Cognitive Decline Remains for Some 1 Year After Concussion

A new study published in Neurology, suggests individuals with mild traumatic brain injuries may be more likely to result in cognitive impairment, cognitive decline, or both 1 year later. 

Out of 656 individuals with mild brain injuries, 86 (14%) had poor cognitive outcomes 1 year later. Of those 86 individuals, 10% had cognitive impairment only, 2% had cognitive decline only and 2% had both. This is in comparison to 5% (8 of 156) of individuals without concussions who had poor cognitive outcomes one year later. Of those healthy people, 3% had cognitive impairment, none had only cognitive decline, and 1% had both.

Individuals who had good cognitive outcomes were more likely to have higher life satisfaction 1 year after concussion. The life satisfaction test given to participants ranges in score from 5 to 35, with lower scores indicating lower life satisfaction. 

Individuals with good cognitive outcomes scored an average of 26 on the test and those with poor cognitive outcomes scored an average of 21. Individuals who had depression before their injury, no health insurance, or had a high school education or less were more likely to have a poor cognitive outcome. 

“Our results suggest that clinically meaningful poor cognitive outcomes, which we defined as cognitive impairment, cognitive decline or both, one year after a concussion may be more common than previously thought,” said study author Raquel Gardner, MD, of the University of California San Francisco. “They also highlight the need to better understand the mechanisms underlying poor cognitive outcome, even after relatively mild brain injuries, to improve therapy for recovery.”
 
Study participants were individuals, mean age 40, admitted to trauma center emergency rooms with and concussions or without head injuries. Participants had up to 3 neurologic evaluations after their injury, at 2 weeks, 6 months and 1 year. Each evaluations provided 5 scores from 3 tests of recall, language skills, and other cognitive domains.

“Previous studies of people with moderate to severe brain injuries show that early, intensive rehabilitation can improve people’s cognitive outcomes over time. More research is needed to find out the role of cognitive rehabilitation on people with more mild brain injuries who are also at risk for poor cognitive outcomes, and how to predict who falls into this risk category,” Gardner said.