Effect of Repetitive Head Impacts on Neurocognition in Motor Sport Athletes

Poster Title: Effect of Repetitive Head Impacts on Neurocognition in Motor Sport Athletes

Student: Connor Hile, Class of 2024

Faculty Mentor and Department: Jillian Urban, PhD, MPH, and Joel Stitzel, PhD, Biomedical Engineering

Funding Source: The Harry O. Parker Neuroscience Research Fund

ABSTRACT

Background: With 1.6-3.8 million sports-related concussion (SRC) occurring annually, mild-traumatic brain injury (mTBI) has become both a growing health concern and public health issue. Concussion, often used interchangeably with mTBI, can result from a direct or indirect blow to the head resulting in a slew of symptoms – somatic, cognitive, mood, and sleep. Recent studies have investigated subconcussive hits – head impacts that do not present with traditional symptoms associated with a concussion – and found alterations to neuropathology and decreased cognitive scores. Historically, most concussive and subconcussive research focuses on contact sports (football, soccer, hockey, etc.). However, head injury in motor sport has not garnered as much attention until recently. Motor sport drivers are exposed to concussion during crash events while also experiencing intense driving conditions with various terrains that can result in vehicular vibrations that are transmitted to the head, both of which can result in subconcussive exposures throughout the duration of the event. The aim of this study was to evaluate the effect of repetitive head impacts on neurocognitive measures in motor sport athletes at preseason and postseason timepoints. This was a post-hoc analysis that analyzed motor sport drivers at three different timepoints using the ImPACT test, SCAT5, and Conners Continuous Performance Test (CPT3). 

Hypothesis: It is hypothesized that over the course of the season, the motor sport drivers will show a decrease in cognitive function (executive function, reaction time, etc.) and an increase in total symptoms.  

Methods: Before the season, 18 motor sport drivers completed the ImPACT test, NIH Toolbox, and CPT3. These tests were then repeated after the first quarter (n=15) and second quarter of the season (n=12). The ImPACT test gathered basic demographic information and provided a series of tests measuring verbal memory, visual memory, visual motor speed, reaction time, impulse control, and a total symptom score. The NIH Toolbox measured executive function, attention, episodic memory, language, processing speed, and working memory. The CPT3 measured attention-related problems (inattentiveness, impulsivity, sustained attention, and vigilance). 

Results: Between the baseline and the first quarter, a significant difference was found in the NIH Toolbox List Sorting Working Memory (p=0.0051), ImPACT Composite Verbal Memory score (p=0.03), and CPT3 Hit Reaction Time Standard Deviation (p=0.0018). Between the baseline and the second quarter, a significant difference was found in the ImPACT Total Symptom Score (p=0.04) and NIH Toolbox List Sorting Working Memory Test (0.006). Between the first quarter and second quarter, a significant difference was found in the ImPACT Reaction Time (p=0.03)

Conclusions: The accumulation of subconcussive exposures experienced in motor sport drivers over the course of a season may negatively impact various neurocognitive domains, particularly working memory, as this functionality was hindered at two different timepoints. Future studies should incorporate a larger sample size and control for practice effects if repeating neurocognitive measurements. 

Source of mentor’s funding or other support that funded this research: Department of Biomedical Engineering, Childress Institute for Pediatric Trauma