CORTICAL THICKNESS: PLAYERS VS. CONTROLS
Minuzzi went back and re-analyzed each subject four times because he couldn’t believe what he was seeing. The goal of the project was to examine the long-term effects of concussions and repeated hits to the head suffered by former football players.
Left and right lateral images of the cerebral cortex. Any areas in blue represent areas where the retired CFL players, on average, showed significant thinning compared to controls. The lighter the blue, the more significant the thinning. About 65 per cent of the cortical area was thinner in players.
Minuzzi said the cortical thinning experienced by the players are “very, very strong results that we were not expecting.”
“It’s almost like seeing the brains of much older people,” said Minuzzi. “They are not matching in terms of age.
“I was shocked,” he added. “There’s something really serious happening.”
Minuzzi is part of the research team for the Spectator’s CFL concussion project, a unique collaboration between the newspaper and six researchers from McMaster University.
The project, which took more than two years to complete, involved comprehensive testing of 22 retired CFL players and another 20 healthy men of similar ages with no history of concussions who acted as control subjects.
Using a variety of sophisticated tests, the goal of the project was to examine the long-term effects of concussions and repeated hits to the head suffered by former football players.
The dramatic amounts of cortical thinning weren’t the only horrifying results to emerge.
The retired players also underwent electroencephalogram (EEG) testing to measure the strength of the brain’s electrical activity as they paid attention to different stimuli, again compared to healthy volunteers.
In some cases, the EEG results from players were no different than the results that would be seen in some types of coma patients.
The findings are almost hard to believe, said John Connolly, a McMaster professor and the Senator William McMaster Chair in Cognitive Neuroscience, who specializes in EEG analysis and concussions.
“In the coma patient, you can understand it — the person has had a catastrophic brain injury of some description,” said Connolly, a member of the project’s research team.
“But these men we tested are living their lives, they probably drove themselves here, some of them are running businesses.
“I’m not suggesting they’re in a coma, quite the contrary,” he added. “They came in, we chatted to all of them.
“Are there ways they’re getting around this? I think there must be.
“There must be some way they’re compensating for what amounts to a really disastrous attentional problem.”
The disturbing differences found between the players and controls throughout the various forms of testing suggest strong evidence of a link between football, repeated hits to the head and long-term effects on the brain.
The findings raise very serious concerns about the future health prospects of former football players.
“It seems that their brains are already very fragile,” said Minuzzi.
“The saddest part of this is that if the cortical thinning has been caused by neuronal loss, once those cells are dead, they are dead,” he added.
“It’s not something where we can do physiotherapy and recover, like a
muscle can be increased with exercise.”
Michael Noseworthy, an MRI imaging expert and part of the research team, said he too was shocked by the results.
“These players are unquestionably abnormal compared to the normal population of the same age,” said Noseworthy, director of McMaster’s School of Biomedical Engineering and director of Imaging Physics and Engineering at St. Joseph’s Healthcare.
“I feel really bad for these players,” he said. “And the current players, too.”
Noseworthy was asked if there’s any chance the players’ results aren’t connected to football.
“No, this is football,” he said. “That’s the common denominator.”
The findings from this project are believed to be the first to report such a wide array of brain imaging and EEG results from living former professional football players.
“I’ve never seen a study that’s done what you’ve done,” said Robyn Wishart, a Vancouver-based lawyer who specializes in the litigation of brain trauma cases involving athletes. “It’s mind-blowing what your images show.”
Wishart has launched two separate lawsuits against the CFL on behalf of more than 200 former players who allege the league’s negligence caused them to suffer brain injuries.
The project’s findings raise grave questions about the safety of a dangerous sport that is popular precisely because of its violent nature.
“The players are getting stronger and faster and that’s just adding to this issue,” said Bob Macoritti, a study participant who played six seasons, mostly with Saskatchewan, in the mid to late 1970s.
“You can’t get stronger, faster and heavier and not have more damaging collisions.”
