Lower Back Pain. Science, Assessment, and Treatment

Posted By SHL Librarian

Presented by: Sean Mackey, MD, PhD
Professor of Anesthesia
Stanford University Medical Center
October 3, 2013

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More than 100 million Americans suffer from some form of back pain, and its incidence is increasing in all age groups. Low back pain is considered the No. 2 reason for disability (the common cold is No. 1) and is the most commonly prescribed condition for painkillers. Its consequences have a huge impact on health care costs and will most likely become even more pervasive as the population ages.

“There are three givens in life: death, taxes, and back pain,” said Sean Mackey, MD, PhD, the Redlich Professor of anesthesiology, perioperative, and pain medicine – and division chief of the Stanford Pain Division, at a presentation sponsored by the Stanford Hospital Health Library. “Anyone who says they have never had back pain either forgot about it or is lying.”

Most cases of low back pain fall into two categories: acute or chronic. Acute pain is usually caused by an activity, movement, or spasm, can be nonspecific, and lasts a short time. When back pain does not abate, the condition becomes chronic: Chronic pain can be a disease in its own right—one that fundamentally alters the nervous, inflammatory, immune, and endocrine systems.

While back pain can be both physically and emotionally draining, most people do recover. In fact, 80 percent of cases resolve on their own within one month, and another 10 percent dissipate in about three months.

“Part of the question is, why are some people more vulnerable to chronic pain than others? Why do people respond differently? Why does a condition become chronic pain?” said Dr. Mackey, a specialist in pain research and treatment.

Intricate Network
Pain is a complicated experience that involves an intricate interplay of chemicals and signaling in the peripheral and central nervous system (the brain and spinal cord). A stimulus, like hitting your thumb with a hammer, activates specialized nerve cells called nociceptors that convert the information into electrochemical messages that are transmitted via nerves to the brain, where the ultimate perception of pain occurs.

“The stimulus does not equal pain,” said Dr. Mackey. “It’s not pain until the stimulus has been processed by the brain. The brain takes the stimulus input and shapes it by factors the can increase or decrease the final experience. These factors can include expectations, anxiety, fear, depression, early life experiences about pain, and genetic predisposition.”

In a healthy situation, we live in a balance between excitatory signals coming from our body and the natural inhibitory systems in our brain and spinal cord. These inhibitory systems serve to filter out information that isn’t important. Pain can result when there is too much excitation or too little inhibition. For some people, the homeostatic balance of nociception goes awry: The filtering system stops working, and the brain becomes oversensitized to pain.

Another factor is called central sensitization, a normal process after injury. After a minor injury, you develop swelling and redness a few hours later.  The next day a much larger area of your body is stiff, achy, and sore. What has happened overnight is that your central nervous system has rewired and lowered the threshold for pain in larger areas of your body outside the area that was injured. This serves as a message to protect the injured area. After healing, the neural systems revert back to normal.

“Unfortunately, in some people, those neural systems just don’t turn off,” he said. “The areas that are perceived as painful can expand and even persist after the original injury has healed.”

Dr. Mackey is involved in a number of NIH and philanthropically funded research projects that image the brain to determine: what causes the wide variability of responses to pain, the role of the brain in perpetuating pain after injury, and individual differences in treatment responses. His ultimate goal is to develop a personalized and tailored approach to pain management.

Clinical Assessment
The most effective way to prevent back pain, and to alleviate it when it does occur, is to move. Physical activity has been proven to reduce risks of back pain, particularly exercise that focuses on the core and posture.

“Gone are the days of bed rest for low back pain,” said Dr. Mackey, who promotes exercise, yoga, massage, or relaxation training. “Muscles deteriorate rapidly—it’s a matter of ‘use it or lose it.’”

If the pain does not diminish in a month, it’s time to see a physician. The first step is an extensive evaluation to determine the source of the pain and to rule out any serious underlying conditions, such as cancer, fracture or systemic illness. An exam will include a detailed medical history, a physical, a neurological exam, and sometimes lab tests.

Most back pain fits into a general category of mechanical low back pain—often requiring no further expensive or invasive tests. For most people, MRIs for most mechanical low back pain are not necessary and can even lead to unnecessary surgery. Many people who have no pain show MRI evidence of bulging disks or degenerative disk disease—both of which are normal part of the aging process that may have nothing to do with pain.

Multidisciplinary Treatment
While most back pain does go away on its own, treatment involves a toolbox of different approaches, what Dr. Mackey refers to as “Five Ps and a C.”

  • Personal management: The first step incorporates self-care, exercise and stretching, and personal education
  • Pharmacology: More than 30 medications are available to treat lower back pain, from opiates to anti-inflammatories like non-steroidal anti-inflammatory drugs (NSAIDs), anticonvulsants, and antidepressants. Many of these medications were FDA approved for conditions other than pain, but in fact work quite well.
  • Psychological: Skills for coping like cognitive behavioral therapy and mindfulness meditation can help break the pain-stress cycle and impart a sense of control over the situation.
  • Procedural: Interventions like trigger-point injections, facet injections, epidural steroid injections, and more invasive therapies such as intraspinal drug delivery systems and spinal cord stimulation can help reduce pain and get people moving again.
  • Physical therapy: Core strengthening, back education, endurance training, and weight loss activities are all part of the main treatment for low back pain.
  • Complementary and alternative medicine: Acupuncture, hypnosis, biofeedback, and nutriceuticals (i.e. over-the-counter vitamins and herbals) are options that have shown some relief in some cases

Stay Active
Protect the lower back by maintaining a healthy weight, appling sensible ergonomics, and keeping muscles strong. Because staying active is crucial for preventing and treating lower back pain, physical therapy and exercise are key.

“There’s not one approach that works for everybody. An individualized plan is much more effective,” said Nicholas Karayannis, MPT, PhD, the lead physical therapist at the Pain Management Center. “You need to determine what exercise routine you respond to best based on what feels right and gives you relief.”

He advised augmenting stretches and core strengthening exercises with aerobic activity, aiming for at least 30 minutes three to five times a week. He demonstrated a number of movements to encourage postural awareness and to identify triggers. The primary goal is to develop self-awareness, flexibility, strength, and coordination, he said.

About the Speaker
Sean Mackey, MD, PhD, is the Redlich Professor and the divison chief of Stanford Pain Medicine. He recently co-authored the Institute of Medicine report, “Relieving Pain in America: A Blueprint for Transforming Prevention, Care, Education, and Research. He has published more than 100 articles and book chapters and is regularly listed in “Top Doctors in America,” published by the Guide to Top Doctors. Dr. Mackey received his undergraduate and master’s degrees in bioengineering from the University of Pennsylvania, and MD and PhD in electrical engineering from the University of Arizona. After completing a residency in anesthesia and a fellowship in pain medicine at Stanford, he joined the faculty in 1999.

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About Dr. Mackey

Stanford Pain Management Center

Stanford Systems Neuroscience and Pain Lab