Saturday, August 30, 2008

Evaluation of the patient with neck pain and cervical spine disorders

Evaluation of the patient with neck pain and cervical spine disorders

Author
Zacharia Isaac, MD
Bruce C Anderson, MD
Section Editor
Steven J Atlas, MD
Deputy Editor
H Nancy Sokol, MD



Last literature review version 16.2: May 2008 | This topic last updated: June 12, 2008 (More)


INTRODUCTION — Approximately 10 percent of the adult population has neck pain at any one time [1] . This prevalence is similar to low back pain, but few patients with neck pain lose time from work and less than 1 percent develop neurologic deficits.

Clinical disorders affecting the cervical spine can be categorized as those that predominantly cause neck pain, and those that most often cause extremity pain and/or neurological dysfunction. Disorders that cause neck pain include cervical strain, internal disc disruption syndrome/discogenic pain, cervical facet-mediated pain, cervical "whiplash" syndrome, and myofascial pain. Disorders that predominantly cause extremity symptoms and/or neurological dysfunction include cervical radiculopathy and cervical spondylotic myelopathy.

The evaluation of the patient with cervical spine disease is reviewed here. The management of disorders of the neck are discussed separately. (See "Treatment of neck pain"). Evaluation of a patient with acute neck trauma is also discussed separately. (See "Management of spinal column injuries in adults").

ANATOMY — The cervical spine is comprised of seven vertebrae. The articulation between the occiput and the first cervical vertebra (the atlantooccipital joint) allows for approximately one-third of flexion and extension and one-half of lateral bending of the neck [2] . The articulation between the first and second cervical vertebrae (the atlantoaxial joint) allows for 50 percent of rotational range of motion. The articulations between the second and seventh cervical vertebrae allow for approximately two-thirds of flexion and extension, 50 percent of rotation, and 50 percent of lateral bending.

The most severe injuries and greatest wear and tear occur between C4 and C7 [2] ; the nerve roots passing through the intervertebral foramena in these areas are C5, C6, and C7. Uncovertebral articulations (also known as joints of Luschka) are present in the C3-7 spinal segments, located on the posterolateral border of the intervertebral disc, and in the anteromedial portion of the intervertebral foramen. These articulations are not true synovial joints, but can hypertrophy, associated with disc degeneration, and result in narrowing of the intervertebral foramen. This foramenal narrowing is a common cause of cervical radiculopathy [3] .

The cervical and trapezius muscles have two major functions: to support and provide movement and alignment for the head and neck, and to protect the spinal cord and spinal nerves when the spinal column is under mechanical stress. The normal cervical spine has a shallow lordosis, maintained by the neck muscles.

This lordosis can be decreased, in patients with degenerative changes. Severe degenerative changes in the cervical spine can result in reversal of the lordosis. The lordosis may also become accentuated, in compensation for patients with prominent thoracic kyphosis. Alterations in spinal alignment, however, have not definitively been demonstrated to cause cervical pain.

Neuroanatomy — There are eight cervical spinal nerves. Each spinal nerve arises from the spinal cord by two roots, the ventral and dorsal spinal roots. The ventral root contains motor efferent fibers from alpha motor neurons in the ventral horn of the spinal cord. The dorsal root carries primary sensory afferent fibers from cells in the dorsal root ganglion. The dorsal and ventral spinal roots combine to form the spinal nerve.

This spinal nerve then divides into two branches, a dorsal primary ramus and a ventral primary ramus. The dorsal ramus divides and supplies innervation to muscular, cutaneous, and articular branches for posterior neck structures. The ventral rami supply the prevertebral and paravertebral muscles and form the brachial plexus which subsequently innervates the upper limb. The sensory cervical dermatomes are illustrated in the figure (show figure 1).

A myotome is the group of muscles innervated by a spinal nerve. The diaphragm is innervated by C3 to C5 spinal nerves and respiratory paralysis may result from spinal cord injuries above C5.

Cervical radiculopathy may be caused by degenerative changes in the spine that impact the ventral root and cause focal weakness. Specific findings with different levels of nerve root involvement are discussed below (see "Cervical level correlates to findings" below).

