What is Chronic Low Back Pain?
Chronic Low Back Pain
Low back pain is pain in the area between the bottom of the ribs and the buttocks. This area includes the five vertebrae of the lower spine, called the lumbar spine (L1 to L5), which support the weight of the upper body. Between the vertebrae are soft, rubbery discs that act as shock absorbers as you move. Ligaments, which work like flexible tape, connect the vertebrae to each other and hold them in place, and tendons attach the muscles to the bones. The spinal cord runs through a canal in the middle of the spine and ends near the top of the lower back, where it continues as a bundle of nerve roots. Spinal nerves exit through openings on each side of the spine, called intervertebral foramina. They control the muscles that move your body and carry sensory signals back to the brain.
Some back pain needs urgent medical care. Get emergency care right away if back pain comes with new trouble controlling your bladder or bowels, numbness in the groin or inner thighs, or weakness in your legs that is getting worse. See a medical provider promptly for back pain with fever, unexplained weight loss, a history of cancer, a recent serious fall or injury, or pain that is severe at night or doesn’t ease with rest.
How Common Is Chronic Low Back Pain?
Back pain is one of the most common reasons people see a doctor or miss work. Experts estimate that 50% to 80% of people will have low back pain at some point in their lives, including school-age children (1). Back pain has been estimated to account for more than 264 million lost workdays each year (2). About 20% of people with a new episode of low back pain go on to develop chronic low back pain (3).
What Are the Early Signs of Chronic Low Back Pain?
Low back pain can range from a dull, constant ache to a sudden, sharp pain that may shoot into other parts of the body. Acute low back pain lasts from a few days to a few weeks, though it can take a few months to fully go away. Most cases of acute low back pain get better on their own. But back pain often comes back, and for many people it becomes chronic over time. Chronic low back pain is pain that lasts 12 weeks or longer (3).
What Are the Later Symptoms of Chronic Low Back Pain?
Over time, chronic low back pain may spread to other areas or become more intense and disabling. If nerves are involved, there may be numbness, tingling or other unusual sensations in the low back or, more often, in the legs and feet. These changes can affect balance and stability. Chronic pain often brings fear of movement and avoidance, along with anxiety and depression. Fear of movement and avoiding activity can keep pain going and slow recovery (4).
What Causes Chronic Low Back Pain?
Most low back pain is mechanical, meaning it isn’t caused by inflammatory arthritis, infection, fracture or cancer (5). It is often caused by sprained ligaments, strained muscles, herniated discs or irritated joints. These problems can come from sports injuries, accidents, repetitive movements done with poor mechanics, or sometimes the simplest movement. Other factors that can contribute include excess weight, arthritis, poor posture, inactivity and psychological stress (6). Less often, back pain is caused by other medical conditions, such as kidney stones, kidney infections, blood clots or bone loss, which is one reason a thorough evaluation matters.
What Happens in the Nervous System With Chronic Low Back Pain?
It’s important to understand that pain is not just a sensation. It is a perception and an experience created by the brain. Most people think of their pain system as an on-off switch, so if they aren’t feeling pain, the system must be off. But that’s not how it works.
Your body has sensors called nociceptors that respond to heat, cold, chemical irritants and pressure. When they’re stimulated enough, they send signals through small nerve fibers into the spinal cord. Like other nerve cells, they always have some background level of activity. So why aren’t we in pain all the time?
The answer is that your spinal cord and brainstem have systems that filter and block these signals before they reach the conscious parts of your brain. When there is enough input, such as from tissue damage or inflammation, these filters are overwhelmed, and the signal reaches the parts of the brain that map the body, mainly in the parietal lobe. Even then, the signal doesn’t become pain until the brain attaches a negative emotional meaning to it. That doesn’t mean pain is imaginary. It means pain is real and is shaped by the brain, which is also why the brain is an important target for treatment.
The brain’s pain-control circuits are normally very good at blocking incoming signals before they reach awareness. These circuits involve the frontal and prefrontal cortex, the parietal lobe, the vestibular system, the brainstem and the spinal cord. After an injury, pain signals help the body heal by directing blood flow and inflammation to the injured tissue. Once healing happens, those signals need to be turned back down.
Other brain areas shape how unpleasant pain feels. The amygdala helps detect threats and process fear. The hypothalamus and pituitary gland release stress hormones that help us respond to threats, and some of these hormones can make pain sensors more sensitive. The anterior cingulate cortex is involved in the experience of suffering, and when it’s highly active, pain signals feel more distressing.
Chronic pain is best understood as a loss of balance between the systems that send pain signals and the systems that turn them down, combined with emotional distress that keeps the pain experience going. In acute pain, pain signals tell your brain that tissue has been injured. In chronic pain, these signals persist and grow stronger, and they may continue long after the tissue has healed.
