eMedicine Specialties > Sports Medicine > Spine

Cervical Radiculopathy

Gerard A Malanga, MD, Founder and Director, New Jersey Sports Medicine Institute; Director of Pain Management, Overlook Hospital; Director of Sports Medicine, Sports Medicine Fellowship Director, Mountainside Hospital; Clinical Chief, Rehabilitation Medicine and Electrodiagnosis, St Michael's Medical Center; Medical Director, Consultant, Horizon Healthcare Worker's Compensation Services, Blue Cross and Blue Shield Worker's Compensation
Michael A Romello, MD, Staff Physician, Department of Physical Medicine and Rehabilitation, Kessler Institute for Rehabilitation, University of Medicine and Dentistry of New Jersey, New Jersey Medical School
Contributor Information and Disclosures

Updated: Mar 31, 2008

Introduction

Background

Cervical radiculopathy is a dysfunction of a nerve root of the cervical spine. The seventh (C7; 60%) and sixth (C6; 25%) cervical nerve roots are the most commonly affected.^{1, 2, 3, 4, 5, 6, 7}

In the younger population, cervical radiculopathy is a result of a disc herniation or an acute injury causing foraminal impingement of an exiting nerve.⁸ Disc herniation accounts for 20-25% of the cases of cervical radiculopathy. In the older patient, cervical radiculopathy is often a result of foraminal narrowing from osteophyte formation, decreased disc height, degenerative changes of the uncovertebral joints anteriorly and of the facet joints posteriorly.

Factors associated with increased risk include heavy manual labor requiring the lifting of more than 25 pounds, smoking, and driving or operating vibrating equipment. Other, less frequent causes include tumors of the spine, an expanding cervical synovial cyst, synovial chondromatosis in the cervical facet joint, giant cell arteritis of the cervical radicular vessels, and spinal infections.^{9, 10} The purpose of this article is to provide information on the presentation, evaluation, differential diagnosis, and treatment of cervical radiculopathy.

For excellent patient education resources, visit eMedicine's Back, Ribs, Neck, and Head Center. Also, see eMedicine's patient education articles Shoulder and Neck Pain and Neck Strain.

Frequency

United States

Cervical radiculopathy occurs with much less frequency than radiculopathy of the lumbar spine. The annual incidence rate is approximately 85 per 100,000.

Functional Anatomy

Seven cervical vertebrae and 8 cervical nerve roots exist. The C1-2 (atlantoaxial) joint forms the upper cervical segment.^{1, 3, 11, 12} This joint allows for 50% of all cervical rotation motion. The occipitoatlantal joint is responsible for 50% of flexion and extension. Below the C2-C3 level, lateral bending of the cervical spine is coupled with rotation in the same direction. This is due to the 45° inclination of the cervical facet joints.

The vertebral bodies of C3-C7 are similar in appearance and function. They articulate via the zygapophyseal or facet joints posteriorly. On the lateral aspect of the vertebral bodies are sharply defined margins, which articulate with the facet above. These articulations are called uncovertebral joints, or the joints of Luschka. These joints can develop osteophytic spurs, which can narrow the intervertebral foramina.

Intervertebral discs are located between the vertebral bodies of C2-C7. The discs are composed of an outer annular fibrosis and an inner nucleus pulposus and serve as force dissipators, transmitting compressive loads throughout a range of motion (ROM). The intervertebral discs are thicker anteriorly and therefore contribute to normal cervical lordosis. The foramina are largest at C2-C3 and progressively decrease in size to the C6-C7 level.

The nerve root occupies 25-33% of the foraminal space. The neural foramen is bordered anteromedially by the uncovertebral joints, posterolaterally by facet joints, superiorly by the pedicle of the vertebra above, and inferiorly by the pedicle of the lower vertebra. Medially, the foramina are formed by the edge of the end plates and the intervertebral discs. The nerve roots exit above their correspondingly numbered vertebral body from C2-C7. C1 exits between the occiput and atlas, and C8 exits below the C7 vertebral body. Degenerative changes of the structures that form the foramina can cause nerve root compression. This compression can occur from osteophyte formation, disc herniation, or a combination of the 2.

Related eMedicine topics:
Herniated Nucleus Pulposus
Nerve Entrapment Syndromes

Related Medscape topic:
Resource Center Spinal Disorders

Sport-Specific Biomechanics

Cervical radiculopathy in athletes can occur from several mechanisms. These injuries can occur from an extension, lateral bending, or rotation mechanism, which closes the neural foramen and results in ipsilateral nerve root injury. Conversely, a traction injury can occur with a sudden flexion or extension, coupled with lateral bending away from the affected nerve root.

Additionally, cervical disc herniations can occur with a sudden load with the neck in either flexion or extension. In elderly persons with osteophyte formation, repetitive neck extension and rotation in certain sports, such as swimming or tennis, may result in a more insidious injury.

