This occurs due to compression of a nerve root(s) in the cervical spine after it has exited the spinal cord. It can be caused by a number of different pathologies, but the presentation for each is similar. In most cases, the pain begins in the neck and travels down into the shoulder and then into the arm. The pain can be in a different area depending on the nerve root that is being compressed. It is often described as being like an electric shock, or a burning type pain. It can be made worse with certain neck movements. There can also be altered sensation (pins and needles or numbness) and weakness.
As the disc ages the amount of water begins to reduce, leading to a loss of height and a disc bulge, as well as becoming stiffer and less mobile. The body responds to this process by forming more bone – bone spurs, or osteophytes – and this increases the stiffness of the spine on top of the already less mobile disc. The decreased height of the disc, the bulge of the disc, and the bone spurs can all contribute to narrowing of the nerve exit foramen and cause the radiculopathy.
The inner portion of the disc (nucleus pulposus) can herniate through the outer portion of the disc (annulus fibrosis) and lead to compression of a nerve root. This direct pressure, as well as inflammation, result in the typical neck pain that goes into the shoulder and/or arm depending on the nerve root being compressed. It can also lead to numbness and weakness.
Often an acute disc prolapse can occur with an injury, twisting, bending or when lifting a heavy object. It may also occur with a minor trauma or normal movement if there is already degeneration within the disc outer ring (annulus).
Xray is often used to show the overall alignment of the cervical spine in an upright position, as well as any degeneration of the cervical spine. This is important as it can alter the treatment options offered. CT scan is used to look for bone spurs or to determine if a disc prolapse has become calcified. MRI scan is used to look at the nerves in detail and determine if there is compression of the nerve root. It is the most accurate at looking for a disc prolapse.
Nerve conduction studies and electromyography is used to measure the electrical impulses that travel in the nerves as well as the response of the muscles at rest and during contractions. This can help to differentiate pain caused by compression of the nerve within the neck, and that caused by another site of compression (such as carpal tunnel syndrome) or a condition that leads to damage to the nerves (such as diabetes).
The majority of patients with cervical radiculopathy will improve without any surgical intervention. It is important to manage the symptoms of cervical radiculopathy while waiting for the pain to improve. The pain can recur over time, but again it will often get better without any surgical intervention.
Non-surgical treatment consists of lifestyle modifications (avoiding activities that cause the pain to increase, avoiding long periods of time sitting and using a computer screen), physical therapy, warm packs, analgesic medications, use of a soft collar, and cervical nerve root injection.
If the symptoms are severe, often including weakness, and do not respond to initial non-surgical treatment, surgical intervention may be offered. The main aim of surgery is to decompress the nerve root to improve neck and arm pain. This can be done via an anterior approach (anterior cervical discectomy and fusion, anterior cervical disc replacement), or a posterior approach (cervical laminectomy or foraminotomy), and this depends on the underlying cause for the compression.