Incidence and Prevalence

Kondo et al. found the combined incidence of symptomatic herniations and protrusions to be 5.5 per 100,000 people, with occurrence in men being 6.5 per 100,000 compared with 4.6 per 100,000 in women. The incidence in both sexes was highest at 45 to 54 years, followed closely by the incidence at 35 to 44 years. The most common disk involved was C5-C6 followed by C4-C5 and then C6-C7. Kelsey et al. reported that the C5-C6 and C6-C7 levels were involved in 75% of patients, based on review of myelograms and radiographs.

Risk Factors

Risk factors for neck pain in the adult population include smoking and exposure to tobacco and poor psychological health. The prognosis was better in younger patients as well as in patients with greater optimism, less need to socialize, and patients in which coping involves self-assurance. Poor psychological health, anger, frustration, and worrying were associated with a poor prognosis. Between 50% and 75% of patients experienced recurrent pain within 1 to 5 years. In the working population, risk factors for neck pain include age, previous musculoskeletal pain, high quantitative job demands, low social support at work, low physical capacity, job insecurity, poor work posture, and sedentary, repetitive, and precision work. Headaches, emotional problems, smoking, ethnicity, and poor job satisfaction may be associated with neck pain. Women are more likely to suffer neck pain than men. General exercise and white collar employment were positive prognostic factors, whereas a poorer prognosis was associated with workers who had little influence over their work situation, blue collar workers, those with prior neck pain, and those with prior sick leave. Between 60% and 80% of workers reported recurrent pain within 1 year.

Definition and Causes

Cervical radiculopathy is a disease of the cervical nerve roots that results in pain that radiates into one or both upper extremities. It occurs as a result of compression or inflammation (radiculitis) of the nerve root. Compressive causes of radiculopathy include cervical disk herniation, cervical spondylosis, synovial cysts, fractures that cause compression of the nerve root, trauma with nerve root avulsion, intraspinal tumors, osseous malignancies or metastasis, meningeal cysts, arteriovenous fistulas, and vertebral artery compression. Radiculitis may also occur as a result of herpes zoster or with diabetic and autoimmune etiologies. It may even be idiopathic.

Differential Diagnosis

The differential diagnosis of radiculopathy includes brachial plexopathy and mononeuropathies, including the long thoracic, suprascapular, and axillary nerves. Acute onset of pain suggests the differential diagnosis of neuralgic amyotrophy (Parsonage-Turner syndrome). Distal nerves, such as the ulnar, median, and radial nerves, can cause distal pain and paresthesias that can simulate radiculopathies. Mechanical problems involving the shoulder and wrist must be considered as well. Rotator cuff dysfunction or medial and lateral epicondylitis are in the differential diagnosis of the etiology of pain in the extremity and can also develop as a result of muscular imbalances secondary to cervical radiculopathy. Cervical and thoracic myofascial pain, discogenic disease, and facet dysfunction may cause pain to radiate into the upper extremity as well, especially from the lower cervical spine.

Cervical myelopathy ( Fig. 53-1 ) can be caused by trauma with fractures or dislocations, cervical herniated nucleus pulposus, spondylosis with stenosis, tumor, arteriovenous malformations and dural arteriovenous fistulas, syringomyelia, subacute combined degeneration (vitamin B ₁₂ deficiency), infection (epidural abscess; tabes dorsalis, a late form of syphilis; lymes, human immunodeficiency virus–related myelopathy), and hereditary paraparesis. The differential diagnosis must include other reasons for upper motor neuron dysfunction, including brain syndromes (stroke, encephalomyelitis, tumor), anterior horn syndrome, and multiple sclerosis.

Cervical magnetic resonance imaging with sagittal view of T2 image showing signal change secondary to myelopathy resulting from cervical stenosis.

