Cervical disc degeneration is one of the most common causes for neck pain. Several symptoms may indicate the presence of degenerative conditions in the cervical spine. These symptoms include: neck and/or pain, pain around the shoulder blades, arm numbness or weakness. The disc(s) may be injured by sudden movements, herniate, or it may gradually wear out. With a herniated disc, the nucleus bulges through the annulus, or the annulus tears and can eventually impinge on the nerves exiting the spine resulting in numbness, tingling, or burning sensation in patient’s arms. This condition also is known as cervical radiculopathy.
In addition, abnormal bone spurs can form on the vertebrae, foramen, and spinal canal causing stenosis. The narrowing of the spinal canal places pressure on the spinal cord and results in neck pain, weakness or numbness in the shoulders, arms, and legs; loss of coordination, gait and balance disturbances, or even bladder and bowel control problems. The condition that presents with some or all of these symptoms is called myelopathy. One of the first symptoms usually are increased knee and ankle reflexes, followed by changes in gait (clumsiness, loss of balance) and loss of sensitivity in hands, which makes it difficult to button a shirt or open a jar.
Cervical radicular pain (cervical radiculopathy) is a pathological process originating from the spinal nerve roots and is a commonly seen condition across many patient populations. It typically presents with neck pain and radicular pain radiating to the shoulder and arms, and is often unilateral. The most common causes of cervical radiculopathy is cervical disc herniation and foraminal impingement as a result of decreased disc height or degenerative changes of the cervical joints. It is seen most commonly at the C5/ C6 and C6/C7 levels. Besides mechanical compression, chemical irritation caused by inflammatory changes also plays an important role as it may lead to irreversible changes in the affected nerve.
Classic cervical radicular pain may be accompanied by paresthesias or sensory loss and may follow a dermatomal sensory nerve root distribution, but that is not necessarily the case in all patients. Non-dermatomal pain referred from other anatomical structures such as the shoulder, or direct neural impingement with an overlap between dermatomes, can result in radicular pain perceived in a wider area. Musculoskeletal pain associated with ulnar or median nerve peripheral neuropathy or shoulder joint pathology may sometimes be confused with cervical radiculopathy. Careful history and physical examination are usually suficient to distinguish between these pathologies.
Diagnostic imaging studies should be typically be reserved to the patients who don’t improve after at least 4 – 6 weeks of conservative management in absence of red flag symptoms and low index of suspicion. MRI is a primary imaging examination for most cases of cervical radiculopathy and has a greater sensitivity than other imaging modalities for diagnosing tumors and infections. Plain films are very useful if spinal instability is suspected or there is a history of trauma. Degenerative changes in the cervical spine are an inevitable part of normal aging processes, therefore cervical radiculopathy is primarily a clinical diagnosis with imaging testing providing only supportive evidence.
Warning Signs/ Red Flags
The goal of diagnosis is to identify the anatomic pain generator(s); a patient history and examination are important in identifying red flags and distinguishing potential causes. A referral to a specialist is warranted and the etiology of radicular pain should be further investigated in patients with a history of malignancy or unintentional weight loss, unremitting pain, particularly at night, patients that are immunocompromised, or have fever, chills or a history of intravenous drug use.
Other warning signs that warrant referral to a spine specialist and more specific work-up are:
- Progressive weakness and numbness
- Intractable arm pain
- Persistent symptoms > 6 weeks