THE FLAWS OF THE FA­MOUS 99 PER CENT

Critic says study of NFLers’ brains ex­ag­ger­ates the con­cus­sion is­sue

Windsor Star - - SPORTS - JOHN KRYK jokryk@post­media.com twit­ter.com/JohnKryk

Sce­nario: Over the course of a few years, 111 kids at an amuse­ment park are taken to first aid, nearly all com­plain­ing of queasy stom­achs. Paramedics di­ag­nose 110 with nau­sea.

Con­clu­sion: more than 99 per cent of kids who ever go to an amuse­ment park get nau­se­ated. Right? Of course not. But this is the kind of un­sup­ported ex­trap­o­la­tion many have made since late last month, when the lat­est study co-au­thored by a lead­ing brain-dis­ease re­searcher, Boston Univer­sity’s Dr. Ann McKee, was re­leased. She and 26 other med­i­cal re­searchers iden­ti­fied chronic trau­matic en­cephalopa­thy — the neu­rode­gen­er­a­tive mal­ady known as CTE — in 110 of the 111 do­nated brains of one-time Na­tional Foot­ball League play­ers.

“My hope is we’ll stop ar­gu­ing about whether or not this is a problem, or whether or not it needs to be ad­dressed,” said McKee, di­rec­tor of BU’s CTE Cen­ter.

The world’s fore­most ex­perts on trau­matic brain in­juries agree the mat­ter needs to be ad­dressed, and ur­gently. In­ter­na­tional ex­perts just won’t go as far as to chain-link con­cus­sions to CTE. Af­ter the fifth In­ter­na­tional Con­sen­sus Con­fer­ence on Con­cus­sion in Sport held last au­tumn in Ber­lin, ex­perts reached the fol­low­ing con­sen­sus con­clu­sion, re­leased pub­licly in April, which stops far short of defini­tively link­ing trau­matic head hits to brain dis­eases.

“There is still much to learn on the po­ten­tial as­so­ci­a­tion be­tween con­cus­sion/re­cur­rent head trauma and long-term ef­fects.

“There con­tin­ues to be a need for ad­di­tional re­search to fully un­der­stand the cause-ef­fect re­la­tion­ship es­tab­lished be­tween con­cus­sion and CTE.”

Does such a cause-ef­fect re­la­tion­ship ex­ist? If so, to what de­gree? And how preva­lent is CTE in all re­tired NFL play­ers? No re­searchers can say.

By her own ad­mis­sion, McKee has not yet stud­ied a ran­dom sam­ple of for­mer foot­ball play­ers, but rather a “con­ve­nience sam­ple” con­sist­ing of only the do­nated brains of one-time play­ers, nearly all of whom ex­hib­ited vary­ing de­grees of brain-dis­ease symp­toms be­fore dy­ing.

What about the brains of all those for­mer NFL play­ers who ex­hib­ited no such brain mal­adies in later life? Or brains ran­domly se­lected from the gen­eral pop­u­la­tion? What if the brains of those who never played foot­ball or any con­tact sports also ex­hibit se­ri­ously high lev­els of CTE? And to what de­gree, if any, did sub­stance abuse ex­ac­er­bate CTE in the brains of those McKee and the oth­ers ex­am­ined?

To ask these ques­tions is not to un­der­mine the ground­break­ing work of McKee and her re­searchers this decade, es­pe­cially the work of her part­ner Dr. Chris Nowin­ski, founder of the Con­cus­sion Legacy Foun­da­tion and co-founder of McKee’s brain bank. For years, he has been the sharpest critic of feet-drag­ging pro sports leagues and the loud­est ad­vo­cate for the wide im­ple­men­ta­tion of safer, more con­ser­va­tive pro­to­cols for con­cus­sion di­ag­no­sis and re­turn-to-play at all lev­els of con­tact sports.

Nowin­ski and McKee have un­doubt­edly saved lives and aided the con­cus­sion re­cov­er­ies of count­less ath­letes be­cause of their tire­less ad­vo­cacy in rais­ing aware­ness of con­cus­sions and CTE. It’s just that not all ex­perts in their field con­cur with all of their con­clu­sions.

Dr. Lili-Naz Hazrati is a Toronto neu­ropathol­o­gist. She is an as­so­ciate pro­fes­sor at Univer­sity of Toronto and works at both Toronto’s Hos­pi­tal for Sick Chil­dren and the Cana­dian Con­cus­sion Cen­tre. She has ex­am­ined dozens of brains of for­mer pro­fes­sional ath­letes.

In a phone in­ter­view from Toronto, Hazrati told Post­media she has not found nearly the high in­ci­dence of CTE as McKee and the oth­ers. What’s more, Hazrati said she’s trou­bled by the study’s lump­ing of brains show­ing mi­nus­cule traces of CTE (stages 1 and 2) with much more se­vere Stage 3 or 4 cases, and that as a re­sult of the shock­ing 99 per cent preva­lence fig­ure, she is con­cerned me­dia and the pub­lic are in­fer­ring an un­sup­ported con­clu­sion that not only foot­ball, but all con­tact sports, are ex­tremely dan­ger­ous for all par­tic­i­pants.

“When you look at their num­bers (in the study), quite a bit of their CTE di­ag­noses are just, like, that tiny lit­tle spot,” Hazrati said. “Stage 1 means that they’ve looked through the whole brain and have found one tiny lit­tle spot where there are a few cells pos­i­tive with tau pro­tein (a pri­mary CTE marker). In that whole brain there are very lim­ited amounts of tau, and in one small area.

