The Role of Your Central Nervous System in Chronic Pain

Central amplification of chronic back pain

The brain and spinal cord receive signals from your nerves and also send out massive patterns of signals to our muscles that control our arm, leg, and spine movements. These signal patterns develop over years and explain how we learned to walk, run, ride a bicycle, dribble a basketball, and even play a musical instrument. The signal patterns constantly update the spinal cord to include the status of sensors that detect our muscle flexibility, strength, and endurance.

We think chronic pain starts when these sensors in your muscles (peripheral signals), misfire or malfunction, and your brain and spinal cord adapt improperly to those malfunctioning sensors and become “short-circuited.” In a way, what happens is the spinal cord amplifies a normally harmless pain signal, which creates a loud chronic pain signal.

Chronic pain involves many complex physical as well as cognitive aspects and can be hard to understand. Believe it or not, many of the predictors for chronic back pain are not related to MRI findings, but by the cognitive environment in which the physical findings are found. If their MRI is considered normal, many people then wonder, “is this in my head?” or “what could be causing my pain?” This confusion can cause more uncertainly and increase a cycle of pain, frustration, and immobility.

Understanding how central amplification affects your back pain is important

Central sensitization, or amplification, of chronic pain is a real phenomenon that occurs, but is a difficult concept to understand. As peripheral pain signals are sent to the spinal cord, tiny cells determine whether the spinal cord nerve cells should respond or not. For example, an itchy sensation, or even a sensation of having one’s sock fall down is typically filtered away from the spinal cord as not important and this signal would normally be filtered.

A weak, stiff, or poorly contracting muscle’s signals can be amplified and then interpreted as pain. When your spinal cord has become exceptionally irritable, instead of filtering normal pain signals, it incorrectly amplifies them. Some patients have intense pain with even the weight of a bed sheet over their feet or while engaging in physical activities that are followed by increased pain. When this occurs, we call it central amplification of the peripheral pain signal.

It is important to understand that this central amplification process is not voluntary. You are not doing this yourself! Like the sound of fingernails scraping down a chalkboard, your spinal cord has amplified a particular peripheral pain signal so that it is interpreted as unbearable.