DEGENERATIVE SPINE DISORDERS
Understanding Your Condition - Degenerative Spine Disorders
The aging process takes its toll on all of us. As the years go by, we may start to discover fine lines on our faces or a few gray hairs here and there. In addition to the signs of wear and tear that appear on the outside, we may also start to feel like we’re slowing down on the inside. Maybe you can’t jog quite as far as you used to, or carry heavy bags up the stairs. Perhaps your alarm goes off in the morning and your joints feel stiff. Small aches and pains all over our bodies are fairly normal as we get older, and are usually no cause for alarm. The majority of individuals simply make small adjustments in their daily routine to accommodate any age-related issues they may be having, and continue to lead active, fulfilling lives.
As you deal with the natural aging process, it’s important to remember that, although most forms of pain and discomfort will likely abate after a few hours or a few days, there could be certain conditions that become chronic and may require attention from a doctor or physical therapist. But how do you tell the difference? Basically, you just need to listen to your body. For instance, if you wake up and your knees feel stiff, but after about fifteen minutes of walking and gentle stretching you feel like you’re back to your old self again, there’s probably nothing to be concerned about. However, if you find that you experience pain in your knees throughout the day, every day, and the discomfort starts to affect how you navigate your day-to-day activities, it may be time to seek medical help. You could be suffering from arthritis or a variety of other conditions that are specific to age and anatomical degeneration.
The jointed areas of the body, such as the knees, elbows, and fingers, are especially susceptible to age-related deterioration. The neck and the back are also extremely common areas for aches and pains to occur, as the entire spine is really a column of jointed bones that are supported by a network of other anatomical components. Like the outside of the body – laugh lines, crow’s feet, or salt-and-pepper hair – the elements of the spine may also start to show signs of deterioration over time. To you, this deterioration may feel like a stiff neck, spasms in the lower back, or a pinched feeling around the tailbone. At this point, you may be asking yourself: How do I know the difference between normal aches and pains in the spine and a condition that could be more serious? The answer is: Sometimes it’s impossible to know for sure unless you are diagnosed by a medical professional. But it can help to become familiar with the spinal anatomy, pay attention to your symptoms, seek advice from a doctor, and know how to avoid risk factors that could accelerate spinal degeneration or exacerbate your symptoms.
The Anatomy of a Degenerative Spine
The spinal column is a fairly complicated structure, the parts of which work together to facilitate movement, keep your body upright, and protect the delicate spinal cord. The spinal cord, as you likely know, is the nerve center of your body. It is a long, thin, rope-like structure of nerve tissue that begins at the base of the skull and extends all the way down to the lower back, or lumbar spine. It is basically the conduit between the brain and the body. You touch something hot with your fingers, and nerves from your hand send a warning message through the spinal cord to your brain, so that your brain can tell your arm – again, through the spinal cord – to move away from the hot object. The spinal cord and the brain themselves are referred to as the central nervous system, and the nerves that branch off the spinal cord and travel to other parts of the body make up the peripheral nervous system.
Clearly, the spinal cord is so important that it requires a great deal of protection. The spinal column is like a suit of armor surrounding this cord of nerves, and it is made up of alternating vertebrae (small bones) and intervertebral discs (spongy pads of cartilage). Below are some things you should know about each of these components:
Vertebrae –
There are usually 33 vertebrae in the spinal column, most of which are cylindrical segments of bone with a hollow canal at their center.
Stacked on top of one another, the vertebrae form a long, hard cylinder through which the spinal cord runs.
Nerve roots are also intertwined within the vertebrae. In between the vertebrae are foramina, or channels, which provide space for nerve roots to branch off the spinal cord. Nerve roots carry sensory and motor signals to and from the spinal cord and the rest of the body. When impinged or “pinched,” by bone or other tissue, nerve roots can produce painful, debilitating symptoms. This is discussed in more detail under “Symptoms of a Degenerative Spine.”
Seven vertebrae comprise the cervical spine (neck), 12 vertebrae comprise the thoracic spine (middle back), five vertebrae (six, in some cases) comprise the lumbar spine (lower back), and typically nine fused vertebrae make up the sacrum and coccyx (tailbone).
Intervertebral discs –
These are round discs of cartilage that are wedged between adjacent vertebrae. Not only do discs help protect the spinal cord and absorb shock, but they also serve as joints to allow slight movement up and down the vertebral column, as well as play a ligamentous role by holding the vertebrae together.
