Cognitive Effects Persist After Concussion
— At 1 year, poor cognitive outcomes were common in people with mild TBI
by Judy George, Senior Staff Writer, MedPage Today February 18, 2022
Mild traumatic brain injury (TBI) affected cognition 1 year later, data from the prospective TRACK-TBI study showed.
At 1 year, 13.5% of people with mild TBI had a poor cognitive outcome compared with 4.5% of controls (P=0.003), reported Raquel Gardner, MD, of the University of California San Francisco, and co-authors.
Poor 1-year cognitive outcomes were associated with non-white race, lower education, lower income, lack of health insurance, hyperglycemia, pre-injury depression, and greater injury severity in univariate analysis (all P<0.05), the researchers reported in Neurology.
« 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, » Gardner said in a statement.
« Traumatic brain injury is highly heterogenous and the cognitive issues resulting from it are heterogenous, ranging from direct damage to parts of the brain subserving cognitive function to secondary effects of concussion-related depression, anxiety, post-traumatic stress disorder [PTSD], and sleep problems, » she added.
Previous research from the TRACK-TBI cohort demonstrated that one in five people have PTSD or major depressive disorder 6 months after concussion.
Earlier TRACK-TBI findings also reported that women tended to have more cognitive and somatic effects than men.
Gardner and colleagues assessed 656 people who presented to Level 1 trauma centers within 24 hours of mild TBI with a Glasgow Coma Scale (GCS) score of 13 to 15 from February 2014 to May 2016, and 156 demographically similar healthy controls.
The researchers defined poor 1-year cognitive outcome as cognitive impairment (less than the 9th percentile of normative data on two or more cognitive tests), cognitive decline (a drop at 1 year that exceeded a 90% reliable change index from previous scores on two or more cognitive tests), or both.
Testing captured different aspects of cognitive function from the Rey Auditory Verbal Learning Test (RAVLT), the Trail Making Test (TMT) parts A and B, and the Wechsler Adult Intelligence Scale, 4th edition.
Participants were tested in up to three in-person visits at 2 weeks, 6 months, and 1 year. Propensity weighting accounted for missing outcome data and study attrition.
People with mild TBI had an average age of 40; 37% were women and 77% were white. In about one in three cases, concussion was caused from being in a car during a collision; these people were more likely to have a poor 1-year cognitive outcome (42.8%) than a good one (34.3%).
Of the 13.5% of mild TBI patients who had poor cognitive outcomes a year later, 10.1% had cognitive impairment only, 1.6% had cognitive decline only, and 1.8% had both.
Of controls, 3.3% had cognitive impairment only at 1 year, 0% had cognitive decline only, and 1.2% had both.
Mild TBI patients were most likely to meet criteria for cognitive impairment and decline based on RAVLT scores.
The greatest percent difference in impairment and decline between concussion patients and controls was seen on the RAVLT, and on the TMT part A for impairment.
« This suggests that the domains of memory and processing speed are most affected at 1-year post-mild TBI, » Gardner and co-authors observed.
Poor 1-year cognitive outcomes were associated with worse 1-year functional outcomes, more neurobehavioral symptoms, greater psychological distress, and lower satisfaction with life (all P<0.05), which established concurrent validity of the cognitive outcome definition.
A model including education, health insurance, pre-injury depression, hyperglycemia, and Rotterdam CT Score (severity of intracranial trauma) had an AUC of 0.69 (95% CI 0.62-0.75) in predicting poor 1-year cognitive outcome.
The results highlight the need to better understand the mechanisms underlying poor cognitive outcome even after relatively mild brain injuries, Gardner noted.
« A thorough evaluation is necessary to unravel treatable contributors and refer to the best rehabilitation program to optimize recovery, » she said.
A limitation to the study was that people were enrolled at the time of concussion, and their pre-injury cognitive status was not known.
Judy George covers neurology and neuroscience news for MedPage Today, writing about brain aging, Alzheimer’s, dementia, MS, rare diseases, epilepsy, autism, headache, stroke, Parkinson’s, ALS, concussion, CTE, sleep, pain, and more. Follow
TRACK-TBI was funded by the NIH National Institute of Neurological Disorders and Stroke and by the Department of Defense.
The researchers reported no disclosures.