatomal distribution.

Patients with nerve root compression present with the acute or gradual onset of posterior neck pain that radiates to the shoulder and down one arm. The pain may radiate into the lower arm and often into the hand itself. The pain often radiates into a finger that corresponds to the dermatome of the nerve root involved. The pain may be made worse by movement of the neck and extreme neck positions. In addition, the patient may complain of decreased sensation and paresthesias in the arm and hand. Patients may have nerve root compression in the cervical spine but have little or no neck and arm pain, instead reporting arm weakness and loss of sensation. Nerve root compression can be caused by impingement of the nerve by a cervical disk—most common in younger patients—or by osseous proliferation that can impinge on the nerve as it exits through its foramen—most common in patients

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older than 50 years (Fig. 70.1B). Thoracic outlet syndrome may be confused with cervical disease associated with nerve root compression and should be ruled out (see Chapter 69).

Patients with spinal cord compression may have numb clumsy hands or spastic paraparesis. The complaint of neck pain does not need to be prominent, and radicular symptoms may be present. The presence of radicular findings of weakness and fasciculations in addition to long tract findings, such as hyperreflexia, spasticity, and clonus, raises the possibility of motor neuron disease. In younger patients, noncompressive causes of spinal cord dysfunction, such as multiple sclerosis and motor neuron disease, must be considered.

Management

Patients with evidence of myelopathy (i.e., involvement of the spinal cord) must be referred to a neurologist or neurosurgeon to establish the cause. Investigation usually includes MRI or CT myelogram. If the myelopathy is secondary to a cervical disk or cervical spondylosis, surgery often is indicated—either laminectomy or anterior cervical fusions. Symptoms of myelopathy, particularly chronic myelopathy, may not remit after decompression, so the goal of surgery is to prevent progression.

Patients with nerve root compression leading to muscle weakness and sensory impairment should be referred to a spine specialist for more complete examination and followup. The consultant may further evaluate these patients with CT, MRI, or myelography. Typical surgical criteria include severe, uncontrollable pain; neurologic deficit or myelopathy; and/or bowel or bladder dysfunction. The timing of surgery in these situations remains controversial in the surgical community. Some studies have demonstrated improved outcomes with early surgery, whereas others have not supported this finding (5). If the neurologic deficit would be acceptable should it be permanent, then conservative therapy is an option and has a good chance of success (6).

A period of bedrest may be necessary in rare circumstances. Activity modification and avoidance of exacerbating activities or position are most appropriate during the acute phase. A cervical collar may be helpful in providing some relief of the neck pain for short periods. It may be helpful to place a small pillow under the nape of the neck to provide proper positioning. If muscle spasm is present, moist or dry heat applied to the neck may give symptomatic relief. Analgesia using a nonsteroidal anti-inflammatory drug (NSAID) (see Chapter 77) or acetaminophen may help. If a stronger analgesic becomes necessary, a short-acting narcotic may be added. Although not a first-line agent, a muscle relaxant may be helpful (see Chapter 71) if symptoms persist after 3 or 4 days.

The acute phase usually lasts only 1 or 2 weeks. When symptoms become recurrent or chronic (lasting >2–3 weeks), cervical traction may provide relief. This procedure is performed initially under the supervision of a physical therapist or physiatrist, after x-ray films of the cervical spine have been obtained to rule out instability. For 30 minutes, 15 to 20 lb of chin halter traction is applied to the neck. The neck must be positioned in slight flexion; extension could worsen symptoms and must be avoided.

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After several sessions, the patient can be instructed on the use of a home cervical traction unit, which can be applied for 30 minutes at a time, up to three times per day, for several months. If symptoms persist for more than 2 or 3 weeks, a brief course of steroids, although somewhat controversial, may be clinical benefit (7). Prednisone 60 mg/day is administered for 3 days, followed by a 4-day taper. Even when signs and symptoms subside, the rate of symptom recurrence is high. Therefore, it is important to educate the patient on activities or positions that should be avoided and on exercises that may help relieve muscle spasm (Figs. 70.2 and 70.3).

