Cervical Radiculopathy

Etiology

Any condition that causes compression or irritation of a spinal nerve root can result in radicular symptoms. In younger patients, typically in the third and fourth decade, disc trauma and herniation are the most frequent causes of impingement.[4] With increasing age, the causation is degenerative. Disc degeneration is the most common cause in the fifth and sixth decades. In the seventh decade, causation stems from foraminal narrowing due to arthritic change.

Epidemiology

Less frequent than lumbar radiculopathies, cervical radiculopathies occur at an incidence rate of approximately 85 persons per 100,000. The C7 nerve root is most frequently impacted, with more than half of all cases affecting this level. Roughly a quarter of cases involve the C6 nerve root. Nerve roots C1 to C5 and C8 are less impacted. Risk factors for developing radicular disease include manual labor with heavy lifting, driving, or operating vibrating equipment. Chronic smoking history can increase the risk of radiculopathies.

Pathophysiology

In nearly all cases of cervical radiculopathy, the key pathophysiologic feature is inflammation. That inflammation can result from acute herniation of an adjacent cervical disc impinging on the nerve root. The inflammation can also exacerbate degenerative changes so that osteophytes or changes associated with disc dehydration can affect the nerve root. The direct compression of the nerve root leads to pain, numbness, tingling, and weakness.

History and Physical

The history of patients with a complaint of radicular pain or muscle weakness should include inquiries about occupational risk factors, history of trauma, and pain patterns. Cervical radiculopathy is almost always unilateral, although, in rare cases, both nerves at a given level may be impacted. Those rare presentations can confound physical diagnosis and require acceleration to advanced imaging, especially in cases of trauma.

When performing a physical examination, it is crucial to position the patient in a way that allows for the isolation of individual reflex arcs. This helps accurately assess the patient's overall reflex response. Given the individual variation in deep tendon reflexes, comparing both sides of the neck is more important than overall magnitude. If there is nerve impingement, the affected side is reduced relative to the unaffected side. Reduced muscle strength, innervated by the affected nerve, is a significant physical sign.

The spurling test, which compresses the foramina, helps diagnose likely radiculopathy. With the head extended, the head should then be rotated. The test is positive if the pain radiates down the upper limb of the ipsilateral side of the rotation. In some cases, cervical traction can provide relief of radicular pain.

Evaluation

Plain x-ray studies of the cervical spine are commonly ordered for neck and upper extremity pain evaluation. Lateral views may show disc space narrowing. Oblique views may show foraminal narrowing at the level of radicular symptoms. Open mouth views are only necessary if disruption of the atlantoaxial joint is suspected.[5][6][7][8]

Computed tomogram (CT) scanning may be helpful in the acute setting for diagnosing traumatic injuries resulting in radicular symptoms. Poor visualization of soft tissue makes CT less effective outside of this setting.

Magnetic resonance imaging (MRI) is the preferred modality for evaluating radiculopathies. MRI provides excellent visualization of soft tissue abnormalities, including disc herniations and nerve compressions. While disc herniations and foraminal narrowing strongly correlate with radicular symptoms, they may not be causative in every case. False positives are a risk in MRI studies.

Electromyography is useful in confirming the dysfunction of the affected nerve root. Selective nerve root blocks can provide short-term pain relief and confirm the nerve root origins of radiating pain.

Treatment / Management

Treatment of cervical radiculopathy should be approached in a stepwise fashion. Also, while surgery can provide significant relief, there is little evidence that surgery provides a clear advantage over non-surgical treatment in an acute setting. Over 85% of acute cervical radiculopathy resolves without any specific treatments within 8 to 12 weeks.[9][10][11] (A1)

However, to facilitate reduced nerve root inflammation and improve radiculopathy, it is important to implement non-surgical treatments, including oral anti-inflammatory drugs, physical therapy, and translaminar epidural steroid injections. An aggressive, well-designed physical therapy program can provide significant relief. In the setting of surgical intervention, physical therapy can speed recovery. Medical durable goods and appliances can provide significant symptom relief. Nighttime use of a cervical pillow can relieve symptoms and make sleeping easier during recovery. Short-term use of a soft cervical collar can provide some relief. 

Since the main cause of pain in cervical radiculopathy is inflammation, the use of non-steroidal anti-inflammatory drugs (NSAIDs) for 1 to 2 weeks can provide symptom relief and treat the proximate cause. The use of oral steroids should be limited to short-term due to controversies surrounding their use. Tricyclic antidepressants and drugs such as gabapentin are useful adjuncts in the treatment of cervical radiculopathy. Opioid pain medications are not recommended for routine use, but they can be useful in managing radicular pain. It should be noted that the use of opioid medications is a risk factor for slow recovery and delayed return to work for patients where surgical intervention is clinically necessary.[12][13](B2)

Studies have shown that epidural steroids can provide significant pain relief and accelerate the return to normal function for many patients. Relief from a single treatment can be significant and long-lasting. Half the treated patients reported at least 50% relief for weeks following injection.

Using acupuncture as an adjunctive therapy has also been shown to provide significant symptomatic relief. Chiropractic or direct osteopathic manipulation can worsen radicular symptoms. Conversely, indirect osteopathic techniques can facilitate the relief of symptoms. 

Surgical management can provide relief to patients who have failed non-surgical approaches. Two main surgical techniques can be used: anterior and posterior approaches. Usually, the anterior approach requires complete discectomies filled by fusion or disc replacements. The posterior approach involves laminectomy, partial discectomy, and foraminotomy with or without fusion. Both approaches have proven effective. As always, surgical treatments are reserved for failed non-surgical treatments, and patients have acute deterioration of their neurological function. No matter the approach, surgery-related complications can occur, including complications caused by anesthesia or complications from the procedure itself, including nerve palsies, vascular impairment, and laryngeal nerve damage.

Differential Diagnosis

The following diagnoses should be considered in the differential:

1. Brachial plexus injury in sports medicine
2. Cervical disc injuries
3. Cervical discogenic pain syndrome
4. Cervical facet syndrome
5. Cervical spine sprain
6. Rotator cuff injuries
7. Strain injuries