History

The history includes any incidents or repetitive activities that may precipitate the painful syndrome. The patient should draw a picture of the location of the pain or specifically point to the areas where pain occurs as well as the pattern of paresthesias. The semantics of medicine are such that patients may describe pain in the shoulder and really mean the trapezius or shoulder blade, or even the cervical spine. Thus, it is important to identify the areas involved in a graphic manner. Inquire specifically about activities that exacerbate symptoms in the cervical spine, shoulder, or arm. Paresthesias in the area of the shoulder and lateral elbow are reminiscent of problems with the C4 and C5 nerve roots, respectively. The thumb is classically C6, the middle finger is C7, the small finger is C8, the medial elbow is T1, and the axilla is T2. Diffuse upper extremity paresthesias raise concerns about brachial plexopathy. Weakness in the lower extremities or bowel or bladder retention or incontinence raise concerns about cervical myelopathy.

A full medical history must be taken to evaluate the patient for visceral problems that may contribute to the pain or may impair aspects of treatment. Causes of visceral pain that may result in pain in the area of the shoulder and shoulder blade include cardiac disease (myocardial infarction/ischemia, aortic aneurysm, pulmonary pathology (malignancy, pneumonia, and pulmonary embolism), and gastrointestinal disorders (peptic ulcer disease, cholecystitis, pancreatitis). Previous medications, exercise therapies, modalities, and injection treatments must be reviewed as well as the response to each of these treatments. A full functional and social history must be reviewed to look for activities that may be contributing to maintaining the pain syndrome or are limited secondary to the pain syndrome.

Physical Examination

Physical examination begins with watching the patient walk into the room, when possible, to see whether there is a spastic gait. The patient should disrobe sufficiently so that the muscle bulk of the upper back and upper extremities can be observed. Atrophy may be seen by comparing one side of the body with the other side. Scapular winging should be evaluated by looking at the patient while the patient is standing still and with provocative testing. Winging with scapular protraction correlates with serratus anterior weakness secondary to a long thoracic nerve lesion. The upper, middle, and lower trapezius must also be examined for weakness to determine the integrity of the spinal accessory nerve. Palpation of the cervical paraspinal musculature and trapezius is performed to look for tender points and trigger points. Range of motion in the cervical spine must be evaluated for flexion, extension, rotation, and side bending to each side. Spurling’s test requires the patient to extend the neck and rotate and side bend the neck as the examiner applies downward pressure to the top of the head. Findings are consistent with cervical radiculopathy when pain radiates into the limb that is ipsilateral to the side of rotation. Tong et al. ^, used electrodiagnosis to establish a sensitivity of 30% and a specificity of 93%.

Imaging Studies

If pain is reproduced in the shoulder with range-of-motion screening, the shoulder should be examined for subacromial impingement syndrome and rotator cuff dysfunction. The elbow should be examined for regional nerve compression syndromes, such as cubital or radial tunnel or tendinopathies of the common extensor tendon (tennis elbow) or common flexor tendon (medial epicondylitis). The chapters on shoulder and elbow examination and specific clinical conditions provide further information to assist with comprehensive examination and differential diagnosis. Motor testing, sensation, and deep tendon reflexes are evaluated in the upper and lower extremities. If the patient has brisk reflexes or lower extremity spasticity, clonus, or a Babinski’s sign, then upper motor neuron pathology is a consideration. When upper motor neuron pathology is suspected, the cranial nerves must be evaluated to ensure that the pathology is not cephalad to the cervical spine. If there is bowel or bladder incontinence, then sensation of the genitalia and rectum to pinprick must be evaluated. Voluntary rectal contraction and rectal tone are evaluated. In upper motor neuron pathology, there may be rectal weakness with an increase in tone (after spinal shock has resolved). Bulbocavernosus and anocutaneous reflexes are brisk in upper motor neuron pathology.