CLINICAL CLASSIFICATION — A 2007 task force on neck pain, representing multiple specialties and institutions, recommends a classification system for neck pain severe enough to cause patients to seek care [4] :

• Grade I: No signs of major pathology and little interference with daily activities.
• Grade II: No signs of major pathology but may impact daily activities.
• Grade III: Neck pain with neurological signs or symptoms (radiculopathy)
• Grade IV: Neck pain with major pathology (eg, fracture, myelopathy, neoplasm, spinal infection)


These classifications can be helpful in determining urgency of care and appropriateness of intervention. (See "Treatment of neck pain").

AXIAL NECK PAIN SYNDROMES — Neck pain can arise from a variety of causes [5] . Systemic diseases, such as rheumatoid arthritis, spondyloarthritis, polymyalgia rheumatica, or bone metastases should be considered in appropriate patients. Degenerative changes are the most common etiology for axial neck pain. An approach to diagnosis is described below, for patients in whom there is no evidence of rheumatologic, oncologic, and infectious etiologies on history and examination.

Cervical strain — Cervical strain is a nonspecific diagnosis, classically used to describe an injury to the cervical paraspinal muscles and ligaments with associated spasm of the cervical and upper back muscles. The diagnosis of cervical strain is reasonable in patients with acute axial neck and trapezius pain, where neurological dysfunction has been excluded.

Cervical strain may result from the physical stresses of everyday life, including poor posture and sleeping habits. Typically, symptoms are experienced as pain, stiffness, and tightness in the upper back or shoulder, and last for up to six weeks. Patients with chronic symptoms that extend beyond the expected time frame for resolution should not receive this nonspecific diagnosis; muscle pain alone should not be routinely considered a chronic nociceptor.

Potential mechanisms for chronic pain include cervical discogenic pain, facet mediated pain, cervical spondylotic myelopathy, cervical radicular pain, myofascial pain, and centrally mediated pain.

Cervical spondylosis — The term cervical spondylosis is variably used to include soft tissue, disc, and degenerative bony lesions [6] . Degenerative changes in the cervical spine are apparent on radiographs of many adults over the age of 30 [7] . The abnormalities include a sequential change in the intervertebral discs, with osteophyte formation along the vertebral bodies, and changes in the facet joints and laminal arches. There is a continuum from normal aging to the overtly pathologic state. (See "Clinical features and diagnosis of cervical radiculopathy", section on Pathophysiology).

Correlation between the degree of radiographic change and the presence or severity of pain is poor [7] . Given the prevalence of radiographic abnormalities in asymptomatic subjects, clear distinction of the clinical entity of cervical spondylosis is difficult [5] .

Cervical discogenic pain — Cervical degenerative disc disease is more aptly a radiologic diagnosis, rather than a clinical syndrome, as it is commonly seen on x-ray studies in both symptomatic and asymptomatic patients. For this reason, other terms have been introduced to describe patients who are symptomatic with disc-related neck pain: cervical internal disc disruption syndrome or cervical discogenic pain [8,9] . Cervical discogenic pain may be the most common cause of neck pain.

In contrast to patients with cervical disc herniations, cervical discogenic pain refers to derangement in the architecture of the disc that results in mechanical neck pain with or without features of inflammation. The degenerative process that occurs in the intervertebral disc is associated with an inability to effectively distribute pressures between the disc, vertebral endplates, and facet joints.

Axial pain is more severe than extremity pain in cervical discogenic pain. Extremity pain can occur, but is felt to result from somatic referral rather than spinal nerve root impingement. Symptoms are often exacerbated when the neck is held in one position for prolonged periods, such as occurs with driving, reading, or working at a computer. There is often associated muscle tightness and spasms.

Examination should demonstrate axial neck discomfort with range of motion, a decreased range of motion, and a benign neurological examination. MRI imaging demonstrating the degree of degeneration does not accurately implicate which discs are symptomatically painful; asymptomatic degenerative changes are common [10,11] .

Cervical facet syndrome — The zygapophyseal joint, commonly referred to as the facet joint, can cause axial pain and is probably the most common cause of whiplash-related neck pain and headaches [12,13] . Historically, patients often have a history of trauma with an abrupt flexion-extension type injury, or an occupation which leads to repeatedly positioning the neck in extension.

Pain is often midline or offset slightly to one side. Symptoms can be somatically referred to the shoulders, periscapular region, occiput, or proximal limb. As with cervical discogenic pain, axial symptoms are greater than extremity symptoms.