Related eMedicine topics:
Cervical Discogenic Pain Syndrome
Cervical Facet Syndrome
Spinal Cord Trauma and Related Diseases
Torticollis

Related Medscape topics:
Resource Center Spinal Disorders
Resource Center Trauma

Clinical

History

Obtaining a detailed history is important to establish a diagnosis of cervical radiculopathy.

• The examiner should first determine the main complaint (eg, pain, numbness, weakness, location of symptoms).
  • A visual analog scale from 0-10 can be used to determine the patient's perceived level of pain.
  • Anatomic pain drawings can also be helpful in giving the physician a quick review of the patient's pain pattern.
• Activities and head positions that increase or decrease symptoms are also helpful in making the diagnosis, as well as in guiding treatment.
• When did the injury occur, what was the mechanism of injury, and what was done are all important inquiries for the patient. Previous episodes of similar symptoms or localized neck pain are important for the diagnosis and ultimate treatment.
• Symptoms suggestive of a cervical myelopathy, such as changes in gait, bowel or bladder dysfunction, or lower-extremity sensory changes or weakness should also be obtained.
• The examiner should ask what previous treatments have been tried, including the use of ice and/or heat and medications (eg, acetaminophen, aspirin, nonsteroidal anti-inflammatory drugs [NSAIDs]).
• Questions regarding previous medical treatment should include physical therapy, traction, manipulation, previous injections, or surgical treatments. A social history should include the patient's sport and position, occupation, and the use of nicotine and/or alcohol.
• The typical patient with cervical radiculopathy presents with an insidious onset of neck and arm discomfort. The discomfort can range from a dull ache to a severe burning pain. Typically, pain is referred to the medial border of the scapula, and the patient's chief complaint is shoulder pain. As the radiculopathy progresses, the pain radiates to the upper or lower arm and into the hand, along the sensory distribution of the nerve root that is involved.
• The older patient may have had previous episodes of neck pain or give a history of having arthritis of the cervical spine.
• Acute disc herniations and sudden narrowing of the neural foramen may also occur in injuries involving cervical extension, lateral bending, or rotation and axial loading. These patients complain of increased pain with neck positions that cause foraminal narrowing (eg, extension, lateral bending, or rotating toward the symptomatic side).
• Many patients report a reduction in their radicular symptoms by abducting their shoulder and placing their hand behind their head. This relief in symptoms is thought to occur by decreasing tension at the nerve root.
• Patients may complain of sensory changes along the involved nerve root dermatome, which can include tingling, numbness, or loss of sensation.
• Some patients may complain of motor weakness. A small percentage of patients will present only with weakness, without significant pain or sensory complaints.