Myotome testing should be performed of the elbow flexors (biceps/brachialis, C5), wrist extensors (extensor carpi radialis, C6), elbow extensors (triceps, C7), finger flexors to the middle finger (flexor digitorum profundus, C8), and small finger abductor (abductor digiti minimi, T1). The deep tendon reflexes evaluated include biceps (C5), brachioradialis (C6), and triceps (C7). Dermatomal sensory testing with a light touch or pinprick is performed. Dermatomal distribution is as follows: C2, occipital protuberance; C3, supraclavicular fossa; C4, over the acromion; C5, lateral epicondyle; C6, extensor surface of the thumb; C7, extensor surface of the middle metacarpophalangeal joint; C8, extensor surface of the fifth metacarpophalangeal joint; and T1, over the medial epicondyle. Chapter 10 provides a comprehensive review of the upper quarter screen described in this chapter.

Pulses in the upper extremities should always be evaluated, especially the radial pulses and carotid artery pulses. Blood pressure should be checked in one and possibly both arms for diagnostic and therapeutic purposes. Medications that may be used to treat radiculopathy may have cardiovascular side effects, and the baseline blood pressure must be known before initiation of treatment with muscle relaxants as well as nonsteroidal anti-inflammatory drugs (NSAIDs).

Cervical spine plain films are of limited use in the diagnosis of radiculopathy. They show age-related degenerative changes, alignment, congenital abnormalities, and gross fractures. Flexion and extension films can show dynamic instability. However, the presence of cervical degenerative changes alone is not diagnostic of pain because these changes are frequently seen in asymptomatic patients.

Magnetic resonance imaging (MRI) is the study of choice for cervical radiculopathy. It can accurately evaluate neural structures and the intervertebral disks painlessly, noninvasively, and without radiation exposure. The spinal cord can be evaluated for intrinsic damage, including edema, blood, tumor, and syrinx. MRI can also help to differentiate between a soft and a hard disk, which may add information about the acuity of disk herniation ( Figs. 53-2 and 53-3A and B ). In a retrospective review of 34 surgical patients, Brown et al. found that MRI predicted 88% of lesions versus 81% for computed tomography (CT) myelography and 50% for CT scan.

Sagittal image of osteophytic cervical disc herniation at C5-C6.

A, T2 image of sagittal view of cervical stenosis. B, T2 image of axial view of cervical stenosis.

CT myelography is invasive and is not as sensitive as MRI in viewing the spinal cord or intervertebral disk. However, in cases where there is instrumentation, or if MRI is contraindicated (e.g., pacemakers, metallic implants, spinal cord stimulators), then CT myelography is an alternative. A plain CT scan provides excellent visualization of the bony elements and is used to detect nonunion of fusions and acute fractures. It may be used to look for disk herniations if MRI is contraindicated and myelography is deemed too invasive.

These studies do not provide a definitive diagnosis without a clinical context. The results must be matched with the history and physical findings, and potentially with complementary studies to make a diagnosis. CT scan findings can be abnormal in asymptomatic patients. Myelograms show disk abnormalities in 21% of asymptomatic patients. Boden et al. found abnormalities in MRI scans of 19% of asymptomatic patients. Abnormalities were found in 14% of patients younger than 40 years and 28% of patients who were older than 40 years.

Electromyography and nerve conduction is a physiologic test that evaluates the peripheral nervous system. It is used not only to evaluate for radiculopathy but also for plexopathy, individual peripheral nerve lesions, and myopathy. The electromyography and nerve conduction findings may not become abnormal for 10 days to 6 weeks postinjury. The sensitivity of needle electromyography and nerve conduction in cervical radiculopathy is 61% to 67% compared with the gold standards of clinical evaluation, myelogram, and intraoperative impression. Radiculopathy is confirmed by showing spontaneous activity in two or more muscles innervated by the same root level but different peripheral nerve roots. Muscles innervated by root levels above and below the involved levels should be normal. In the lumbar spine, abnormal paraspinal musculature alone does not diagnose radiculopathy and can be abnormal in up to 30% of asymptomatic patients older than 40 years. Chapter 15 provides detailed information on electrophysiologic evaluation of the upper quarter.