Unfortunately, there is no specific historical examination, or imaging finding, that provides confirmatory diagnostic information. A fluoroscopically guided intraarticular injection of a small aliquot of local anesthetic, or anesthetization of the innervation of the joint resulting in relief are considered the definitive diagnostic tests.

Whiplash injury — The cervical "whiplash" syndrome is caused by a traumatic event with an abrupt flexion/extension movement to the cervical spine. Symptoms of whiplash include severe pain, spasm, loss of range of motion in the neck, and occipital headache. Pain can be persistent with little identifiable abnormality seen on MRI, CT, x-ray, or bone scan imaging. Often multiple structures can be injured including soft tissues, spinal nerve, intervertebral disc, posterior longitudinal ligament, interspinous ligaments, alar ligaments, facet joints, or other osseous structures.

The injury is common but remains poorly understood [14] . In a case controlled study of 1843 drivers involved in a motor vehicle accident, 26 percent of whom had neck pain for more than one day, eight variables were identified as risk factors for whiplash injury: female, younger age, prior history of neck pain, rear collision, stationary vehicle, severity of collision, not being at fault, and monotonous work [15] . In a systematic review of 47 studies, approximately 50 percent of adults with whiplash injury reported neck pain symptoms at one year [16] .

The pathology of the condition is unclear. Microvascular bleeding and local release of inflammatory mediators may explain the acute symptoms, but some patients remain symptomatic for many months or even years. Soft tissue injury may be associated with the degree of impairment. A study using high resolution MRI imaging of the C spine in patients with a remote history of whiplash injury (mean 6 years), and symptoms that had persisted at least 3 months following injury, demonstrated soft tissue damage, particularly of the alar ligaments, not seen in MRI images in control patients [17] .

In a study in the United Kingdom (UK), the most important predictors of pain at one year were pain severity at the time of the rear-end collision and the presence of a compensation claim [18] . Chronic whiplash symptoms may also be associated with different cultural expectations; 50 percent of Canadian and British subjects surveyed anticipated chronic neck pain following a hypothetical whiplash injury compared to negligible numbers from respondents in Lithuania and Germany, where late neck pain prevalence is very low [19,20] . A legislative change in Australia, removing financial compensation for pain and suffering from whiplash injuries, was associated with improvement in functional status and pain indices in patients with whiplash, compared to historical controls [21] .

Cervical myofascial pain — Regional pain with associated trigger points, taut bands, and pressure sensitivity has been called myofascial pain. Myofascial pain can be a nonspecific manifestation of any pathologic condition which causes pain from the neck to the shoulder and should not be considered a defining diagnosis. Myofascial pain can also be associated with muscle sensitivity, depression, and insomnia, much akin to fibromyalgia.

Diffuse skeletal hyperostosis — Diffuse skeletal hyperostosis (DISH) is a syndrome of inappropriate bone deposition in the insertions of the ligaments and tendons. Large osteophytes connect adjacent vertebral bodies in a somewhat asymmetric fashion. The diagnosis is based on three criteria for spinal radiographs [22] :

• The presence of calcification or ossification along the anterolateral aspects of at least four contiguous vertebral levels.
• Relative preservation of intervertebral disc height in the involved vertebral segments without extensive changes of primary degenerative disc disease.
• The absence of apophyseal joint ankylosis or sacroiliac joint erosions, sclerosis, or intraarticular bony ankylosis.

DISH can be associated with stiffness, loss of mobility, and pain, but can also often be asymptomatic. The bony fusion that results from the hyperostosis may cause mechanical pain at segments adjacent to the fused segments. Prominent anterior vertebral hyperostosis associated with DISH can cause dysphagia. (See "Diffuse idiopathic skeletal hyperostosis (DISH)").

EXTREMITY PAIN AND/OR NEUROLOGIC DEFICIT

Cervical spondylotic myelopathy — Cervical spondylotic myelopathy is defined by degenerative changes narrowing the spinal canal, resulting in cervical spinal cord injury or dysfunction. Cervical spondylotic myelopathy can result from an extradural mass, as seen with endplate hyperostosis, herniated nucleus pulposus, ossification of the posterior longitudinal ligament, spondylolisthesis, congenital narrowing, or degenerative C1 to C2 (atlantoaxial) or subaxial cervical instability due to rheumatoid arthritis. (See "Cervical subluxation in rheumatoid arthritis"). Patients may present with a variety of neurological complaints: weakness, coordination impairment, gait disturbance, bowel or bladder retention or incontinence, and sexual dysfunction.

