What Is Central Sensitisation
The easiest way to describe Central Sensitisation would be over a 2 day seminar, but we will try to do it in a few paragraphs.
Central sensitisation is a condition of the nervous system that is associated with the development and maintenance of chronic pain. When central sensitisation occurs, the nervous system goes through a process called wind-up and gets regulated in a persistent state of high reactivity.
Central sensitisation phenomena have been well recognized in the development of migraine attacks and tension type headache. It is also known that headache frequency is related to sensitisation.
Central Sensitisation and Headache Pain
The base of the skull and upper neck has an intense concentration of sensory nerves that innervate the muscles, discs, ligaments, joints, skin and blood vessels that influence head movements, posture and shoulder movements. All these nerves converge in an area in the brain stem called the cervical nucleus.
The second player is the Trigeminal Nerve, a nerve that originates in the brain and has branches that look after your temple, sinuses, inner ear, eye sockets, jaw joint, teeth, chewing muscles, hard palate, blood vessels and eustachian tube.
There are so many impulses coming along this nerve that there literally isn’t room in the brain to process them all, so they are outsourced to the brain stem, where they are processed in the same factory as the nerves from the neck and shoulders, called the Cervico-Trigeminal Nucleus.
Nerve Signals and Pain Inhibition
There are over 20,000,000 nerve signals that travel from the neck, head and face every minute to the brain stem and most of this is normal stimulus which is processed here and disregarded.
If you (for example) break a tooth, a stress signal travels to the brainstem which is recognised as a noxious stimulus and a pain signal is sent to your brain to alert you of a problem. This nerve keeps triggering pain signals until you take appropriate action, and when you do, the brain sends a signal back to the nerve in the tooth to tell it the crisis is over and to calm down, this is called Pain Inhibition i.e. the brain inhibits the pain.
The nerves that carry pain signals to your cortex carry signals from the neck and the head, and when the neural system is compromised from trauma or adverse stress, the brain loses the ability to tell whether that pain is coming from the neck or the head and expresses itself as headache. The stress signal travels from the neck via the cervical nucleus and then the pain signal travels outwards via the trigeminal nerve. This is called Referred Pain.
The Central Nervous System (CNS) has a threshold of how much stress can go through it before it triggers a pain response. Most of the 20,000,000 signals that go through the nucleus fall well short of the intensity required to trip a pain response. i.e, you can sit still to watch a movie for 2 hours without pain.
When the CNS becomes sensitised, the frequency and intensity of incoming nerve signals remains exactly the same, but the threshold of what is perceived as noxious is much less, so pain is triggered from a smaller stimulus. i.e. you get a headache after 10 minutes watching the same movie in the same seat. Same feedback; different response due to the CNS being sensitised and over-responsive.
To make matters worse, the Pain Inhibition pathway becomes compromised, so there is no self-regulation of the pain signals.
How the Headache Neck and Jaw Clinic treats Headache Pain and Central Sensitisation
At the Headache Neck and Jaw Clinic we understand central sensitisation and the impact this has on headaches and pain, and this is incorporated into our treatment approach.
We can identify whether your CNS is sensitised and use correct and safe techniques that restore normal thresholds centrally to control your headache.