Normally, when you stub your toe or burn your hand, the signal travels from your skin to your spinal cord and up to your brain. Your brain locates the problem, triggers healing, and the pain fades. In chronic pain, these pathways can overreact, and pain can continue weeks later. This is called central sensitization. When the pain-control systems don’t turn the signals back down after healing, the pain nerves keep firing and become more sensitive. Eventually, light touch, gentle pressure and even the normal chemical environment of the body can trigger pain (7).
Chronic pain also changes the brain’s maps of the body. As the brain’s map of the affected area is reorganized by ongoing pain signals, the brain may have more trouble knowing exactly where that body part is, and more trouble sending signals to turn down the pain coming from it (8).
The brain areas involved in the unpleasant side of pain also change in chronic pain. The anterior cingulate cortex can become highly sensitized (7). Many people with chronic pain notice that negative emotions feel stronger than before their injury and that negative thoughts are harder to manage. This is one reason depression and anxiety are so common with chronic pain (9).
These changes can also affect the body’s stress system, called the hypothalamic-pituitary-adrenal axis, raising stress hormone levels, which can further feed chronic pain (7). They also promote inflammation in the spinal cord and brain, which can make it even harder to turn pain down (10).
The result is that pain responses can become exaggerated and long-lasting. Pain can become disconnected from tissue damage and continue long after the tissue has healed, or in response to normal everyday sensations. The emotional effects of chronic pain can also spill into every part of a person’s life, affecting mood, motivation and thinking (7).
Many people with chronic pain move from provider to provider and try increasingly invasive treatments aimed at the injured tissue. When pain continues after the tissue has healed, it often means the nervous system itself has changed, and those changes need attention too.
How Is Chronic Low Back Pain Diagnosed?
Low back pain is diagnosed with a detailed medical history and physical exam, which help identify any serious conditions that could be causing the pain. A neurological exam is also important to help find the cause and guide treatment. Most of the time, imaging isn’t needed, but it may be ordered to rule out specific causes, such as a tumor or spinal stenosis. Other tests your physician may order include (3):
Blood and urine tests, to look for problems in the organs or bones, and for signs of inflammation, infection, cancer or arthritis.
Bone scans, to detect or monitor infection, fracture or other bone problems.
Discography, which tests specific discs suspected of causing pain.
Electrodiagnostic studies, to look for problems with the nerves in the back and legs.
Imaging such as X-rays, CT scans and MRI, which show the body’s structures without surgery.
Myelograms, which make the spinal cord and nerves easier to see on X-ray or CT to look for compression from herniated discs or fractures.
How Is Chronic Low Back Pain Usually Treated?
Many treatment guidelines now recommend starting with non-drug approaches, such as staying active, exercise, heat, massage, spinal manipulation and acupuncture. Supervised exercise from a trained provider, such as a physical therapist, occupational therapist or chiropractor, is increasingly common. Cognitive behavioral therapy and biofeedback can help people change how they think about and cope with pain. Electrical therapies such as TENS units can help reduce pain locally (3).
Medications are also used, including over-the-counter pain relievers, anti-inflammatory medications like ibuprofen, muscle relaxants and creams applied to the skin. Opioids are sometimes prescribed, but they should be used only for a short time and under a physician’s close supervision.
When other care doesn’t help enough, more invasive options may include trigger point injections, epidural steroid injections, or radiofrequency ablation, which disables the nerves sending pain signals. Spinal surgery may be considered when other treatments haven’t worked. The right surgery depends on the specific problem, and surgery doesn’t always relieve pain (3).
How the NeuroRescue Program Can Help
Our care is designed to work alongside your physician and other providers, never in place of them. Please don’t change or stop any medication without talking with your prescriber.
Your brain has a powerful influence on how much pain you feel. It can turn pain signals up or down at the level of the spinal cord, a process called descending pain control. This helps explain why pain changes with mood, stress, sleep and what you expect to feel. For example, chronic pain and anxiety tend to make pain worse, while expecting relief can reduce it.
Pain is uncomfortable, but it isn’t always a sign that something is dangerously wrong. Nociceptive pain comes from actual or threatened damage to tissues like muscles and ligaments, and it can be triggered by temperature changes, stretching or chemical irritation. Neuropathic pain comes from damage to the nervous system itself. In most chronic low back pain, the pain comes from pain sensors being stimulated, not from damaged nerves.
Even so, people in pain often start avoiding movements they expect to hurt, out of fear of causing more damage. The fear-avoidance model of chronic pain describes a cycle: worrying that pain means serious harm leads to fear of movement and constant watchfulness, which makes the nervous system more sensitive and pain worse, which leads to even more avoidance.
Modern pain science has a much better understanding of how the nervous system becomes more sensitive the longer pain lasts. This is called central sensitization, defined as increased responsiveness of pain-signaling nerve cells in the central nervous system to normal or even weak input (11). In other words, the longer pain pathways stay active, the more sensitive they become, even to things that aren’t harmful.
