Many scientific studies present initial data that can
provide a promising basis for future experiments. Unfortunately, those studies are often misrepresented in the
popular press and falsely raise the hopes of affected individuals.
In a study published this week in the American Journal of
Geriatric Psychiatry researchers performed PET scans on
the brains of five former NFL players.
The results indicated that the tau protein, believed to be responsible
for chronic traumatic encephalopathy (CTE), could be identified in living
subjects. Tau could previously
only be identified by staining brains recovered at autopsy.
CTE was actually first described in 1928 based on studies of
deceased boxers. It was called “Dementia
Pugilistica” or “Boxer’s Dementia.”
Modern staining techniques have identified the deposition of the tau
protein in certain areas of the brains of athletes who have suffered repetitive
brain trauma.
The clinical presentation of CTE consists of cognitive
decline, personality changes and movement disorders. Although there is a clear correlation between tau protein
and CTE, not everyone who has tau protein also has the syndrome of CTE.
The current report gives the impression that the scan
performed as part of the research can now identify patients who will develop
dementia. This is not true and
very misleading.
“Tau can be a marker of the presence of disease but may not
be a biomarker of disease activity. Placing too much emphasis on a marker of
disease as a true biomarker without years of clinical disease correlation may
lead to treating a finding without clinical relevance,” said Dr. Kevin
Crutchfield, a neurologist and Director of the Comprehensive Sports Concussion
Program at Sinai Hospital of Baltimore.
Another criticism of the proposed correlation is the fact
that this study involved only five athletes.
While many researchers and clinicians are hopeful that we
will someday be able identify and treat all forms of dementia before they cause
significant impairment, this is many years away.
