Cervical Radiculitis

Sensory deficits, namely numbness, paresthesias and pain, as well as deficient motor functions are the most common symptoms of CR [7]. They may affect occipital and neck regions, shoulders and arms. The above detailed assignment of cervical nerves to their respective supply areas may serve as an orientation for a more precise localization of CR. And in fact, sensory deficits and muscle weakness follow dermatomal and myotomal patterns, respectively. However, peripheral nerves are usually composed of fibers originating from more than one spinal nerve. Thus, complex symptomatic patterns result from a monoradiculopathy and, even more so, from a polyradiculopathy. Indeed, none of the aforementioned symptoms should be considered an exclusion criterion. Although less common, CR cases without significant pain have been reported.

Certain movements, particularly neck flexion towards the side of pain and rotation as well as spine extension, may increase the pressure exerted on the inflamed cervical nerve root and thus often augments pain [8]. This phenomenon does not only occur during clinical examination: Patients have often avoided determined movements involuntarily for some time and therefore regularly present with muscle tension and a stiff neck. Depending on the severity of pain and on the affected cervical nerves, patients may adopt a bad overall posture and subsequently develop additional musculoskeletal problems.

A thorough anamnesis may reveal excessive strains or traumas that have been sustained within weeks before. However, discopathy and spondylosis account for the majority of CR cases and may not be associated with acute onset of pain. Here, a medical history of previously diagnosed similar issues may be the most explicit hint given in the initial interview.

Diagnostic imaging is the method of choice to identify the causes of subacute and chronic neck pain. Because mechanical compression of cervical nerve roots is most commonly triggered by skeletal anomalies, i.e., by spondylosis, osteophytes of other origin or changes of vertebrae positions relative to each other, plain radiography is still considered the most appropriate initial study. Laterolateral, anteroposterior and oblique views allow for a precise diagnosis in a large share of patients suffering from symptoms matching CR.

If doubts remain after radiography, magnetic resonance imaging and/or computed tomography scans may be carried out. While the former allows for good visualization of soft tissues like intervertebral discs, ligaments and nerves themselves, the latter permits three-dimensional views on the skeletal system. Neurologic symptoms and normal radiographs indicate magnetic resonance imaging, whereas complex or otherwise non-visualizable spine pathologies require computed tomography screens.

Of note, polyradiculopathies are not uncommon. Thus, if certain sensory and motor deficits cannot be explained by a lesion detected in early analyses, additional nerve insults should not be ruled out. More extent neurological deficits may also result from a cervical myelopathy and its diagnosis requires realization of a myelography.

If all imaging techniques reveal normal findings, intrinsic neuromuscular dysfunctions should be considered. Electromyography may be very helpful to identify them [7].

In case it is not even possible to localize the affected nerve root, selective nerve root blocks may be employed as diagnostic tool. Anesthesia of the injured nerve root should significantly alleviate if not revoke pain [9].

Patients benefit most from a multidisciplinary approach towards CR treatment: A large share of CR patients may achieve complete recovery after initial immobilization, realization of physiotherapy and compliance with drug therapy. Some of these patients may continue to suffer from intermittent neck pain, though. Patients who do not respond to conservative therapy for prolonged periods of time may be submitted to surgery. However, retrospective studies have shown that residual disabilities are much more severe in this group of CR patients than in those individuals who merely received physical therapy and analgesics [10]. Of note, this conclusion needs to be interpreted with care because the initial condition of patients pertaining to these two groups differs widely.

Thus, in general, the patient's neck should be immobilized for about one week with a cervical collar to reduce movement-induced compression of the affected nerve root. Cervical traction may serve as an alternative if decompression is required. The latter is contraindicated in patients who are suspicious for cervical myelopathy. Non-steroidal anti-inflammatory drugs are the analgesics of choice to relieve neck pain, but opioids have been used in more severe cases. Furthermore and similar to selective nerve root blocks, corticosteroids may be injected to reduce pain. This technique has been the controversially debated, but may efficiently provide analgesia [11]. Additionally, muscle relaxants may be administered to release muscle tension.

Physiotherapy aims at restoring the physiological range of movement. At the same time, physical therapy will help to decrease muscle tension. Easy exercises like stretching, flexion or rotation of the neck to the contralateral side, may significantly contribute to diminishing cervical nerve root compression. Specific neck stabilization exercises don't seem to improve the outcome [12]. However, massages, application of heat, cold and electrical stimulation is recommended.

If neither of the above mentioned treatment options achieves long-term improvements, patients may be considered for surgical interventions. The specific procedure will largely depend on the underlying skeletal pathology.

Patients who continue to suffer from chronic intermittent neck pain may be treated with non-steroidal anti-inflammatory drugs or opioids. In these cases, antidepressants may also be required.

Prognosis for CR is very good, the condition is usually self-limiting. In most cases, conservative treatment merely aims at relieving pain and preventing an exacerbation of damage to cervical nerves or adjacent tissues. About 90% of all patients achieve nearly complete or full recovery without requiring surgical interventions. Here, "nearly complete" refers to the possibility of intermittent neck pain that may not resolve.

Cervical radiculopathy most commonly results from mechanical compression of cervical nerve roots. Degenerated and subsequently herniated discs, spondylosis and osteophyte formation due to other primary diseases are most frequently cause this condition. Trauma, infection and neoplasms may also account for it [3]. Chemical nerve insults may trigger CR without any mechanical compression being detectable.

