P1 First Person: The psychophysiological mechanisms of excited delirium

By Cpl. Jordan Ferguson
Spokane (Wash.) Police Department

Most articles list references at the end, but I would like to take a moment to introduce my sources. Books by LeDoux, Panksepp, and Sapolsky are first on my list. Articles from the Journal of American Medical Association, the National Institute of Health, and Stephen Porges have helped fill in the blanks. The theories involved cover our synaptic self, affective neuroscience, polyvagal theory, psychophysiology, voodoo death, heart rate variability, and takotsubo.

Humans are animals. We have similar physiological designs as other mammals. Or as the old commercial slogan stated, “parts is parts”. We need to eat, drink, and sleep just like animals. We even share the same biological drives (hormones) to procreate and save the species — these hormones have been helping fat ugly people have sex for eons). The difference, the bright line, is our brain. Whether it is due to divine intervention and design or processes of natural evolution, the result is the same. Our brain is better.

Sapolsky’s book, Why Zebras Don’t Get Ulcers, does an excellent job of explaining the physiological changes our body goes through during stress. These changes are almost magical. Epinephrine (adrenaline) is dumped into the body; corticoid steroids are released to increase our pain tolerance. The “oldest” parts of our brain are activated — brain structures that we share in common with the most primitive creatures. Our bodies are going through the same transformations they did when we were fighting saber tooth tigers. This response is so powerful that the body begins to cannibalize itself to survive the immediate threat.

The big problem is the part of our brain that sets this cavalcade in to motion doesn’t realize that there are different levels of threats. For some people, going in front of an oral board sets off the same reaction as being attacked by a bear — the initial response does not differentiate between fatal and non-fatal threats. Only our clear-thinking human brain can put the on brakes and pull us out of this response. In law enforcement this is achieved by training to keep the critical, the most advanced, part of our brain functioning during stress. This allows our system to take advantage of the neuro-chemical changes in our body and use these changes to allow us to function in stressful, life and death situations.

We are a psychophysiological animal. Heart Rate Variability (HRV) is the study of the inter beat difference of our heart. If your resting heart rate is 60 beats per minute, one would assume that the heart is beating every second. This is a false assumption. The time between two beats may be one second; the time for the next beat might be .88 seconds, the next .93 seconds, the next 1.02 seconds and so on. What this means is that our heart and brain communicate on every single heartbeat, and the heart makes adjustments based on this communication. These changes in time are the HRV. The more changes between heartbeats, the less stress you are under. When you become overwhelmingly stressed, you hear beats at exact intervals. That is zero variability. Zero variability is one of the most accurate predictors of mortality in humans.

Porges’s “Polyvagal Theory” offers an explanation of how we deal with threats as human. Initially (when there is time) we deal with threats socially, using the most advanced areas of our brain. Eye contact or a facial expression (smile) is used during this threat level. How often does a law enforcement officer “know” how things are going to work out in an encounter, just by the expressions on a subject’s face? When this social reaction is not effective we drop in to the lower areas of our brain. The areas of our brain that control our fight or flight response become activated allowing us to orientate to a threat and prepare for fight or flight. The subject stops talking, the thousand yard stare kicks in and other clues that law enforcement is familiar with.

When this is not successful and we are not going to be able to fight our way out of the situation or runaway, the brain (and body) drops in to the lowest areas of survival. Ever watched somebody pass out or faint during stress? Porges labels this “Feigning Death.” Other neuroscientists have documented this as voodoo death or psychophysiological death. This is threat level red (and if not corrected, fade to black) or Excited Delirium.

A physiological symptom of this is takotsubo cardiomyopathy (an enlargement of the left ventricle of the heart caused by emotional stress)

All of this occurs in normal healthy humans. Throw in mental illness and drug abuse (which put the brain on overload without stress), and excited delirium is a normal outcome.

Non-fatal examples of this in the animal world are “playing possum” or “fainting goats.” The fatal example is Capture Myopathy. Myopathy is muscle damage. In this scenario it is caused by the neuro chemicals (i.e. ATP) that are released in the cells and the damage done when the mitochondria explode. The muscle cells die and are processed by the circulatory system. Kidney failure is the most common cause of death in an animal that suffers from Capture Myopathy. The kidneys become plugged with the dead muscle tissue.

Excited Delirium is not some sort of weapon. It is an absolutely normal condition that occurs when the subject’s brain overreacts to stress and can’t come back. An Excited Delirium patient is locked in to a fatal spiral accelerated by their own brain. At this point it is a medical condition something that the Emergency and Trauma Rooms have to deal with. With my research I am sure that their procedures will be to turn off the stress response in the brain (sedatives, anti-psychotics) and heal the body of which hypothermia therapy appears to be one of the most promising treatments.