Cervical facet syndrome may be the cause of pain in the cervical spine as well as the head and proximal upper extremity. Diagnosis of cervical facet (zygapophyseal joint) dysfunction is made by diagnostic injection into the zygapophyseal joint directly or by diagnostic block of the medial branch of the dorsal rami above and below the symptomatic joint. Referral patterns of facet joints were mapped by Dwyer et al. ^, History and physical examination as well as degenerative changes found on anatomic images do not provide a diagnosis. A single uncontrolled diagnostic injection carries a 27% false-positive rate. The patient must have 50% to 80% relief with provocative pain maneuvers on at least two occasions to make a definitive diagnosis. Comparative injections include placebo versus local anesthetic or short-acting versus long-acting anesthetic.

Cervical selective nerve root injections may be used for diagnosis as well. They should be used as an adjunct to the history, physical examination, and previously mentioned diagnostic studies, and not in isolation. The diagnostic injection may help to determine whether a given nerve root is involved in cases where: (1) the pain radiation is not classic for a given root; (2) there are multiple anatomic abnormalities that could result in cervical radiculopathy; or (3) there is a distal pain generator, such as a median or ulnar nerve lesion, that may be causing confusion as to the etiology of the symptoms. Anesthetic joint injection of the shoulder or elbow may also be a useful adjunct to determine whether other mechanical problems can be contributing to the pain syndrome instead of or in addition to radiculopathy. In the lumbar spine, false-positive responses have been noted. Placebo and blocking afferents from mechanical structures and peripheral nerve generators may be a part of the reason for false-positive responses.

Drug Treatment

The primary treatment medication categories used for cervical radiculopathy include NSAIDs, muscle relaxants, opioid analgesics, oral corticosteroids, topical agents, antidepressants, anticonvulsants, and acetaminophen. For most cervical conditions, NSAIDs are the first-line intervention. NSAIDs have anti-inflammatory, analgesic, and antipyretic effects. Reducing inflammation is important in treating cervical radiculopathy. NSAIDs achieve their anti-inflammatory effects at high dosages and reduce pain at low dosages. The choice of NSAID must be individualized. If an individual NSAID is not effective, the patient may respond to an NSAID from another class. However, major risk factors include gastrointestinal side effects, renal and hepatic failure, and cardiovascular disease. The results of studies with COX-2 inhibitors are contradictory with regard to gastrointestinal safety profiles. ^,

Oral corticosteroids may be useful in the treatment of cervical radiculopathy. They are generally well tolerated, effective, and safe. There have been no documented cases of avascular necrosis when the total prednisone dose or equivalent stayed below 550 mg.

Peloso et al. reviewed the effects of medication on primary outcomes in adults with mechanical neck disorders and whiplash. Although 36 trials were reviewed, a limited number of medications were studied. These included oral NSAIDs and analgesics, psychotropics, corticosteroid injections, local anesthetics, and botulinum toxin A injections. The benefits of muscle relaxants, analgesics, and NSAIDs were questionable. Results showed that botulinum toxin A is no better than saline injections at reducing pain and disability. Chronic neck pain showed some benefit with local anesthetics, and patients with chronic neck pain and associated arm symptoms benefited from epidural injections of a corticosteroid plus a local anesthetic agent. If given within 8 hours of an injury, corticosteroid injections appear to reduce the pain of whiplash.

Muscle relaxants fall into two main categories, antispasmodics and antispasticity medications. Muscle relaxants are not more effective than NSAIDs and have more side effects. ^, Their sedative side effects may help patients with pain to rest better when they are used at night.

Opioid analgesics are an option, but should only be used for a time-limited course. Physicians who prescribe opioids must incorporate government-mandated documentation and should use opioid contracts and screen for high-risk patients with a history of substance abuse or substance-seeking behavior. Because of the potential of these drugs for physical dependence, other options should be considered.

Topical agents, including a lidocaine 5% patch and NSAID-containing patches, are attractive to patients who wish to avoid systemic side effects. Common patient complaints include cost, adhesive allergy, and movement of the patch. Compounded topical agents may be beneficial, but there is little evidence-based research to support their off-label use.