Upper extremity pain can be precipitated when spondylotic changes or a focal protrusion lead to cervical foramenal stenosis. In this setting, a concurrent radiculopathy is often present and this is termed cervical myeloradiculopathy. Inherent to this disorder is a clinical picture of mixed upper and lower motor neuron abnormalities, such as hyperreflexia and spasticity simultaneously present with depressed reflexes and weakness.

Spinal cord compression due to spondylotic change tends to occur in the lower cervical spine; degenerative changes are more severe and more common between C5 and T1 and the spinal cord is enlarged between C4 and T2 [23] .

The differential diagnosis for cervical spondylotic myelopathy includes multiple sclerosis, syringomyelia, tumor, epidural abscess, and amyotrophic lateral sclerosis. Distinguishing cervical spondylotic myelopathy from other causes of neck pain is critical because optimal neurological recovery depends on early surgical decompression. (See "Treatment of neck pain", section on cervical spondylotic myelopathy).

Cervical radiculopathy — Cervical radiculopathy refers to dysfunction of the spinal nerve root that may manifest with pain, weakness, reflex changes, or sensory changes. Multiple conditions can give rise to cervical radiculopathy, including cervical foramenal stenosis, cervical herniated disc, herpes zoster, Lyme radiculopathy, or diabetic polyradiculopathy, but degenerative changes in the spine are overwhelmingly more common than the other causes, accounting for 70 to 90 percent of cases.

Diagnosis and clinical features of cervical radiculopathy are discussed separately (see "Clinical features and diagnosis of cervical radiculopathy").

NON-SPINAL CAUSES OF NECK PAIN

Thoracic outlet syndrome — The thoracic outlet syndrome can present as neck and shoulder pain with referred pain to the upper extremities and variable neurovascular signs and symptoms. The triad of numbness, weakness, and a sensation of swelling of the upper limbs is strongly suggestive of thoracic outlet syndrome. Examination may demonstrate a positive Roos sign (repetitive and vigorous hand grip while the arms are abducted overhead) or a positive Adson's test (diminution of the radial pulse when the arm is abducted, extended backward, the head is turned ipsilaterally, and the patient inspires). (See "Brachial Plexus syndromes" section on Thoracic outlet syndrome).

Herpes zoster — Herpes zoster (shingles) may present with unilateral radicular symptoms without neurologic findings. The rash may not appear for several days after the onset of pain. (See "Epidemiology and pathogenesis of varicella-zoster virus infection").

Diabetic neuropathy — Diabetes mellitus can be associated with various neuropathic pain syndromes related to vasculitis of the vasa vasorum. Cervical and thoracic polyradiculopathy, plexopathy, and peripheral entrapments can be associated with neck, thoracic, scapular, extremity pain and/or weakness. (See "Clinical manifestations and diagnosis of diabetic polyneuropathy").

Other causes — The differential diagnosis of neck pain is broad. Although the majority of neck pain complaints are related to musculoskeletal causes, numerous other conditions can present with a constellation of symptoms that include neck pain. While the differential listed below should be kept in mind in evaluating the patient with neck pain, diagnosis of these conditions is usually evident from accompanying symptoms (ie, fever, neck stiffness, diffuse joint pain, etc.):

• Malignancy: tumors involving the cervical spinal column.
• Vascular: vertebral artery or carotid artery dissection
• Cardiovascular: angina and myocardial infarction (causing neck, chest, and arm symptoms that may mimic cervical radicular pain)
• Infection: pharyngeal abscess, meningitis, subdiaphragmatic abscess, herpes zoster, Lyme disease
• Visceral: esophageal obstruction, biliary disease, apical lung tumor
• Referred shoulder pain: impingement, adhesive capsulitis, rotator cuff tear
• Rheumatologic: polymyalgia rheumatica, fibromyalgia
• Neurologic: cervical dystonia, tension headache, Chiari malformations

PHYSICAL EXAMINATION — The approach to the patient who has suffered serious head or neck trauma differs dramatically from the typical office evaluation of neck complaints ("See "Management of spinal column injuries in adults").

