Effects of Subconcussive Head Impacts on Neural Integrity and Function in ADHD

Summary

The purpose of this study is to examine the acute neural responses to subconcussive head impacts in individuals with Attention-deficit/hyperactivity disorder (ADHD). The study is designed to identify the effects of 10 controlled soccer headings in college-aged soccer players diagnosed with ADHD and without ADHD, through the use of neural-injury blood biomarkers, functional and diffusion MRI, and ocular-motor function across three acute timepoints. The central hypothesis is that neuronal structural, physiological, and functional impairments from subconcussive head impacts will be amplified by ADHD. The neural-injury blood biomarkers neurofilament light (NF-L), glial fibrillary acidic protein (GFAP), ubiquitin C-terminal hydrolase-L1 (UCHL-1), and Tau will be measured in plasma, with the hypothesis that 10 soccer headings will significantly increase plasma NF-L levels in both groups at 24h post-heading compared to baseline, but this increase will be higher in the ADHD group; plasma UCH-L1, GFAP, and Tau levels will increase significantly after 10 headings in the ADHD group at 2h and 24h post-heading, but levels in the non-ADHD group will remain consistent throughout the time points. It is also hypothesized that repetitive subconcussive head impacts will impair neurocognitive function, as measured by regional changes in fMRI activation during working memory and attention-based tasks, in the ADHD group. Ten headings will significantly alter fMRI activation in the ADHD group from baseline. This impairment will not be observed in the non-ADHD group, rather the non-ADHD group will show consistent fMRI activation even after 10 headings. White matter microstructure will be measured by diffusion imaging metrics, with the hypothesis that 10 soccer headings will significantly disrupt microstructure in the ADHD group compared to baseline, but not in the non-ADHD group. The study will also assess neuro-ophthalmologic function as measured by the King-Devick test (KDT) and oculomotor function as measured by the near-point-of-convergence (NPC) in response to subconcussive head impacts. The hypothesis is that NPC performance will be significantly impaired and persist for longer than 24 hours in both groups, but this impairment will be greater in the ADHD group, and that the learning curve and expected improvement of KDT will be significantly blunted in both groups, with a display of worsening in the ADHD group.

Conditions

• Sport Injury
• Attention-deficit/Hyperactivity Disorder

Interventions

OTHER

Soccer Heading

A standardized and reliable soccer heading protocol will be used for the experiment. A triaxial accelerometer embedded in a head-band pocket and positioned directly below the external occipital protuberance (inion) to monitor linear and rotational head accelerations. A JUGS soccer machine will be used to simulate a soccer throw-in with a standardized ball speed of 25mph. The ball speed is similar to when soccer players make a long throw-in from the sideline to mid-field. Soccer players frequently perform this maneuver during practice and games. Subjects will stand approximately 40ft away from the machine to perform the heading. Participants perform 20 standing headers with 1 header per 30 seconds. The subjects will be instructed to direct the ball back toward the JUGS soccer machine in the air.

OTHER

Soccer Heading

A standardized and reliable soccer heading protocol will be used for the experiment. A triaxial accelerometer embedded in a head-band pocket and positioned directly below the external occipital protuberance (inion) to monitor linear and rotational head accelerations. A JUGS soccer machine will be used to simulate a soccer throw-in with a standardized ball speed of 25mph. The ball speed is similar to when soccer players make a long throw-in from the sideline to mid-field. Soccer players frequently perform this maneuver during practice and games. Subjects will stand approximately 40ft away from the machine to perform the heading. Participants perform 20 standing headers with 1 header per 30 seconds. The subjects will be instructed to direct the ball back toward the JUGS soccer machine in the air.

Sponsors & Collaborators

• Indiana University

  lead OTHER

Study Design

Allocation

NON_RANDOMIZED

Purpose

OTHER

Masking

DOUBLE

Model

PARALLEL

Eligibility

Min Age

18 Years

Max Age

26 Years

Sex

ALL

Healthy Volunteers

Yes

Timeline & Regulatory

Start

2021-03-15

Primary Completion

2022-03-15

Completion

2022-03-15

Countries

• United States

Study Locations