Antidepressants have been used successfully to decrease radicular pain and improve restorative sleep. Although selective serotonin reuptake inhibitors lack many of the side effects of tricyclic antidepressants, their efficacy in relieving neck pain compared with tricyclic antidepressants is not known. Dual-action reuptake inhibitors (serotonin and norepinephrine) may offer an advantage over single-action agents because of their effects on norepinephrine. Currently, there are no studies to support this conclusion.

Anticonvulsants, such as gabapentin, are increasingly being used to treat radicular pain. They have been shown to be safe and effective for other types of neuropathic pain conditions. There are no randomized, placebo-controlled, crossover studies that support monotherapy or combined therapy for radicular pain.

Therapy

The primary goals of treatment of cervical radiculopathy are reduction of pain, restoration of strength and function, and prevention of recurrence. Physical therapy is, in most cases, among the recommended first-line treatments. The evidence that physical therapy is of benefit in cervical radiculopathy derives mainly from case series, case reports, and anecdotal experience, because there are few randomized controlled trials addressing this subject in the literature. Therapy should be initiated as soon as possible after symptom onset because patients with acute (<1 month) cervical pain and radiculopathy have been shown to have significantly greater functional improvement after physical therapy intervention than patients with chronic (>6 months) symptoms.

A physical therapy program is generally performed two to three times a week for approximately 4 weeks and may consist of any or all of the following interventions: isometric neck exercises, postural exercises, mechanical traction, cervical manipulation, and the use of modalities such as a cervical collar or transcutaneous electrical nerve stimulation (TENS). Isometric neck exercises are performed early in the course of treatment, when movement of the neck is painful. As pain diminishes, stretching exercises are added to the therapy program to restore neck range of motion. Stretching and strengthening exercises target the cervical paraspinal, shoulder girdle, scapular stabilizing, and lumbar muscles. In a small case series, Cleland et al. found that 10 patients showed significant improvement in pain and function after a physical therapy program that consisted of cervical traction or mobilization and strengthening exercises of the neck flexors and scapulothoracic muscles. In their review of 88 randomized controlled trials, Gross et al. found moderate evidence that various types of neck stretching and strengthening exercises were beneficial for patients with mechanical neck disorders and whiplash-associated neck pain.

Modalities such as heat and ice, electrical stimulation, and use of a cervical collar are employed in the acute phase of disease to reduce pain. No consensus exists regarding the use of soft cervical collars in cervical radiculopathy. Soft collars have been shown in several studies to be of no benefit or less benefit than active therapies and rest. Collars may provide some comfort during sleep or activity during the acute stage of disease, but their use should be limited to no more than 2 to 3 weeks to prevent the development of weakness of the cervical paraspinal musculature.

TENS is a modality that delivers electrical current to the painful area via surface electrodes. TENS is postulated to reduce pain by modulating sensory afferent signals to the substantia gelatinosa (gate-control theory) as well as causing the release of endogenous endorphins. There is conflicting evidence regarding the usefulness of electrotherapies in the treatment of neck pain. A small number of studies have shown TENS to be useful in reducing pain and restoring mobility in patients with acute nonradiating neck pain. In contrast, a Cochrane review found no definite evidence supporting the use of electrotherapies in the treatment of acute neck pain. Precautions and contraindications for electrotherapy should be considered before treatment and are discussed in detail in Chapter 117 . Gross et al. and Hurwitz et al. reported that patients with acute cervical pain as a result of whiplash injury or mechanical neck disorder who were treated with phosphatidylethanolamine N-methyltransferase were found to have less pain and analgesic use compared with a placebo group.

