David Chao, MD: What I Think Happened To Patrick Mahomes; Why He Should Be Fine To Play Sunday

After analyzing the video and reports and using my NFL medical experience, I believe Patrick Mahomes will be cleared to safely play on Sunday, and not because the Chiefs or the NFL have pulled any shenanigans to make it happen.

We have detailed in the past what the concussion protocol entails. On a recent OutKick podcast, we also explained that it is unlikely that anyone or any organization would use malfeasance to get Mahomes cleared to play. 

They wouldn't need to. It is my impression that Mahomes did not have a concussion at all. By video, it is clear that he never directly hit his head, though his facemask did hit the ball on the ground. Certainly one can get a concussion from an indirect blow, but the hard tackle Mahomes sustained did not seem to have that type of energy. Initially, Andy Reid said after the game that Mahomes was hit in the back of the head, but in the days since this press conference, the team has made no specific reference to any blows to the helmet. They have also not even confirmed that Mahomes suffered a concussion. All they have said is that Mahomes remains in the protocol

A player does not need to have a concussion to enter concussion protocol. Mahomes demonstrated clear signs of neurologic abnormality when he stumbled getting up, which is enough to enter him into the protocol. Though he could answer most protocol questions immediately following the hit, he missed one question and was thus ruled out for the rest of the game. It almost cost his team the win.

Missing even one question can be the "proverbial nail in the coffin" on any same-game return. Earlier this season, D'Andre Swift was in concussion protocol, even though he had migraine headaches. Once in protocol, all the rules need to be followed, even if doctors no longer believe the player is concussed.

Many in social media have suggested that Mahomes was "choked out." However, that assessment does not make any medical sense. Mack Wilson may have had his forearm around the neck of the Chiefs QB, but only for second or two. It wasn't long enough to deprive the brain of enough blood flow or oxygen to cause unconsciousness.

Others have implied that Mahomes has a nerve issue in his neck. This may be true, but I don't believe it is a classic cervical spine, spinal cord or nerve root issue. By video, there was not enough torque on the neck to cause an issue in the bones or ligaments. A nerve root or brachial plexus issue would not cause weakness in the legs. A spinal cord issue would not cause the distanced look in his eyes.

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.

This type of carotid/vagal nerve issue may look scary, but in reality, it is transient. It is not dangerous and causes no long-term effects. This is why I am certain that fans will be treated to a fantastic matchup between the Bills' Josh Allen and the Chiefs' Mahomes.

Note: this article was penned prior to the latest report of optimism from the Chiefs on Mahomes.

Written by
David Chao, MD -- known digitally as Pro Football Doc -- is an expert contributor for Outkick. Chao spent 17 seasons as the team doctor for the San Diego Chargers (1997-2013) and is part of the medical team at OASIS in San Diego where he treats and specializes in orthopedic sports injuries, working with high-profile professional athletes from the NFL, NBA, and MLB.