By Keiana Smith-McDowell, NAMI Intern
The study, which was published in JAMA Neurology, revealed that these impairments are directly linked to white matter abnormalities and changes in cerebral blood flow.
White matter carries signals to cells in different parts of the brain, and is at risk of being damaged in times of head injury and concussion.
To conduct the study, Dr. John Hart and his colleagues examined cognitive impairment, depression, and neuroimaging in retired professional football players and compared the results of the cross-sectional study to those of healthy control subjects. Thirty-four retired NFL players with and without history of concussion underwent neurologic and neuropsychological testing at a research center in North Texas.
Researchers compared neuroimaging data in 26 players and in 26 healthy control adults matched for age, education and IQ.
The findings showed of the 34 participants, 20 were cognitively normal; four were diagnosed with a fixed cognitive deficit, eight with mild cognitive impairment, and two with dementia. Eight were diagnosed with depression.
“We wanted to see how best we could find who had a problem with cognition and mood, and to see if those people who had problems had anything on their brain imaging that could serve as a marker,” said Hart in an interview with PBS.
Of the subgroup in which neuroimaging figures were attained, cognitively impaired participants exhibited the greatest deficits on tests of naming, word finding, and visual/verbal sporadic memory.
Regional blood flow differences in the cognitively impaired participants resembled regions associated with impaired neurocognitive performance (problems with memory, naming, and word finding).
“When we looked at the NFL players who had abnormal connections, we also saw that in the areas where those connections are supposed to be—the areas for word finding and memory and thinking—the blood flow to the brain cells they're connecting was abnormal,” said Hart.
These findings suggest an active process underlying cognitive dysfunction in these aging players, and that their deficits do not simply reflect the static effects of previous damage. The increased cortical blood flow is speculated to reflect temporary cortical compensatory efforts to overcome reduced efficiency of interregional neural communications due to white matter deterioration. The decreased blood flow is suggested to reflect regions having reduced function as a consequence of longer-term disconnection.
“When these guys are developing problems, it's not just an old injury that's aging. Something is actively happening in their brain that is associated with problems,” said Hart. “And for those players that had problems, we were then able to find them treatments that could either help reverse those problems in terms of the depression and slow down cognitive decline.”
Dr. Hart said that concussion-associated depressions are often less about mood disorders but have a lot of the other symptoms that still could lead to suicide and death but are treatable.
He also believes that if current NFL guidelines are followed properly, these injuries that lead to cognitive disorders can be prevented, but if athlete starts having difficulties, they should seek evaluation from a medical professional immediately.