Cervical syndromes are associated with restricted mobility of the cervical spine, increased tension of the shoulder and neck muscles, and (in some cases) radicular signs in the upper limbs, as well as autonomic manifestations. “Cervical syndrome” is a purely clinical term. The painless partial immobilization of the cervical spine that often occurs in old age because of advanced osteochondrosis and spondylosis is not considered a cervical syndrome.

The involutional changes of old age profoundly affect the morphology of the cervical disks, which lie immediately adjacent to important parts of the central nervous system and the vascular system. Clinical manifestations of several different kinds may result, as will be explained below.

Classification. The cervical syndromes are classified by their cardinal manifestations and duration, and treated accordingly. They are divided into acute and chronic conditions with and without radicular manifestations. The duration of symptoms is correlated with the age of the patient: acute manifestations are more common in younger individuals, while chronic cervical spine conditions are more common in older adults. Traumatic cervical spine syndromes form a class in themselves.

The wide variety of possibilities for the spatial and temporal distribution of pain and other symptoms often makes it impossible to give a more precise and cogent name to a particular instance of a cervical syndrome. The clinical findings are the most important determinant of the treatment to be applied, and the treatment must be continually adapted to the patient’s changing symptoms and to their previous response to the treatments already given. “Polypragmasia,” i.e., a multiple-component treatment strategy, is often the best approach.

The uncinate processes develop during the growth period of the cervical spine and finally assume the shape of shovel-like crests of bone sticking out from the lateral edges of the vertebrae. Because of the uncinate processes, the cervical disks are mainly bordered by bone laterally, unlike the disks elsewhere in the spine. Our studies of cervical spine biomechanics (Stahl 1977) showed that the uncinate processes are located more laterally on the edge of the vertebrae in the upper segments of the cervical spine and more dorsolaterally in the lower segments, with a transition at C6.

The transition at C6 regarding the lateral vs. dorsolateral position of osteophytes was mentioned above. In consequence, the formation of large osteophytes is more likely to cause vascular compression in the upper and middle cervical segments and neural compression in the lower cervical segments (Faustmann 2004).

Von Luschka (1858) was the first to describe horizontal fissures in the cervical disks, which he designated as lateral half-joints. These fissures develop in childhood at the level of the uncinate processes and tend to progress in a medial direction. They are so commonly seen that they are considered a normal finding. Horizontal fissures are a sign, not of degeneration, but rather of adaptation of the cervical spine to allow greater mobility (Töndury 1958, Ecklin 1969, Shark and Parke 1983, Faustmann 2004).

Unlike the degenerative radial fissures of the disks elsewhere in the spine, the horizontal fissures of the cervical disks appear in the midst of entirely normal disk tissue. They begin in the outer lamellae of the anulus fibrosus and gradually narrow as they proceed toward the center of the disk. Often, a meniscus-like wedge of tissue grows into the fissure from the neighboring paravertebral connective tissue. According to Ecklin (1960), an anatomical situation arises that is in all respects comparable to a joint: the fissure possesses an enclosed space with smooth borders, layers of hyaline cartilage on the uncinate process and on the opposite pole (von Luschka’s joint facet), a meniscus-like articulation, and, often, tough fibrous bands separating the “joint” from the spinal canal, in the manner of a capsule (Stahl and Huth 1980). In our own anatomical studies, we have found synovium-lined cavities in the uncovertebral region in all decades of life.

The uncovertebral region lies in the immediate vicinity of both the vertebral artery and the cervical sympathetic chain. The age-associated changes of the uncovertebral region can impinge on either or both of these structures, producing neurovascular manifestations of various kinds. The cervical sympathetic chain, which communicates with the spinal nerves through the rami communicantes, and its three associated ganglia provide autonomic innervation to the head, neck, and upper limbs. The upper ganglion serves segments C1–C4, and the middle ganglion serves C5–C6; the lower ganglion is fused with the uppermost thoracic ganglion to form the stellate ganglion, which serves C7–T2. The stellate ganglion is the most important relay station among these ganglia, because all of the efferent and nearly all of the afferent sympathetic fibers of the head, neck, upper limb, and upper part of the thorax pass through it. From the sympathetic chain ganglia, the sympathetic fibers travel upward by various routes, including along the sympathetic arterial plexus of the vertebral artery.

