There are more than 100 million people in chronic pain in the United States. The rate of providing healing is hardly successful. Microglia, the ever-vigilant guardian cells of the central nervous system (CNS), are now providing a clue as to why some of us stay sick and fail to recover.
Microglia are thin, thread-like immune cells responsible for collecting debris and pathogens in the brain. They become active in response to any number of stressors on the body, and when properly regulated, secrete inflammatory chemicals that allow for harmful bacteria to be killed, and for healing to occur.
However, if the microglia are stimulated to react too often they become hyper-reactive, which can trigger system-wide inflammation that can be difficult to stop. Microglia cells remember emotional and physical assaults from the past, which if not resolved, sustain the microglia’s hyper-reactive state, leading to unresolved chronic pain.
Research confirms the link between microglia activation and neuro-inflammatory conditions such as pain and depression.
- A study published in "Nature" in 2010 demonstrated the link between microglia and obsessive-compulsive behavior in mice. Microglia originate from bone marrow and Nobel laureates, Dr. Mario R. Capecchi and Dr. Shau-Kwaun Chen, found that mice with a genetic mutation causing a deficiency in microglia groomed excessively, leading to bald patches and open wounds. When the scientists transplanted healthy bone marrow, and thus healthy microglia, into these mice the obsessive-compulsive grooming stopped in 60 percent of the animals within four months and their wounds healed.
- Texas A&M’s Dr. Adam Walker and his research team showed a link between neuroinflammation, pain, and depression in their 2013 paper in Pharmacological Reviews where they found that chronic inflammation resulted in a shift from illness-induced pain to chronic pain and depression.
- In one of the most comprehensive reviews to date, a 2014 article in "Nature Reviews Immunology" discusses the relationship of microglia cell immune chemicals and chronic pain. What is now known is that the potential for treating chronic pain via the manipulation or altering of these immune cells brings promise to new therapies for pain control.
Essential Steps in Treating Chronic Pain
In order to accurately diagnose and treat the causes of neuro-inflammation that manifest as chronic pain, physicians must:
- Take a comprehensive medical history of each individual
- Work to correctly identify and treat the underlying root cause(s) of chronic pain
- Address the complication that once the brain becomes inflamed, it can burn like a wildfire. (Although the research linking chronic pain syndromes to brain inflammation is clear, our understanding of how to quiet the fire once it starts is still, sadly, incomplete.)
- Educate people about their relationship with chronic pain. Like all relationships, how this is managed can make life substantially better or worse.
A Way Forward in Chronic Pain Management
One of the biggest challenges in diagnosing and managing chronic pain is the fact that physicians have to rely almost exclusively on the individual’s description of their pain and the disability it causes. There is no biomarker, blood test, or imaging study that can objectively detect the presence and severity of pain. However, a growing body of medical research is shedding new light on the processes in our brains and nervous systems that initiate and sustain severe chronic pain. These studies point to the same conclusion - that chronic pain, in and of itself, is not the problem to be treated.
In my 30 years of treating chronic pain, I know that these 3 things are essential if we are to turn the tide on the chronic pain mismanagement epidemic that’s plaguing our country:
- Individuals suffering with chronic pain must be offered a comprehensive work-up with an individualized treatment approach. I have had cases where a blueberry allergy was at the root of depression; where gene combinations prevented a teenager from effectively eliminating toxins, resulting in chronic migraine and fatigue; where exposure to mold and a ruptured appendix was at the root of IBS, chronic fatigue, and fibromyalgia – symptoms that manifested 23 years after the initial exposure. Without a comprehensive medical history in all of these cases, we would never have gotten to the root cause of these illnesses.
- We need to continue with research into the causes of inflammation in the brain, while also working on developing treatment for brain inflammation that leads to chronic pain.
- We need to develop testing that will provide us with an objective indicator or biomarker of the chronic pain/underlying disease and its response to treatment.
In the interim, we must focus on improving the lives of people suffering from chronic pain by using targeted therapies that address the biology of their pain. It’s time to move beyond treating individual “symptoms.” To heal, we need to redefine conditions such as chronic pain and depression as inflammatory states with a single root cause – inflammation of the brain.