A Multi-Modal Approach to Assessing Recovery in Youth Athletes Following Concussion

Summary

This article provides an overview of a multi-modal approach to assessing recovery following concussion in youth athletes. The described protocol uses pre- and post-concussion assessment of performance across a wide variety of domains and can inform the development of improved concussion rehabilitation protocols specific to the youth sport community.

Abstract

Concussion is one of the most commonly reported injuries amongst children and youth involved in sport participation. Following a concussion, youth can experience a range of short and long term neurobehavioral symptoms (somatic, cognitive and emotional/behavioral) that can have a significant impact on one’s participation in daily activities and pursuits of interest (e.g., school, sports, work, family/social life, etc.). Despite this, there remains a paucity in clinically driven research aimed specifically at exploring concussion within the youth sport population, and more specifically, multi-modal approaches to measuring recovery. This article provides an overview of a novel and multi-modal approach to measuring recovery amongst youth athletes following concussion. The presented approach involves the use of both pre-injury/baseline testing and post-injury/follow-up testing to assess performance across a wide variety of domains (post-concussion symptoms, cognition, balance, strength, agility/motor skills and resting state heart rate variability). The goal of this research is to gain a more objective and accurate understanding of recovery following concussion in youth athletes (ages 10-18 years). Findings from this research can help to inform the development and use of improved approaches to concussion management and rehabilitation specific to the youth sport community.

Introduction

Concussion can be defined as "a complex pathophysiologic process affecting the brain induced by traumatic biomechanical forces"¹, and can result in short and long-term somatic, cognitive and/or emotional/behavioral symptoms². Functionally, concussion and related symptoms can have a significant impact on one's participation in daily activities and pursuits³. It has been estimated that within the United States, between 1.6 and 3.8 million concussion occur each year as a result of sport participation⁴. Specific to children and youth involved in sports, concussion is one of the most commonly reported injuries^5-7. Despite the impact concussion can have on daily activities and the prevalence of concussion amongst children and youth, there remains a lack of scientific data reporting how the youth brain responds to concussion across a variety of performance domains.

Baseline testing, or the use of pre-injury testing scores as a benchmark for comparison against post-injury testing scores to inform recovery, is a practice of growing popularity within the youth sport community and has been suggested internationally⁸ to be "helpful to add useful information" (p.3) during the management of concussion. In order to best represent the varied nature of post-concussion symptoms (somatic, cognitive and emotional/behavioral), it is important that the assessment of post-concussion recovery include a variety of outcome measures. Further, current concussion management relies heavily on subjective report of post-concussion symptoms. The validity of this subjective report can be influenced by a variety of factors⁹ and may lead to both under-reporting of symptoms^10,11 and a less accurate and reliable index of recovery. As a result, there is a significant need to explore approaches to measuring post-concussion recovery across performance domains that are both objective and sensitive.

It has been demonstrated that cognition, balance, strength and agility can be impaired in youth following concussion and brain injury^12-17. The measures included within this testing protocol were chosen to provide insight into recovery across these domains following concussion and to incorporate the use of validated clinical testing tools that are commonly used across clinical settings focused on concussion management. Further, from a more exploratory perspective, resting state HRV can be seen as an accurate measure of sympathovagal balance^18,19 . In a healthy population, sympathovagal balance is defined as the parasympathetic system being dominant at rest, while the sympathetic system is under tonic inhibitory control. It is hypothesized that post-concussion, due to physiological stress, an imbalance between the two systems will exist and resting state may shift to hyperactivity of the sympathetic system and hypoactivity of the parasympathetic system²⁰.

The goal of this study's protocol is to conduct a multi-modal assessment of pre- and post-concussion performance amongst youth athletes (ages 10-18 years) in order to gain a more holistic, objective and accurate understanding of recovery following concussion. This study aims to provide insight into the development and delivery of concussion management and rehabilitation protocols specific to children and youth.

