The Evaluation of Patients With Neck Pain

Donald R. Gore, MD

Disclosures

Medscape Orthopaedics & Sports Medicine eJourn. 2001;5(4) 

In This Article

Other Causes of Neck Pain

There are conditions that deserve special consideration because their presentation may mimic pain of neck origin. When these conditions coexist with primary neck pain, they render the separation of symptoms a clinical challenge. The following discussion is not exhaustive but includes the most common areas of confusion.

The thoracic outlet is the area where the subclavian artery and vein and the brachial plexus leave the thorax and enter the arm.[6] These structures pass over the first rib and under the clavicle. The subclavian vein is the most anterior structure and is immediately posterior to the scalenus anterior muscle and its attachment to the first rib. This muscle is divided into 2 parts. The medial portion attaches to the copula of the lung. The subclavian artery leaves the thorax by passing over the first rib and between these 2 portions of the scalenus anterior muscle. At the level of the first rib, the lower cervical nerve roots combine to form the 3 trunks of the brachial plexus. The lowest trunk is formed by the union of C8 and T1, and this trunk lies directly posterior to the artery and is in contact with the superior surface of the first rib. A number of congenital anomalies can cause neurovascular compression (Figure 18). The neurologic symptoms suggestive of thoracic outlet syndrome that may be confused with cervical nerve root compression are pain, paresthesia, and weakness of the upper extremities. These symptoms, if of thoracic outlet origin, are in the C8-T1 distribution, which is an unusual location for cervical nerve root compression. In addition, vascular compression that can be elicited by various provocative maneuvers is present. The authors' experience has been that pure neurological complaints are rarely, if ever, on the basis of thoracic outlet compression. Diagnosis of thoracic outlet syndrome without a vascular component should be viewed with suspicion.

Figure 18.

Bilateral asymptomatic cervical ribs (arrows).

Primary shoulder problems invariably cause pain or dysfunction in the region of the shoulder. The problem is that neck pathology can reproduce most of the signs and symptoms of shoulder disease. Pain of shoulder origin may extend distally to the midarm but rarely extends above the superior aspect of the shoulder and not above the base of the neck. Weakness and limitation of active motion may occur with rotator cuff disease and mimic cervical radiculopathy. Occasionally, peripheral nerve injury and neurologic diseases cause weakness of shoulder muscles. Peripheral nerve examples are axillary nerve damage, suprascapular nerve entrapment, and brachial plexus damage that occasionally occur with immune reactions to vaccines. Shoulder weakness may be part of a generalized neurologic disease such as amyotrophic lateral sclerosis, but then the weakness is not isolated.

Resistance to passive motion is also accompanied by the patient's inability to perform active functions. Passive resistance of shoulder motion not caused by spasticity or muscle rigidity is invariably the result of intra-articular or periarticular shoulder disease.

Peripheral nerves of the upper extremity are formed by various combinations of cervical nerve roots C5-T1. These nerve roots combine in the brachial plexus to form the individual nerves. Because of this origin, there is an overlap between peripheral nerve entrapments and cervical nerve root lesions. When the cause of the patient's symptoms is one condition or the other, the 2 can usually be distinguished by their individual characteristics. However, when nerve root compression and peripheral nerve root entrapment coexist, the contribution of each may be indistinguishable on clinical grounds.

Ulnar nerve entrapment. The ulnar nerve originates from the cervical nerve roots C8-T1. Once formed, the nerve descends on the medial side of the arm to the elbow, where it passes behind the medial epicondyle of the humerus and anterior and medial to the olecranon. At the level of the elbow, the nerve is superficial and vulnerable to external pressure as may occur with resting the elbow on a table or bed (Figure 19 ). With flexion of the elbow, the nerve is stretched behind the medial epicondyle. In some people, the fascial covering is firm and unyielding, causing compression. In some, the fascial covering is thin and allows the nerve to sublux around the epicondyle, causing a friction neuritis.

Figure 19.

With the elbow flexed, the ulnar nerve is stretched and is easily compressed with external pressure.

Characteristically, ulnar lesions at the elbow are not particularly painful but cause numbness and tingling in the ulnar distribution of the hand. If the damage is severe, there may be motor weakness and/or atrophy of the ulnar innervated hand muscles. The nerve can usually be palpated behind the medial epicondyle. If the nerve subluxes, this can be felt when the elbow is flexed. With compression or irritation at the level of the elbow, lightly tapping on the nerve (Tinel's sign) results in exacerbating the patient's symptoms, frequently described as a shooting sensation by the patient.