If the acute symptoms do not subside or if new signs develop, referral to a spine surgeon is necessary for confirmation of the diagnosis and consideration of surgery (most commonly a discectomy and anterior interbody fusion). The surgery should be performed to relieve compression of neural structures as demonstrated by signs, symptoms, and radiologic findings (8). A trial of conservative therapy is indicated in all cases except those with evidence of myelopathy, functionally significant weakness, or spinal instability. In some patients, neurologic deficits can take months to resolve postoperatively and may never resolve, particularly in the case of myelopathy.

Pain without Neurologic Findings

Diagnosis

Most patients with neck pain have no objective neurologic findings. The patient may present with either acute-onset pain or a slowly progressive discomfort (most often from osteoarthritis) that has been building over several months. In the acute disk herniation syndrome, the patient experiences sudden onset of neck pain that is associated with decreased range of motion of the cervical spine, bilateral muscle spasm, or occasionally asymmetrical muscle spasm that produces torticollis (wry neck). The patient may have pain in the shoulder or arm but have no objective weakness or sensory findings on examination. Other patients may have quite debilitating neck pain without evidence of significant disk herniations. MRI of the cervical spine may demonstrate evidence of disk degeneration (i.e., loss of disk height or hydration). This group of patients with axial, “discogenic” neck pain, presumably from disk degeneration, remains one of the most controversial and difficult groups to treat. The surgical outcomes are inferior to those achieved in patients with radiculopathy. Provocative discography may aid in determining the concordance of the imaging findings of disk degeneration and the patient's pain complaints of neck pain (9). Provocation of the patient's pain by injection of saline into the disk space and relief of the pain by injection of local anesthetic is assumed to implicate that particular level in producing the patient's pain. However, the utility of these findings in predicting the ultimate surgical outcomes remains an area of intense controversy, and a great deal of research is needed to more clearly define the role of this technique.

Treatment

Initial treatment is the same as that outlined for patients with neurologic findings. The neck can be “immobilized” with a cervical collar. Several cervical collars are available, but a soft collar often is prescribed first, although it may serve only as a reminder to the patient not to move the neck too quickly or too far. Local heat and analgesics or NSAIDs (see Chapter 77) also may provide symptomatic relief. Muscle relaxants (see Chapter 71) may be tried if symptoms persist after 3 or 4 days of initial treatment. In patients who have a chronic more insidious onset of pain, examining the patient's occupational situation more closely may help determine any exacerbating circumstances (10). Any activity that creates a prolonged extension of the neck, such as overhead work (e.g., painting), or prolonged flexion of the neck, such as sitting at a computer or typewriter, may aggravate a pre-existing problem. If pain lasts for >2 or 3 weeks after initial treatment, x-ray films of the cervical spine should be obtained. The treatment is based on the severity of symptoms. A rapidly acting oral agent, such as ibuprofen 400 mg three times per day, may be tried over a course of 2 or 3 weeks. (Alternative NSAIDs, including aspirin, also can be tried, see Chapter 77.) The patient should be informed that symptoms often may be chronic or recurrent and should be advised about how to avoid recurrences (Fig. 70.2).

If an acute severe episode of neck pain does not respond to treatment within a few weeks, the patient should be referred to a spine specialist. When the symptoms are more mild and chronic, a trial of treatment for several months would be reasonable before referral. Anterior cervical fusions carried out on the basis of positive discograms are sometimes effective in treating patients with neck pain without neurologic symptoms (11).

Cervical Sprain Syndrome

Mechanism

Cervical sprain syndrome is a term given to acute injuries of the neck caused by sudden extension of the cervical spine (whiplash). Patients involved in rear-end automobile accidents may have such acute hyperextension injuries to the neck. In experiments, monkeys subjected to acute hyperextension forces can show tearing of sternocleidomastoid and longus colli muscles in the absence of injuries to the anterior longitudinal ligament or disk. Thus, this syndrome may have physical causes (12), although a psychological contribution may be important, particularly in the case of litigation or workman's compensation (13).

