Doctor Notes No Supporting Literature That Chokes in MMA Contribute to CTE

Last year a physician published a case study highlighting a mixed martial artist who developed CTE.  The physician suggested that in addition to brain trauma from strikes, frequent chokes in MMA could have played a role in the development of the disease.  More recently Dr. Samuel J. Stellpflug, a practitioner of Emergency Medicine in wrote a reply, published in the International Journal of
Environmental Research and Public Health, critical of this conclusion noting “the absence of supporting literature” for such a conclusion.

The full reply reads as follows:

I have reviewed the article “Dangers of Mixed Martial Arts in the Development of Chronic
Traumatic Encephalopathy” by authors Lim, Ho, and Ho, which was published in the International
Journal of Environmental Research and Public Health (2019; 16: 254). I want to congratulate the
authors on their case presentation and discussion; chronic traumatic encephalopathy (CTE) is a very
important and current issue. I would like to make some contributions to the portion of the authors’
discussion on the topic of “asphyxia” resulting from “neck chokes” in the context of mixed martial
arts (MMA) training and competition. In the paragraph of the discussion extending from page 5 to
page 6, the authors offer the theory that there is a potential of CTE-related effects, caused by not only
head contact and traumatic brain injury but also from “asphyxia.” They present the premise that,
over the course of an MMA athlete’s career, repeated momentary episodes of asphyxia from being
choked might result in hypoxic ischemic brain injury (HI-BI). They highlight literature establishing
that HI-BI occurs in scenarios in which the brain is deprived of oxygen, such as cardiopulmonary
arrest, respiratory failure, and carbon monoxide poisoning. Their summation point is that the patient
in the presented case exhibited decreased neuropsychological testing performance over time and that
HI-BI, resulting from repeated choking, may have contributed to this decline.

An initial issue to address is the terminology used to describe this topic. The authors repeatedly
use “asphyxia” to describe the induced physiologic effect from neck compression which occurs as
an attempt to submit an opponent during MMA training and competition. Readers could easily
misinterpret the situation based on the use of that term. Asphyxia typically describes deprivation of
oxygen via obstruction of breathing. Although obstruction of breathing can occur with compression of
the airway in the context of MMA as well as grappling training and competition, the goal and typical
outcome of neck compression is to occlude the major vasculature, namely, the carotid arteries and

jugular veins. This is a more efficient and safer way to make the person submit prior to unconsciousness,
which can occur on the order of 5–10 s [1,2]. Although it would most appropriately be referred to
medically as a “strangle”, this vascular neck compression is described as a “choke”, and the term has
been adopted and accepted by the fighting and grappling communities. The authors use the term
choke several times, but repeatedly describe asphyxia, which paints the wrong picture for the reader
familiar with medical terminology. One use of the term choke is in their description of the “rear naked
neck choke”. In this case, they are referring to the Rear Naked Choke (this compression is described as
Mata Leao in Portuguese or Hadaka Jime in Japanese). They mention that this common and effective
choke causes momentary asphyxiation or the opponent to pass out. Although this could rarely be the
case, when applied correctly, only the blood flow is cut off, not the airflow. Similarly, because of the
interaction between training partners, actual unconsciousness is exceedingly rare.

The other issue to address is the logical gap between the description of the vascular neck
compression, or choke, and the presumption of potential neurologic injury. The authors establish that,
over the course of an athlete’s career, they will experience many chokes, which is a fair assessment. They
describe some of the pertinent compression forces necessary for the jugular veins, the carotid arteries,
and the trachea to be collapsed, which are referenced and in line with literature on the topic [1–4].
However, they next make an unsubstantiated statement: “…HI-BI may develop in the long term in
MMA athletes as they are subjected to frequent repeated transient asphyxiation and strangulation…”.
The attempt to draw on literature support relies on a loose comparison with several serious prolonged
hypoxic scenarios, such as cardiac arrest. The only instance where these comparisons, with extended
periods of brain oxygen deprivation, would be appropriate would be a training or competition situation
where the competitors and/or referee were acting in a completely nonstandard fashion. The training
necessary to learn the choking techniques referred to in this article, both for executing them and for
defending against them, is similar across many grappling applications, including but not limited to
MMA, jiu jitsu, judo, and catch wrestling. The techniques are typically applied and then stopped when
the person being choked “taps” or offers the person applying the technique a verbal or physical signal
indicating that the technique has been performed effectively and would render unconsciousness if
continued. This interaction between the person executing the choke and the person being choked also
extends to live resistance training, where, if a choke is applied effectively in the flow of the struggle, it
is subsequently released with a tap prior to unconsciousness. To illustrate the common nature of this
practice and the rarity of unconsciousness, I have been choked thousands of times training in similar
combat scenarios as the athlete described in this report; I was rendered briefly unconscious only three
times, resulting in no subsequent symptoms. My experience is the rule as opposed to the exception.
During a formal grappling competition or MMA fight, a choke will be either released when the person
being choked taps or submits, or when the referee stops the action due to apparent unconsciousness.
Again, if unconsciousness occurs, it is brief and essentially uniformly without persistent symptoms.
Given this information, rather than comparing these events to cardiac arrest or complete respiratory
failure, a better analogy would be a comparison to presyncope or syncope due to vagal stimulation or
orthostasis that improves with brief observation without neurologic sequelae. This would be much
less dramatic but much more accurate.

As the authors illustrate, the literature supporting the link between traumatic head injury and CTE
is both established and growing. The literature linking CTE or HI-BI and repeat execution of choking
techniques in MMA and grappling sports is nonexistent. This lack of evidence is especially significant
given the hundreds of thousands of athletes, both past and present, who participate in choke-inclusion
sports worldwide. The absence of supporting literature is also significant given the length of time
since indexed establishment of the physiologic basis of the presyncope or syncope due to these specific
choking techniques, now more than 75 years old [3,5]. I understand and respect the authors bringing
up choking techniques in the context of this article, but it would be most reasonable to bring up as
a question for possible further study with inclusion of the above information as opposed to likely

falsely theorizing that the particular presented patient may have suffered some of his CTE-related
neurological decline from repeated chokes.
Thank you to the authors for their manuscript and to the editors for fostering this educational


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