Air Neck Traction

Cervical Radiculopathy

Uncomplicated neck pain and cervical strain is the result of muscular and ligamentous factors related to posture, sleep habits, ergonomics such as computer monitor position, stress, chronic muscular fatigue, postural adaptation to other primary pain sources such as the shoulder, or degenerative changes of the cervical discs or facet joints. This is termed axial neck pain (ICD-9 code 723.1.)

Axial neck pain is the most common cause of neck pain and has a high rate of spontaneous resolution. Axial neck pain typically presents as pain or soreness in the posterior paraspinal neck muscles, with radiation to the occiput, shoulder, or parascapular region. Stiffness in one or more directions of motion and headache are common along with localized areas of muscle tenderness (tender points). Neck pain is defined in a region bounded superiorly by the superior nuchal line, laterally by the lateral margins of the neck, and inferiorly by an imaginary transverse line through the T1 spinous process.

Cervical radiculopathy (ICD-9 723.4) is motor and/or sensory changes in the upper extremity resulting from extrinsic pressure on a cervical nerve root. The pressure is usually by encroachment from annular disc bulging without frank herniation or from disc degeneration/spondylosis (hard disc pathology) or disc material from loss of internal containment such as herniation or extrusion (soft disc pathology). An inflammatory response is most likely associated with initiation or exacerbation of symptoms and inflammatory chemical pain mediators are known to be involved with disc herniations.

According to Humphreys et al, foraminal heights, widths and areas were larger in asymptomatic patients. Inferior facet hypertrophy tended to decrease the width of the foramen and significantly affects the available area for the exiting nerve root in aging people.

Additionally, in Lu J, et al noted, reduction of the foraminal area after a 1 mm narrowing of the disc space was 29% to 30%. Reduction of 30% to 40% of the foraminal area was noted with a 2 mm narrowing of the disc space. Reduction of 35% to 45% of the foraminal area was noted with a 3 mm narrowing of the disc space. Therefore, the size of the intervertebral foramen is directly related to the height of the disc space. Sever neuroforaminal narrowing is associated with a 3 mm vertical reduction of the disc space.

Henderson et al studied radiculopathy symptoms and noted 99% had arm pain, 85% had sensory deficits, 79% had neck pain, 71% had reflex deficits, 68% had motor deficits, and 52% had scapular pain.

In contrast to the patient with isolated axial neck pain, the patient with radiculopathy more frequently has unilateral neck pain that then radiates ipsilaterally into the distribution of the affected nerve root.

The most common levels of root involvement in cervical radiculopathy are C6 and C7; high cervical radiculopathies (C2-C4) are less common. The absence of radiating symptoms in a dermatomal distribution does not rule out the presence of symptomatic nerve root compression. Regardless of the root level that is compressed, a patient may report upper trapezial and interscapular pain. In many patients with cervical root compression, the focal point of pain is not uncommonly the shoulder girdle area, regardless of the root level involved, and the symptoms may not radiate any farther down the arm.

According to Yasuhisa Tanaka et al, neck or scapular pain may often precede arm or finger symptoms in cervical root compression. Free nerve endings have been identified in the dural sheath of the cervical roots and are responsible for the mediation of pain. In the authors experience, during diagnostic root injections to detect the involved level the patients perceive first only neck or scapular pain and afterwards arm or finger pain as the needle is inserted deep into the root. Accordingly, neck or scapular pain is probably the initial symptom of cervical radiculopathy when the compression is confined to the dural sheath. In clinical practice, it is common to see patients who have neck or scapular pain unaccompanied by radicular symptoms in the arm or fingers.

Most physicians doubt that the pain originates from a nerve root. However, the pain is usually the initial symptom in radiculopathy and can last alone as long as a few weeks or more before the arm or finger symptoms develop. Therefore, neck and scapular pain without symptoms in the arm or finger can originate in the root.

Pain in the suprascapular region indicates C5 or C6 radiculopathy. The same applies to the relationships between the pain in the interscapular region and C7 or C8 radiculopathy, and between pain in the scapular region and C8 radiculopathy.

Crossover between myotomes and dermatomes may be present. Cervical nerve roots exit above their correspondingly numbered pedicles; for example, the C6 root exits between C5 and C6. The exception to this rule is the C8 root, which exits above the T1 pedicle. In contrast to the lumbar spine, where posterolateral pathologies usually impinge on the traversing nerve roots and foraminal pathologies on the exiting nerve roots, compressive lesions in the cervical spine tend to produce radiculopathy of the exiting nerve root. For example, both a posterolateral C5- C6 disk herniation and C5-C6 foraminal stenosis from an uncovertebral osteophyte usually lead to C6 radiculopathy. It is possible, however, for a large central to midlateral disk herniation or stenosis to affect the subjacent root.

As Bogduk would remind us, cervical radicular pain has conventionally been addressed in the context of cervical radiculopathy, but it is not synonymous with cervical radicular pain. Cervical radiculopathy is a neurologic condition characterized by objective signs of loss of neurologic function, that is, some combination of sensory loss, motor loss, or impaired reflexes, in a segmental distribution. None of these features constitutes pain.

