Cervical Degenerative Disc Disease

What is Cervical Degenerative Disc Disease?

Degenerative disc disease in the neck affects both men and women, and it usually develops as people get older. The most common symptom is pain, which can sometimes be accompanied by other symptoms similar to those of a neurological disorder. In some cases, surgery might be needed to relieve this pain. The treatment options range from non-surgical methods to decompression or instrumented fusion surgeries, or a combination of the two known as laminoplasty. This article will help you understand the structure of the spine, the causes and progression of the disease, and the available treatment options.

The region of the spine in your neck, known as the cervical spine, consists of seven vertebrae labeled C1 to C7. These bones allow for a wide range of movements. C1 and C2 are special bones that allow for a significant amount of movement. Nearby, you can find important structures like the spinal cord, nerves, blood vessels, and the tube through which you breathe (trachea) and the one through which food passes (esophagus).

The intervertebral disc, found between the neck vertebrae from C2 and C3 downwards, helps in the movement and stabilization of your neck. Unlike the lower back and chest vertebrae, neck vertebrae have a unique extension called the uncinate process. This structure together with the intervertebral disc provides additional stability and movement to your neck.

This disc is made up of two parts – annulus fibrosus located towards the periphery and nucleus pulposus located in the center. The annulus fibrosus is mostly made up of layered collagen, a protein that gives strength to the disc, and other substance like proteoglycans and glycoproteins.

The nucleus pulposus has a gel-like substance made up mostly of water. The amount of water decreases from 90% at birth to 70% at 60 years of age. This part also contains collagen and proteoglycans, which help in resisting loads.

After the first few years of life, the intervertebral disc becomes the largest avascular (lacking blood vessels) structure in the body. Most of the nutrients reach the disc by diffusing through the vertebrae. With time, the disc starts losing not just its water content but also its proteoglycans, leading to a harder and more fibrous center of the disc, and eventually to the cracking of its surface.

There are different types of herniations (protrusions) of this disc. If the central part of the disc herniates but remains within the covering, it’s called disc protrusion. If it breaks through the exterior covering, it’s called disc extrusion and when bits of it separate from the main part, it results in disc sequestration.

The degeneration of the neck vertebrae occurs in three stages – dysfunction, instability, and stabilization. Dysfunction can occur in people between 15 to 45 years old, characterized by tears in the annulus fibrosus. It can lead to instability in people between 35 to 70 years old, resulting from further degeneration of the disc and facet joints – small joints between the vertebrae responsible for spine movements. The final stage, stabilization, generally occurs in people above 60 years old and involves hardening of the spine due to overgrowth of bony tissue.

Interesting to note that each spinal segment of your neck could be at different degenerative stages. Hence, it is possible to find a patient with a combination of herniated discs and spine narrowing known as spinal stenosis. The region of C5-6 is commonly affected due to the biomechanics of the neck.

Patients with neck disc degeneration can experience a range of symptoms from intermittent to constant pain, with or without neurological symptoms. When the pain doesn’t get worse, and there are minimal neurological problems, patients usually receive non-surgical treatments. Surgery, which is typically elective, can be delayed in the hope of symptomatic improvement. One exception is cervical myelopathy that requires more urgent surgical treatment to prevent further progression.

Diagnosing and treating spondylolytic cervical myelopathy can be quite challenging, particularly in patients with or even without ongoing neck pain with possible nerve pain known as radiculopathy. Around 20% of patients with neck narrowing may also have lower back narrowing. While many patients are diagnosed based on symptoms, medical history, physical examination, and confirmatory images, there are some instances where the patient has pain without experiencing neurological symptoms and the images may not correlate with the physical exam findings. In such cases, other diagnostic methods could be used for accurate diagnosis. That’s why a thorough and systematic evaluation is crucial for appropriate treatment.

What Causes Cervical Degenerative Disc Disease?

Cervical degeneration, or the wearing down of the discs in the neck, is a normal part of aging. This process usually begins in our early twenties. As we age, these discs lose water content, become less flexible, and may start to crack. This can lead to decreased disc height and even a collapse.

These changes can put stress on the back part of the neck and lead to other changes in the spine called “spondylotic changes,” such as an increase in the size of the facet joints. The process further weakens the outer part of the intervertebral discs as the force exerted on the discs is not absorbed, leading to tear and cracks. This, in turn, results in the discs losing more height due to the bulging and subsequent cracks in the disc’s outer border.

