Experts Call for Research On Prevalence of Delayed Neurological Dysfunction After Head Injury
One of the most controversial topics in
neurology today is the prevalence of serious permanent brain damage
after traumatic brain injury (TBI).
Long-term studies and a search for genetic risk factors are
required in order to predict an individual's risk for serious
permanent brain damage, according to a review article published by
Sam Gandy, MD, PhD, from the Icahn School of Medicine at Mount
Sinai in a special issue of Nature Reviews Neurology dedicated to
TBI.
About one percent of the population in the developed world has
experienced TBI, which can cause serious long-term complications
such as Alzheimer's disease (AD) or chronic traumatic
encephalopathy (CTE), which is marked by neuropsychiatric features
such as dementia, Parkinson's disease, depression, and aggression.
Patients may be normal for decades after the TBI event before they
develop AD or CTE. Although first described in boxers in the 1920s,
the association of CTE with battlefield exposure and sports, such
as football and hockey, has only recently begun to attract public
attention.
"Athletes such as David Duerson and Junior Seau have brought to
light the need for preventive measures and early diagnosis of CTE,
but it remains highly controversial because hard data are not
available that enable prediction of the prevalence, incidence, and
individual risk for CTE," said Dr. Gandy, who is Professor of
Neurology and Psychiatry and Director of the Center for Cognitive
Health at Mount Sinai. "We need much more in the way of hard facts
before we can advise the public of the proper level of
concern."
Led by Dr. Gandy, the authors evaluated the pathological impact
of single-incident TBI, such as that sustained during military
combat; and mild, repetitive TBI, as seen in boxers and National
Football League (NFL) players to learn what measures need to be
taken to identify risk and incidence early and reduce long-term
complications.
Mild, repetitive TBI, as is seen in boxers, football players,
and occasionally military veterans who suffer multiple blows to the
head, is most often associated with CTE, or a condition called
"boxer's dementia." Boxing scoring includes a record of knockouts,
providing researchers with a starting point in interpreting an
athlete's risk. But no such records exist for NFL players or
soldiers on the battlefield.
Dr. Gandy and the authors of the Nature Reviews Neurology piece
suggest recruiting large cohorts of players and military veterans
in multi-center trials, where players and soldiers maintain a TBI
diary for the duration of their lives. The researchers also suggest
a genome-wide association study to clearly identify risk factors of
CTE. "Confirmed biomarkers of risk, diagnostic tools, and long-term
trials are needed to fully characterize this disease and develop
prevention and treatment strategies," said Dr. Gandy.
References and further information