Routine cervical spine evaluation includes the following:

• Observe movement and resting posture of the head and neck
• Estimate cervical range of motion
• Palpate the paraspinal and upper trapezial muscles
• Evaluate for radicular neurological symptoms: reflexes, motor and sensory testing
• Evaluate for upper motor neuron signs
• Perform provocative maneuvers for radicular pain
• Examine the shoulder for painful range of motion

General observation — The routine examination begins by noting the movement of the head and neck. Posture and general movements (rigid and guarded, general stiffness, or loose and free) should be consistent during the interview phase as well as during the actual examination. Lack of consistency may be the only clue to malingering in the case of trauma- related whiplash and cervical radiculopathy that are under litigation.

Range of motion — Neck rotation and lateral bending, when combined with palpation of the trapezius and paraspinal muscles for tenderness and spasm, are used to assess the degree of cervical spine involvement. The presence of torticollis can be consistent with acute muscle spasm or a herniated disk. Assessment of the shoulder is important since overlapping symptoms can occur.

• The cervical spine can rotate an average of 90 degrees (show picture 1). Less rotation is abnormal.
• The cervical spine can bend an average of 45 degrees laterally (show picture 2).
• The cervical spine can forward flex to 60 degrees
• The cervical spine can extend backward 75 degrees

Abnormal neck range of motion suggests an injury to the cervical spine but does not indicate a specific diagnostic etiology. Conditions such as cervical strain, pain inhibited movement, cervical discogenic pain, cervical facet syndrome, DISH, cervical radiculopathy, and cervical myeloradiculopathy can all be associated with range of motion alterations. Neck rotation may be more prominently affected by upper cervical spine abnormalities (C1 to C3) whereas lateral flexion impairment may be more prominent with lower cervical spine disease (C4 to C7).

Range of motion of the cervical spine appears to be an important predictor of outcome in patients with whiplash injury. In one prospective study of 141 patients with acute whiplash, reduction in cervical range of motion was the single best predictor of long-term handicap, with a sensitivity and specificity of 73 and 91 percent, respectively [24] .

Muscle palpation — Local muscular tenderness can result from trauma (a direct blow to the upper back or trauma to the head), or can be a nonspecific feature of a number of cervical spine syndromes. The upper trapezius and paraspinal muscles should be palpated to determine the degree of tenderness and spasm (show picture 3).

Trapezius muscle tenderness is a nonspecific finding seen in many conditions and is consistent with a diagnosis of cervical muscle strain, fibromyalgia, whiplash, or cervical radiculopathy. Severe muscular rigidity and guarding are associated with severe neck strain, occult vertebral body fracture, and fracture/dislocation. Muscle spasm is so dramatic with neck fracture that the neck is totally rigid.

The superior division of the trapezius muscle is often quite hard to palpation in the elderly. The dorsokyphotic posture (prominent C7 spinous process, drooped shoulders, and head forward) places the trapezius under constant tension. The extremes of rotation may show endpoint stiffness and mild pain.

Neurologic examination — A detailed upper extremity neurologic examination is warranted for patients with radicular symptoms. The neurological exam should involve the following components: muscle strength, reflex testing, muscle tone, gait, and testing for upper motor neuron signs. A detailed neurological examination is described separately. (See "The detailed neurologic examination in adults").

A negative neurological examination indicates a low likelihood of root compression; positive findings, however, are not specific for root compression [4] . These correlations, however, are tempered by variability in the quality of the neurological examination performed.

The majority of patients with pure sensory radiculopathy have a good prognosis and respond to a combination of rest, exercise, and occasionally medication or corticosteroid injection. In contrast, patients with sensorimotor involvement (with or without spinal cord compression) have a less predictable prognosis; they are more likely to have more dramatic degrees of disk herniation, are at higher risk for nerve damage, and are more likely to require surgical intervention.

Muscle strength — Strength should be evaluated by testing the following actions against resistance: shoulder abduction, elbow flexion and extension, wrist flexion and extension, and lower limb extension and flexion. Strength should be recorded using the Medical Research Council manual muscle testing scale as follows:

• 0 = No contraction
• 1 = Visible muscle twitch but no movement of the joint
• 2 = Weak contraction insufficient to overcome gravity
• 3 = Weak contraction able to overcome gravity but no additional resistance
• 4 = Weak contraction able to overcome some resistance but not full resistance
• 5 = Normal; able to overcome full resistance

Reflex testing — Deep tendon reflexed should be checked at the bicep, brachioradialis, and tricep muscles and compared from side to side. Grading scale is as follows:

• 0 = No observable reflex
• 1 = Trace reflex
• 2 = Normal reflex
• 3 = Brisk reflex
• 4 = Nonsustained clonus ( two or less beats of clonus)
• 5 = Greater than 3 beats of clonus or sustained clonus

Cervical level correlates to findings — There is some overlap in clinical symptoms and physical findings that suggest involvement of a specific nerve root. In general, however, assessment of strength, reflexes, and sensory examination, in combination with patient symptoms, can target a specific root lesion (show table 1).

