In the 1999 movie The Matrix, Neo emerges from a vat of jelly shortly after taking the Red Pill. It suggested that there is a separation between the mind and the body and that the brain as the master driver of experiences could be hijacked to keep the body subjugated until its useful life—under the control of an outside force—had terminated. Likewise, students taking philosophy are often introduced to Rene Descartes’ “Cogito ergo sum,” which translates as, “I think, therefore I am.” The central idea of the discourse is that the mind is proof of existence, even if the body cannot be verified. Indeed, many of us seem to live one life inside our heads while our body moves through a different, physical world. By way of introducing the mind-body dichotomy, it also suggested an unintended hierarchy. Do any of us really believe we are mere “brain in a vat”?
What comes to mind at the mention of “Neuroscience”? For many, it is some combination of brain function and science fiction. In reality, human neurosciences encompasses three large subdivisions: the central nervous system (CNS) which includes the brain and spinal cord, the peripheral nervous system (PNS) involving the ganglia and nerves after leaving the CNS, and the autonomic nervous system (ANS) which comprises a combination of the sympathetics and parasympathetics to govern involuntary physiological processes, such as heart rate, blood pressure, digestion, and sexual arousal. We refer to that latter of those as the “4 F’s: Feeding, fighting, fleeing, and f…ornicating.”
Most of us will have health issues that impact the ANS and PNS more than the CNS. For example, non-structural heart dysrhythmias are hypothesized to result from autonomic malfunction with increasing age. The increasing interest in heartrate variability (HRV) is recognition that our organ systems are integrated through proper nervous system function. When the steady waltz of its beating becomes erratic, other bodily functions decline as well.
The peripheral nerves control muscle movement and are responsible for pain signals. With rare exception, everyone will seek treatment to manage pain at some point in their life. For most, this is temporary, and they will stop using medications or treatments when the problem is resolved. For others, some prone to addiction, this can lead to a protracted course. For some unfortunate individuals, due to mysteries of the body that have yet to be uncovered, small injuries can be life changing.
Take complex regional pain syndrome (CRPS) for example. Previously known as Sudeck’s Atrophy or reflex sympathetic dystrophy (RSD), it affects around 200,000 persons in the United States each year. It is a poorly understood positive feedback loop of severe pain which is out of proportion with the inciting injury. There is a clinical constellation of sensory, autonomic, motor, and trophic symptoms which can no longer be explained by the initial trauma. The inflammatory response is exaggerated, involving—at a minimum—the endocrine and immune systems. Some have suggested this is a form of autoimmune disease affecting adrenergic and cholinergic receptors. The sensory experience is called “allodynia” (“allo-” meaning other or foreign, and “-dynia” meaning pain). The person feels severe pain out of proportion with the stimulus, for example light touch or a slight breeze can feel like hot lava sand scraping across that area. The CNS undergoes plastic changes, forcing the body to move in alternative ways. This is important: The brain will sacrifice the body to avoid experiencing pain inside its multiple protective barriers. This is an example of how the three subparts of the nervous system turn against each other.
Devices prescribed to manage pain have typically been pharmaceutical interventions taken orally, parenterally, implants [e.g., temporary catheters, intrathecal devices, spinal cord modulators (SCS)], or those directly acting on the peripheral nerves (e.g., TENS units, tape, and topicals).
Kinesio-taping is a topical option for many who do not tolerate the effects of medications. Some find relief with salves and liquids with ingredients that dull or alter the sensation. Icing down after activity is another method to address local inflammation. Iontophoresis is a method of combining electronics and active ingredients to force the ingredients past the skin to those receptors.
For those with more serious traumas and injuries, peripherally acting methods and devices are frequently deferred and escalated to “stronger” analgesics to numb the brain’s experience. The paradigm is changing within medicine to utilize a stepwise escalation in pain-management, although adoption has not been swift. After several decades of experimenting with short- and long-acting opioids, medical practitioners are becoming more selective in their use.
The brain is prone to addiction. From its perspective, if, by creating a symptom, it can cause the body to ingest a substance that keeps it comfortably numb rather than manage the withdrawal symptoms, it will continue to create that sensation. The body unquestioningly responds to those sensations and will go on complex quests to obtain that substance that temporarily dull those symptoms, which are created by the CNS. Chronic noncancerous pain can be thought of as a self-serving venture of the CNS by way of pain experienced by the PNS. The brain is siloed from much of the body by elaborate systems of protection, such as the tight junctions of the blood brain barrier (BBB) internally and an enclosed protective shell of hardened bone. It is a privileged, gated community that can dictate the tenure of the body without suffering the effects of opioid ingestion, such as depressed respiration or constipation until the body dies, taking the brain with it to the grave. The symptom narratives feel as real as a dream during sleep, causing complex drug-seeking behaviors.
Must we appease the CNS especially at the expense of worsening peripheral function, when it is the cause of the burden it places on the body? What technology can be created to interrupt this one-sided feedback loop?
Treatment of pain, be it physical, mental, or emotional has contributed to the ongoing opioid overuse and misuse problem throughout human history. In recent human history, such as in the 1800s, China lost entire generations to opium dens. Present day, non-prescription fentanyl (a heroin-derivative) is finding its way into recreational substances. There have been some devices engineered to manage pain at the PNS level, but much of pain management has been relegated to the pharmaceutical and botanical industries which act in the brain. As a clinician, it seems curious that we want to make changes at the brain level, as if central modulation is the only solution. For many diseases, this is like using a sledgehammer for a finishing nail or using the breaker to turn the lights on and off.
On the other hand, persons with complete spinal cord injury above the midthoracic area are especially prone to autonomic dysreflexia. The parts of the body that is no longer in contact with the brain will send distress signals through the ANS. If there is an injury or a systems malfunction (most commonly excessively full bladder, severe constipation, or skin injury), the parts of the body below that site of injury will send a distress signal causing increase in heart rate and blood pressure through unopposed sympathetic nervous output. This sudden onset of non-emotional anxiety or “boost” lets the brain know that things are not well where it cannot feel them. Persons with higher level SCI will have a sense of impending doom when dysreflexia strikes. This message starts as a subtle discomfort and will continue to escalate until the problem is addressed. Left unchecked, it can cause stroke or death.
Medicine strives to treat the root cause of the problem when it can be identified. This is the metaphorical Red Pill that allows us to see the real events behind the illusion. If there is not a verifiable diagnosis, treatment of the symptoms is the next best solution. When it comes to the treatment of chronic pain, there continues to be some disconnection between doing what is right for the body vs appeasing the master organ (brain) that attempts to keep the status quo by creating the symptoms, as is the case in chronic pain. It’s hard to beat the system when it is creating the scenarios from which we seek to be freed. Let’s find technology that can better evaluate and scale relief of suffering at the site of the injury, lest it become a way for the CNS to escalate its victim narratives to feed its addiction.