The research results, Wishart said, will help parents better understand the risks of the sport for their children.
“I think the parents have a right to know what a long career in the sport of football could mean to the longterm health of their child,” she said.
In the second part of the series,
you’ll read stories from the retired players who took part in this project — the hardest hits they ever took, their thoughts on the damage they may have suffered and the fears they have for the future.
“We were putting ourselves through multiple car accidents every game,” said one former Toronto Argonaut receiver now in his 50s.
“People wanted to see train wrecks,” Ticat hall of famer Ben Zambiasi added. “People paid to see train wrecks.”
In the third part, you’ll read about the shocking lack of options that exists for CFL players, past and present, when it comes to compensation for on-the-job injuries — and the two lawsuits against the CFL that could change that.
And in the final part, you’ll read about the ticking time bomb that hangs over the heads of retired players: CTE — chronic traumatic encephalopathy — the degenerative neurological disease that has been linked to repeated brain trauma.
WHEN THE NFL agreed last
The project’s findings raise grave questions about the safety of a sport that is popular precisely because of its violent nature.
year to a $1-billion settlement of lawsuits related to brain trauma, the league acknowledged as many as 6,000 former players may develop Alzheimer’s or other forms of dementia.
Research into concussions and their connection to sports is now an area of growing interest across North America.
A long-term study of concussions and CFL players has been underway for more than two years at Toronto’s Krembil Neuroscience Centre, which is affiliated with Toronto Western
Hospital and the University of Toronto.
In addition to brain imaging research of living retired players, the Toronto project is also analyzing the brains of deceased players that have been donated for the study of CTE.
BY VIRTUALLY EVERY measurement examined in The Spectator project, the retired players’ results were worse than those of the healthy control subjects.
In many cases, the results were shockingly worse.
Here’s what we found:
Magnetic Resonance Imaging (MRI)
MRI is a method of using very strong magnetic fields to generate highly detailed images of organs and tissues. It’s particularly well-suited to looking at the brain.
MRI can show in real time which areas of the brain are activated — and how much activation is taking place in those areas — during the resting state or when tasks are being performed during the scans.
One main use of MRI scans is to look at so-called “white matter tracts” in the brain.
These are the various bundles of nerve fibres — much like electrical cables — that join different areas of the brain and distribute the signals between nerve cells.
Some of these tracts join the two halves of the cerebrum through a broad C-shaped band in the centre called the corpus callosum, and some of the tracts join together different areas within each half of the cerebrum.
Damage to these bundles could interfere with brain function or processing speed.
Four different types of analyses were applied to the MRI data and each analysis looks at different measures of the structural integrity of the nerve fibres that connect various areas of the brain.
OUR RESULTS
The MRI analyses showed significant differences between the retired players on average and the controls in a number of white matter tracts across the cerebrum.
About 95 per cent of the players showed decreased activity in some of the brain’s networks — specifically, a part of the prefrontal cortex believed to be associated with decision-making.
The area showing the most consistent differences across all measures was the corpus callosum, the large band that connects the left and right halves of the brain.
The differences seen in the retired players suggest two separate issues at work.
The first is that the nerve fibres in these bundles are showing signs of injury, degeneration, or the loss of the insulation around the fibres that help transmit the electrical signal smoothly.
The second is that large swaths of the corpus callosum showed signs of premature aging in the retired players compared to the control group.
Previous studies have shown the corpus callosum to be a common point of trauma in repetitive brain injuries. Because this large band connects the two halves of the brain, it can be damaged as the force of a blow is transferred back and forth through it, like a shock wave.
What’s most disturbing about the results is that the differences seen in the retired players’ brains were more consistent with the results that would be seen in someone who had just recently suffered a concussion.
Yet in the case of the retired players, it had been years — perhaps decades — since they’d last suffered a concussion or repeated blows to the head.