There are numerous factors that can increase the risk of developing disc disease in your neck. Some of these include aging, environmental factors, and genetics. Lifestyles that involve heavy use of electronics, such as smartphones, are of particular interest. Sitting for extended periods while using these devices puts the neck in a constant flexed position, increasing stress on the discs.

The head’s weight, which is roughly 12 lbs in a neutral position, can increase the more the neck is flexed. For example, a 15-degree neck bend can put approximately 27 lbs of weight onto your discs. The weight rises to 40 lbs at 30 degrees, 49 lbs at 45 degrees, and 60 lbs at 60 degrees of flexion. This extra weight over time increases stress on the discs, particularly the nucleus pulposus (the soft, gel-like substance at the center of each disc), leading to poor diffusion and nutrition to the discs and resulting in degeneration.

Several other risk factors have been considered, which include smoking, certain types of jobs, genetic predisposition, buildup of fats in the blood vessels (atherosclerosis), playing certain sports, and having had previous surgeries. However, it’s important to note that there is conflicting evidence about the role of body mass index, sex, sports, smoking, and alcohol consumption in this process. Studies have found no significant evidence suggesting that smoking or weightlifting increases the risk of cervical spine degeneration.

Risk Factors and Frequency for Cervical Degenerative Disc Disease

Cervical disc degeneration, like the one in the lower back, is a natural process that happens as people get older. This condition can develop regardless of whether a person is feeling symptoms or not. Research shows that about 25% of people under the age of 40 have signs of disc degeneration or shrinkage at one level. This percentage increases to about 60% in people older than 40.

A study in Japan looked at 497 patients who did not have symptoms and found that nearly 90% of people over 60 (both men and women) had abnormal results. In contrast, only 17% of men and 12% of women in their 20s showed abnormalities. Multiple studies have found that the most common location for disc degeneration to occur is between the fifth and sixth cervical vertebrae (C5-6), followed by the spot between the sixth and seventh cervical vertebrae (C6-7).

• Cervical disc degeneration occurs naturally as people age.
• About 25% of people under 40 have signs of this condition.
• In people over 40, this number rises to 60%.
• Nearly 90% of symptom-free people over 60 show signs of disc degeneration.
• But only 17% of men and 12% of women in their 20s show these signs.
• The most common place for this to occur is in the fifth and sixth cervical vertebrae (C5-6).
• The second most common place is between the sixth and seventh cervical vertebrae (C6-7).
• Research has shown that cervical disc degeneration is linked to similar degeneration in the lower back.
• It can also cause pain in the neck, shoulder, and upper arm area in people with moderate to severe cases of the condition.

Signs and Symptoms of Cervical Degenerative Disc Disease

The medical approach to a patient with potential degenerative changes starts with a thorough check of their health history. This involves understanding the patient’s basic symptoms, whether they’ve lost weight, experienced fever, chills, or sweats, and their history of infection, cancer, or trauma. If pain is also a symptom, it’s important to know the severity of the pain, what triggers or alleviates it, and associated symptoms. It’s equally crucial to consider any neurological symptoms such as weakness, loss of sensation, or problems with walking.

The physical examination begins with taking the patient’s vital signs, which include checking if they have a fever. The neurological examination includes checking their strength, testing their cranial nerves, assessing their balance and gait, their sensitivity to touch, and their reflexes. The flexibility of the neck is examined to see how much it can move and whether movement causes any symptoms.

• The most common symptoms patients present with are neck pain and difficulty moving their neck.
• A smaller number of patients may complain of headaches or shoulder pain.
• One-sided nerve pain can also be a common symptom and is typically caused by a herniated disc or bone spurs pressing on nerves.
• Symptoms may also include changes in muscle reflexes, muscle shrinkage, a reduction in sensitivity to touch, tingling or weakness.

Special tests can help diagnose nerve-related symptoms. Assessments of the neck muscles for spasms, and any tender points, are carried out. It’s also crucial to assess the upper body, as symptoms may be related to other conditions such as carpal tunnel syndrome or nerve root inflammation in the neck.

Typically, cervical disc disease may show no symptoms and be identified only through imaging tests like CT scans, X-rays, or MRI. If a patient does have symptoms, they may include nerve pain, weakness, or changes in sensation. Muscle weakness in particular places, like the triceps or the deltoid muscle, can be a symptom if certain nerves are compressed or irritated.