Imagine someone in your home jumps out and scares you every day. Before long, you’re on edge, and you might jump at something as harmless as a door closing. Your nervous system can do the same thing with pain. Once it becomes sensitized, it can affect other systems too, changing how the brain processes sensation, weakening the pathways that normally turn pain down, strengthening the pathways that send pain signals, and making pain feel worse when painful experiences come close together.
In many of these cases, certain parts of the brain become overactive, which can increase pain over time. Interestingly, people whose nerves become more sensitive to pain may also become more sensitive to light, sound, smell, heat or cold (7).
Our care focuses on the nervous system side of chronic back pain, including the systems that help you know where your body is in space and keep your spine stable. Your brain uses information from your muscles and joints, your inner ear and your eyes to understand where you are in the world. Your vestibular system sends signals down the spinal cord to the deep muscles that help stabilize your spine during everyday movements (12). Research suggests that problems with vestibular function, or with how it combines with other senses, may affect how well the spinal muscles are coordinated (13).
Your eyes are constantly scanning the world to build a map of your surroundings, using fast eye movements called saccades, which need to be fast, accurate and quick to start. Research has found that saccades can be affected in chronic pain, and that problems with saccades are linked to poorer control of posture (14), which depends on the muscles that stabilize the spine. Our testing measures these eye movements, and your program may include precise exercises to train them, with the goal of supporting balance and postural control.
Antisaccades are a more complex eye movement, where you must resist looking at a target and look the other way instead. They depend on brain systems involved in executive function. Research has found antisaccade differences in people with chronic pain, linked with catastrophizing, paying more attention to pain, anxiety, depression and trouble with emotional regulation (15). Training these eye movements is one way we work to support those brain systems.
Research suggests spinal adjustments may do more than move a joint. Studies using EEG, brain stimulation and brain imaging have found that adjustments can produce short-term changes in how the brain processes sensory and movement information, including in the prefrontal cortex and the areas that plan and control movement (16, 17, 18, 19). Researchers are still working to understand how long these changes last and how they relate to symptoms, but they help explain why we look at how your whole nervous system is working, not just your spine.
Depending on your needs and test results, your program may also include:
Spinal manipulation and manual therapy. Chiropractic adjustments are used when appropriate and safe for you, and spinal manipulation and manual therapy have been studied for reducing pain and fear of movement (4).
Pain neuroscience education. Learning how pain works has been shown to help reduce pain and improve function (20).
Vestibular rehabilitation and visual stimulation exercises, to support balance, walking, postural control and spinal stability (13, 21).
Electrical stimulation to support pain control.
Exercises in a virtual reality environment, which have been studied for improving function and reducing pain (22).
Transcranial magnetic stimulation (TMS), which has been studied for chronic pain and for the anxiety and depression that often come with it (23). At our clinic, TMS is provided by our psychiatric mental health nurse practitioner, who will evaluate whether it may be appropriate for you.
No two cases of chronic back pain are alike, and the same is true for your NeuroRescue Program. The therapies we recommend are always chosen based on your testing and exam findings.
How the NeuroRescue Program Works
Your NeuroRescue Program begins with your Discovery Day. We start with a detailed history of your condition and your life on a timeline, including your daily activities, job demands, past accidents and procedures, and family medical history. This helps us understand the factors that may have contributed to where you are now, and identify related conditions that may be making it harder to move forward.
We measure how your visual, vestibular and balance systems are working through computerized analysis of your eye movements, inner ear reflexes and balance under different conditions. Our testing includes videonystagmography and saccadometry to measure several types of eye movements, the video head impulse test to measure inner ear reflexes, and CAPS computerized posturography to assess your balance under different sensory conditions. We also use NeuroSensoryMotor Integration testing to evaluate hand-eye coordination and cognition, and Virtualis testing to assess dynamic eye tracking and your perception of vertical in a virtual reality environment.
We combine this with a thorough physical and neurological exam of your sensory, motor, autonomic and cognitive systems. We also review any relevant lab work, imaging and prior testing, and integrate it with our findings.
Together, this helps us understand which parts of your nervous system are working well, which are struggling, and how quickly they tire. We use that information to design your personal NeuroRescue Program, aimed at improving function in the systems that need support and helping them work together. Our testing also helps us decide when to push and when to let you rest.
Our goal is to help you move with more confidence and less pain, so you can bend, lift, sit and get back to more of the things you enjoy.
Your Next Step
Living with chronic back pain can wear you down, especially after trying treatment after treatment. You don’t have to keep searching alone. To find out if the NeuroRescue Program is right for you, contact one of our patient care coordinators to schedule your Discovery Day.
It’s never too late to take the next step.
References