The studies of Hovelacque (1925), Werte (1934), Kummer (1984), Kehr and Jung (1985), Bogduk et al. (1988), Lang (1991), Faustmann (2004), and Heller et al. (2005) demonstrate the interconnections of the cervical sympathetic innervation with the cervical spinal nerves and the sympathetic arterial plexus of the vertebral artery. Sympathetic fibers from all three cervical ganglia pass from the sympathetic chain to spinal nerves C4–C8 and partially encircle the vertebral artery.

The vertebral artery originates from the subclavian artery and passes upward through the foramina of the transverse processes of cervical vertebrae C6 through C2. At the level of each intervertebral disk from C5/6 to C2/3, it lies immediately adjacent to the uncinate process. Jung et al. (1974) and Lang (1991) pointed out the relative narrowness of the transverse foramina in relation to the lumen of the vertebral artery. Even head movements within the normal range of motion, in individuals with normal anatomy, can narrow the arterial lumen. The joints of the craniocervical junction create further possibilities for compression of the vertebral artery on movement.

Our own studies have demonstrated that blood flow in the vertebral arteries depends on the position of the head (Oppel and Fritz 1986).

The blood flow in the vertebral artery may be tenuous because of arteriosclerosis, anatomical variants, or (most commonly) lateral osteophytes arising from the uncinate processes. If so, any additional factor, such as trauma or an abnormal posture of the cervical spine, may induce vertebrobasilar insufficiency, which can then be compensated for by mild flexion of the neck.

The lower cervical nerve roots and nerve root sleeves are of special clinical significance, particularly with respect to cervical spinal nerve analgesia. In this procedure, which is discussed in greater detail toward the end of this chapter, the nerve roots to be treated are flooded with local anesthetic injected via a dorsal approach. The physician doing the procedure must be aware of the topographical anatomic relationship of the bone, specifically the lateral mass of the cervical vertebra, to the exiting nerve root. As in all other regions of the spine, the proximal segment of a cervical nerve root is bathed in cerebrospinal fluid for a short distance within the so-called nerve root sleeve. If the local anesthetic is improperly injected into the nerve root sleeve because of faulty technique, it will enter the cervical subarachnoid space and affect the cervical spinal cord, with ensuing respiratory arrest and circulatory collapse.

No layer that was separable from the nerve itself could be found lateral to the ganglion, even with sharp dissection. The ganglion lies proximal to the exit of the spinal nerve through the intervertebral foramen. It follows, therefore, that there is a safety zone (extending, in this study, from the outer mark on the root to the deepest point of the root sleeve than can be reached with the probe) in which the direct intrathecal injection of local anesthetic is not possible.

The remaining segments of the cervical spine all possess intervertebral disks; most of the mobility of the cervical spine is at C4/5–C6/7. The position of the joint facets enables movement in all directions at these levels as well, but forward and backward bending are favored, because the sagittally oriented uncinate processes serve as guides for these movements along their entire range (Jofe et al. 1983, Panjabi et al. 2005). The track-like uncinate processes thus limit rotatory movements of the cervical spine that might place excessive strain on the disks.

Flexion of the cervical spine, like flexion of (e.g.) the knee, is a process of rolling and sliding. The vertebral bodies do not merely tilt, they also slide in the dorsoventral direction, particularly in younger individuals. Radiographs reveal a typical staircase-like arrangement of the posterior edges of the cervical vertebrae. Flexion from the midposition leads to 2–3 mm of anterior displacement of each vertebra with respect to the one immediately below it, and extension leads to 1–2 mm of displacement in the opposite direction (Exner 1954).

