I have discussed the effects of nutrition, stress-reduction, sleep, and circadian rhythm on pain in previous posts . I have not yet discussed the theory of how chronic pain develops and persists. This post discusses some of the mechanisms involved in chronic pain as well as therapeutic approaches that have proven to be effective in addressing the root causes of chronic pain and suffering.
THE CENTRAL NERVOUS SYSTEM (BRAIN AND SPINAL CORD) CAN INDEPENDENTLY CAUSE PAIN AND OTHER PHYSICAL SYMPTOMS THROUGH THE DEVELOPMENT OF LEARNED NERVE PATHWAYS. THESE PATHWAYS INCLUDE CIRCUITS WITHIN THE BRAIN AND CIRCUITS CONNECTING THE SPINAL CORD TO VARIOUS PARTS OF THE BRAIN. THEY CAN PRODUCE PAIN EVEN IN THE ABSENCE OF ONGOING TISSUE DAMAGE.
THESE LEARNED NERVE PATHWAYS CAN DEVELOP AS A RESULT OF SEVERAL WEEKS OR MONTHS OF CONTINUOUS PAIN CAUSED BY AN INJURY OR DEGENERATIVE-INFLAMMATORY DISEASE. IF WE EXPERIENCE RELENTLESS PAINFUL IMPULSES COURSING THROUGH THE BODY THESE BOMBARD THE SPINAL CORD AND BRAIN WITH PAINFUL MESSAGES AND OUR BRAIN AND SPINAL CORD EXPERIENCE A CHANGE SIMILAR TO THE CHANGES THAT CAN OCCUR WITH PTSD CAUSED BY ONE OR MORE TRAUMATIC EVENTS.
THESE LEARNED NERVOUS SYSTEM PATHWAYS REPRESENT “NEUROPLASTICITY” MEANING CHANGES IN THE NERVOUS SYSTEM BROUGHT ABOUT BY EVENTS SUCH AS TRAUMA AND STRESS. THEY REPRESENT A “MEMORY” OF THE PAIN, TRAUMA AND STRESS IMPRINTED ON THE NERVOUS SYSTEM. THIS “MEMORY” INCLUDES NEWLY (AND OFTEN PERMANENTLY) FORMED CIRCUITS THAT OFTEN CONNECT VARIOUS PARTS OF THE BRAIN ASSOCIATED WITH PAIN, ANXIETY, DEPRESSION AND ANGER TO PARTS OF THE BRAIN AND SPINAL CORD THAT MEDIATE SENSATIONS OF LIGHT TOUCH AND PRESSURE. THESE CONNECTIONS PRODUCE “ALLODYNIA” WHICH IS A PAINFUL RESPONSE TO A STIMULUS WHICH IS USUALLY NOT PAINFUL. WE CAN ALSO EXPERIENCE “HYPERALGESIA” WHICH IS AN EXAGGERATED PAIN EXPERIENCE, OUT OF PROPORTION TO THE PAINFUL STIMULUS.
THE NERVOUS SYSTEM HAS A BUILT IN “MUFFLER” DESIGNED TO DAMPEN DOWN PAIN MESSAGES BUT IN CHRONIC PAIN THIS MUFFLER BECOMES AN AMPLIFIER THAT NOT ONLY AMPLIFIES THE TRANSMISSION OF PAIN BUT ALSO CONNECTS THIS AMPLIFIED PAIN SYSTEM TO PARTS OF THE BRAIN ASSOCIATED WITH ANXIETY, ANGER, AND DEPRESSION.
