Guest column: The NHL's concussion crisis

By Louisa Nicola

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Medical staff attend to injured Maple Leafs forward John Tavares in Game 1 of a first-round playoff series against the Canadiens on May 20. Tavares suffered a knee injury and concussion on a hit from Ben Chiarot and a knee to the head from Corey Perry. (Getty Images)

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Louisa Nicola is a clinical neuroscientist and neurophysiologist who works with NFL, NBA and MLS athletes. She writes a weekly newsletter for 18,000 athletes on neuroscience and physiology. You can fund her Substack column here: https://neuroathletics.substack.com

You can find Nicola on Twitter here: https://twitter.com/louisanicola_

Louisa Nicola

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On May 20, Maple Leafs captain John Tavares fell to the ice after a collision with Canadiens’ defenseman Ben Chiarot, followed by a knee to the head from Montreal forward Corey Perry. Tavares left the game on a stretcher, giving a thumbs-up as he was taken off the ice.  

Two weeks later, in a game against Winnipeg, Canadiens’ forward Jake Evans scored an empty-net goal to ice Game 1 of Montreal’s second-round series against the Winnipeg Jets. A split-second after the goal, Winnipeg’s Mark Scheifele leveled Evans, and Evans was also stretchered off with a similar thumbs-up sign.

Tavares and Evans were diagnosed with concussions, or what athletes like to describe as “getting their bells rung.” They joined seven other NHL players who were also diagnosed with concussions during the 2020-2021 season,  according to CBS Sports' NHL Injury Tracker.  

Between 2006 and 2010, the NHL games averaged 6.05 concussions per 100 games. Further analysis showed that the causes were:  

• 88 percent from contact with opponents, including 9.2% from fighting

• 10 percent from accidental fall, tripping, or collision with teammates

In terms of position as a risk factor:  

• 65 percent of concussions were suffered by forwards  

• 32 percent by defenseman  

• 3 percent by goalies 

What is a concussion?  

A concussion is a temporary neurologic dysfunction resulting from a blow to the head. During a concussion, the brain undergoes a neurometabolic cascade in which there is an unregulated release of neurotransmitters called glutamate that causes ionic (K+ and Ca2+) imbalance in the cells.

To fix this neurochemical imbalance, the brain needs more energy. However, the supply of energy is limited by the impaired blood flow in the brain, thus resulting in a mismatch between energy supply and demand (energy crisis). As a result, the person experiences symptoms like disorientation, dizziness, headaches, confusion and visual disturbance.  

Now, you may be thinking: Is this the same as a CTE? That is a great question, Let’s explore that for a brief moment. 

What is CTE?  

Chronic Traumatic Encephalopathy, also known as CTE, is a progressive neurodegeneration disease. The most commonly known neurodegeneration disease is Alzheimer’s disease.

Evidence of CTE was first described almost 90 years ago when symptoms were observed among boxers. However, the neuropathology and clinical presentation differ somewhat from how CTE is characterized today.  

Although the incidence and prevalence are unknown, it has been diagnosed in former amateur and professional contact athletes as well as military veterans. In 2017, a study conducted at Boston University showed that 110 out of 111 brains of deceased former football players showed signs of CTE. Given the millions of contact sport athletes and military service members exposed to repetitive head impact each year, CTE has become a major public health concern. New research suggests nearly 6 percent of the general population may have CTE. Results from the largest and broadest study of CTE to date show that although the highest rates of disease are in athletes, a significant number of non-athletes also have the neurodegenerative disease. 

Repetitive head impact linked with CTE

CTE is believed to be triggered by repeated traumatic brain injuries, including concussions and repeated hits to the heads, called subconcussive head impacts (head impacts that do not cause symptoms of concussion) in contact sport athletes and also in military veterans. After a sufficient amount of head trauma, this disease develops in the brain and becomes a progressive widespread brain disease as time goes on. It’s like smoking. It’s not one cigarette that kills you. It’s the repetitive exposure that does.  

Consequences of concussions in NHL players 

In his 12-year career, Tavares has had two known concussions while Evans has had three since his debut in 2018.  

With more games ahead of them, that means more chances of adding to their history of concussions. This puts them at risk of developing post-concussion syndromes and chronic traumatic encephalopathy (CTE), a disease that can only be diagnosed posthumously.  

Veterans such Daniel Carcillo, Connor Crisp, and Nick Boynton all were forced to retire from head trauma after at least seven concussions.  

“The quality of life that repetitive traumatic brain injuries rob from you is… I would give back all of my money, I would give back all of my time. You can take my name off the Stanley Cup twice over… I can’t live like that anymore,” Carcillo, a two-time Stanley Cup winner who retired at the age of 30, told The Players Tribune.  

Crisp, another former NHL player who retired at the age of 24, and who used to see the NHL as his dream told The Players’ Tribune:  

“Hockey is a game and this is life and this is no joke. To wake up and then go to bed and have a headache all day, and… it’s just… enough is enough.” 

While at least seven concussions have cost them their quality of life — at least 19 concussions have cost the life of Steve Montador, Derek Boogard, Todd Ewen, and several junior hockey players who never made it to the NHL, including Andrew Carroll and Kyle Raarup. All of them, like the eighty-seven deceased former NHL players, were diagnosed with CTE.  

What should we do about it? 

When Steve Montador died at age 35 with a cocktail of drugs in his system, the NHL should have mandated a new law against playing with a concussion. While the medical community’s knowledge of this disease is advancing, there is still much research that needs undertaking in order to better understand the nature of this neurodegenerative disease.  

While efforts are being made in other sectors to advance the concussion protocols, it seems that the NHL is still lagging behind in both action and education. The statement made by commissioner Gary Bettman when he publicly insisted that “there is no proof that hockey can lead to CTE at all” shows what little effort is being made in this unfortunate realm.

The NHL has earned the dubious distinction of being the only league still denying what most consider a national emergency (the NFL could do better as well) but I do believe that with fiscal and monetary policy and a sound public health response, we can help counter this situation. With better helmets, longer recovery times and a thorough post-concussion screening process, we can expect players to live a healthier life without the detrimental effects of a long-lasting brain disease.