Physical

• Observation
  • The physical examination begins with observation of the patient during the history portion of the evaluation. This includes head and neck posture and movement during normal conversation. Typically, the patient exhibits a head tilt away from the side of injury and holds his or her neck stiffly.
  • Active ROM is usually reduced, particularly in extension, rotation, and lateral bending, either toward or away from the affected nerve root.
  • Increased pain with lateral bending away from the affected side can cause increased displacement of a disc herniation upon a nerve root, whereas ipsilateral pain would suggest an impingement of a nerve root at the site of the neural foramen. 
• Palpation
  • On palpation, tenderness is usually noted along the cervical paraspinal muscles, and it is usually more pronounced along the ipsilateral side of the affected nerve root.
  • Muscle tenderness may be present along the muscles where the symptoms are referred (eg, medial scapula, proximal arm, lateral epicondyle).
  • Associated hypertonicity or spasm on palpation in these painful muscles may occur.
  • Letchuman et al showed that cervical radiculopathy is associated with increased tender spots (both trigger and tender points) on the side of the radiculopathy, with a predilection toward the muscles innervated by the involved nerve root.¹³ This study revealed that not only pain, but also tenderness may be referred in radiculopathy.
• Motor
  • Manual muscle testing is an important aspect of determining an affected nerve root level on physical examination. Perform manual muscle testing to detect subtle weakness in a myotomal distribution.
  • Place the limb of the affected side in the antigravity position; the force is applied just proximal to the next distal joint. For example, the extensor carpi ulnaris muscle should be tested with the forearm in full pronation and resting on a table or supported and then resisted against the dorsum of the fifth metacarpal bone in the direction of flexion toward the radial side. Muscle strength is then graded on a scale of 0 to 5 as follows:
    • 0 – No muscle contraction
    • 1 – Muscle contracts but is not able to move the joint/limb
    • 2 – Muscle is able to move the joint/limb, but not against gravity
    • 3 – Muscle is able to move the joint/limb against gravity, but not through a full ROM
    • 4 – Muscle is able to move the joint/limb through a full ROM, but the strength against resistance is not equal to the opposite limb (if normal)
    • 5 – Muscle strength is normal (equal to the opposite, normal limb)
  • Radiculopathies by nerve level
    • C5 radiculopathy: shoulder abduction weakness
      • Test: Have the patients hold their shoulders in abduction, against downward force by the examiner. 
    • C6 radiculopathy: elbow flexion, wrist extension weakness
      • Test: Have the patients lift their arm against resistance by the examiner.
    • C7 radiculopathy: elbow extension, wrist flexion weakness
      • Test: Have the patients push with their arm away from their chest against resistance by the examiner.
    • C8:  thumb extension, wrist ulnar deviation weakness
      • Test: Have the patients hold their extended fingers together against the examiner's attempts to open the fingers.
• Sensory
  • On sensory examination, a dermatomal decrease or loss of sensation should be noted in patients with clear-cut radiculopathy.
  • In addition, patients with radiculopathy may have hyperesthesia to light touch and pin-prick examination. However, the sensory examination can be quite subjective because it requires a response by the patient.
• Deep tendon reflexes
  • The deep tendon reflexes—or, more properly, muscle stretch reflexes because the reflex occurs after a muscle stretch is obtained (most commonly by tapping the distal tendon of a muscle)—are helpful in the evaluation of patients who present with limb symptoms that are suggestive of a radiculopathy. The examiner must position the limb properly when obtaining these reflexes, and the patient needs to be as relaxed as possible. Any grade of reflex can be normal, so it is the asymmetry of the reflexes which is most helpful.
  • The biceps brachii reflex is obtained by tapping the distal tendon in the antecubital fossa. This reflex occurs at the C5-C6 level.
  • The brachioradialis reflex is another C5-C6 reflex that can be obtained by tapping the radial aspect of the wrist.
  • The triceps reflex can be obtained by tapping the distal tendon at the posterior aspect of the elbow, with the elbow relaxed at about 90° of flexion. This tests the C7-C8 nerve roots.
  • The pronator reflex can be helpful in differentiating C6 and C7 nerve root problems. If this reflex is abnormal in conjunction with an abnormal triceps reflex, then the level of involvement is more likely to be C7. The pronator reflex is performed by tapping the volar aspect of the distal radius with the forearm in a neutral position and the elbow flexed. This results in a stretch of the pronator teres, resulting in a reflex pronation.
  • In patients that demonstrate concern about possible myelopathy, the lower-extremity reflexes and Hoffman and Babinski reflexes should also be assessed. Diffuse hyperreflexia and/or positive Hoffman and abnormal Babinski reflexes would indicate that the patient has a cervical myelopathy.  
• Provocative tests
  • The foraminal compression test or Spurling test is probably the best test for confirming the diagnosis of cervical radiculopathy. It is performed by extending the neck and rotating the head and then applying downward pressure on the head. The test is considered positive if pain radiates into the limb ipsilateral to the side to which the head is rotated. The Spurling test has been found to be very specific (93%), but not sensitive (30%), in diagnosing acute radiculopathy.¹¹ Therefore, it is not useful as a screening test, but it is clinically useful in helping to confirm cervical radiculopathy.
  • Manual cervical distraction can be used as a physical examination test. With the patient in a supine position, gentle manual distraction often greatly reduces the neck and limb symptoms in patients with radiculopathy.
  • Lhermitte sign is performed by flexing the neck and asking the patient about symptoms of an electric shocklike sensation radiating down the spine, and in some patients, into the extremities. This sign has been found in patients with cervical cord involvement, cervical spondylosis, and also in patients with tumor and multiple sclerosis (MS); however, the Lhermitte sign should be negative in those with cervical radiculopathy. Manual distraction may reduce the neck and limb symptoms in patients with cervical radiculopathy.

Related eMedicine topics:
Cervical Spondylosis
Multiple Sclerosis

Related Medscape topic:
Resource Center Spinal Disorders

Causes

Little is known about the natural history of cervical radiculopathy. The pathogenesis of radiculopathy occurs from the inflammatory process initiated by nerve root compression. Evidence exists that inflammatory mediators, including nitric oxide, prostaglandin E2, interleukin-6, and matrix metalloproteinases, are released by herniated intervertebral discs.^{14, 15} This results in nerve root swelling. The compression may be from a disc herniation, degenerative changes about the neural foramen, or a combination of the 2.

A study regarding patients under local anesthesia found that compression of a nerve root produced limb pain, whereas pressure on the disc produced pain in the neck and medial border of the scapula.¹⁶ Results from intradiscal injection and electrical stimulation of the disc have also suggested that neck pain is referred by a damaged outer annulus.^{17, 18, 19, 20, 21, 22, 23} Muscle spasms of the neck have also been found after electrical stimulation of the disc.

Related eMedicine topics:
Degenerative Lumbar Disc Disease in the Mature Athlete
Lumbar (Intervertebral) Disk Disorders
Nerve Entrapment Syndromes

References

• Brachial Plexus Injury
• Cervical Disc Injuries
• Cervical Discogenic Pain Syndrome
• Cervical Facet Syndrome
• Cervical Spine Sprain/Strain Injuries
• Rotator Cuff Injury

• Back, Ribs, Neck, and Head Center
• Shoulder and Neck Pain Overview
• Shoulder and Neck Pain Causes
• Shoulder and Neck Pain Symptoms
• Shoulder and Neck Pain Treatment
• Neck Strain Overview