“These players are unquestionably abnormal compared to the normal population of the same age. I feel really bad for these players.” MICHAEL NOSEWORTHY DIRECTOR, MCMASTER SCHOOL OF BIOMEDICAL ENGINEERING
“I’ve never seen a study that’s done what you’ve done. It’s mind-blowing what your images show.” ROBYN WISHART LAWYER, SPECIALIZING IN BRAIN TRAUMA CASES INVOLVING ATHLETES The area showing the most consistent differences across all measures was the corpus callosum, the band connecting the left and right halves of the brain.
“For these players, with who knows how many concussive hits or sub-concussive hits, it’s pretty striking and clear that the damage has never been repaired,” said Noseworthy.
The MRI scans also showed significant areas of premature aging in several of the white matter tracts that join areas within one hemisphere or the other. The results also suggest that it’s not necessarily the violent but less frequent concussive types of hits that cause the most damage.
Offensive and defensive linemen, who endure frequent but less violent blows to the head, showed greater damage to the white matter tracts of the brain than players such as receivers and defensive backs, who suffer higher-energy hits but fewer of them.
The results also showed that there was a significant and accelerated decline in the integrity of the white matter tracts as the age of the retired players increased.
Cortical thickness
MRI scans can provide details about the brain’s anatomy. This is useful for measuring the thickness of the cerebral cortex, the outer folded shell of so-called “grey matter” that covers the two halves of the cerebrum.
The cortex is made up of the bodies of billions of nerve cells, called neurons, which are responsible for organizing many of the higher-level functions of the human brain, such as memory, attention, emotion and problem solving.
Using some high-powered math, the thickness of the cortex can be calculated across the brain. A thinning of the cortex suggests either a loss of the neurons themselves, a loss of connections between the neurons, a loss of blood vessels that supply the nerve cells, or a combination of all three.
Cortical thickness is a very important measure because once nerve cells are lost, they can’t be regenerated. OUR RESULTS
These were the most shocking of all our findings.
On average, 65 per cent of the cerebral cortex area showed significant thinning in the players compared to the control group.
Minuzzi, the psychiatrist and brain imaging expert, said he expected to see small spots of cortical thinning, perhaps localized to the areas where concussions occurred.
Instead, “they show global reduction,” Minuzzi said. “The whole brain has been affected.”
Some of the players are in their 40s, Minuzzi said, but “they have the brain of an 80-year-old, maybe 90year-old.”
The images from the players and the thinning of the cortex, he added, were “compatible to someone very old or someone with a neurodegenerative disorder.
“Something really wrong is happening here,” he said.
“It’s impossible to fake this. This is an objective measure of the thickness of your brain.”
Altogether, the results showed, on average, that about 20 per cent of the mass of the cerebral cortex has been lost in the retired CFL players compared to the controls, which is a stunning amount of damage.
As Minuzzi studied the brain scans of the players, one image popped into his head — “the gladiators of the past,” he said.
“People were cheering for someone to die,” he said. “I was wondering if that’s what’s happening now when we turn the TV on.
“Are we seeing people who are being exposed to something that is quite negative that will change their lives forever?”
Compared to the control subjects, 85 per cent of the retired players showed significant amounts of cortical thinning.
The area of the cortex most affected were the occipital and temporal lobes. The occipital lobe, at the back of the head, is involved in vision. The temporal lobe, located just above the ear, is responsible for such things as hearing and understanding speech.
Electroencephalogram (EEG) testing
An EEG is a measurement of the electrical activity taking place across the brain.
While MRI imaging and cortical thickness analysis reflect the structure of the brain, EEG measurements help provide answers to the question of what functional consequences arise from these structural changes.
A series of 64 electrodes scattered across the outside of the skull pick up changes in electrical activity caused when nerve cells fire. The more cells that fire, the stronger the electrical signal.
In addition, an EEG is very good at picking up the timing of nerve cell activity in response to stimuli.
Our EEG experiment was designed to measure two different states — how does the brain respond when a subject is consciously paying attention to stimuli, and how does the brain respond when a subject is not paying attention to the same stimuli?