Cervical radiculopathy has a common feature of compressing or otherwise compromising a cervical spinal nerve or its roots. The axons of these nerves are either compressed directly or are rendered ischemic by compression of their blood supply. Symptoms of sensory loss or motor loss arise as a result of blockage of conduction along the affected axons. The features of cervical radiculopathy, therefore, are essentially negative in nature–they reflect loss of function. In contrast, pain is a positive feature not caused by loss of nerve function. If compression is to be invoked as a mechanism for pain, it must explicitly relate to compression of a dorsal root ganglion.

Radicular pain is shooting, stabbing, or electric in nature, traveling distally into the affected limb, consistent with a massive discharge from multiple affected axons. Radicular pain is commonly associated with paresthesia.

Unlike the sensory loss of cervical radiculopathy, the pattern of cervical radicular pain is not dermatomal. Radicular pain is perceived deeply, through the shoulder girdle and into the upper limb proper. Radicular pain from C5 tends to remain in the arm, but pain from C6, C7, and C8 extends into the forearm and hand. These patterns of distribution indicate that the pain is not restricted to cutaneous afferents. It involves afferents from deep tissues, such as muscles and joints, as well. Because the segmental innervation of deep tissues is not the same as that of skin, radicular pain cannot be, and is not, dermatomal in distribution.

Muscles of the shoulder girdle are innervated by C6 and C7, well away from the dermatomes of these nerves. If anything, the segmental innervation of muscles is a much better guide to the distribution of radicular pain than are the dermatomes. Dermatomes are nonetheless relevant for the distribution of the neurologic signs of radiculopathy, but this distribution of neurologic signs has nothing to do with the distribution of pain.

Letchuman noted that cervical radiculopathy was associated with increased tender spots on the side of radiculopathy, with predilection toward muscles innervated by the involved nerve root. It was stated, "The presence of tender spots that are primarily unilateral should alert clinicians to look for a source of referral, and radiculopathy or radiculitis should be considered as a diagnosis within a broad differential that includes internal disk derangement and facet arthropathy. If tender spots are accompanied by other confirmatory signs of cervical radiculopathy, such as reflex and strength changes, the presentation should not be interpreted as 2 distinct pathologies (eg, C7 radiculopathy and myofascial pain syndrome). In that case, cervical radiculopathy with referred tenderness should be considered. Injection, ice, therapeutic ultrasound, electric stimulation, and acupressure are widely used to treat tender spots. However, in cases of cervical radiculopathy with tender spots in the upper extremity, our results suggest that treatment should be directed to the cervical spine where the pathology is located."

Lack of agreement in distinguishing trigger points from tender points, even among experienced clinicians, leads to classify both as simply “tender spots” for the purpose of this diagram.

Cyriax proposed that tender spots could be referred from cervical disks and/or neural structures. He noticed that tender spots in the scapula region moved to different locations within minutes after the neck was treated with traction and manipulation.

Cannon’s law from Cannon and Rosenblueth, implies that cervical radiculopathy could cause a phenomenon of “myalgic hyperalgesia” or “denervation supersensitivity” in the muscles supplied by its axons. If tender spots in the parascapular and upper extremity could be referred from cervical structures, treatment in those cases should be directed to the spine and not to the tender spot.

Because they are innervated, all of the muscles, synovial joints, and intervertebral discs of the neck are potential sources of neck pain, along with the cervical dura mater and the vertebral artery.

It has been shown that stimulation of the cervical zygapophysial joints causes neck pain and referred pain. Pain from the cervical zygapophysial joints tends to follow relatively constant and recognizable segments patterns. From the C2-3 level pain is referred rostrally to the head. From C3-4, and C4-5, it is located over the posterior neck. From C5-6 it spreads over the supraspinous fossa of the scapula. From C6-7 it spreads further caudally over the scapula. Essentially similar patterns of pain have been produced by mechanical stimulation of cervical intervertebral disks. This fact underscores the rule that it is not the structure that determines the pattern of pain stemming from it; rather, the pattern of pain is determined by the nerve supply of the structure. Thus, any structure innervated by the same cervical segmental nerves will have the same distribution of pain. Clinically, discogenic pain cannot be distinguished from zygapophysial joint pain, but the distribution of pain serves as a reasonable guide to the most likely segmental location of its source.

In principle, this rule would also apply to neck muscles. Pain from muscles innervated by a particular segment should be perceived in the same location as pain from articular structures innervated by the same segment.

In a clinical setting there are Provocative Tests for Radiculopathy which may help to determine the nature of pain and the possibility of response to simple therapeutic measures.

References for Cervical Radiculopathy

Additional Sources for Cervical Radiculopathy Cervical Radiculopathy: Nonoperative Management of Neck Pain and Radicular Symptoms | Cervical Radiculopathy Diagnosis and Nonoperative Management | Pain Patterns and Descriptions in Patients with Radicular Pain | A Systematic Review of the Diagnostic Accuracy of Provocative Tests of the Neck for Diagnosing Cervical Radiculopathy | Cervical collar or physiotherapy versus wait and see policy for recent onset cervical radiculopathy: randomised trial | Resolution of cervical radiculopathy in a woman after chiropractic manipulation