Cervical Discogenic Syndrome

Etiology

Cervical discogenic pain syndrome can be caused by degenerative changes in the intervertebral discs. These changes are usually caused by mechanical influences. Predisposing factors include sitting with prolonged neck flexion or with a protruded head posture, frequent flexion, sudden unexpected movements, and trauma. Sports-related spine injuries may also predispose individuals to CDPS.

Epidemiology

Cervical discogenic pain syndrome is a common source of neck pain with a reported prevalence between 16% to 41%.[2] In spinal intervertebral disc disease, cervical intervertebral disc disease is second only to lumbar disc disease. It accounts for one in five orthopedic practice visits. In terms of years lost to disability and prevalence, neck pain is one of the top five chronic pain conditions.[1] Although present in both males and females, cervical discogenic pain syndrome is more common in females.[4] Its prevalence increases with age.

History and Physical

It is essential to obtain an accurate description of the pain. The history of a patient with cervical discogenic pain syndrome can vary greatly. Patients may have pain that is localized, referred, or even experience radiation across a specific dermatome. It is typically worse in positions involved in prolonged sitting. This pain is especially noticeable with prolonged flexion or with a protruded head posture. Bending can exacerbate this pain. Patients usually find improvement in pain with lying supine as it decreases pressure on the discs. Some may find relief following frequent positional changes. It may be worse in the morning, secondary to inappropriate postural positions while sleeping.

Physical examination should include assessment for a disease presentation similar to myelopathy. Patients should be observed and examined for neurological deficits, including altered balance, motor/sensory deficits in all extremities, and upper/lower motor neuron findings. Strength and reflexes can be intact, but these findings may vary depending on the cause and degree of the condition. Patients may experience decreased sensation along a specific dermatome. They may have poor posture and limited range of motion.

The exam may include the following provocative tests in the examination of the spine: 

• Spurling test may be performed by passive neck extension with rotation and lateral flexion of the neck towards the affected side. A positive test with reproducible pain may be indicative of cervical radiculopathy.[5]
• Lhermitte test may be performed by neck flexion with the patient in a sitting position. A positive test will produce an electric shock-like sensation down the spine and/or arm and may be indicative of cervical spondylosis or myelopathy.
• A shoulder abduction relief sign may be performed by having the patient actively abduct their shoulder rest their hand on top of their head. A positive test is relief (or decrease) of radicular pain with this maneuver and may be indicative of cervical radiculopathy.[6]
• Arm squeeze test may be performed by squeezing the middle one-third of the upper arm. If pain is elicited, it may indicate the etiology of the shoulder pain to be cervical rather than a shoulder pathology.[7]

Evaluation

Laboratory studies are not indicated in the diagnosis of cervical discogenic pain syndrome. Radiograph imaging is usually indicated in patients with a history of trauma or if there is any concern for a possible fracture or instability on clinical examinations. In cervical discogenic pain syndrome, radiographic findings may be normal. It may show degenerative changes, but there is little correlation with symptomatic vs. asymptomatic individuals based solely on these findings. Although MRI may identify degenerative cervical discs and offer more clarity and physiological information, it still cannot differentiate a disc that is pathologically painful from an asymptomatic degenerative disc.[2][8] If evaluation to this point has not revealed an answer, adjunct testing may be indicated.

The most important adjunct in the evaluation of CDPS is cervical provocation discography. It is an image-guided procedure where a contrast agent is injected into the nucleus pulposus of the suspected intervertebral disc. This test not only identifies the level but can also depict internal derangements as well.[9] MRI may be used as a screening tool to find potential levels of interest to perform discography. If performed properly, discography can discriminate painful, symptomatic discs from non-painful, asymptomatic discs.[10] The combination of clinical symptoms, MRI, and cervical provocative discography can help diagnose and provide direction for the management of cervical discogenic pain syndrome.

Treatment / Management

There are many approaches to the management of cervical discogenic pain syndrome, which are dependent on the cause, severity, and clinical presentation. The initial approach is always aggressive nonsurgical treatment. This includes the use of NSAIDs, partial rest, proper posture, and body mechanics, along with home-based exercise programs. Spontaneous recovery is usually common within the first few weeks. Physical therapy should be focused on maintaining proper posture and body ergonomics. The McKenzie approach has been utilized to develop a specific rehabilitation exercise program based on baseline ROM and repetitive motions of the cervical spine.[11] In some cases, patients with cervical discogenic pain syndrome may require cervical epidural injections or nerve root blocks to facilitate their participation in physical therapy. These interventions should be used as an adjunct to therapy and are not usually effective alone.

Patients who do not respond to appropriate conservative therapies and have persistent radicular pain, progressive neurologic deficits, motor weakness, or signs of cord compression may consider surgical intervention. Patients with discogenic neck pain can potentially benefit from anterior cervical discectomy and fusion surgery.[10] For better surgical outcomes, it is important to obtain a preoperative cervical provocative discography to determine surgical levels. This intervention has shown to be effective in pain relief and improved functional outcome.[12](B2)

Differential Diagnosis

Differential diagnoses may include cervical disc injuries, cervical spine sprain/strain injuries, atlantoaxial joint pain, cervical facet syndrome, cervical myofascial pain, fibromyalgia, or spondylosis.

Cervical discogenic pain syndrome is initially treated conservatively, so it is important to rule out the following clinical parameters promptly:

• Cancer (age over 50, history of cancer, unexplained weight loss)
• Infection (recent surgery, history of drug use, fever/chills)
• Trauma (motor vehicle accident, work-related injury, sports-related injury, previous neck surgery)
• Neurological deficits (weakness, loss of reflex, bowel/bladder issues)

Prognosis

Prognosis varies greatly in CDPS depending on the clinical presentation and cause of cervical discogenic pain. Some patients find relief within the first few weeks of onset with conservative measures. Early intervention seems to produce better outcomes. Pain refractory to this management may need further work-up and possible surgical intervention.

Complications

Surgical intervention complications may include

• Intraoperative hemorrhage
• Surgical site hematoma
• Damage to the carotid or vertebral artery resulting in a stroke
• Recurrent Laryngeal nerve injury leading to hoarseness or dysphagia
• Chronic dural CSF leak
• Damage to the spinal cord or nerve roots leading to more pain
• New-onset neurological deficits
• Instrument and implants related complications
• Pseudarthrosis
• Adjacent segment disease