The only vertebrae that are not separated by intervertebral discs are the first two cervical vertebrae (C1 and C2) and the fused vertebrae of the sacrum and coccyx, which means most individuals have 23 discs (24 in some cases).
The discs have a tough outer shell of fibrocartilage called the annulus fibrosus and a jelly-like inner nucleus called the nucleus pulposus, which primarily consists of protein, water, and collagen.
Other anatomical elements that further ensure the stability of the spine and the safety of the spinal cord include the spinal ligaments, muscles, tendons, and facet joints. The ligamenta flava are ligaments that connect the laminae of adjacent vertebrae; these ligaments are extremely elastic and help your spine to resume an upright position after you bend forward. The erector spinae muscles and tendons run up and down the back of the spine and are attached to the spinous processes, which are bony knobs on the back of each vertebra. The facet joints connect adjacent vertebrae via the articular processes (bony protuberances on each side of the vertebrae) and allow for almost all of our spine’s movements.
Now that we’re familiar with the components of the spine and the roles that they play, let’s look at how each part can degenerate over time.
Vertebrae – These bony cylinders can lose vitamin D and calcium, making them porous and weak. This condition is commonly referred to as osteoporosis. A vertebra can slip out of place (a condition called spondylolisthesis) if it develops a fracture or otherwise becomes unstable.
Intervertebral discs – The discs lose water and collagen over time, which makes them far less elastic than they previously were. Furthermore, the pressure from the spine’s movements can cause the nucleus pulposus of a disc to balloon out to one side of the disc (called a bulging disc), or the annulus fibrosus can develop a tear and allow the nucleus pulposus to leak out (called a herniated disc).
Facet joints – These vertebral joints are covered in cartilage, which allows them to move smoothly and without friction. However, just as the cartilaginous discs become thin and weak over time, the cartilage lining on facet joints also can wear away and lead to a condition called spinal osteoarthritis, a form of degenerative arthritis that is sometimes called facet syndrome or facet disease.
Muscles, tendons, and ligaments – These tissues can lose elasticity over time as their collagen fibers become overstretched. They can also ossify (a hardening due to new bone growth) or calcify (the buildup of calcium salts in soft tissue) and become abnormally enlarged.
The above degenerative changes will likely affect most individuals in one way or another as they get older, but it’s hard to predict who is more likely to develop severe spinal degeneration. For instance, two women who are both 50 years old and are in about the same state of health may have vastly different experiences with spinal degeneration. While one may only experience the occasional ache, another may find that she is continuously plagued with chronic herniated disc symptoms. Certainly, certain lifestyle factors can affect the rate at which a person’s spine degenerates, but what it truly boils down to is how every person’s body goes through the aging process.
Causes and Risk Factors of a Degenerative Spine
We’ve already established that the aging process is the primary cause of a degenerative spine, but we’ve also noted that age alone – in the chronological sense – is not always indicative of degeneration. To understand this further, let’s really take a look at what happens to the entire body as we get older, and what choices we can make throughout our lives to possibly stave off degeneration for as long as possible.
In addition to the changes in the bones, joints, muscles, tendons, ligaments, and intervertebral discs that we’ve already discussed, the following factors can also play a role in spinal degeneration, albeit indirectly:
Metabolism – As we get older, our basic metabolic rate slows down (about 5 percent per decade after the age of 40). This means the body doesn’t require as much fuel (measured in calories that we consume in food and beverages) to keep essential organs like the heart, lungs, and brain going. However, just because our bodies don’t need as much fuel as we get older, this doesn’t mean we necessarily eat fewer calories than we used to, or that we exercise more to compensate for the difference. Any excess calories we eat are stored away as fat. This is a main reason why weight gain commonly occurs after the age of 40. Being overweight can greatly affect the neck and the back because extra body weight puts far more pressure on the vertebrae, intervertebral discs, and the facet joints.
Pulmonary function – Circulation tends to slow down as we get older because the heart muscles get weaker and can no longer deliver such large quantities of blood at the rate that they used to. The blood delivers nutrients to different parts of our body, so if this delivery system slows down, the health of certain anatomical components may deteriorate and they are less able to heal themselves when damaged.
Hormone changes – Disturbances in hormone levels, as happens during menopause and with the development of conditions like diabetes, can affect bone and joint health. For instance, estrogen helps reduce inflammation, which is why arthritic joints can flare up during or after menopause, when estrogen levels gradually recede. In men, testosterone levels decrease about one percent per year after the age of 30, which may result in increased body fat, decreased bone density, and reduced muscle bulk.