Any movement of the cervical spine also alters the width of the intervertebral foramina at each level. Studies of dissected specimens, as well as radiological studies in vivo, have shown that the foramina are wider on the convex side of the laterally inclined cervical spine, and narrower on the opposite (concave) side. Forward bending or kyphosis of the cervical spine widens all of the intervertebral foramina, whereas backward bending or lordosis narrows them. These facts explain the posture that individuals suffering from an acute cervical syndrome typically assume to lessen nerve compression (acute torticollis, wry neck). The position in which the head is held, and the directions in which movement is resisted, are clinical clues pointing to the site of the lesion.

Grob (1968) estimated the stress on the lower cervical disks at 550 kPa with normal head position and muscle tone, and 3900 kPa if muscle tone is absent. Panjabi et al. (2005) carried out biomechanical experiments on the cervical spine that yielded similar results. They also calculated the reduction of stress on the cervical spine that could be obtained with the Glisson kyphotic traction method (stretch test), demonstrating the potential usefulness of this method in the conservative management of cervical syndromes.

Such tissue displacements play a role in the pathogenesis of cervical syndromes.

Degenerative changes of the lower cervical motion segments begin to appear at an early age, though they are not evident in radiological studies till later on in life. Their main cause is the mechanical stress associated with the larger excursions of movement in these segments, compared to the relatively immobile thoracic spine. The intradiscal pressure is also higher at cervical than at thoracic and lumbar levels, because of the weight of the head. Nor is there, in the cervical spine, any counterpart to the mechanism of reducing the intradiscal pressure in the lumbar spine by raising the intra-abdominal pressure (abdominal pressing, Valsalva maneuver).

Persistent mechanical stress and the wide range of motion of the cervical spine, particularly with regard to rotation, lead to overstretching of the anulus fibrosus, which, in turn, results in anular tears and intradiscal tissue displacement. This situation predisposes to disk protrusion.

All other degenerative changes, such as spondylosis, osteochondrosis, and spondylarthrosis, occur in the cervical spine just as they do elsewhere in the spinal column.

Loss of disk height causes a loss of lordosis and a fixed, extended position of the osteochondrotic segments, which is compensated for by hyperlordosis of the segments above and below.

Arthrotic changes of the intervertebral joints (spondylarthrosis) are rarer than was previously thought. As the cervical disks lose height, the uncinate processes come into contact with the vertebral bodies above before the joints can be exposed to any marked elevation of mechanical stress. Intervertebral joint arthrosis is generally more severe in the upper and middle portions of the cervical spine than at C5/6 and C6/7.

Fibrous ankylosis with ingrowth of organized vascular connective tissue finally leads to a comfortable rigidity of the affected cervical motion segments.

Osteophytes and areas of bony thickening regress once the bony support elicited by slackening of the intervertebral disks is no longer needed. The loss of function resulting from the immobilization of multiple motion segments is well tolerated by older individuals because most of the mobility of the head is provided by the two uppermost (i.e., atlanto-occipital and atlantoaxial) segments.

Summary

The special feature of the anatomy of the cervical intervertebral disks is their proximity to important neural and vascular structures. The vertebral artery, the spinal nerve, and the spinal cord are all immediately adjacent to the disk, and these structures may be impinged upon in acceleration–deceleration injuries of the cervical spine, during sporting activities, or during passive movement of the neck in manual therapy. Mild flexion of the neck optimizes (i.e., increases) the distance between the skeletal and neurovascular elements, whereas extension decreases it. This explains the marked positional dependence of disk-related symptoms in the cervical spine.

A special biomechanical feature of the human cervical spine is the apparent disproportion between the relatively heavy head and the relatively small cervical disks. This, combined with the wide range of motion of the neck in all directions, results in a high potential for injury. Because of their unfavorable biomechanical situation, the lower cervical motion segments tend to show early signs of wear and tear. Clinical manifestations tend to be produced particularly by such changes occurring in the region of the uncinate process and intervertebral foramen.

