Trauma, Brain
Conditions
Keywords
soccer heading, subconcussive head impacts, hypoxia
Brief summary
The purpose of this study is to examine the combined effects of hypoxia and a short bout of subconcussive head impacts on neurocognitive and ocular-motor function and plasma expression of brain-derived blood biomarkers.
Detailed description
The purpose of the pilot study is to observe preliminary trends in neural response to subconcussive head impacts in hypoxic condition. This work will provide a critical un-tested knowledge regarding the combined effects of subconcussion and hypoxic condition (mimicking high altitude), which will be used in our upcoming grant proposal to the Department of Defense (DoD). Military personnel, particularly those who are deployed to Afghanistan, are constantly subjected to hypoxic condition, given that the majority of military land operations in Afghanistan occur at 2000-3000 meters (6500-10,000 feet). This level of altitude does not elicit major side effects, yet neural functions may experience some degree of perturbation (i.e., slowed reaction time, altered night vision). Concurrently, these military personnel, who operate at high altitudes, often incur subconcussive forces to the head. These subconcussive head impacts can be induced by exposure to, for example, flash-bang grenades, artillery fire, recoilless rifle, improvised explosive devices (IEDs), and head collision. The combined effects of these two stressors have the potential to attenuate one's readiness, operational efficiency, and overall brain function, but the combined effects have never been studied to date. As a result, one of four study topics that the Defense Centers of Excellence deems urgent is: Document the effects of altitude exposure on mild traumatic brain injury (mTBI) and blast-induced neurotrauma (BINT). To answer the question, we hypothesized that there will be an exponential worsening in neurocognitive function and in ocular-motor system functioning, and increased plasma expression of brain-derived biomarkers, after subconcussive head impacts under hypoxic conditions.
Interventions
BEHAVIORALSoccer heading
A standardized and reliable soccer heading protocol will be used to induce subconcussive impacts for the experiment. A triaxial accelerometer (Triax Technologies, Norwalk, CT) embedded in a head-band pocket and positioned back of the head to monitor linear and rotational head accelerations. A JUGS soccer machine (JUGS Sports, Tualatin, OR) will be used to simulate a soccer throw-in with a standardized ball speed of 25 mph across all groups. 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 practices and games. Participants will stand approximately 40ft away from the machine to perform the heading. Participants will perform a total of 10 headers at a rate of 1 header per minute and will be instructed to direct the ball back towards the JUGS machine. Previous uses of this soccer heading model have reported an average peak linear acceleration per header of 14.5 to 33.5 g.
Sponsors
Indiana University
Study design
Allocation
RANDOMIZED
Intervention model
CROSSOVER
Primary purpose
DIAGNOSTIC
Masking
SINGLE (Subject)
Eligibility
Sex/Gender
ALL
Age
18 Years to 26 Years
Healthy volunteers
Yes
Inclusion criteria
* Between 18 and 26 years old * Current or former soccer player (i.e., collegiate, intramural, club, professional) * At least 3 years of soccer heading experience * Participants can read and speak English * Participants have cell phone or computer with internet access to schedule for follow-up visits via email or text message * Participant is willing to refrain from participating in any sport activity that purposefully uses one's head to maneuver (American football, ice-hockey, rugby, wrestling, and soccer heading) during study participation
Exclusion criteria
* Any head, neck, or face injury in the 1 year prior to the study (e.g., concussion, eye injury) * History of vestibular, ocular, or vision dysfunction (e.g., macular degeneration) * Currently taking any medications that trigger drowsiness * Pregnancy * Any history of neurological disorders (e.g., seizure disorders, closed head injuries with loss of consciousness greater than 15 minutes, CNS neoplasm, spinal cord injury/surgery, history of stroke) * Lower extremity injury that would prohibit normal walking * Metal implants in the head Conditional
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Acute change in neurocognitive function from pre-heading at 0 hour post-heading | Neurocognitive function will be assessed at pre- and 0 hour post-heading | Participants will complete a computerized neurocognitive assessment (Immediate Post-Concussion Assessment and Cognitive Testing). |
| Acute change in convergence function from pre-heading at 0 hour post-heading | Conversion function will be assessed at pre- and 0 hour post-heading | Participants will undergo near-point of convergence (in centimeter) to evaluate how closely one can visualize a moving target without double vision occurs. |
| Acute change in brain-derived blood biomarkers from pre-heading at 0 hour post-heading | Blood samples will be collected at pre- and 0 hour post-heading | Blood samples will be collected and centrifuged at 1500 x g for ten minutes at 4 degree celsius. Plasma will be aliquoted and stored at -80 degree celsius until analysis. Plasma samples will be assayed for neurofilament-light (NfL), glial fibrillary acidic protein (GFAP), and tau. |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Acute change in saccadic eye movement function from pre-heading at 0 and 24 hour post-heading | Saccadic eye movement function will be assessed at pre- , 0, and 24 hour post-heading | Participants will undergo King-Devick Test--a brief assessment of saccadic eye movements, attention, and visual and language processing |
| Change in neurocognitive function at 24 hours post-heading follow-up | Neurocognitive function will also assessed at 24 hours post-heading | Upon their return to the laboratory, participants will again complete a computerized neurocognitive assessment (Immediate Post-Concussion Assessment and Cognitive Testing). |
| Acute change in smooth eye pursuit function from pre-heading at 0 and 24 hour post-heading | Smooth eye pursuit function will be assessed at pre- , 0, and 24 hour post-heading | Participants will undergo the EYE-SYNC smooth pursuit task. |
| Change in ocular-motor function at 24 hours post-heading follow-up | Ocular-motor function will also assessed at 24 hours post-heading | Upon their return to the laboratory, participants will again undergo three ocular-motor assessments: 1) near-point of convergence; 2) King-Devick Test--a brief assessment of saccadic eye movements, attention, and visual and language processing; and 3) the EYE-SYNC smooth pursuit task. |
| Change in brain-derived blood biomarkers at 24 hours post-heading follow-up | A third blood sample will be collected at 24 hours post-heading | Blood samples will be collected and centrifuged at 1500 x g for ten minutes at 4 degree celsius. Plasma will be aliquoted and stored at -80 degree celsius until analysis. Plasma samples will be assayed for neurofilament-light (NfL), glial fibrillary acidic protein (GFAP), and tau. |
Countries
United States
Outcome results
None listed