Chronic Pain. Such a common two word duo, yet such a complex and difficult group to tackle. Which makes this post tricky to write... trying to simplify such a complex phenomenon ain't that easy, so here goes nothing!
When someone presents with physical discomfort caused by illness/injury that lasts beyond the normal physiological time of healing (>3 months), our ears should perk up. This is usually when we begin to raise a flag... carefully.
Let's look at low back pain for an example. A certain subgroup of people with low back pain can present with persistent pain that cannot be explained purely by an obvious anatomic defect or tissue damage. Upon physical evaluation, there is no real pattern to their pain and the pain is usually disproportionate to the nature of the injury. So what is going on? When all other suspects have been ruled out, you can bet your bottom dollar that #CentralSensitization (CS) is guilty at charge for continuing this low back pain.
So what is CS? Picture the pain pathways in the central nervous system (brain and spinal cord) being hooked up to an amplifier... a quiet stimulus can become very loud. CS is the amplifier, its job is to trigger pain hypersensitivity. Despite not following the "normal" black and white trajectory, the perceived pain is very real and we need to respect this. In order to properly treat this subgroup of people we need to dig deeper and get a better understanding of the entire story. What is causing CS? What is causing the hyperactive pain pathway? Sometimes the story can become quite spiritually complex, but because we have to start somewhere I like to begin with the basics.
A lot of the information posted below is based on a paper that was published in 2016 "Clinical biopsychosocial physiotherapy assessment of patients with chronic pain: The first step in pain neuroscience education". I think this paper is very good at guiding an evaluation. By recognizing certain factors at the beginning, we are better equipped for treatment. How do you find out where someone hurts? You keep poking until you find the right spots. Well think of these as the non physical pokes. (Remember, I am trying my best to keep it as simple as possible, if you would like more details and explanation of the following, please refer to the original paper).
The PSCEBSM model. The non physical pokes.
Step 1: Determining the type Pain (Nociceptive, Neuropathic, Non-Neuropathic CS)
Step 2: What factors could be involved? Somatic, Cognitive, Emotional, Behavioral
Step 3: Determining the level of Motivation
Step 1: Before jumping to the conclusion that someone presents with central sensitization, we must rule out Nociceptive (related to tissue damage ex. meniscus tear) and Neuropathic pain (related to a lesion or disease of the nervous system ex. MS or stroke). There can be combinations of the 3 types of pains in one presentation but we want to clearly recognize the difference. As mentioned earlier, "pain is more likely to be related to central sensitization when the perceived pain and disability are disproportionate to the nature of the injury or pathology".
Step 2: Okay so lets say we have ruled in central sensitization, now what? We need to investigate factors that are contributing to the continuation of this sort of pain. The point is to provide a framework for a better gathering of information. The more information, the more individualized and effective treatment can be. The 5 categories below are areas that can contribute to the persistence of pain and pain hypersensitivity.
Somatic & Medical Factors: Regular physical examination, previous medical history and medications. The results of regular strength, range of motion and clinical tests will be altered in people who present with CS. Remember that the central nervous system is sort of on fire, the mechanical stimulus can cause increased sensitivity, so all movement tests can elicit pain... Again, there is no real pattern.
Cognitive/ Perceptions Factors: Catastrophizing, perceived injustice, perceived harm
Emotional Factors: Anxiety, anger, fear, depressive feelings and posttraumatic stress
Behavioral Factors: Healthy, avoidance or persistent. To note, cognitive and emotional information can contribute to conscious and nonconscious behavior.
Social Factors: Housing/ living, social, work, partner relationships, prior/ other treatments
I know there are a ton of terms here. I could define and explain each part, but that might put your average reader to sleep. My goal is to paint the umbrella and highlight how many elements can be contributing to someone's pain story.
Step 3: Motivation: Finding out how ready someone is to make a change is crucial for future treatment.
The purpose of this blog is to share information on the topic of chronic pain, central sensitization and the importance of digging a little deeper in the evaluation. As physiotherapists, if we want to make any sort of positive impact on this common subgroup of chronic pain, we need to understand all the players. We cannot treat chronic low back pain the same way we treat a muscle spasm. We need to listen and not only look... I like to say: listen with your magnifying glass. Physiotherapists have the power to refer to different specialists if they think the stuff they are hearing is beyond their scope. However, we as physiotherapists do need to remember the tools we have to help conquer #ChronicPain. It starts with the evaluation and ends with individualized, patient-focused pain neuroscience education (stay tuned for its own blog).
You can't solve a mystery without knowing where to look or who your suspects are.