The inflammation of cervical nerve roots may be provoked by inflammatory mediators such as interleukin-6, interleukin-8, tumor necrosis factor α, nitric oxide, prostaglandin E2 and matrix metalloproteinases [3] [4]. These mediators are presumably released from inflammatory cells attracted to the site of initial insult. They evoke nerve root swelling and thus exacerbate compression in cases of mechanical stress. Inflammation is presumably the main mediator of CR after chemical insults.

CR is a common condition. An epidemiologic survey considering CR cases occurring between 1976 and 1990 in Rochester, MN, USA, estimated the overall incidence of this disease to be 107 per 100,000 men and 64 per 100,000 women [5]. These data indicate that men are affected twice as often as women. CR was diagnosed in patients of all ages except for early childhood.

Herniated discs and spondylosis accounted for approximately three out of four cases.

Cervical nerves emerge from the spinal canal through a narrow sulcus delimited by the inferior and superior articular facets of the respective vertebrae, their pedicles and bodies. Within this sulcus, nerve roots are located. In the vast majority of cases, both mechanical compression and inflammation of nervous and surrounding tissues contributes to further restriction of this space and subsequent impairment of nerve function. Pathohistological analyses have repeatedly proven the development of an intraneural edema. Moreover, if mechanical stress affects blood vessels, ischemia may further contribute to tissue damage, subsequent inflammation and nerve compromise.

Mechanical pressure may be exerted by herniated discs, degenerative spondylotic changes and hypertrophic osseous tissue as well as primary tumors or metastases originating from diverse tissues [6]. If such insults affect the spinal cord passing through the inner spinal canal, patients are diagnosed with cervical myelopathy rather than with CR.

No specific measures can be recommended to prevent CR resulting from degenerative conditions like discopathy or spondylosis. However, a significant share of CR is provoked by traumas, possibly sustained while playing American football, rugby or practicing any other sport. Safety measures should be complied with in order to avoid such injuries. Responsible behavior while driving a car may help to prevent motor vehicle accidents and subsequent CR.

The cervical spine consists of seven vertebrae which are generally numbered from C1 to C7. C1 and C2 are also designated atlas and axis, respectively. Similar to other regions of the spine, spinal nerves emerge between those vertebrae. With regards to the anatomical taxonomy, each cervical nerve receives the name of the vertebra below it, i.e., cervical nerve C1 emerges above C1. The spinal nerve C8, however, originates between the seventh cervical vertebra and the first thoracic one.

Cervical nerve roots are located in very close proximity to the cervical spine. They may be compressed by herniated discs, osteophytes or any other space-occupying mass developing here. This condition results in cervical radiculopathy, but because inflammatory processes seem to play a major role in the disease progress, the term cervical radiculitis (CR) may be considered more precise [1]. Colloquially, this disorder is often called "pinched nerve".

Because spinal nerves carry sensory and motor fibers, both input and output of neuronal signals may be affected in cases of CR. Numbness, paresthesias and pain may be experienced in those areas supplied by the respective cervical nerve. In detail, cervical nerve injury may manifest in the following regions:

• C1 and C2 mainly supply occipital and neck regions.
• C3 and C4 also account for innervation of the neck.
• The phrenic nerve receives fibers from C3, C4 and C5.
• C6, C7 and C8 form the brachial plexus and innervate the upper limb.

Additionally, patients may report having sustained a trauma, but this is not always the case. Compression of cervical nerves can be confirmed applying magnetic resonance imaging or computed tomography, ideally combined with administration of contrast agents to depict the spinal canal to perform myelography.

Treatment and prognosis depend on the underlying disease, but most patients recover completely under conservative therapy. Any treatment should be aimed at resolving the primary disorder. Patients may benefit from initial immobilization and subsequent physiotherapy. Supportive drug treatment may be provided in form of analgesics that may be administered systemically or by means of selective nerve root blocks [2].

The spinal cord passes through the spinal canal which, in turn, is formed by vertebrae. At the interface of any two neighboring vertebrae, spinal nerves emerge from the vertebral spine. They supply a plethora of distinct tissues, allow for the execution of movements and the perception of peripheral stimuli.

Those spinal nerves emerging between the upper seven vertebrae of the spine are called cervical nerves. If they are compromised by any pathological process affecting surrounding structures or the nerves themselves, their nerve root may be compressed and show signs of inflammation. This condition is designated cervical radiculitis (CR). The medical term cervical radiculopathy refers to the same disease.

Causes

Mechanical compression of one or more cervical nerve roots is the most common cause of CR. This may be provoked by a prolapsed intervertebral disc, spondylosis, any other condition promoting the development of bone spurs, trauma, infection and tumors. Basically any space-occupying process located in close proximity to the respective nerve root may trigger CR.

Symptoms

Cervical nerves supply the occipital and neck region, shoulders and arms. Symptoms often experienced by CR patients are numbness, tingling and pain in the aforementioned parts of the body. Muscle weakness may be noted, too.

Diagnosis

Diagnostic imaging will be applied to confirm CR and to localize the site of lesion. In many cases, plain radiography is sufficient. If doubts remain after radiography, magnetic resonance imaging and/or computed tomography scans may be carried out. They allow for a more detailed visualization of soft tissues (intervertebral discs, ligaments and nerves themselves) and the vertebral spine, respectively.

Treatment

Most CR patients achieve complete recovery with conservative treatment consisting in immobilization, physiotherapy and medication. The latter will help to reduce pain and resolve muscle tension.

In rare cases, CR requires surgery. Here, the specific procedure depends on the underlying disease.

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