For veterans who live with a chronic pain condition, constant pain is not the only thing they endure. The last few decades have produced studies which indicate that chronic pain not only affects the body, but the brain as well. In this blog post, we are going to discuss how chronic pain affects the brain, and how chronic pain is related to anxiety and other mood disorders.
Studies have shown that the brain has a state of rest, known as the Default Mode Network. This involves some of the regions being more active while other regions become less active, depending on the task or activity. The Default Mode Network is the natural balance of the brain, preventing the brain from working too much and causing unnecessary stress on the body. It is believed that chronic pain disrupts the natural resting state of the brain, thereby preventing the brain to function properly.
In 2008, the Feinberg School of Medicine, from Northwestern University in Chicago, IL, published a study (Beyond Feeling: Chronic Pain Hurts the Brain, Disrupting the Default-Mode Network Dynamics) that compared 15 healthy individuals (seven female and eight male) to 15 individuals with chronic back pain (seven female and eight male). A functional MRI was used to image their brains while performing a simple task which involved tracking the height of a bar as it moved with a modified joystick. The purpose of the study was to compare the Default Mode Networks of the healthy participants against that of the participants with chronic back pain.
The researchers found that the brains of the healthy participants demonstrated a properly-functioning Default Mode Network (resting state), with parts of the brain increasing in activity while others decreased in activity. However, the brains of the participants with chronic back pain were not able to quiet parts of their brain like their healthy counterparts. This means that their brains were not able to achieve the proper resting state. This phenomenon led the researchers to believe that “the brain of a chronic pain patient is not simply a healthy brain processing pain information, but rather is altered by the persistent pain in a manner reminiscent of other neurological conditions associated with cognitive impairments.” For those of us that do not have Ph.D.’s in neurology, this means that the brain of a person with chronic pain gradually develops cognitive deficiencies (in concentration, focus, decision making, etc.). The researchers believe that this happens because chronic pain is always present as a feeling in the brain, which makes it difficult for the brain to lower the activity in certain areas (as explained in Chronic Pain Disrupts the Brain’s Resting State).
In 2002, a joint study was conducted between SUNY Upstate Medical University in Syracuse, NY, and Northwestern University Medical School in Chicago, IL. The study (Brain chemistry reflects dual states of pain and anxiety in chronic low back pain) examined the relationships between regions of the brain (dorsolateral prefrontal cortex, orbitofrontal cortex, thalamus, and cingulate), chronic pain, and anxiety disorders. The researchers found that the prefrontal cortex is associated with reception of chronic pain. As the researchers note, the prefrontal cortex is also associated with multiple cognitive functions, such as working memory, language, attention, emotion and decision-making processes. The researchers speculated that the “involvement of this ‘cognitive’ region in chronic pain and anxiety may be associated with natural survival strategy that requires specific cognitive abilities to escape from a situation of personal threat or damage.” The researchers argued that chronic pain is associated with neuronal loss and degeneration most likely due to the continuous engagement of the prefrontal cortex in the ongoing pain perception. In layman’s terms, this means that the constant perception of pain in the prefrontal cortex directly affects the brain’s cognitive functions. This study solidified the pre-existing theory that chronic pain affects cognitive functions and causes anxiety.
What does all this mean to veterans?
The VA has already recognized that depression can be caused by a chronic pain condition. However, these studies have affirmed that a chronic pain condition can also cause anxiety and a variety of related conditions. So for a veteran with chronic back pain, but with no history of a traumatic experience in service, obtaining service-connection for a mental condition is actually possible. It will not be an easy fight, but when armed with a favorable private doctor’s opinion, victory is in the wind.