The term “cervical syndrome” refers to any disease state directly or indirectly caused by degenerative changes of the cervical intervertebral disks. Thus, it covers not only conditions with painful limitation of movement of the cervical spine, but also excessive muscle tension in the shoulder and neck, segmental radicular syndromes of the upper limb, cervicogenic headache and dizziness, spinal cord syndromes, cochleovestibular irritative conditions, and various functional disturbances arising in the internal organs. Any systematic classification of such a wide-ranging group of illnesses is necessarily imperfect, regardless of whether it is based on a fundamental subdivision by localization (upper vs. lower) or by disease course (acute vs. chronic).

A strict separation of each one of these conditions from all the others is often not possible, because each condition may consist of a large number of different symptoms that change, or vary in severity, over time, and the clinical pictures of different conditions often overlap. We consider a division of cervical syndromes into upper, middle, and lower to be potentially misleading, as it is definitely not the case that all of their symptoms can be attributed, respectively, to pathology in the upper, middle, or lower regions of the cervical spine.

A separation of cervical syndromes into acute and chronic is likewise problematic, because the course of disk-related complaints is highly variable.

Our classification is mainly based on the participation of individual spinal nerve roots in the generation of symptoms. In most cases, multiple roots participate, with one root playing the most prominent role.

The patient’s own description of the symptoms is all the more important as a clue for the diagnostician because objective signs are often absent (for which reason medicolegal assessment is often difficult). In our series of patients presenting to private orthopedic practices, we always record the patient’s chief complaint in their own words.

In addition to the specific symptoms just described, patients also complain of general accompanying symptoms such as fatigue, irritability, and impaired concentration. Functional disturbances of the internal organs, including the heart, may also arise. In contrast to the relatively stereotypic complaints of organic heart diseases, spondylogenic pseudo-cardiac symptoms come in a dazzling variety of forms, including palpitations or a stabbing, pulling, rippling or tearing sensation. These symptoms are induced by certain postures of the cervical spine and can be relieved by traction in a Glisson sling.

Most patients presenting with cervical complaints to a physician’s office or outpatient clinic seem to have a certain degree of emotional coloring of symptoms. We have confirmed this impression in our own outpatient clinic with psychological testing.

There is no longer any doubt about the purely mechanical and organic cause of cervical syndromes. It therefore seems to be the case that continual, deep pain in the shoulder and neck, present day and night and interfering with sleep, can in the long run disturb the patient’s emotional balance. The physician must bear this in mind when dealing with such patients, and especially when prescribing treatment and observing its effects.

The clinical findings in patients with cervical syndromes fall into two major categories. In the first category are those findings that generally indicate a disorder of the cervical spine, such as muscle tension in the shoulder and neck, painful restriction of cervical movement, and tenderness to pressure in the entire region of the neck; in the second category are the findings that allow precise segmental localization. These include circumscribed tenderness of a single spinous process to pressure or shaking, restriction of movement of a single motion segment, segmental radicular manifestations, and, lastly, the findings of special tests such as EMG, neurography, myelography, discography, CT, MRI, and the distension test.

The clinical examination begins, as always, with inspection. The experienced clinician will immediately notice a certain degree of neck stiffness that is maintained while the patient undresses and dresses. The shoulders are often held high. Above all, the patient takes care not to rotate the head and prefers to turn with the entire trunk. The oblique posture of the head in torticollis (wry neck) is unmistakable and often grotesque. Only by keeping the head in this position can the patient derive some relief of symptoms (as the examiner must remember while testing the range of motion). The cervical spine is not only laterally flexed and rotated, but also bent forward (kyphosed) to a certain degree, as can be seen in a lateral plain radiograph. Our studies have shown that this position decompresses the neurovascular structures in the uncovertebral region to the greatest possible extent.