In the first case, the subjects were told to pay attention to the sound of tones being played through earphones.
Most of the time, the tone was exactly the same and it was repeated over and over — beep, beep, beep, beep. The brain’s electrical response to the regular tone dulls quickly as it becomes habituated to it.
But every so often, the tone would differ — perhaps it was longer, or louder, or a different pitch.
When the abnormal tone is played, the electrical activity spikes in response to this new stimulus.
It’s well established from research that the electrical spike occurs around 300 milliseconds after the stimulus and this is called the “P300 wave.”
Recordings from the electrodes allowed us to measure the size of the wave — which corresponds to the amount of electrical activity — and whether there was a delay in the response between the players and the controls.
In the second part of the experiment, the subjects watched a nature movie while the same beep-beepbeep tones were being played through their earphones. Again, the tone would differ every so often, as it did in the first part.
The subjects were told to disregard the background sounds of the tones and simply watch the movie.
Even though the subjects aren’t consciously paying attention to the tones, the brain is still monitoring the sounds.
And the same process is at play — the response to the normal tones becomes habituated and there’s a spike in electrical activity when the tone changes.
In this case, the phenomenon is known as the Mismatch Negativity effect, or MMN, and the spike occurs about 150 to 250 milliseconds after the abnormal stimulus.
Our experiment measured the conscious (P300) and unconscious (MMN) responses to the abnormal tones for the retired players and controls.
OUR RESULTS
When consciously listening to the tones, the P300 responses of the players on average were only half as strong as the control group responses, regardless of whether the tone changed in pitch, length or loudness.
These results were highly statistically significant.
Since an EEG measures the strength of electrical activity, the results suggest there was considerably less firing of nerve cells, on average in the players’ brains compared to the controls.
“You can have various theories as to what’s going on, but it means that they cannot pay sustained attention,” said Connolly.
For some of the retired players, there were no signs of P300 electrical activity shown, regardless of how the tone changed — a result that would be consistent with some types of coma patients.
“To show a P300 is not something only shown by geniuses or only people in peak physical condition,” Connolly said. “Everybody shows this thing.
“But some of these fellows do not show P300s and that to me is simply stunning.
“It might be that someone has a reduced one or a delayed one but to not see it at all, I’d never seen that before, literally,” Connolly added. “And I’ve been doing this for 30-plus years.”
The players, on average, also exhibited a delay in response when the abnormal tones were louder or longer.
A delay in response suggests that it might be taking longer for the signal to be processed in the brain.
When subconsciously listening to the tones, the players’ MMN responses were significantly reduced compared to the control group, particularly when the abnormal tones were longer or of a different pitch.
These responses come from areas in the brain that include the auditory (hearing) cortex and areas that control our ability to pay attention and focus.
Both the P300 and MMN responses are linked to different types of memory formation.
One possible explanation for the reduced strength of the electrical activity in the players is that the overall number of nerve cells in their brains has been reduced because of the cortical thinning that’s taken place. Health and depression surveys
All of the retired players and control subjects were asked to fill out a self-reported health survey, a concussion symptom survey, as well as the Beck Depression Inventory, a standardized test that can show if a subject exhibits signs of depression and if so, how severe it might be.
The health and symptom surveys asked subjects to rate themselves on more than a dozen measures, including general health, pain, emotional well-being, memory difficulties, sleep difficulties and irritability. OUR RESULTS
The players’ average score on the Beck Depression Inventory was nearly four times higher than the average for the control subjects.
Seven out of 22 players showed some signs of depression.
Not one of the 20 controls showed signs of depression.
When it came to the symptom scoring for measures such as irritability, difficulty in remembering and emotional sensitivity, the results were even worse.
The players’ total concussion symptom scores were five times higher than the control subjects.
For every one of the six categories, the players scored worse than the controls.
What’s most disturbing is that for many of the retired players, it had been years — if not decades — since they last suffered a concussion. In fact, a few of the players reported they had not been officially diagnosed with a concussion during their playing careers.
