Cognitive Deficits Following Concussion: A Systematic Review

Abstract

Context In the U.S., approximately 1.6 to 3.8 million concussions occur yearly as a result of sports. Athletes are especially at risk of sustaining cognitive deficits as a result of a concussion. These can manifest as impairments of attention, verbal and visual memory, visual perception, and executive function. Objective The purpose of this study was to examine cognitive deficits following sport-related concussions in the acute, intermediate, and long-term time period after initial head trauma. Data Sources A systematic review of the literature was performed according to PRISMA guidelines using the PubMed, Psychinfo, and Web of Science databases. Study Selection Search terms included sports-related concussion, traumatic brain injury (TBI), and cognitive impairments. Studies were excluded if they measured non-cognitive deficits or had subjective results. Participant characteristics such as average age, gender, and athletic status were also included from all articles. Study Design Systematic Review. Level of Evidence Level 4. Data Extraction Studies were included if they met the following criteria: explicit time points following injury, focus on cognitive deficits, and injuries were not self-diagnosed. Results Twenty-six studies, with a total of 4,534 patients, were included. Ten of twenty-six (38.4%) studies were separated into control groups versus concussed groups, while nine of twenty-six (34.6%) compared baseline scores to post-injury scores. In the included studies, cognitive deficits were seen across all of the domains in all three time periods following an initial concussion. Conclusion A sports related concussion could result in cognitive deficits in the domains of visual memory, verbal memory, processing speed, executive function, and reaction time. Additionally, athletes typically experience cognitive deficits for only days to weeks following a sports related concussion, but symptoms can continue for months or years following the injury, depending on severity. These conclusions should be taken into consideration when determining inidivudalized return-to-play protocol for each athlete.