In severe cases, patients may develop cervical spondylotic myelopathy, which is a condition caused by severe wear and tear on the neck bones, calcification of spinal ligaments, or herniated discs. This condition more commonly affects people aged 50 or older. It can present with a variety of symptoms, including stiff or rigid legs, numbness and tingling from the fingertips to the hands, challenges in writing and other tasks requiring fine motor skills, increased reflexes, problems with walking, and even bladder and bowel issues in severe cases.

Testing for Cervical Degenerative Disc Disease

Lab tests can be used to help diagnose your condition, particularly if there’s a chance you might have an infection (like Lyme disease), an immune system ailment that causes joint pain and swelling (autoimmune arthritis), or a disorder related to diet or your body’s ability to absorb certain nutrients (like folate or vitamin B12 deficiency). These tests might include a complete blood count (CBC), as well as tests for erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP). However, none of these tests can definitively prove the presence or absence of spinal infections. It might also be necessary to take samples of your blood to grow in a lab (blood cultures) if an infection is suspected.

Alongside laboratory tests, different types of imaging might also be performed to get a more detailed view of the situation. You might start with a plain X-ray, which can show abnormalities in the normal inward curve of your neck (‘cervical lordosis’), changes related to arthritis (‘hypertrophic changes’) and narrowed spaces between the bones in your neck where the discs are (‘disc space narrowing’). X-rays can also help to rule out other potential problems like broken bones or instability of the neck vertebrae. If you are found to have bony growths sticking out from the back of your vertebrae (‘dorsal osteophytes’) or ossified posterior longitudinal ligament (OPLL), a computed tomography (CT) scan might be helpful in planning any potential surgery.

However, the most detailed images of the neck, especially when looking for age-related wear and tear of the cervical spine (‘degeneration’), are obtained from a magnetic resonance imaging (MRI) scan. An MRI scan gives a clear image of the soft tissues like ligaments and disks, as well as neural structures. It measures the width of the spinal canal and spinal cord in multiple angles and is superior to a CT scan or an X-ray in this regard.

An important point to note is that a narrower spinal canal could increase the risk of spinal cord compression – a serious condition that can cause problems with movement and sensation (‘myelopathy’). Because the space around the spinal cord decreases in the lower segments of the neck, the risk is higher in these areas. On an MRI scan, the inner parts of the disc spaces should appear brighter, with a dark outline (the ‘annulus fibrosus’). If the brightness extends to the back of a disc space, it can indicate a slipped disc (‘disc herniation’). Patients with myelopathy might not show changes to the spinal cord right away, but over time, these might become apparent. These can include increased brightness at the point of cord compression, indicating swelling of the spinal cord (‘edema’) or even softening and damage to the spinal cord tissue (‘myelomalacia’).

In addition to these measures, other tests might be performed to rule out other potential causes of your symptoms. For example, an electromyography (EMG) test could help determine if your symptoms might be due to nerve damage caused by diabetes, exposure at work, or folate/vitamin B12 deficiencies.

Treatment Options for Cervical Degenerative Disc Disease

Treatment for cervical disc disease, a condition that affects the cushions between your neck bones, aims to reduce pain, improve function, and decrease the recurrence and duration of symptoms. The approach often starts with non-surgical care and may lead to surgery if needed.

Non-surgical Treatment

Non-surgical treatments include rest, modifying your activity, medication, physical therapy, manipulation, some types of injections, and acupuncture. You might also be advised to wear a cervical collar for severe neck pain. There isn’t enough evidence to suggest whether cervical traction (a technique that uses weights to relieve pressure on the joints of the spine) reduces disc herniation. However, it could help in decongesting the area where the nerves exit the spine, leading to some relief.

Medications such as nonsteroidal anti-inflammatory drugs (NSAIDs), steroids, and/or muscle relaxants can help provide symptomatic relief. NSAIDs work by interfering with chemicals in the body that cause inflammation. Steroids might be used for a short time to manage initial symptoms as they can have side effects. Muscle relaxants can be used if you have muscle spasms.

Physical therapy should start early and includes passive activities like using heat, massages, and mechanical traction, among others. Heat can decrease pain and reduce muscle spasms, while massages can stimulate blood flow and promote muscle relaxation. Active exercises like aerobic conditioning, dynamic muscle training, and range of motion exercises can also be part of rehabilitation.

It’s important to note that the diagnosis and treatment of severe spinal cord pressure from cervical disc disease can be challenging. The symptoms can progress fast in some patients, or they might remain stable in others, but usually, they progress over time. Spontaneous improvement is rare, and sometimes, doctors may suggest keeping an eye on mild symptoms that aren’t getting worse.

