What Can Happen When a Nervous System Gets TOO Sensitive?
By Kathleen Pratt, MSW, RSW, Certified Yoga Teacher
When we have pain, the tendency is to focus on trying to find out what’s wrong in the tissues. With persistent (chronic) pain lasting more than several months, it can be more helpful to look at what’s going on with the nervous system. The nervous system consists of the brain, spinal cord and nerves that carry messages back and forth between the brain and body. The nervous system is exquisitely well-designed. However, it can make or break our health and well-being. The nervous system is a major factor in determining sensitivity to stress, pain, and other stimuli, such as lights, scents, sounds, and skin irritants.
A condition called “Central Sensitization” can develop when the nervous system becomes highly reactive in response to an injury and stays this way after the injury has healed.
Central Sensitization (CS) (also known as Central Sensitivity Syndrome (CSS)) occurs when the neural signalling in the nervous system is amplified, resulting in hypersensitivity to pain, and sometimes other stimuli. CS can occur from a stroke or spinal cord injury. It is often related to physical or emotional trauma and can result from certain infections including Lyme disease, Hepatitis C or Epstein Barr Virus.
I became interested in this topic after reading a study finding that pelvic floor muscle tenderness is associated with CS. CS is identified with a wide range of conditions where there is no evidence of tissue trauma or disease, including: overactive bladder, irritable bowel syndrome (IBS), some chronic pelvic pain syndromes, fibromyalgia, chronic fatigue syndrome, restless legs syndrome, Temporomandibular Joint Disorder (TMJ), migraine/tension headaches, multiple chemical sensitivities, post-traumatic stress disorder (PTSD), and chronic hives. In studies, CS has been identified in some people who have tissue trauma or diseases such as multiple sclerosis (MS), rheumatoid arthritis, or post-surgical breast cancer.
Once CS develops, it requires little to no actual stimulus to elicit real pain or other symptoms. For example, a light touch might feel like a searing pain, or stubbing a toe could elicit pain throughout the body. A person experiencing CS can undergo extensive medical investigation, receive multiple medications, have surgery, see numerous specialists in conventional and alternative medicine, and suffer for months to years without finding relief from their symptoms. I have observed that some people’s lives revolve around their symptoms, which has a devastating impact on quality of life.
A validated instrument that is used to measure nervous system sensitivity is called the Central Sensitization Inventory (CSI). This test can help differentiate people with persistent pain for treatment as well as predict need for pain medication post-surgery. This is important because a biopsychosocial approach is most effective and acute pain that is not treated effectively can develop into CS.
Each item is scored 0 to 4: 0 for ‘never’, 1 for ‘rarely’, 2 for ‘sometimes’, 3 for ‘often’ and 4 for ‘always’. Click here to see how a total score is interpreted.
A score of 40 or above may indicate the presence of CS/CSS.
A biopsychosocial approach considers what’s happening in the tissues, as well as the nervous system. It considers factors such as a person’s lifestyle, history of trauma, coping strategies, values/beliefs, and social support that can contribute to pain. A biopsychosocial approach makes room for evidence-based mind-body practices such as yoga and meditation that are effective in addressing persistent pain. The nervous system is innately intelligent and can evolve and rewire itself. We can help ourselves by listening to the messages it is sending us. This empowering approach gives people with pain hope for a better life and more control over their symptoms.
Dr. Andrea Furlan reviews mind-body therapies for chronic pain that are supported with evidence in the following video: Mind body therapies for pain, CBT, hypnosis, mindfulness and more