When you injure your body, pain is a predictable outcome. For the most part, your brain is good at mapping pain onto your body. Pain sometimes produces a sharp, stabbing feeling. At other times, pain feels more like an ache. This predictable kind of pain usually makes sense to the person experiencing it. Thankfully, this is also the type of pain that most people know and have experienced in their life.
When you injure an internal organ or nerve, however, pain becomes much harder to map onto your body. Visceral pain might radiate across your jaw or down your back. It can be hard to find the right words to describe this pain. Take the example of cardiac pain:
Pain from a heart attack is rarely felt in the chest, and often referred to the left arm. For some people with neck tension, this heart attack pain may actually be referred to the back of the neck. The mapping of heart pain is notoriously inaccurate.
People experiencing a cardiac event describe variable feelings of pressure, tightness or fullness. Some people think they just need to burp, while others try go to the washroom or rest. Visceral pain takes most people by surprise, creating diagnostic uncertainty with every confused guess at what could be the cause of pain. Perhaps if visceral pain was better understood, care would be more accurate.
When the Brain Maps Pain
Research has shown that the brain’s ability to localize pain (essentially, its pain map) is constantly changing. For example, pain-related cognitions frequently change in response to real-life actions taken by the person experiencing pain. Sitting still on a couch might provoke pain, while gently stretching or walking sometimes makes pain more manageable.
This shifting pain pattern can lead to phenomenon like referred pain, where pain is felt in different parts of the body or areas where no damage actually occurred.
Pain mapping can be complicated by ‘static’ (or noise) in the pain signal. For example, some pain is caused by nerve damage or axonal injuries.
A nerve without sufficient circulation in the leg may start to ‘flicker’ at rest. This might produce a diffuse burning sensation or increased sensitivity to pain from normal touch (e.g. allodynia).
It is important to consider that nerve pain is rarely mapped accurately by the brain.
Pain maps are simply arbitrary calculations by the brain, intended to approximate where pain may emanate from. They are not definitive locations of a pain signal, nor are they unprocessed ‘signals’ of natural phenomena. Pain is actually a highly interpreted emotion, translated from unconscious reactions and conscious experiences.
Processing the Signal vs. the Brain
Pain receptors send information to the brain via peripheral nerves. And, when experiencing pain, the brain processes signals from these ‘nociceptors’ located in our skin, muscles, bones and other tissues.
The pain-brain activations occur in sequence, invoking multiple regions and neural pathways for signal processing. Upon arrival in the brain, these signals are interpreted and mapped onto specific body parts.
The process of mapping pain primarily occurs within the parietal lobe, in an area called the primary somatosensory cortex. However, other parts of the brain also have sensory zones for monitoring pain.
Other brain regions that monitor pain include the anterior cingulate cortex (ACC), reticular activating system (RAS), insula, and thalamus. These regions are less so involved in localizing pain, and instead produce many of the emotional and cognitive shifts associated with pain perception. For example, the thalamus may initiate a maelstrom of brain activity to radically shift attention to an unpleasant pain signal. This emotional response can then make pain grow in scope and intensity.
How to Create a (New) Pain Map
Visualization is a powerful tool to identifying and modifying the brain’s understanding of pain. However, you may be surprised to learn that pain signals are ‘linked to feelings and experiences’ moreso than specific parts of the body.
A pain map is not a geographical exercise, but a conscious experience.
Pain maps should bring pain into greater awareness, so we can honour and accept latent features of pain that perhaps would cause suffering. There is no right or wrong way to create a pain map, but we will illustrate one evidence-based practice here:
1. Visualize your innermost ‘core’.
It sounds weird, but a recommended first step in pain mapping is to visualize your self. This is easiest done by imagining the deepest ‘energy’ within you, sometimes referred to as your core self.
You can picture this as the ‘little ball of wool’ inside of you. Some may resonate with thinking of this as their innermost spirit, or their inner flame.
Let your hand guide you, describing the energy of your core with each stroke of the pen.
Is your core chaotic or highly regimented? Sprawling or dense? Full and bursting? Alternately, maybe it’s empty… a flickering light?
Gently guide your pen to keep drawing the core, and meditate on this visualization until you can easily picture (and access) your innermost self.
Let your hand guide you, and honour the intuitions it brings. Smile if this feels silly. Cry if it evokes some element of pain. There is no right, and no wrong. There is just noticing and sketching what you see.
2. Locate your pain outside the ‘core’ self.
The second step is to locate your pain outside of your ‘core’. Pain is often located by letting your pen wander along the page until you get a sense you should stop, or head in a different direction.
Again, let your hand guide you as you decide where to draw your pain on the piece of paper.
Once you stop in a location, ask yourself if your pain is distant from your core self, or overlapping with it?
Is your pain chaotic or highly regimented? Sprawling or dense? Full and bursting? Maybe you have two or three pain centres.
Continue to add to your sketch, documenting the feeling of pain as your pen glides in a continuous loop.
Is your pain’s energy jagged or smooth? Does it form a pattern or is it unpredictable? How does it feel when you look at this part of the drawing?
Pause to reflect on how your pain looks, and feel free to add anything else you notice.
3. Illustrate interactions between your pain and the core.
The third step is perhaps the most abstract. However, it is imperative to spend the most time on this step.
At this point, you should have at least one “pain centre” and a “core self”.
Without lifting your pen from the page, draw energy continuously flowing between pain and your core.
Let your pen guide you in this process, without thinking too much about where the interactions lie. Is energy swirling in circles or linear? Maybe your pen is getting stuck, ripping the paper? Are some parts shut-off, or disconnected? Maybe other parts are intertwined, and entangled.
Compassionately notice these entanglements. Let your hand guide you, and honour the intuitions it brings.
Smile if this feels silly. Cry if it evokes some element of suffering.
4. Compassionately notice what you drew, its deeper meanings and decide on next steps.
Many people choose to reflect on this illustration, to then write out the “themes” they notice. They may simply reflect on it, or decide to discuss these new insights with a trusted health care provider. Other people have chosen to destroy their paper after this visualization. Even so, others translated this sketch into a painting.
There is no right or wrong, other than to compassionately notice this (new) map and reflect on next steps for your pain management plan.