Rumored Risk Of CEWs Put To Rest (No, They Don’t Cause ExDS)

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Some researchers have speculated that shocks from conducted energy weapons may induce excited delirium in resistant arrestees. But a new study serves to debunk that rumored risk.

The speculation has centered on serotonin, an important chemical and neurotransmitter in the human body. Abnormally high levels of serotonin can be life-threatening, while producing some of the same symptoms commonly associated with excited delirium syndrome (ExDS), including high body temperature, agitation, sweating, tremor, muscle rigidity, altered mental state, etc.

Serotonin levels can be influenced by stress and are also known to be raised significantly by electroconvulsive therapy, often referred to as shock treatment. So a plausible link led to the hypothesis that the high-stress electrical exposure from a CEW could spike serotonin to a level that triggers or exacerbates sometimes-fatal ExDS.

A research team headed by Dr. Mark Kroll, a biomedical engineer with the U. of Minnesota and California Polytechnic U., has now tested that theory for the first time with reassuring results for law enforcement.


Trainers attached a TASER X26 via alligator clips to the torsos of 31 cadet volunteers at a Texas police academy and discharged the unit for five seconds to obtain the highest level of involuntary muscle contraction of the subjects upper and lower limbs.

Blood draws taken before, immediately after, and 24 hours later by certified EMTs were tested to measure any changes in concentrations of serotonin and two other stress-related chemicals.

In a paper recently appearing online in the journal Forensic Science, Medicine and Pathology, Kroll reports: With a very broad [i.e., effective] electrode spread, CEW exposure did not significantly raise [blood] serotonin levels in any of the tests. All remained within the clinically normal range.
Indeed, Kroll says, the trivial increase recorded in serotonin levels was far less than that shown in previous studies to be produced by low-intensity (50% maximum heart rate) physical exercise.

Addressing the speculative comparison of a CEW event to electroconvulsive therapy (ECT), Kroll points out that typical ECT [exposure] delivers 20 watts vs. the CEW which delivers less than 2 watts of electrical power.


While the cause(s) of ExDS are not yet fully understood, Kroll writes that the serotonin-provoked hypothesis is not supported by the findings of this new study. Even if the negligible effect on serotonin levels had been tripled, he says, the result would not have been clinically significant compared to the shifts seen with [mere] exercise.

The full report on Kroll’s study, titled Electrical weapons and excited delirium: Shocks, stress, and serum serotonin, can be accessed for a fee by clicking here. An abstract is available there without charge.
Kroll is a use-of-force litigation consultant who serves as a scientific advisor to the manufacturer of the TASER CEW.

Our thanks to Atty. Michael Brave, director, CEW Legal for Axon Enterprise Inc., for alerting us to this research.

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