The Pain Pathway and Your Brain

The formal definition of pain as coined by the International Association for the Study of Pain (IASP) is “A noxious sensory and emotional experience.” This means that something not only hurts because your body feels it, but also hurts because it is a negative experience as perceived by your brain. Chronic pain is defined as pain that lasts longer than three months or pain that does not dissipate in an acceptable amount of time for a particular healing process to occur.

Chronic pain specialists work to minimize the severity of pain and its interference on activities of daily living, regardless of whether the pain is due to normal aging and degenerative processes or an injury, such as a surgical procedure or trauma. My approach is to identify, as specifically as possible, the “pain generator.” This is the area of the body—be it muscle, bone, nerve, fat, ligament, etc.—that is causing the pain. Unfortunately, this is usually not a very straight forward process because there may be multiple pain generators and external factors influencing pain and the perception of pain.

In order for a person to experience pain, a succession of events occur. Initially there is “Nociception,” or the injury itself, then there is “Transmission,” which is the pain signal carried by the nerves. Lastly, there is “Processing,” which occurs in the brain. The brain is the ultimate judge of whether the offending injury hurts or not. Over many years, the study of pain has revealed that these events are not straight forward either. At each level of the pain pathway, there are different factors that can change the overall cycle or procession of the pain signal.

As a pain specialist, I try to block the pain at as many points as possible. For example, most medications are used to try to block pain at the level of the injury or nociception. The most common medication that I use for this is the anti-inflammatory type of medication such as Ibuprofen or Naproxen. If medications fail or a patient isn’t a good candidate for a medication regimen, then I try to intercept the pain at the transmission level. I use nerve blocks and steroid injections and other techniques to “calm” the nerve and slow down the pain signal.

The most important aspect of the pain pathway is the processing of pain or what the brain thinks about the information that it is receiving. Studies have shown that not everyone experiences pain the same way; even movies, books and anecdotes will tell you that one person’s pain may be another person’s pleasure. The good news is that despite what doctors and medical therapies may not be able to do to alleviate pain, the brain can.

Research studies done on the psychology of pain have proven that the brain changes in response to pain and that pain can be alleviated by the brain changing in response to specific treatment “exercises.” We now realize that patients have much more control over a very real phenomenon that occurs in the brain to cause chronic pain. For example, it is well known that depression and anxiety reduce the pain threshold and those individuals who suffer from those disturbances are at greater risk of any type of pain becoming chronic. We have also identified that patients who tend to “catastrophize” medical issues and ruminate on the potential negatives of situations are highly likely to develop chronic pain and disability. These emotional states actually make the body and the nervous system more susceptible to pain. On the contrary, similar studies have shown that patients who are in love or who have positive thoughts and hopeful outlooks on their medical conditions are much less likely to suffer with chronic pain.

Cognitive and behavioral therapy is a type of psychology treatment that helps the brain learn to modify and change the pain signal that is coming in from the body. It is real medical therapy and we are just beginning to understand how truly powerful a tool it is in chronic pain management.