The muscles in the hand that are innervated by the ulnar nerve are responsible for extension at the proximal interphalangeal joints of the ring and small fingers, abduction and adduction of all the fingers, and adduction of the thumb (Figure 20 ). When these functions are disturbed, the patient is incapable of fine motor movements. If the thumb adductor muscle is weak or nonfunctioning, the patient may substitute the long flexor of the thumb when pinching between the thumb and the index finger. This is called Froment's sign (Figure 21 ).

Figure 20.

The left hand of this patient shows severe interosseous atrophy (arrow) and clawing of the ring and small finger caused by an ulnar nerve lesion at the elbow.

Figure 21.

Froment's sign. When the patient attempts to pinch with the thumb and index finger, the long flexor of the thumb is used to substitute for the thumb adductor, resulting in flexion of the thumb at the interphalangeal joint. This characteristic appearance is present in this patient's left hand, caused by an ulnar nerve lesion at the elbow.

It is important to realize that symptoms from ulnar nerve dysfunction are common but involvement of cervical nerve roots that make up the ulnar nerve is uncommon.

The ulnar nerve may also be trapped as it passes into the hand through Guyon's canal. In this situation, the numbness is on the volar surface only because the dorsal superficial branch of the ulnar nerve arises proximal to the wrist. If the motor portion of the nerve is involved, the muscles innervated by the deep branch of the nerve will be abnormal.

Carpal tunnel syndrome. Carpal tunnel syndrome is by far the most common peripheral nerve entrapment. The carpal canal is formed by bone on 3 sides and covered on its volar surface by the rigid transverse carpal ligament. The median nerve shares the canal with the long flexor tendons of the fingers and their synovial coverings. Anything that causes swelling in the synovium decreases the space available for the nerve. As with ulnar nerve entrapments, the predominant symptom is paresthesia. However, in this syndrome, the symptoms are in the distribution of the median nerve. Patients frequently describe their whole hand falling asleep, but with careful questioning, the small finger is not involved. Paresthesia characteristically occurs at night and when driving. It can usually be brought on by holding the wrist in flexion, which is called a Phalen's test (Figure 22). Tapping on the nerve just above the wrist may elicit a shooting sensation into the fingers, which is called Tinel's sign (Figure 23). The median nerve originates from C6 to T1, which are the roots that are most commonly compromised by intervertebral disc protrusions and cervical spondylosis. With an isolated carpal tunnel syndrome, the symptoms rarely extend above the mid-forearm; however, when the condition coexists with a cervical radiculopathy, this distinction is of less value. The coexistence of these 2 conditions has been called a double crush syndrome, and the patient's symptoms may be more than would be expected if the conditions existed alone.

Figure 22.

Phalen's test is performed by asking the patient to hold her wrist in maximum flexion. The test is positive if the portion of the thumb and finger that are innervated by the median nerve becomes numb.

Figure 23.

Tinel's sign is performed by briskly tapping a nerve, the median nerve at the wrist in this case. The test is positive if it results in shooting electric-like sensations in the distal distribution of the nerve.

Motor weakness and atrophy, which are common in long standing carpal tunnel syndrome, involve the thenar eminence.

The suprascapular nerve originates from cervical roots C5 and C6. The nerve has no sensory component, so there are no areas of numbness. Nerve entrapment occurs when the nerve enters the supraspinous fossa by passing under the superior transverse scapular ligament. The nerve innervates the supraspinatus and passes around the spine of the scapula ending in the infraspinatus. Symptoms are a dull, aching type of pain in the back of the shoulder, exacerbated by shoulder motion, especially elevation of the arm as occurs in working overhead. In well-established syndromes, weakness of the supra- and infraspinatus muscles may be demonstrated, and, in thin individuals, atrophy is evident.

Coronary artery disease is prevalent, serious, and may require immediate treatment. The classic pain is in the precordium and left upper extremity. However, pain can be in the neck and occur in all the locations as pain of neck origin. In addition, cervical nerve roots C4-C8 contribute to the innervation of the anterior chest wall. Compression of any one of these nerves can mimic true angina (Figure 24).[7]

Figure 24A.

T2-weighted MRI showing a moderately sized cervical disc protrusion at C5-6 (arrow). The patient is a 41-year-old male with left precordial pain.

Figure 24B.

Post-operative roentgenogram showing a bone graft between C5-6 (arrow). The precordial pain was completely relieved in the immediate postoperative period.

The most important distinguishing characteristic between pain of coronary artery disease and radicular pain is that pain of cardiac origin is brought on by total body exertion, whereas pain from cervical nerve root compression is exacerbated by arm or neck motion.

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