ONCE THESE CIRCUITS OR PATHWAYS ARE IN PLACE (“LEARNED”) THEY CAN NOT BE ELIMINATED (“UNLEARNED”). EFFECTIVE PAIN REDUCTION REQUIRES ACTIVATING ON A REGULAR BASIS ALTERNATIVE PATHWAYS THAT ALREADY EXIST SUCH AS THOSE ASSOCIATED WITH PLAY, MUSIC, DANCE, HUMOR, LAUGHING. ACTIVATING OTHER PATHWAYS CAN ALLOW THE PAIN PATHWAYS TO BE “TURNED OFF” OR MUFFLED. AS CHILDREN WE LEARN TO PLAY AND THOSE LEARNED PATHWAYS STAY WITH US FOR LIFE. WITH PRACTICE WE CAN REGULARLY ACTIVATE THOSE BRAIN PATHWAYS AND MAKE THEM AND OTHER PATHWAYS THE PREDOMINANT PATHWAYS OF OUR BRAIN ACTIVITY.
BUT BEFORE WE CAN UTILIZE THE PLEASANT ALREADY-LEARNED PATHWAYS IN THE BRAIN TO CIRCUMVENT THE PAINFUL-ANXIOUS PATHWAYS WE MUST FIRST DEAL WITH OUR ANGER. DEALING WITH OUR NATURAL AND JUSTIFIABLE ANGER REQUIRES FORGIVENESS. UNTIL THE ANGER IS RELEASED AND FORGIVENESS ACHIEVED WE CANNOT MAKE USE OF THE THERAPIES AND STRATEGIES AVAILABLE TO DECREASE AND MANAGE OUR PAIN. ANGER BLOCKS THE PATH TO HEALING AND PAIN REDUCTION.
The brain processes an emotional insult in exactly the same way that the brain processes a physical insult. Stressful life events and our emotional reactions to them may cause pain that is severe. This is why chronic pain becomes worse when we experience a stressful event. Vicious cycles develop as multiple circuits connecting pain pathways to areas of the brain associated with anxiety and depression become activated and stay activated.
COGNITIVE BEHAVIORAL THERAPY: Over the course of months and years, our reaction to chronic pain often includes repetitive negative thoughts. Cognitive behavioral therapy helps us learn techniques to avoid repetitive negative thoughts.
Mindfulness Based Stress Reduction is another technique that can help mitigate the suffering associated with pain. Mindful Meditation practiced 30 minutes per day produces measurable changes in brain activity that can be seen on Functional MRI scans of the brain within 90 days. These changes demonstrate decreased brain activity in areas associated with pain, depression, anxiety and anger. Scientific studies have also demonstrated that MBSR produces improved immune function, reduces blood pressure, reduces heart rate, improves sleep and provides other beneficial physiologic changes associated with healing and wellness. Yoga and meditation are essential components of an MBSR program.
SLEEP: Pain cannot be managed or successfully treated unless an individual gets 8-9 hours of restorative sleep per night. Sleep hygiene recommendations are an essential part of the path to wellness. Daily exposure to sunlight outdoors and restoring normal circadian rhythm are essential for pain management. Going to bed at the same time every evening and sticking to a regular schedule is the most important part of improving sleep. Daytime exposure to sunlight and dimming the lights in the evening are also required. Regular exercise (daily walking) is essential. Wearing blue-light blocking glasses for 2-3 hours before bedtime can facilitate sleep. When blue light wavelengths (light bulbs, computer screens, TV screens) hit the retina of the eye a message is immediately relayed to the “internal clock” of the brain that tells the brain there is still daylight. This inhibits the production of melatonin (the “sleep hormone”). Avoiding bright light (especially from TV or computer screens) for 2-3 hours before bedtime is important. If you must watch TV or work on the computer in the evening that blue light blocking glasses or goggles are a must. There are free software programs that will eliminate the blue light from your computer screen as an alternative to blue light blockers.
NUTRITION: Pain involves inflammatory pathways. An anti-inflammatory diet is essential for treating pain and providing the nutritional components necessary for healing tissue and establishing better brain chemistry. A Paleo Diet removes potential sources of inflammation from the diet. If a patient suffers from an auto-immune disorder the more restrictive Autoimmune Protocol version of the Paleo-diet can help put the disease into remission and decrease the inflammation associated with the auto-immune process.
