This is what Jay glazer said he thought it was, I believe. Brachial stun.
Excerpt:
So what happened to Patrick Mahomes?
In my opinion, Mahomes experienced momentary trauma to the carotid sinus area, where the vagus nerve and baroreceptors are located. When people who are afraid of needles or the sight of blood faint, it is often the result of a vasovagal reaction. A direct blow or trauma to this area of the neck, such as the one sustained by Mahomes, can cause the same kind of momentary excitement of the nerve, sending the signal to the brain and causing him to “pass out.” Others in martial arts or police/military maneuvers have described this phenomenon a “brachial stun.” Carotid sinus massage is a medical way to alter a heartbeat through the autonomic nervous system, and it is done by pressing on the same area of the neck that Wilson’s forearm contacted.
I will admit that in my two decades as a NFL team physician, I have never seen this happen on the football field. It is unusual that the Browns linebacker’s forearm got underneath the helmet but above the shoulder pad. The initial blow and sustained pulling on the neck to prevent the first down would be enough to provide a “short circuit,” and the vagus nerve and baroreceptors would then have caused Mahomes to faint and stumble as he got up.
Of course this analysis is from afar, but I have discussed my thoughts with two other previous NFL physicians. They also find my theory plausible and to be the best explanation of the events.
The good news is that there is no long-term worries with this type of issue. There is no risk of CTE, spinal cord or permanent nerve damage. It is a transitory phenomenon.
Mahomes won’t be cleared until later this week, as he needs to go through the five-step protocol as though he has a concussion. The final step includes participating fully in practice. That will likely come by Friday, when he will likely seek final clearance from an independent neuro. Such clearance should come Friday afternoon or Saturday AM.
I would expect the top medical staff of the Chiefs, led by Rick Burkholder, to be creative in adjusting his shoulder pads and helmet or in adding a neck roll to protect Mahomes from a repeat blow