Although we can’t control or stop the aging process, and there is no magic wand that can be waved to ensure spine health later in life, there are risk factors we can avoid throughout our lives to diminish the risk of developing a degenerative spine as we get older, including:
Maintain a healthy weight – Eat a sensible diet that includes plenty of nutrition and appropriate calorie levels, try to exercise and remain active even as you start to experience the signs of aging, and see a dietician or nutritionist if you feel you may be losing control of your diet or body weight.
Don’t smoke – The chemicals introduced into your body when you smoke cigarettes wreak havoc on nearly every other part of your body, including the spine. The ligaments, tendons, and intervertebral discs of the spine already have a limited blood supply, and this is compounded by the aging process as circulation slows, so adding smoking to the mix would dangerously inhibit your spine’s ability to heal itself and remain strong and healthy.
Avoid high-impact activities and overexertion – There is a fine line between staying active and taking part in activities that could cause injury to the back or neck. Therefore, use proper techniques when lifting heavy objects and avoid playing high-impact sports like football or rugby. Many older individuals who participated in rigorous activities in their youth, or who previously sustained back or neck injuries, have experienced accelerated spinal degeneration in their adult years.
It can be frustrating to know that there are so many variables involved in the development of spinal degeneration. It may even seem like, no matter what precautions you take and no matter how healthy you are, there’s nothing you can truly do to avoid the complications and conditions associated with age-related deterioration. The good news, however, is that not everyone whose spinal anatomy has deteriorated will experience symptoms, and those who do feel discomfort or pain may only have to deal with it intermittently and for short periods of time. It’s usually only in the minority of cases that degenerative spine conditions produce chronic, debilitating symptoms.
Degenerative Spine Symptoms
So far we’ve learned that the spine is made up of many different parts, and a main function of these parts is to protect the spinal cord and its nerve roots. In our discussion of spinal anatomy, we found out that nerve roots branch off the spinal cord, exit through channels (foramina) located between the vertebrae, and travel to other areas of the body. Finally, we established that these nerve roots transmit motor and sensory signals.
Armed with this information, we can better understand why there are generally two types of symptoms that can occur when the anatomical elements of the spine have deteriorated: localized symptoms and radiculopathic symptoms. The difference between the two is basically that, in the former, symptoms of pain, stiffness, or muscle spasms are felt very close to the location of a spinal abnormality. In the latter, compression of one or more nerve roots is involved and the discomfort usually travels along the path of the nerve. This discomfort is also known as radiculopathy.
When a nerve root is disturbed, its signals can be disrupted, which can result in the following symptoms along the nerve’s path:
Pain
A tingling or “pins-and-needles” sensation
Numbness
Muscle weakness
Whether your symptoms are local or traveling, the location and the nature of symptoms experienced will depend largely on the injury or anatomical abnormality that has occurred due to the spinal deterioration, and the location of the abnormality within the spine.
Two of the main degenerative conditions that we’ve mentioned are spinal osteoarthritis and deteriorating discs. Both can exist without producing any symptoms at all, but they also have the potential to cause conditions like herniated discs, bulging discs, spondylolisthesis, and bone spurs. Any of these can lead to localized and radiculopathic symptoms:
Spinal osteoarthritis – As cartilage wears away from the spine’s facet joints, local nerves feeding out of the joints can become irritated by joint instability and increased friction. When irritated and inflamed, these facet joint nerves, called medial branch nerves, can become the epicenter of chronic, localized pain.
Herniated discs – Extruded disc material can leak into the spinal canal and press on a spinal nerve root, which can cause radiculopathy. Small nerve fibers in the disc’s outer wall can also become irritated by the extruded disc material or the tear itself, which may lead to localized disc pain.
Bulging discs – A ballooned disc can press on a nearby spinal nerve root and cause radiculopathic symptoms that affect the upper or lower limbs on one side of the body.
Bone spurs – When joint cartilage and/or discs deteriorate and vertebral bones begin grinding against each other, bone spurs, or osteophytes, may form, which are small nodules of bone that can come into contact with nerve roots. Bone spurs can also lead to joint stiffness and spontaneous joint lockage.
Spondylolisthesis – A displaced vertebra can press on a spinal nerve root, or, in more severe cases, can cause someone to develop lordosis (swayback), kyphosis (round back), or a change in gait.