• C4 radiculopathy may affect the levator scapular and trapezius muscles, resulting in weakness in shoulder elevation. There is no reliable associated reflex.

• C5 radiculopathy is associated with weakness of the rhomboid, deltoid, bicep, and infraspinatus muscles. Patients may have weakness of shoulder abduction and external rotation. The bicep reflex may be diminished.

• C5-C6 paracentral and/or foramenal herniation or foramenal stenosis at C5-C6 affects the C6 nerve root and produces pain at the shoulder tip and trapezius with radiation to the anterior upper arm, radial forearm, and thumb, and sensory impairment in these areas. C6 radiculopathy can easily be confused for C5 or C7 radiculopathy. Weakness can overlap with the C5 or C7 muscles. Muscles affected include: infraspinatus, bicep, brachioradialis, pronator teres, and tricep. Weakness involves flexion at the elbow, or shoulder external rotation. The bicep or brachioradialis reflex may be diminished.

• C6-C7 paracentral and/or foramenal herniation or foramenal stenosis at C6-C7 affects the C7 nerve root and produces pain at the shoulder blade, pectoral area, and medial axilla with radiation to posterolateral upper arm, dorsal elbow and forearm, index and medial digits or all of the fingers, and sensory impairment in these areas. C7 radiculopathy can result in weakness of the tricep, pronator teres, flexor carpi radialis. Weakness involves the elbow extensors, and forearm pronators. There may be a diminished tricep reflex.

• C7-T1 paracentral and/or foramenal herniation or foramenal stenosis at C7-T1 causes C8 radiculopathy. Weakness can be present in the opponens pollicis, flexor digitorum profundus, flexor pollicis longus, and hand intrinsic muscles. Clinically, patients present with symptoms similar to an ulnar or median motor neuropathy and can have weakness of finger abductors and grip strength; they may also have findings suggesting median motor neuropathy. No reliable reflex test is available.

• Central disc herniation at any cervical level — Large central disc herniation or any cause of spinal cord compression in the midline can produce a cervical myelopathy with bilateral upper motor neuron signs in the extremities. Small central herniations are common and are often not clinically associated with radicular pain or myelopathic features.

Provocative maneuvers

• Spurling's maneuver — The Spurling's and modified Spurling's maneuver can reproduce the patient's radicular pain (show picture 4). The Spurling's maneuver (also called the neck compression test) is performed by keeping the head in a forward flexed, ipsilaterally rotated, and ipsilaterally tilted position. The modified Spurling's maneuver is performed by keeping the head extended, ipsilaterally rotated, and ipsilaterally tilted. Additional axial load by applying pressure on top of the head can be applied. Reproduction of symptoms beyond the shoulder is considered positive. Reproduction of neck pain alone is nonspecific.

This maneuver is highly specific for the presence of cervical root compression, but the sensitivity is low [25] . One study, as an example, using electrodiagnostic testing as a reference, found a sensitivity of 30 percent and specificity of 93 percent for the Spurling's maneuver [26] . Thus, a positive test is helpful, but a negative test does not rule out radicular pain.

The Spurling maneuver should be performed with caution in patients with suspected rheumatoid arthritis, cervical malformations, or metastatic disease since it may cause further injury to the spine in these patients.

Upper limb tension test — The Elvey's upper limb tension sign is a root tension sign for the upper extremity, akin to the straight leg raise in the lower extremity. The head is turned contralaterally, the arm is abducted with the elbow extended. Reproduction of arm symptoms is considered positive. The sensitivity and specificity of Elvey's upper limb tension test were 0.97 and 0.22 in one study [27] . This test is most useful for ruling out radiculopathy.

A combination of tests may provide the most accurate diagnostic assessment. One study analyzed a cluster of four tests: Spurling's maneuver, Elvey's upper limb tension test, cervical rotation less than 60 degrees, and diminution in neck symptoms with distraction. The post test probability for radiculopathy in patients with two, three, or four positive tests was 21, 65, and 90 percent, respectively.