Surgical Treatment

If non-surgical treatments don’t work, particularly if you’re experiencing unmanageable pain, progressive or significant neurological problems, surgery might be suggested. There are various approaches to cervical spine surgery. It might be performed from the front (anterior) or back (posterior) for different reasons.

Anterior surgery involves removing the disc that’s causing pressure on the nerves or spinal cord (decompression). This often includes a fusion to stabilize the spine and reduce the risk of spinal deformities after surgery. Posterior surgery, on the other hand, is used to give the spinal cord more space to move away from the structures causing pressure. This approach is helpful when multiple levels of the spine are involved or when the spinal canal is narrow from birth (congenital stenosis).

In some cases, a combined approach may be needed. Recently, cervical disc replacement (arthroplasty) has gained popularity. It’s not indicated for degenerative disc disease but rather herniated discs.

Despite the variety of surgical techniques available, the success of surgery depends largely on careful patient selection, accurate operation techniques, and managing complications effectively. It is essential to note that surgery also carries risks such as nerve injury, esophagus or trachea injury, graft dislodgement, pain at the back of the neck, among other complications.

What else can Cervical Degenerative Disc Disease be?

When diagnosing arm or shoulder pain, doctors may consider several conditions that could be the cause. Below is a list of possible diagnoses:

• Brachial plexopathy (nerve damage in the upper arm)
• Carpal/cubital tunnel syndrome (pressure on nerves in the wrists or elbow)
• Peripheral neuropathy or neuritis (nerve damage or inflammation)
• Complex regional pain syndrome (chronic pain affecting an arm or leg)
• Demyelinating disorder (conditions that cause damage to the protective covering of nerve fibers)
• Radiation plexopathy (nervous system damage from radiation therapy)
• Malignancy (such as Pancoast tumor, which can cause nerve pain)
• Myofascial pain (pain in the muscular tissues)
• Cervical spondylosis (wear and tear affecting spinal disks in the neck)
• Sprained ligaments
• Cervical sprain and strain (injuries to the neck)
• Rheumatologic disorder (conditions involving the immune system and joints)
• Fibromyalgia (chronic pain and stiffness throughout the body)
• Shoulder pathology/rotator cuff injury
• Thoracic outlet syndrome (compression of nerves or blood vessels in the lower neck and upper chest area)
• Infectious etiology/osteodiscitis (infection in the bones or discs in the spine)

What to expect with Cervical Degenerative Disc Disease

The future health outcome and progression of a condition known as cervical spondylosis can be hard to predict and can vary greatly from one person to another. Research that dates back to 1956 saw Clark and his team follow the health of 120 patients with this condition. They discovered that in 75% of these patients, the condition would intermittently get worse, in 20% the symptoms slowly got worse over time, and in 5% the patients’ symptoms advanced quickly.

Years later, a study by Lees and his team further highlighted how unpredictable this disease can be. In a different study conducted by Nurick and his team on 37 patients, they found that most had a period of decline, which was then followed by a steady phase that could last for years in some instances. It was found that older patients were more at risk of additional decline.

In a separate study, it was shown that the condition of 26% of patients got worse, 38% remained the same, and more than a third actually showed improvement.

Possible Complications When Diagnosed with Cervical Degenerative Disc Disease

Individuals suffering from diseases affecting the discs in the neck, known as cervical disc disease, may experience severe pain and disability. These adverse effects don’t always match the level of damage in the discs themselves. This condition can lead to decreased productivity at work, a decline in personal life responsibilities and generally poorer health due to less physical activity. There could be severe cases like the loss of function in the lower body and uncontrolled bladder or bowel movements. However, such complications, caused by spinal cord compression or myelopathy, are extremely rare, but are usually quite severe when they occur.

Effects of Cervical Disc Disease:

• Severe pain
• Physical disability
• Decreased productivity at work
• Poor participation in personal life
• Poorer overall health
• Reduced physical activity
• Rare severe complications such as loss of lower body functionality and incontinence

Preventing Cervical Degenerative Disc Disease

Cervical disc disease, a condition concerning the discs in your neck, can greatly affect your quality of life and could lead to disability. If you’re worried about your neck’s discs wearing out, it’s important to learn about this condition. The earlier this condition is identified, the better, as it could prevent possible health challenges or limits in the future. It’s also critical for regular doctors to know about this disease so they can spot the usual signs during check-ups. If your regular doctor is concerned about your neck discs, they should have a system in place to refer you to a specialist.