Early neonatal heart rate variability patterns in different subtypes of perinatal hypoxic-ischemic brain injury.

BACKGROUND: This study aims to compare the longitudinal changes in heart rate variability (HRV) during therapeutic hypothermia in neonates with different subtypes of hypoxic-ischemic brain injury. METHODS: HRV was computed from 1 hour time-epochs q6 hours for the first 48 hours. Primary outcome was brain-injury pattern on MRI at 4(3-5) days. We fitted linear mixed-effect regression models with HRV metric, brain injury subtype and postnatal age. RESULTS: Among 89 term neonates, 40 neonates had abnormal brain MRI (focal infarct 15 (38%), basal-ganglia predominant 8 (20%), watershed-predominant 5 (13%), and mixed pattern 12 (30%)). There was no significant difference in the HRV metrics between neonates with normal MRI, focal infarcts and basal ganglia pattern. At any given postnatal age, the degree of HRV suppression (HRV measure in the brain-injury subtype group/HRV measure in Normal MRI group) was significant in neonates with watershed pattern (SDNN(0.63, p = 0.08), RMSSD(0.74, p = 0.04)) and mixed pattern injury (SDNN (0.64, p < 0.001), RMSSD (0.75, p = 0.02)). HRV suppression was most profound at the postnatal age of 24-30 h in all brain injury subtypes. CONCLUSION: Neonates with underlying watershed injury with or without basal-ganglia injury demonstrates significant HRV suppression during first 48 hour of hypothermia therapy. IMPACT: Our study suggests that suppression of heart rate variability in neonates during therapeutic hypothermia varies according to the pattern of underlying hypoxic-ischemic brain injury. Neonates with watershed predominant pattern and mixed pattern of brain injury have the most severe suppression of heart rate variability measures. Heart rate variability monitoring may provide early insights into the pattern of hypoxic-ischemic brain injury in neonates undergoing therapeutic hypothermia earlier than routine clinical MRI.

Feasibility and Effects of the CO-OP Approach™ in Postconcussion Rehabilitation.

OBJECTIVE: We determined the feasibility and effects of the Cognitive Orientation to daily Occupational Performance (CO-OP) ApproachTM on activity performance and satisfaction, symptoms, and mood of adolescents with persistent postconcussion symptoms. METHOD: In a prospective case series, 3 participants with persistent symptoms 3 mo after concussion and difficulties resuming activities were taught to use a metacognitive strategy (Goal-Plan-Do-Check) to work toward occupation-based goals in a 7-wk intervention (10 sessions, 30-60 min each). Participants were assessed pre- and postintervention and at 3-mo follow-up. Feasibility was determined by positive changes on study measures, ease of administration, and acceptability to participants. RESULTS: Clinically significant, positive changes were found in participants' activity performance and satisfaction. All participants had decreases in symptoms and improved mood scores at posttest. CONCLUSION: The CO-OP Approach to rehabilitation for youth postconcussion is feasible and may make a positive contribution to recovery.

Mindfulness-Based Yoga for Youth With Persistent Concussion: A Pilot Study.

OBJECTIVE: We explored the potential impact of mindfulness-based yoga (MBY) for youth with persistent concussion by examining occupation-based and neurophysiological outcomes. METHOD: In this case series design study, 6 youths ages 13-17 yr with concussion symptoms for >4 wk participated in an 8-wk MBY intervention, 1×/wk for 45 min. Participation, self-efficacy, and heart rate variability (24 hr) were collected before, after, and 3 mo after the intervention. Heart rate variability was also measured during each session. RESULTS: Trends of increased self-efficacy in academic, social, and emotional domains were found after MBY and maintained at 3-mo follow-up. Trends of increasing heart rate variability were also found pre- to postintervention and within the eight MBY sessions. CONCLUSION: Preliminary results reveal positive trends after a novel, safe intervention for youth with persistent concussion symptoms and the value of exploring both occupation-based and neurophysiological measures. Future research with a larger sample and control group is warranted.

Grip Strength in Youth Ice Hockey Players: Normative Values and Predictors of Performance.