“If they call that CTE, fine — but then they bunch it with the ones with more se­vere, ad­vanced CTE, and they call the whole bunch CTE. It’s like count­ing burn pa­tients but even in­clud­ing me, who has a lit­tle burn at the very tip of my fin­ger, and also ev­ery­one who has been burned some­how even any lit­tle bit, and lump­ing us all in with the se­verely burned.”

Nowin­ski, one of the study’s au­thors, takes great ex­cep­tion to Hazrati’s com­ments on this par­tic­u­lar is­sue.

“I think Dr. Hazrati is se­verely mis­char­ac­ter­iz­ing the study,” Nowin­ski wrote in an email to Post­media. “Only 11 of 177 cases (six per cent) were Stage 1, so while a neu­ropathol­o­gist can com­plain that they think they have a bet­ter min­i­mum cri­te­ria for di­ag­no­sis, it has no im­pli­ca­tion on the over­all find­ings.

“A burn on the tip of your fin­ger, which is an in­jury and does not turn into a pro­gres­sive dis­ease, is a com­pletely in­ap­pro­pri­ate anal­ogy for early-stage CTE. Cancer is more ac­cu­rate.”

In her own ex­am­i­na­tions of brains of de­ceased pro­fes­sional ath­letes, Hazrati said she has de­tected less preva­lence of CTE, and less se­vere cases, than her Amer­i­can coun­ter­part.

“What I’m see­ing, in ball­park num­bers, is 30 per cent of our cases have some CTE pathol­ogy,” said Hazrati, who un­der­scored that her re­search re­ceives no fund­ing of any kind from any pro­fes­sional sports body. “Most are ba­si­cally very low-stage pathol­ogy. I’ve got CFL play­ers, I’ve got hockey play­ers and I’ve got brains from some other ath­letes — rugby play­ers, wrestlers, box­ers, sports like that. So it’s a mix, but they’re all pro­fes­sional ath­letes.

“We don’t see that vol­ume of ad­vanced cases that have been re­ported (by McKee). Only 30 per cent of our brains have CTE, and about 30 per cent don’t have any­thing.”

Bot­tom line, Hazrati said: “None of these post-mortem brain au­top­sies are go­ing to solve the CTE (mys­tery) at all. You can­not solve the cause of CTE by look­ing at brains of de­ceased peo­ple.”

As yet, there is no way to de­tect CTE in the liv­ing.

“That first step is not solved yet — whether there’s a de­fin­i­tive link to con­cus­sions,” Hazrati said. “So how can you even think about who’s the most sus­cep­ti­ble, who’s not, what age is the worst? Just look­ing at these brains (posthu­mously), you can­not say any of that. It’s just im­pos­si­ble at this point.”

Hazrati isn’t the only neu­ro­sci­en­tist whose find­ings ap­pear at odds with those of McKee and com­pany.

For in­stance, Dr. Wil­liam Ste­wart — a lead neu­ropathol­o­gist at a hos­pi­tal in Glas­gow, Scot­land, with di­ag­nos­tic and re­search spe­cial­ties in foren­sic neu­ropathol­ogy, es­pe­cially trau­matic brain in­juries — co-au­thored a study pub­lished ear­lier this year. That study ex­am­ined the long-term health of those who suf­fered re­peated con­cus­sions in elite-level rugby, a sport ar­guably as dan­ger­ous as foot­ball.

Re­searchers com­pared the cog­ni­tive func­tion of 52 liv­ing, re­tired for­mer male Scot­tish in­ter­na­tional rugby play­ers — who had suf­fered an av­er­age of 14 con­cus­sions apiece — against 29 non-rugby play­ers of sim­i­lar age.

“There were no sig­nif­i­cant as­so­ci­a­tions be­tween num­ber of con­cus­sions and per­for­mance on cog­ni­tive tests,” the study found. What’s more, al­though “per­sist­ing symp­toms at­trib­uted to con­cus­sion” were more com­mon in rugby play­ers who suf­fered more than nine con­cus­sions, “these symp­toms were not per­ceived to af­fect so­cial or work func­tion­ing.”

Un­til re­searchers are able to study large ran­dom sam­ples of foot­ball play­ers, in­clud­ing those with­out symp­toms — as well as non-foot­ball play­ers in the gen­eral pop­u­la­tion who were never con­cussed — it will be hard for any claims of wide­spread af­flic­tions to hold up to scru­tiny.

Hazrati said we should all be care­ful to read closely what stud­ies have found, and not con­nect more dots than med­i­cal sci­en­tists have pro­vided. It might help, then, to bear in mind that anal­ogy of nau­se­ated kids at amuse­ment parks.

“That de­scribes it pretty well, yes,” Hazrati said.

That first step is not solved yet — whether there’s a de­fin­i­tive link to con­cus­sions … So how can you even think about who’s the most sus­cep­ti­ble, who’s not?

DON­ALD MIRALLE/GETTY IM­AGES FILES

For­mer Buf­falo Bills quar­ter­back Trent Ed­wards is helped up af­ter tak­ing a hard tackle and suf­fer­ing a con­cus­sion in a game in 2008. The long-term brain health of foot­ball play­ers was back in the head­lines af­ter a study, re­leased last month, found signs of CTE in 110 of 111 brains of one-time NFLers.

DR. ANN McKEE/THE AS­SO­CI­ATED PRESS

A re­cent study by Scot­tish neu­ropathol­o­gist Dr. Wil­liam Ste­wart found “no sig­nif­i­cant as­so­ci­a­tions be­tween num­ber of con­cus­sions and per­for­mance on cog­ni­tive tests.”

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