Palpation reveals tension of the shoulder and neck muscles. Pressure-sensitive local muscle hardening (“myogelosis”) is found mainly at the upper edge of the trapezius from the occiput to the acromioclavicular joint, in the scalene region, and in the rhomboid muscles. The spinous and transverse processes are also tender to palpation. The transverse processes of the atlas can be palpated in the mandibulomastoid angle. Tenderness is usually found bilaterally at these preferred sites, but more intensely on the affected side.

Functional testing of the cervical spine in cervical syndromes nearly always reveals a restricted range of motion, though the restriction may be limited to one or a few segments. One should test forward and backward bending (distance of chin from sternum), lateral bending, and rotation. The ranges of motion in each direction should be reported in degrees from the neutral position. The absolute ranges of motion of the cervical spine vary naturally with the length of the neck, the degree of muscularity, and the age of the patient. Thus, pathologically restricted movement is best detected by the difference between the ranges of motion on the two sides and by pain produced at the end of the range of motion in any particular direction.

Testing of segmental mobility is performed with the patient first in the supine position, and then sitting. The edges of the joint facets and transverse processes of each successive segment are fixed by the examiner’s hands while the patient carries out rotatory, lateral bending, and flexion–extension movements of the segment above.

Finally, the clinical examination of a patient with a cervical disk syndrome must always include a neurological examination. The single most important piece of localizing information for a cervical radicular irritation syndrome is the patient’s description of the pattern of radiation of sensory symptoms. The patient should be asked to outline the band of pain and the area of paresthesia as accurately as possible with one finger. Objective neurological signs such as reflex asymmetry, paresis, muscle hypotonia, atrophy, and hyperesthesia should always be sought as well, though they are relatively rarely seen in cervical disk syndromes.

Radiological studies and basic laboratory tests are also a routine part of the evaluation of cervical syndromes. Radiological imaging can effectively rule out tumors (metastases) and infection (spondylitis) as the cause of symptoms. Its usefulness in the precise diagnosis of cervical syndromes and their localization to a particular motion segment is generally overrated, however, and is in fact limited. As already pointed out, cervical spondylosis and osteochondrosis are almost ubiquitous concomitants of aging and are usually of no clinical significance.

In acute cervical disk syndromes, generalized loss of lordosis and segmental kyphosis can also be seen on functional (dynamic) lateral plain radiographs obtained with maximal forward and backward bending of the neck. The abnormal findings on forward bending (inclination) include not only the dorsally convex arch of the cervical spine but also a mild ventral displacement of each cervical vertebra on the one below it, the so-called staircase phenomenon. This is seen mainly in younger individuals and may be more pronounced in a single segment where there is additional pathology of the intervertebral disk.

A further means of “objectifying” degenerative segmental slackening is provided by the radiological stretch test described by White and Panjabi (1978) and Panjabi (2004). Lateral plain radiographs and a neurological examination are carried out before and during Glisson traction of the cervical spine at one-third of body weight.

CT can be used to image the entire cervical spine or only the clinically relevant part of it, to limit radiation exposure. Cervical CT reveals the width of the vertebral canal and the extent of the osteophytic reaction at the uncinate processes. CT after the intrathecal injection of contrast medium enables visualization of the nerve root sleeves.

MRI enables visualization of the entire cervical spine and is particularly good for showing the intervertebral disks. Disk protrusions are best seen in the sagittal sections. Over-interpretation of MR images should be avoided (Siivola et al. 2002, Ullrich 2005).

Neurophysiological methods are useful for the differentiation of nerve root compression syndromes and cervical spondylogenic myelopathy from systemic diseases such as multiple sclerosis and amyotrophic lateral sclerosis, as well as from peripheral compression syndromes such as carpal tunnel syndrome. They also provide important information about the severity and extent of damage of the sensory and motor pathways. Preoperative neurophysiological assessment of the peripheral nerves (neurography, EMG), the pyramidal pathways (motor evoked potentials), and the afferent pathways of the posterior columns (somatosensory evoked potentials) is helpful not just to confirm the indication for a surgical procedure, but also as a baseline test that can be compared with postoperative follow-up studies (Dvořák 1996, 2002)

The more time-consuming motor and somatosensory evoked potentials play a less important role than conventional EMG in the diagnostic evaluation of cervical radiculopathy. Evoked potentials are very useful, however, in the evaluation of spinal stenosis with possible spinal cord compression.

