What is Central Sensitization Syndrome?

Imagine a new acquaintance reaching out and shaking your hand in greeting. Many of us would welcome this type of touch - assuming we’ve moved beyond Covid-19-induced elbow bumps, of course - and then blissfully move on with our day. For people who live with central sensitization, however, this type of innocent contact can cause significant pain and discomfort. Even a slight brush against their skin from something soft might cause intense suffering.

Sounds challenging to deal with daily, right? Most definitely. (Not forgetting the stigma and dismissive attitudes that also tend to surround this type of hard-to-see-and-diagnose pain.) As we already know, chronic pain is difficult to live with every day, affecting all aspects of life from daily functioning and sleep to work and social relationships. Given that several million people live with chronic centralized pain globally (1), there’s a need to understand what causes this extreme hypersensitivity to pain and what can be done to alleviate it. 

What is Central Sensitization Syndrome?

Put simply, central sensitization is hypersensitivity to stimuli that aren’t usually painful (like the touch of clothes on skin, for example, or cold temperatures). This condition was first identified back in 1933 (2), and has two primary characteristics: allodynia and hyperalgesia. Allodynia refers to the pain a person feels from things that aren’t usually considered painful. In a similar vein, hyperalgesia occurs when a painful stimulus is perceived to be more painful than it should be. In other words, pain is amplified.    

We all have what are called nociceptors in our bodies. These are specialized sensory neurons that respond to harmful stimuli like extreme temperatures and pressure, alerting the brain to the potential danger that exists. When someone has a central sensitization dysfunction, “there is a nociceptor-induced sensitization of the somatosensory system” (3). In simpler language, this means that the part of the nervous system that pays attention to stimuli like touch, pressure, movement, temperature, vibration, and pain is hypersensitive. 

As the body reacts over and over again to these perceived dangerous stimuli, the brain trains itself to recognize these stimuli as pain triggers. This sensitization of pain and sensory processing in the central nervous system (our brain and spinal cord) is referred to as nociplastic pain (or primary pain). For more information about it, check out this post on nociplastic pain management.

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What Are The Symptoms of Central Sensitization Syndrome?

Central sensitization disorders tend to be chronic; however, people with these conditions can have symptoms that come and go. In addition, their symptoms can vary in intensity from mild to severe. Symptoms of central pain syndrome can include:

• Sensitivity to odors, sounds, and lights
• Poor short-term memory and concentration
• Emotional distress like anxiety and depression
• Widespread pain
• Poor sleep and fatigue
• Abdominal and pelvic pain
• Headaches
  

There are numerous other symptoms (too many to list here) that may present along with central sensitization and related chronic disorders. For a list of these, refer to this article. Many of the symptoms of the various central sensitization-related conditions overlap; and to make matters a bit more challenging,  sometimes patients carry multiple diagnoses.

What Causes Central Sensitivity or Primary Pain?

Individuals experience central sensitization because of physical changes within their nervous system (i.e., altered sensory processing within the brain), but the reason why these changes occur in the first place isn’t always easily determined. In many cases, the changes and presence of pain appear to be triggered by a specific event like an injury, illness, infection, or emotional trauma.

It has been found that between 5-10% of people who have had a stroke, 20-40% of individuals with spinal cord injuries, and around 30% of multiple sclerosis sufferers are impacted by a sensitized pain system (4). When there is an injury to the spinal cord or brain (stroke), damaging the nervous system, this can clearly lead to the development of central sensitization. 

But how to explain when centralized pain occurs when there hasn’t been damage to the nervous system due to a stroke or spinal cord injury? There are some factors that can predispose someone to experiencing central sensitization outside of a stroke or spinal cord injury scenario, including:

• A potential genetic tendency for a low threshold for pain / high sensitivity to pain (more research needs to be performed to confirm this) (5)
• Pre-existing anxiety about pain
• Prior history of psychological and/or physical trauma
• Prior history of depression
  

A lack of quality sleep can also exacerbate centralized sensitization. 

When it comes to chronic musculoskeletal pain, it frequently starts with an acute, nociceptive injury that triggers the central nervous system to begin regulating the sensitivity of the somatosensory system (the part of the nervous system that attends to stimuli like touch, pressure, movement, temperature, vibration, and pain), thereby establishing central sensitization.

What Conditions Does Central Sensitization Effect?

Nowadays it’s thought that pain sensitization syndrome (central sensitization) can play a role in numerous chronic pain disorders. In fact, central sensitization and nociplastic pain may indeed help explain the pain associated with many chronic musculoskeletal disorders. Some of these conditions include:

• Fibromyalgia
• Irritable bowel syndrome (IBS)
• Chronic fatigue syndrome (CFS)
• Migraines and tension headaches
• Temporomandibular joint dysfunction (TMJ)
• Chronic low back pain
• Chronic neck pain
• Pelvic pain syndrome
• Whiplash
• Motor vehicle accidents
• Skin damage from UV radiation
• Scars from surgery
• Rheumatoid arthritis
• Osteoarthritis
• Endometriosis

What Treatments Can Help With Central Sensitization?

Several treatments can assist in alleviating the symptoms of central sensitization. Most of them target the central nervous system or the inflammation that results from this central nervous system sensitivity syndrome. Take a look below for some treatment options:

• Non-steroidal anti-inflammatory medications
• Cognitive Behavioral Therapy (CBT) 
• Behavioral interventions within a multidisciplinary pain treatment center
• Gentle aerobic exercise (6)
• Pain physiology education (patient education about central sensitization and the role it plays in chronic pain)
• Healthy lifestyle habits
• Psychological therapies (mindfulness, biofeedback, and hypnotherapy)
  

While anticonvulsant medications and antidepressants are also sometimes used to manage some of the symptoms of central sensitization, participation in a multidisciplinary program that incorporates multiple therapies has been found to be more effective in reducing this type of pain. In particular, providing the patient with in-person and written educational information that clears up misconceptions about pain and lessens catastrophic thoughts can drastically improve wellbeing (7). Changing perceived notions about pain and about their condition in many cases can create the psychological openness to alternative therapies that target the symptoms of their central sensitization.

Patients can cope with and self-manage central sensitization using a blend of psychological, behavioral, and medical interventions. Utilizing a biopsychosocial approach (taking biological, psychological, and social factors into consideration) can allow for an effective way to manage symptoms (8), especially since it seems that the interplay between biological and psychological is prominent in cases of central sensitization. While more research is needed, new therapies, such as Pain Reprocessing Therapy and Pain Neuroscience Education, have shown strong promise for central sensitization treatments.

If you’re interested in trying either one of these cutting edge and effective approaches to central sensitization, check out Lin, where our pain specialists are trained in both Pain Reprocessing Therapy and Pain Neuroscience Education. And we won’t just introduce you to these therapies. We’ll connect you with our compassionate and caring health coaches who will work one-on-one with you to create a customized and multifaceted pain relief plan. Sign up today and start getting back to living a fuller life without pain at its center.