CONFIRMATORY TESTS — Radiographic studies, magnetic resonance imaging, electromyography/nerve conduction studies (EMG/NCS), and minimally invasive functional testing are useful tests for determining diagnosis in selected patients with cervical spine disorders.

Because degenerative changes can occur at multiple levels, neurologic findings must be correlated with radiographic abnormalities. As an example, symptoms and signs involving C6 should correlate with the presence of foramenal encroachment at the C5-C6 intervertebral space.

Radiography
Plain films — Plain films are indicated in patients with neck complaints who are age greater than 50 with new symptoms, or constitutional symptoms.

Patients who fail a four to six week trial of conservative care, and patients who present with symptoms and signs of radiculopathy, should have imaging studies as well. A plain film x-ray of the neck may be obtained for these patients, but is probably not necessary if a CT or MRI scan can be performed in a reasonable timeframe.

The routine cervical series of x-rays consists of seven views, including the odontoid, lateral, PA, two oblique views, lateral view in flexion, and lateral view in extension. However, in a series of 258 patients undergoing radiography for evaluation of neck-related disorders (axial cervical, upper extremity radicular, or myelopathic symptoms), flexion and extension views did not lead to findings that changed clinical management [28] . The additional expense and radiation exposure associated with dynamic views are not routinely warranted.

The lateral view demonstrates vertebral alignment; the normal cervical lordotic curve can be replaced by a straightened or even a reversed curve in moderate to severe cases of cervical strain. The lateral view is also used to screen for the degree of osteoarthritis (at the facet and paravertebral joints), disk space narrowing (osteoarthritis or radiculopathy), or bony pathology (compression fracture) (show radiograph 1).

Oblique views are primarily used to determine the role of foramenal encroachment (osteophytes reducing the overall diameter of the neuroforamena) (show radiograph 2). However, radiographic presence of foramenal stenosis can both underestimate and overestimate the degree of foramenal stenosis because of the variable angle of the cervical foramenae.

Severe torticollis may cause a lateral deviation of the cervical spine that is best appreciated on a PA view of the neck. Odontoid views are most appropriate in patients with acute trauma.

• CT scan can detect degenerative changes such as disc herniations, foramenal stenosis, central stenosis, facet osteoarthritis, tumor, and fractures. CT is a better study than MRI when facet osteoarthritis or other osseous changes are suspected. There is significant radiation exposure.

• MRI detects soft tissue processes including disc herniations, foramenal stenosis, central stenosis, and tumor. MRI can also detect spinal cord changes from myelopathy, fractures, and infection. The addition of gadolinium contrast intravenously allows better diagnosis of infection, tumor, or post surgical epidural fibrosis [29-32] . Administration of gadolinium-containing MRI contrast agents should be avoided in patients with moderately or severely impaired renal function (eg, estimated glomerular filtration rate < 15-30 mL/min).

If gadolinium-based imaging must be performed in a patient with moderate to severely impaired renal function, there may be a role for dialysis to reduce the risk of development of nephrogenic systemic fibrosis (NSF). Approaches to prevention of this disorder are discussed separately. (See "Nephrogenic systemic fibrosis/nephrogenic fibrosing dermopathy in advanced renal failure", section on If gadolinium must be given).

MRI does not expose the patient to radiation, but exposes the patient to a strong magnetic field, which precludes patients with pacemakers, intracranial vascular clips, and prior eye injury with metal fragments. Most metal placed as part of orthopedic procedures, including spine procedures, is considered permissible.

A limitation of MRI is that anatomic abnormalities such as disk protrusion or extrusion are present in up to 30 percent of asymptomatic individuals [7,10] . In one study of 100 patients referred for MRI of the larynx who had no neck symptoms, cervical disc protrusion or herniation was seen in 20 percent of patients between the ages of 45 and 54, and 57 percent of those older than age 64 [7] .

CT myelography is utilized at times as part of presurgical planning.
Other studies

Electrodiagnostic testing — EMG should be considered when peripheral nerve entrapment syndromes are a potential cause for extremity symptoms that can mimic cervical radicular pain. EMGs should be considered when there is more prominent pain and dysesthesia in the extremities than in the neck. In some patients, the pain symptoms travel retrograde to the neck. EMG studies are not indicated in patients without suspected radiculopathy [4] .