Traction is one of the most commonly used modalities in the treatment of cervical radiculopathy, although little literature supports its effectiveness. In physiologic studies, cervical traction using 25 pounds of force has been shown to cause spinal elongation of 2 to 20 mm. Intermittent cervical traction with the neck in 30 degrees of flexion has been shown to cause up to a 21% increase in anterior intervertebral space. A small study comparing patients with unilateral C7 radiculopathy treated with either modalities and exercise alone or intermittent mechanical traction and modalities and exercise found that grip strength was significantly greater after five treatment sessions in the group receiving traction. This difference in grip strength had disappeared, however, after 10 treatment sessions, suggesting that the beneficial effects of traction may be immediate and temporary. The increase in posterior cervical intervertebral space seen after traction has been noted to be temporary, returning to baseline 20 minutes after treatment cessation. Gross et al. found moderate evidence that intermittent cervical traction was of short-term (<3 months) benefit for neck and radicular pain compared with control or placebo.

Mechanical cervical traction may be applied via a motorized device or via a free-weight and pulley system. Traction is created using a head or chin sling attached to a system that provides pull in a cranial direction. When initiating traction therapy, a weight of 5 to 10 pounds is recommended, followed by a gradual increase in weight to a maximum of 50 pounds. A treatment duration of 15 to 25 minutes, if tolerated by the patient, is generally recommended. Home traction units may be ineffective or may cause increased pain if not used properly and with supervision. ^, Traction should not be applied with the neck in extension, because of the risk of increased pain, vertebrobasilar insufficiency, or spinal instability. In addition, cervical traction is contraindicated in patients of advanced age or those with ligamentous instability, diskitis, osteomyelitis, vertebral or spinal cord tumor, osteoporosis, uncontrolled hypertension, clinical suspicion of myelopathy, severe anxiety, history suggestive of vertebrobasilar insufficiency, rheumatoid arthritis, midline herniated nucleus pulposus, or acute torticollis.

Manual cervical traction is performed by a physical therapist, usually in conjunction with other spinal manipulation techniques. Low-velocity manipulation, often referred to as cervical mobilization, consists of gentle pressure applied in the available range of cervical flexion, extension, lateral bending, and rotation. Gross et al. found strong evidence that multimodal treatment programs including both exercise and mobilization or manipulation reduced pain and improved function in patients with neck and radicular pain. However, manipulation alone was found to be ineffective in reducing pain. High-velocity manipulations of the cervical spine, often performed by chiropractors or physicians trained in osteopathic manipulation, should be used with caution because such treatment is associated with a small (1/10,000–6/100,000) but serious risk of adverse events, such as stroke, weakness, or paralysis. The risk of these adverse events may be increased in patients with cervical stenosis or vascular disease. Other, more common potential neurologic complications of high-velocity cervical manipulation include headache, fainting, dizziness, lightheadedness, paresthesias in the upper limbs, or transient (6–72 hours) increase in pain. ^, Systemic anticoagulation, uncontrolled diabetes, atherosclerosis, suspicion of vertebrobasilar insufficiency, osteoporosis, ligamentous laxity, spondyloarthropathies, and acute disk herniation are all contraindications to high-velocity manipulation.

A physical therapy program for cervical radiculopathy also includes patient education or “neck school,” instruction in proper body mechanics, and ergonomic assessment. Neck school consists of instruction, often in small groups of 4 to 10 patients, on topics such as neck anatomy and stress reduction techniques. Neck school may be helpful in preventing recurrences of cervical radiculopathy, but has been found to be ineffective in reducing pain.

Regarding body mechanics, patients with cervical radiculopathy should avoid positions that increase load on the cervical intervertebral disks, such as neck forward flexion and rotation or prolonged neck extension, and should take care that the arms and shoulders are supported when patients are seated. An ergonomic evaluation ensures that the patient’s positioning in the workplace, especially when a computer is used, is not exacerbating the symptoms.

Finally, the patient should be reevaluated at frequent intervals throughout the course of physical therapy. If, after 4 to 6 weeks, the patient and therapist do not note improvement in symptoms, the physical therapy program should be discontinued and consideration should be given to other treatment modalities, such as medications or injection procedures. If the therapy program does result in improvement in symptoms, the patient should be instructed in a self-directed home exercise regimen. See Chapter 55 for a detailed review of the therapist’s management of upper-quarter neuropathies.