OBESITY AND OVERWEIGHT: Extra fat around the belly and internal organs causes chronic inflammation throughout the body. The fat cells around internal organs and the immune cells that reside alongside the fat cells both produce a steady stream of chemicals that circulate throughout the body stimulating inflammation everywhere. These circulating chemicals are called cytokines and chemokines. Certain cytokines and chemokines cause fatigue, brain fog, and sensitize the nerves, increasing pain. They also interfere with sleep. Weight loss is an essential component to pain reduction for overweight and obese patients. The best nutritional approach to weight loss includes a Paleo Diet with carbohydrate restriction (low carbohydrate, high-healthy-fat whole food diet). Adding medically supervised intermittent fasting (such as an 18- 24 hour fast every 1-2 weeks, consuming only water for 18-24 hours) can also be effective especially combined with a carbohydrate restricted Paleo Diet and lifestyle.
Exercise and Physical Conditioning: Chronic pain causes sedentary behavior which results in physical de-conditioning. This process involves loss of muscle, decreased bone density, shortening of ligaments and tendons and shrinkage of the tissues that envelope muscle. This leads to more pain when physical activity is increased and a vicious cycle is created. This cycle must be broken with a graduated daily exercise and physical conditioning program. If you follow a medically prescribed exercise program you will not damage your body even though it may be painful during the first several days. Exercise also helps to convert the “amplifier” back to a “muffler” in the nervous system.
Below are some links to articles related to this discussion.
Eat clean, live clean.
Bob Hansen MD
Applying modern pain neuroscience in clinical practice: criteria for the classification of central sensitization pain.
Central sensitization and altered central pain processing in chronic low back pain: fact or myth?
How to explain central sensitization to patients with ‘unexplained’ chronic musculoskeletal pain: practice guidelines.
Addressing sleep problems and cognitive dysfunctions in comprehensive rehabilitation for chronic musculoskeletal pain.
Exercise therapy for chronic musculoskeletal pain: Innovation by altering pain memories.
Efficacy of a modern neuroscience approach versus usual care evidence-based physiotherapy on pain, disability and brain characteristics in chronic spinal pain patients: protocol of a randomized clinical trial.
The effect of relaxation therapy on autonomic functioning, symptoms and daily functioning, in patients with chronic fatigue syndrome or fibromyalgia: a systematic review.
Pro-nociceptive and anti-nociceptive effects of a conditioned pain modulation protocol in participants with chronic low back pain and healthy control subjects.
Vagal modulation and symptomatology following a 6-month aerobic exercise program for women with fibromyalgia.
Brain-derived neurotrophic factor as a driving force behind neuroplasticity in neuropathic and central sensitization pain: a new therapeutic target?
The role of central sensitization in shoulder pain: A systematic literature review.
Chronic whiplash-associated disorders: to exercise or not?
Exercise, not to exercise, or how to exercise in patients with chronic pain? Applying science to practice.
Evidence for central sensitization in patients with osteoarthritis pain: a systematic literature review.
Malfunctioning of the autonomic nervous system in patients with chronic fatigue syndrome: a systematic literature review.
Endogenous pain modulation in response to exercise in patients with rheumatoid arthritis, patients with chronic fatigue syndrome and comorbid fibromyalgia, and healthy controls: a double-blind randomized controlled trial.
You may need a nerve to treat pain: the neurobiological rationale for vagal nerve activation in pain management.
Avoidance behavior towards physical activity in chronic fatigue syndrome and fibromyalgia: the fear for post-exertional malaise.
The role of mitochondrial dysfunctions due to oxidative and nitrosative stress in the chronic pain or chronic fatigue syndromes and fibromyalgia patients: peripheral and central mechanisms as therapeutic targets?
Thinking beyond muscles and joints: therapists’ and patients’ attitudes and beliefs regarding chronic musculoskeletal pain are key to applying effective treatment.
Evidence for central sensitization in chronic whiplash: a systematic literature review.
Pain in patients with chronic fatigue syndrome: time for specific pain treatment?
Kinesiophobia, catastrophizing and anticipated symptoms before stair climbing in chronic fatigue syndrome: an experimental study.
Central sensitization in patients with rheumatoid arthritis: a systematic literature review.