Cervical Radiculopathy

Clinical Presentation

The clinical presentations of cervical radiculopathy depend on the specific root involved. It is unusual to have multiple nerve roots compressed at one time. The usual symptoms are pain, weakness, and sensory disturbance. Neck and/or medial scapular pain commonly occur with cervical root compression; shoulder or arm pain is also often present. Typical clinical findings include both arm weakness and sensory disturbance appropriate to the affected nerve root ( Fig. 56.1 ). Neck movement often exacerbates the radicular pain and may result in an electric shock–like sensation ( Fig. 56.2 ). Very rarely, pressure on the spinal cord as well as the nerve root may result in concomitant evidence of myelopathy. In any patient with cervical radiculopathy, clinical examination requires careful evaluation for evidence of a myelopathy by making certain the neurologic examination does not demonstrate a spastic gait with enhanced muscle stretch reflexes, a Babinski sign, and/or evidence of a spinal cord sensory level.

As a result of the incongruence between the cervical vertebrae (seven vertebrae) and the cervical nerve roots (eight roots), the root that exits is numbered after the vertebra inferior to it. For example the C6 root exits between the C5 and C6 vertebral bodies and the C7 between the C6 and C7 vertebral bodies. However, the C8 root exits between the C7 and T1 vertebral bodies and T1 between the T1 and T2 vertebral bodies. Of the various cervical radiculopathies, the C7 nerve root is the most commonly affected. It exits the spinal canal between C6 and C7. Typically compression leads to pain in the posterior arm. Unlike C5 and C6 lesions, C7 has little functional overlap with other roots. C7 innervates the triceps muscle, which extends the elbow (see Fig. 56.2 ). Unless patients perform activities that demand extension of the elbow—such as hammering, serving in tennis, rowing, or performing pushups—many individuals with a C7 radiculopathy are unaware of significant triceps weakness. To best ascertain the presence of triceps weakness, the examiner must ask the patient to flex his or her arm at the elbow to 90 degrees and then have the patient try to extend against resistance. In contrast, if one first asks the patient to extend his arm fully, relatively subtle degrees of weakness will be missed. In repose, gravity extends the elbow in most cases. Sensory loss in C7 radiculopathy usually extends to the index and middle fingers ( Table 56.1 ).

The C6 nerve root exits the spine between C5 and C6 vertebrae. Compression here leads to pain in the medial scapula and into the arm, frequently to the lateral side of the forearm, as well as to the hand and into the thumb. Motor loss overlaps with C5 root and there is weakness in the proximal arm muscles, particularly the biceps, with difficulty flexing the arm at the elbow and abducting the arm at the shoulder. Sensory changes affect the thumb and index finger.

C8 is the lowest of the cervical roots, exiting the spinal column between the C7 and T1 vertebrae. When this nerve root is compressed, the pain radiates from the neck into the medial forearm and into the medial hand. If there is significant C8 compromise, patients develop weakness of their intrinsic hand muscle function. They also often complain of numbness and demonstrate sensory change in the medial hand as well as the fourth and fifth digits.

C5 is the least frequent level for radiculopathy. The C5 nerve root exits the spine between the C4 and C5 vertebral bodies. Compression of the C5 root produces pain within the medial scapula and into the upper arm; the pain rarely radiates below the elbow. There may be weakness of the deltoid resulting in difficulty carrying out tasks with the arm elevated (see Fig. 56.2 ). Sensory loss will be over the shoulder and upper arm and is often minimal (see Table 56.1 ).

When evaluating a patient with a suspected radiculopathy, it is important to define the temporal profile as well as the degree of progression of the symptoms. Has there been slow progression or rapid worsening? Has there been a plateau or improvement in the condition? How long have the symptoms persisted? The severity and quality of the pain and its provocative factors provide other useful information. In particular, does the arm pain worsen with movement of the neck? Is the pain of an electric quality? It is important to palpate the axilla or supraclavicular fossa, as a mass there could suggest the presence of an extraspinal tumor ( Fig. 56.3 ) or a tumor of the brachial plexus ( Fig. 56.4 ).