Central Sensitization
I’ve said it before and I will say it again. Pain is a threat detection system. Its purpose is to warn us of potential harm. Much like an alarm that goes off when would-be intruders try to break into our home, pain makes us take notice. Most of the time this is a good thing. When pain hangs around and becomes persistent the alarm is less of a good thing and more of an annoyance. It’s not much of an advantage to have that alarm go off with every bump in the night.
An alarm system can be adjusted to be more or less sensitive to a potential threat. If we live in a high crime area we might want the alarm to sound a lot more readily, when it senses any motion around the perimeter of our yard. In a low crime neighborhood that would be unnecessary. We could set it to detect motion only in close proximity to the house.
The central nervous system can do the same thing. It is capable of increasing or decreasing its sensitivity to any given stimuli.
Usually when we sustain some sort of injury the nervous system calls for inflammation and that area becomes more sensitive. We will feel pain sooner and more strongly at the injury site, motivating us to be cautious and protect the injured body part. Most of the time this defense mechanism works like a charm. After resting and allowing the appropriate amount of time for healing, the inflammation disappears and the sensitivity along with it.
Sometimes however, things run amok and this sensitivity can persist. The nervous system gets stuck in a vicious cycle and keeps calling for inflammation even after the damaged tissue has healed. It’s kind of like a stereo that has been cranked up super loud to drown out the noise of nearby construction. Initially this is a great idea, no more construction noise. Then the construction stops but the music is forgotten. The boom box keeps on blasting the tunes and waking up the neighbors (Bryan Adams anyone?).
This is called central sensitization. The central nervous system becomes stuck in a heightened state of reactivity. As the name suggests, it causes an increased sensitivity to pain. Sensations that would have previously caused little or no pain end up causing an inordinate amount of pain (hyperalgesia). The brain may also start to interpret normal non-threatening stimuli, such as light touch or hot and cold, as threatening (allodynia).
We don’t really know why this phenomenon occurs but it is most likely involved, to some extent, in people with chronic pain. In fact, it could possibly be the common denominator in all chronic pain conditions. Diseases such as fibromyalgia, myofascial pain syndrome, osteoarthritis, whiplash, headaches, irritable bowel syndrome and TMJ pain have central sensitization involvement. It may not have been what caused the condition but it may be what keeps it chronic.
People with central sensitization can become extremely frustrated looking for answers to what is causing their pain and often end up seeing many different therapists. Without being able to recognize the hallmarks of this disorder it is unusual for any type of treatment to have any lasting effects. It is only when we understand it’s the nervous system that’s responsible for the persistent pain that there’s an opportunity for lasting change.
If you feel like this condition could be contributing to your pain and want to learn more about it please contact me. I would be more than happy to give a free consult.
Like I’ve said before, learning about pain can be a powerful tool in helping manage pain.
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