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Neck pain from more mild forms of injury that result from repeated hyperextension, such as movements associated with painting a ceiling, usually resolves in 1 to 2 days and is not known to be associated with pathologic changes. The reason why this syndrome can become persistent is unclear. Several clinical studies have found a high initial pain intensity to be an adverse prognostic factor (14), suggesting that psychological variables are important.

Diagnosis

Although patients usually have pain after the accident, patients not uncommonly do not experience discomfort initially. Typically the patient experiences pain in the posterior or anterior region of the neck. It commonly radiates to the occipital aspect of the head and may radiate to the shoulders. Occipital headaches often occur. Disk

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herniation, fracture, or subluxation also can occur in this setting. Therefore, it is essential to visualize the cervical spine radiologically from the occipital condyles down to C7–T1 to rule out a fracture or dislocation. If plain x-ray films are normal, flexion–extension x-ray films should be obtained. Any patient with neurologic findings in this setting should be immobilized in a hard collar and seen urgently by a spine surgeon before flexion–extension x-rays are taken.

Treatment

If muscle spasm or limitation of motion is present without neurologic findings, the patient can be placed in a cervical collar. Analgesics such as acetaminophen or NSAIDs (or occasionally a narcotic for short periods), at adequate dosages, should be given. The patient should be warned that extension of the neck will exacerbate the pain. Heat, either moist or dry, applied to the cervical spine may give symptomatic relief but does not speed healing. Patients

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may seek manipulation for treatment of this condition and should be aware that the value of this modality is uncertain (15). The patient should be encouraged to perform daily work and activities as much as possible. If the patient has severe pain and muscle spasm at the initial injury, the clinical course probably will last 4 to 6 weeks. When the patient's pain subsides and he or she has full range of motion without muscle spasm, the collar can be gradually discontinued, and the patient should be advised of methods for relieving muscle spasm and preventing recurrent symptoms (Figs. 70.2 and 70.3). If no symptoms of nerve root compression are present, the patient with persistent symptoms should be considered for further workup.

Specific References

For annotated General References and resources related to this chapter, visit http://www.hopkinsbayview.org/PAMreferences.

1. Bogduk N. Zygapophysial joint and anulus fibrosus. Spine 1994;19:1771.
2. Tong C, Barest G. Approach to imaging the patient with neck pain. J Neuroimaging 2003;13:5.
3. Kaiser JA, Holland BA. Imaging of the cervical spine. Spine 1998;23:2701.
4. Panjabi MM, White AA 3rd. Basic biomechanics of the spine. Neurosurgery 1980;7:76.
5. Woertgen C, Rothoerl RD, Henkel J, et al. Long term outcome after cervical foraminotomy. Clin Neurosci 2000;7:312.
6. Wolff MW, Levine LA. Cervical radiculopathies: conservative approaches to management. Phys Med Rehabil Clin N Am 2002;13:589.
7. Ellenberg MR, Honet JC, Treanor WJ. Cervical radiculopathy. Arch Phys Med Rehabil 1994;75:342.
8. Rothman RH, Simeone FA, eds. The spine. Philadelphia: WB Saunders, 1992.
9. Carragee EJ, Alamin TF. Discography. a review. Spine J 2001;1:364.
10. Dryer SJ, Boden S. Nonoperative treatment of neck and arm pain. Spine 1998;23:2746.
11. Zheng Y, Liew SM, Simmons ED. Value of magnetic resonance imaging and discography in determining the level of cervical discectomy and fusion. Spine 2004;29:2140.
12. Bogduk N. Whiplash: the evidence for a organic etiology. Arch Neurol 2000;57:590.
13. Berry H. Chronic whiplash syndrome as a functional disorder. Arch Neurol 2000;57:592.
14. Scholten-Peeters GG, Verhagen AP, Bekkering GE, et al. Prognostic factors of whiplash-associated disorders: a systematic review of prospective cohort studies. Pain 2003;104:303.
15. Hurwitz EL, Aker PD, Adams AH, et al. Manipulation and mobilization of the cervical spine. A systematic review of the literature. Spine 1996;21:1746; discussion 1759.