Yet on average, the players consistently reported the types of symptoms expected to be found in people who were recovering from a recent concussion.
The results were particularly dramatic when it came to self-reported problems with memory. The average symptom score was 10 times higher for the players than it was for the controls.
Sixteen of 22 players reported some level of difficulties with memory. Only two of 20 controls reported similar issues.
In all eight of the general health categories, the players’ results on average were worse than those of the controls. The players were significantly worse in the pain and social functioning categories. ImPACT testing
ImPACT, which stands for “Immediate Post-Concussion Assessment and Cognitive Testing,” is a computer-based series of modules that measure motor processing speed, reaction time, visual memory, impulse control, and verbal memory. OUR RESULTS
This was the one aspect of our testing where the results were somewhat inconclusive.
The players performed worse than the controls in four of the six categories, but the differences were not statistically
significant.
The players performed better than the controls in the visual memory and motor processing speed categories, which might be a residual effect of excelling in a sport that requires quick decision-making and the ability to remember visual patterns on the field.
THE SPECTATOR provided the CFL with a lengthy summary of the project’s scientific results and a number of questions related to issues raised by this series.
The league did not make new commissioner Randy Ambrosie available for an interview. Minutes before the series’ deadline, the CFL sent a written statement to the Spectator by email.
The statement cites a number of initiatives taken by the league — including changes to rules and training protocols — designed to improve player safety, particularly with respect to concussions.
“The health and safety of our players is a top priority for our league, particularly when it comes to the assessment, prevention and management of concussions,” according to the statement by Ambrosie.
“We are focused on continuing to develop a culture of health and safety across our entire league, including players, coaches and management.”
CFL Alumni Association executive director Leo Ezerins did not respond to multiple requests for comment.
RETIRED PLAYERS who took part in the project have reacted with a mix of shock and unease at the disturbing results.
Most, however, also acknowledged they weren’t surprised.
“It’s a big eye opener,” said longtime Ticat receiver Mike Morreale, now 46 and the youngest of the 22 players tested.
“What upsets me is that, generally speaking, my peers are suffering like that and it makes me feel very uneasy inside,” Morreale said.
Former Argo Dan Ferrone, who played 12 seasons as an offensive lineman, said the results are “conclusive proof that football does have an impact on your brain matter.”
“I think a lot of guys probably know they have damage,” added Ferrone, now 59. “They’re just not aware of how bad that damage is.”
In addition to his 12 years playing professional football, he also played another nine years of high school and university football. “That’s a lot of abuse,” he said. Ferrone said he was diagnosed with one or two concussions during his career, but now suspects in hindsight he may have suffered as many as 10 concussions.
That’s not unusual, given the findings of a joint Harvard-Boston University study published in 2015.
In a survey of 730 U.S. collegiate football players over one season, the study showed that for every one diagnosed concussion, there were 26 potential concussions that went unreported or undiagnosed.
“These results are clearly an indication of the trauma that can happen from this game, no question about that,” said Don Bowman, a defensive back who played for Winnipeg and Hamilton in the mid to late 1970s.
“Where we go with this, I don’t know.
“There are guys making an awful lot of money playing this sport and perhaps that’s worth it,” Bowman added. “It wasn’t so much that way back when we were playing.”
Bob MacDonald, an offensive lineman with Calgary and Hamilton in the early 1990s, admits he now wonders, “What have I done?”
“My job was to smash guys as hard as I can,” said MacDonald, now a teacher at Saltfleet Secondary School. “So I never really gave it that much thought for a long time.
“When I was growing up, I never thought about impact and inertia and the brain flipping and flopping,” he said. “You just think ‘I’m wearing equipment, I’m safe.’”
“I think a lot of guys probably know they have damage. They’re just not aware of how bad that damage is.” DAN FERRONE FORMER TORONTO ARGONAUT OFFENSIVE LINEMAN For some of the retired players, there were no signs of P300 electrical activity shown, a result that would be consistent with some types of coma patients.