EMG is a major aid to the objectification of cervical root dysfunction. The muscle action potentials, detected either at the skin or directly from muscle with needle electrodes, are amplified, displayed, and recorded to reveal the state of the muscle and of the nerves supplying it. EMG abnormalities can often be seen before any clinical signs such as paresthesia or muscle atrophy.

EMG technique. Muscle action potentials are recorded with a needle electrode at various positions and at various depths to ensure that a representative picture of muscle activity is obtained. The electrical activity of the skeletal muscle is recorded and analyzed. EMG requires the cooperation of the patient; it is time-consuming and, at times, painful. It should be done only in selected cases to answer specific questions (Dvořák and Haldeman 2004).

differentiation from carpal tunnel syndrome

differentiation of isolated discogenic nerve root compression from a systemic neurological disease

differentiation of radicular from peripheral nerve lesions

determination of the severity of neural involvement

assessment of the extent of re-innervation, if any.

Findings. Cervical nerve root compression usually causes no more than a mild slowing of motor and sensory nerve conduction. This is not surprising, as the speed of conduction is measured in the region of the forearm and hand, although the lesion is much more proximal. Only severe, chronic radicular compression syndromes are accompanied by muscle atrophy with reduced amplitude of muscle action potentials and by a low-amplitude or undetectable sensory nerve action potential. F-waves are often harder to generate, or their latency is prolonged (Dvořák 1996, Dvořák and Haldeman 2004). Comprehensive and detailed descriptions of EMG findings can be found in Conrad and Bischoff (1988), Hopf (1988), Dvořák (1998, 2002), Haig et al. (1998), Mumenthaler et al. (1998), Nargol (1998), Balague (1999), Hirayama (1999), Krämer and Nentwig (1999), Perlick et al. (1999), Colloca (2000), Greenough (2003), and Dvořák and Haldeman (2004).

Cervical syndromes produce many different kinds of symptoms and signs and their differential diagnosis is correspondingly broad. Any type of cervical discogenic syndrome must be distinguished from similar clinical pictures due to other kinds of disease. A cervical syndrome can only be confidently diagnosed when all other possibilities have been ruled out.

Similar considerations apply to the cervicobrachial syndrome, i.e., to pain in the neck radiating into the shoulder and arm, no matter whether it is of radicular or pseudoradicular type. Here, too, simple neck and arm pain, with proximal radiation, moderate severity, and brief duration, can be contrasted with complicated neck and arm pain, which is usually in a radicular distribution, radiating as far down as the hand, and sometimes accompanied by weakness.

Etiology and Symptoms

Among the more prominent symptoms of local cervical syndromes is painful muscle tension in the shoulder and neck. The muscles in these areas are supplied by the dorsal branches of the spinal nerves. A precise segmental localization of the etiology of the pain is not possible, because each muscle is supplied by the dorsal branches of more than one nerve (the pattern of innervation of the ventral branches is more highly segregated). The onset of symptoms may be acute, e.g., after abrupt turning of the head, or gradual without any particular precipitating factor. Patients often mention a cool draft as a possible cause; another common precipitant is prolonged sitting in a hunched position with a kyphotic posture of the neck, e.g. while typing, reading, or working at a desk. Pain in such situations is not only discogenic but also partly due to muscular insufficiency.

On examination, the patient can localize the pain fairly precisely. Pain due to involvement of the upper cervical segments is localized to the territory of the dorsal branches of the spinal nerves on the upper border of the trapezius muscle, which stretches from the occiput to the acromioclavicular joint.

In the latter situation, there is tenderness of the rhomboids and of the levator scapulae and subscapularis muscles.

Etiology and Manifestations