Protocol

The described protocol includes pre-injury/baseline testing and post-injury follow-up assessment and is completed using three stations. This testing can be completed individually or in groups of four subjects at each station at a time. Subjects proceed through each station in the order listed below. Table 1 illustrates the protocol’s testing administration schedule. Ethics approval for this research was obtained from the Holland Bloorview Research Ethics Board at the Holland Bloorview Kids Rehabilitation Hospital. All participants and their legal guardians provide signed informed consent prior to completing the protocol and related data collection.

Pre-injury/Baseline Testing

1. Station 1: Obtaining Pre-injury Demographic Information, Post-concussion Symptom Report and Resting State Heart Rate Variability (HRV) Data

1. Prior to subject(s) arriving for testing, ensure all equipment is functioning properly and ready for testing and that the assessment rooms are free from unnecessary distractions.
2. After reviewing parental and subject consent, measure and record the subject’s height and weight. Set up heart rate monitor straps and watches on each subject properly.
3. Administer the demographic information form and collect post-concussion symptom report using the Child version of the Post-Concussion Symptom Inventory(PCSI-C) while each subject is seated for 5 min.
4. Have each subject lay supine on the ground on a clean sanitized mat. Turn on the heart rate monitors to record resting state heart rate variability (HRV) data (with R-R interval function set to [On]). Have each subject remain lying in supine quietly without talking for 10 min while recording HR.
5. After 10 min, click the lap button on the watch to indicate the end of supine lying resting state HRV data collection. Ask the subject to return to a seated position, click the lap button on the watch again to indicate beginning of resting state seated HRV data collection.
6. Have each subject remain in the seated position for 5 min without talking. After 5 min, stop the watch recording function to end the session and resting state HRV data collection. Ask the subject to take off the heart rate strap and watches.

2. Station 2: Obtaining Cognitive Performance Data

1. Have each subject sit at an individual cubicle with a personal laptop set up with a mouse. Ensure testing environment is free from distraction.
2. Administer the Immediate Post-concussion Assessment and Cognitive Testing (ImPACT), a rapid and computerized neuropsychological assessment tool (approximately 25 min to complete).

3. Station 3: Obtaining Static Balance, Grip Strength and Agility/Motor Skills Data

1. Administer the static balance assessment using the modified Clinical Test of Sensory Integration of Balance (m-CTSIB) on the portable balance system. While standing on the balance system forceplate, the subject completes four ordered conditions that include standing with eyes open for 20 sec; standing with eyes closed for 20 sec; standing with eyes open on indexed foam pad for 20 sec; and standing with eyes closed on indexed foam pad for 20 sec.
2. Using a Dynamometer, measure and record hand grip strength in kg for both right and left hands. Record the dominant hand for each subject while still completing 3 consecutive trials for each hand starting with the dominant hand. Out of the 3 trials taken, the maximum hand grip on each hand will also be recorded. For each trial the subject is told to squeeze the grip as hard as they can for 3 sec keeping a neutral upper extremity position (standing upright, straight arm parallel beside the body, palm facing the body and wrist neutral).
3. In a hallway or gym at least 2.5 m wide and 15 m long administer the agility/motor skills assessment using the ABI-Challenge Assessment (ABI-CA) - Concussion Module. Lay tape on the ground in a straight line marking points for every 1 m. In the following order administer these 6 tests following the guidelines and scoring criteria provided in the concussion module.
   1. Jumping-jacks (Timed):
      1. Stand with your arms at your sides and jump into an “X” position with arms and legs, and then instantly jump back into starting position. Count how many can be done in 15 sec.
   2. Pylon/cone obstacle course run (Timed):
      1. Run in and out of the pylons to the end (10 m) and back as fast as you can but at a speed that you feel safe. Do not touch the pylons. Run straight through the finish line. (Pylons located at 3, 5, 7, 10 m)
   3. Backwards tandem walking (Timed):
      1. On the lined track, walk backwards in a tandem pattern for 5 m. Tandem pattern is touching their heel to their opposite toe on each step.
   4. Modified shuttle run (Timed):
      1. Run along the 10 m track, pick up a beanbag at the end of the course, and run back to place the beanbag in a basket at the starting point. They must touch the starting line with their foot each time they return to the basket. Repeat this three times until all the beanbags are in the basket at the starting point.
   5. Ins and outs (Timed):
      1. Stand with both feet inside of two parallel lines (in the path) that are 40 cm apart. Move one foot outside of the corresponding line followed by the opposite leg moving outside of the other line. The first foot is then returned to the inside, followed by the second foot. Cycles must be consecutive and should be performed in a rhythmical fashion (equal time between each step), and will be repeated 10x not moving forward or backward.
   6. Standing long jump: Jump forward from standing with both feet as far as you can and hold the landing for 3 sec. Measure and record the distance from the front of the furthest back foot. Three trials are given to achieve the farthest distance

