Chronic pain is pain that is ongoing or lasts longer than 6 months. And while this pain can be debilitating and affect your daily life, it can also cause other serious health issues and affect the central nervous system.
How Pain Signals Work in Your Body
Your brain and spinal cord work together to receive pain signals from nerves and muscles, which send patterns of signals to the rest of the body. These signals help the body control leg, arm, and spine movements. It’s these signal patterns that develop and allow us to ride bikes, walk, or even play an instrument or knit.
However, when you are experiencing chronic pain, the sensors and nerves that send out pain signals “misfire” and the brain and spinal cord are unable to function properly in accordance with what the signal is trying to communicate. The spinal cord reacts in a way that increases a normally harmless pain signal, creating severe chronic pain.
Why Pain Affects the Central Nervous System
When the spinal cord increases the pain signals, your central nervous system understands them as incredibly intense and painful. Even harmless signals are miscommunicated as horrible pain signals. The central nervous system operates differently than a pain-free nervous system and causes the patient to become more sensitive with less provocation. This is referred to as “central sensitization.”
Not only are patients who suffer from central sensitization extremely sensitive to things that should hurt, but ordinary things like a simple touch or slight pressure can be excruciating. Pain that typical patients may describe as a two on a numeric pain scale (1-10 level of pain) may feel like an 8 or a 9 for patients that have central sensitization. The pain becomes extremely amplified, even doing activities such as doing the dishes or walking to the mailbox.
Central sensitization is a condition that is associated with the maintenance of chronic pain. During flare ups, the nervous system goes into shock and is in a constant state of high reactivity. Being highly reactive lowers the threshold for the cause of pain and the ability to maintain pain after the injury is healed.
Central Pain Syndrome
Central pain syndrome is a neurological condition. It is caused by a dysfunction that affects the central nervous system, such as multiple sclerosis, Parkinson’s disease, or spinal cord injuries. It can take months or even years after an injury or trauma to affect the CNS.
Similar to central sensitization, central pain syndrome is heightened by light touch. However, the most common symptom is the sensation of burning. Pain increases when the temperature drops, and a loss of sensation may occur.
How Central Sensitization Affects Pain
As peripheral pain signals are transmitted to the spinal cord, receptors determine whether or not the spinal cord should respond. Weak muscle signals can be amplified and misinterpreted as pain. The spinal cord becomes highly irritated and misreads the signals from parts of the body which makes them stronger than usual. Patients have even experienced intense pain from the weight of a blanket or bed sheet.
This is the central amplification of a peripheral pain signal. The peripheral and central nervous systems work together to help the body determine how the body reacts to a sensation.
Overtime, chronic pain and the misread signals can physically change the way the central nervous system responds to pain.