The needle portion of the EMG/NCS is the most useful test to identify cervical radiculopathy but will only identify radiculopathy and its associated radicular pain when motor axonal injury is present. It is important to recognize that cervical radicular pain can exist in the absence of axonal injury. Irritation of the dorsal root ganglion and the dorsal sensory afferent fibers can result in pain without motor injury.

The sensitivity of the needle EMG increases with the number of muscles sampled. One study demonstrated that sampling six upper limb muscles along with the paraspinal muscles was sufficient to identify cervical radiculopathy by EMG [33] .

Blood tests — Blood studies are not routinely indicated, but should be ordered, based on individual patient history and examination, when non-spinal causes of neck pain (ie, rheumatologic, infectious, or oncologic) are suspected. Serologic markers of inflammation such as erythrocyte sedimentation rate and c-reactive protein should be normal in degenerative causes of neck pain such as cervical radiculopathy, stenosis, myelopathy, discogenic pain, and facet syndrome. However, the erythrocyte sedimentation rate and c-reactive protein may be elevated in patients with polymyalgia rheumatica, rheumatoid arthritis, or infectious processes such as septic discitis. (See "Polymyalgia rheumatica").

EVALUATION OF THE TRAUMA PATIENT — Patients with significant head and neck trauma should be immobilized, stabilized, and transported by ambulance to an emergency department. A discussion of evaluation of the trauma patient is presented separately. (See "Management of spinal column injuries in adults").

INFORMATION FOR PATIENTS — Educational materials on this topic are available for patients. (See "Patient information: Neck pain"). We encourage you to print or e-mail this topic, or to refer patients to our public web site www.uptodate.com/patients, which includes this and other topics.

SUMMARY AND RECOMMENDATIONS
• Disorders of the cervical spine can cause either neck pain, or extremity pain with or without neurological dysfunction. The most severe injuries and wear and tear occur between C4 and C7, affecting the C5, 6, and 7 nerve roots. (See "Introduction" above and see "Anatomy" above).

• Cervical strain is associated with spasm of the cervical and upper back muscles, often related to posture and sleeping habits, and does not cause chronic pain. (See "Cervical strain" above).

• Cervical discogenic pain is the most common cause of neck pain, with normal neurological findings and discomfort on range of motion. (See "Cervical discogenic pain" above).

• Cervical spondylosis is a nonspecific term referring to degenerative changes in the disc and bones, causing osteophytes, and impacting facet joints. Degenerative changes in the cervical spine are age-related, commonly seen on x-ray, and do not necessarily indicate clinical symptoms. (See "Cervical spondylosis" above).

• Cervical facet syndrome is often associated with a flexion-extension type injury, such as is seen with whiplash. Whiplash symptoms may also involve soft tissues, ligaments, nerves, discs, and other bony structures; the pathology is unclear and testing is not confirmatory. (See "Whiplash injury" above).

• Cervical spondylotic myelopathy may result from central canal narrowing and causes upper motor neuron signs (weakness, coordination impairment, gait disturbance, bowel or bladder retention or incontinence, and sexual dysfunction); surgical decompression is necessary. (See "Cervical spondylotic myelopathy" above).

• Cervical radiculopathy is most commonly due to degenerative changes and is discussed in detail separately. (See "Clinical features and diagnosis of cervical radiculopathy").

• The physical examination should include observation of movement, range of motion, palpation, neurological examination for radicular and upper motor neuron signs, and provocative maneuvers. (See "Physical examination" above).

• Plain films are indicated for patients with history of neck trauma, new symptoms in patients >50 years or with constitutional symptoms. (See "Plain films" above).

• CT scan or MRI should be done for patients with objective neurological impairment, dramatic bony tenderness coupled with dramatically impaired mobility, or persistent symptoms despite conservative care for six weeks. (See "CT scan or MRI" above).

• EMG testing can distinguish peripheral nerve entrapment syndromes from cervical radiculopathy, and should be considered when pain and dysesthesia is more prominent in the extremities than in the neck. Blood testing for patients with neck symptoms is not routinely indicated. (See "Other studies" above).

• Emergency evaluation of the trauma patient requires immobilization, neurological assessment, spinal palpation, and radiographic studies. Patients with neurological deficits should be evaluated by a spinal surgeon. The need for radiographic studies in alert and stable trauma patients can be determined with the Canadian C-spine rule or NEXUS criteria. (See "Evaluation of the trauma patient" above).

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