4. Post-injury/Follow-up Testing

1. Obtaining post-concussion data while subject is experiencing post-concussion symptoms
   1. On the same day a subject suffers an injury, research staff is contacted by subject using either phone or email. Research staff records clinical and functional details regarding the injury.
   2. Immediately following concussion (24-48 hr post injury), collect: resting state HRV data (repeat steps 1.3, 1.5-1.10); post-concussion symptom data (repeat step 1.4); and balance data (repeat step 3.1). If symptoms are exacerbated during testing, stop data collection and allow subject to rest.
   3. Continue to collect resting state HRV data (repeat steps 1.3, 1.5-1.10), post-concussion symptom data (repeat step 1.4), and balance data (repeat step 3.1) weekly until post-concussion symptoms have resolved. If symptoms are exacerbated during testing, stop data collection and allow subject to rest.
   4. Research staff follows up with subject weekly by phone to determine when post-concussion symptoms resolve (using PCSI-C).

5. Obtaining Post-concussion Data While Subject is no Longer Experiencing Post-concussion Symptoms

1. At 1 week after post-concussion symptoms have resolved, collect: resting state HRV data (repeat steps 1.3, 1.5-1.10); post-concussion symptom data (repeat step 1.4); cognitive performance data (repeat steps 2.1-2.2); balance data (repeat step 3.1); hand grip data (repeat step 3.2); and, agility/motor skills data (repeat step 3.3). If symptoms are exacerbated during testing, stop data collection and allow subject to rest.
2. At 1 month after post-concussion symptoms have resolved, repeat step 5.1. At 3 months after post-concussion symptoms have resolved, repeat step 5.1. At 6 months after post-concussions symptoms have resolved, repeat step 5.1.

Results

The presented protocol is an ongoing investigation. Table 1 depicts the protocol’s testing administration schedule. Representative results are presented to demonstrate the feasibility of collecting baseline/pre-injury and post-concussion data across a variety of performance domains known to be impacted by concussion in youth. A single case of a concussed youth who has completed all stages of the protocol is presented to demonstrate recovery trajectories across selected outcome measures. Fig...

Discussion

This protocol presents a multi-modal approach to measuring recovery in youth athletes following a concussion. A critical feature of this protocol is the comparison of post-concussion data across a wide range of performance domains (cognition, balance, strength, agility, resting state heart rate variability, etc.) to pre-injury/baseline. These data serve as a means to indicate recovery amongst individual youth athletes following a concussion. By using common and readily available clinical measures of cognition, b...

Materials

Name	Company	Catalog Number	Comments
Scale	Weight Watchers: Conair	WW30WB
Measuring Tape	Hi-Viz Lufkin	HVC716CME
Heart Rate Monitor (Chest Strap and Watch)	Polar	RS800CX GPS
Exercise/Yoga Mat	Pur Athletics	WTE10126
Sportline Stopwatch (Model 228)	EB Sport Group	#2787
Laptop - MacBook Pro	Apple	A1278
Computerized Cognitive Assessment- Immediate Post-Concussion Assessment and Cognitive Task	ImPACT Application's Inc.
Hand Grip Dynamometer	Sammons Preston- Smedley-Type	5032P
BioSway	Biodex Medical Supplies Inc.	950-510
Painter's Mate Green Tape	ShurTech Brands LLC	#49462
Pylons/Cones (12")	Canadian Tire	84-295-4
Basket	Canadian Tire	42-9919-2
Bean Bags	Eastpoint/Go Gater	1-1-16392