Introduction

The US estimates approximately 1.6-3.8 million sports-related traumatic brain injuries (TBI) occur each year. Given that a TBI involves a traumatic force to the head, face, neck, or other part of the body, individuals who play sports are especially at risk of sustaining cognitive deficits. Cognitive deficits can manifest as impairment of attention, verbal and visual memory, visual perception, and executive function. The purpose of this systematic review was to examine cognitive deficits following sport-related concussion/traumatic brain injury in the acute, intermediate, and long-term periods after initial head trauma.

Methods

This study was performed in accordance with PRISMA guidelines. Publications were identified by searching three databases (Pubmed, PsychInfo, and Web of Science) by using search terms including concussion, traumatic brain injury, and cognitive impairments. Studies were included if they met the following criteria: included explicit time points following injury, a focus on cognitive deficits, and if the injuries were not self-diagnosed. Studies were excluded if they measured non-cognitive deficits, or if they evaluated deficits via purely subjective measures.

Results

Twenty-four studies, (3,300 patients), were included in this systematic review. 67% (16/24) of studies were separated into control groups versus concussed groups or compared baseline scores, while 4% (1/24) separated the symptomatic versus asymptomatic groups, 12.5% (3/24) focused on complicated versus uncomplicated participants, and another 16.7% (4/24) focused on injury severity. Over 95% (23/24) of the included studies found cognitive deficits to be present at least within the acute time period following a concussion. Cognitive impairments spanning multiple categories were seen in these patients, including deficits in executive function, attention, and visual and verbal memory.

Conclusion

In patients who sustained a sport related concussion, cognitive deficits were seen across all the domains of cognitive functioning in the acute, intermediate, and long-term period following initial concussion. Athletes who sustain a concussion will often experience cognitive deficits up to weeks or months following the injury. Physicians and athletic trainers should consider severity of the injury when determining a return-to-play schedule for each individual athlete, and acknowledge the full range of potential cognitive deficits athletes may experience post-concussion.