Toong, T, Wilson, KE, Urban, K, Paniccia, M, Hunt, AW, Keightley, M, and Reed, N. Grip strength in youth ice hockey players: Normative values and predictors of performance. J Strength Cond Res 32(12): 3503-3511, 2018-Grip strength is a simple, valid, and reliable tool for estimating overall muscular strength, a key component of health-related fitness and sport performance. To date, there is a paucity of up-to-date and developmentally sensitive grip strength norms specific to youth-athlete populations. The objectives of this study are to (a) establish normative grip strength values in youth ice hockey players, (b) descriptively compare these values with existing Canadian pediatric norms, and (c) explore the relationship between age, sex, body mass, and hockey playing level on grip strength performance. A sample of 690 male and female youth ice hockey players between the ages of 10 and 16 years were included. Participants completed assessments of maximal grip strength using a hand dynamometer on both hands. In addition, age, sex, body mass, and hockey playing level were collected. Maximal absolute grip strength, stratified by age and sex, was higher than previously published Canadian pediatric norms. Grip strength increased with age in both sexes. Males and females performed similarly until 12 years of age, after which point males had greater strength. Individuals with greater body mass had greater strength. For the nondominant hand, competitive players had greater strength than those playing house league or select. This study describes normative grip strength values in youth ice hockey players according to age, sex, body mass, and playing level. These athlete-specific norms may be used to help evaluate and monitor changes in grip strength over time in youth ice hockey players.

Development and feasibility of an evidence-informed self-management education program in pediatric concussion rehabilitation.

BACKGROUND: Concussion is a considerable public health problem in youth. However, identifying, understanding and implementing best evidence informed recovery guidelines may be challenging for families given the vast amount of information available in the public domains (e.g. Internet). The objective of this study was to develop, implement and evaluate the feasibility of an evidence-informed self-management education program for concussion recovery in youth. METHODS: Synthesis of best evidence, principles of knowledge translation and exchange, and expert opinion were integrated within a self-management program framework to develop a comprehensive curriculum. The program was implemented and evaluated in a children's rehabilitation hospital within a universal health care system. A retrospective secondary analysis of anonymous data from a program evaluation survey was used to evaluate program feasibility, to identify features of importance to program participants and to assess changes in participants' knowledge. RESULTS: The program, "Concussion & You" includes a comprehensive, evidence informed, population specific curriculum that teaches participants practical strategies for management of return to school and play, sleep, nutrition, relaxation and energy conservation. A 'wheel of health' is used to facilitate participants' self-management action plan. Results from eighty-seven participant surveys indicate that the program is feasible and participant knowledge increased in all areas of the program with the highest changes reported in knowledge about sleep hygiene, rest and energy conservation. CONCLUSION: Findings indicate that "Concussion & You" is a feasible program that is acceptable to youth and their families, and fills a health system service gap.

Developmental and gender influences on executive function following concussion in youth hockey players.

BACKGROUND: Concussion is the most common athletic injury in youth who are simultaneously undergoing rapid developmental changes in the brain, specifically the development of executive functions (EF). The developing brain is more vulnerable to concussive injury with a protracted and different trajectory of recovery than that of adults. Thus, there is a critical need to enhance understanding of how concussion affects EF in youth. OBJECTIVE: To investigate the effects of age, gender and concussion history (i.e. concussion incidence, recency, severity) on EF in youth hockey players. METHODS: This 3-year cross-sectional and longitudinal multiple cohort study examined data from 211 hockey players of 8-15 years of age. Mixed-effects modelling was used to examine the influence of age, gender and concussion on EF in youth athletes. FINDINGS: Baseline analyses revealed significant age and gender effects on measures of EF. Multiple effects of concussion history on measures of cognitive flexibility (F = 2.48, p = 0.03) and psychomotor speed (F = 2.59, p = 0.04) were found. IMPLICATIONS: This study highlights the impact of age, gender and concussion on EF in youth. These findings provide foundational knowledge to better manage cognitive sequelae following sports-related concussion.

Autonomic Function Following Concussion in Youth Athletes: An Exploration of Heart Rate Variability Using 24-hour Recording Methodology.

Participation in organized sports makes a significant contribution to youth development, but places youth at a higher risk for sustaining a concussion. To date, return-to-activity decision-making has been anchored in the monitoring of self-reported concussion symptoms and neurocognitive testing. However, multi-modal assessments that corroborate objective physiological measures with traditional subjective symptom reporting are needed and can be valuable. Heart rate variability (HRV) is a non-invasive physiological indicator of the autonomic nervous system, capturing the reciprocal interplay between the sympathetic and parasympathetic nervous systems. There is a dearth of literature exploring the effect of concussion on HRV in youth athletes, and developmental differences preclude the application of adult findings to a pediatric population. Further, the current state of HRV methodology has primarily included short-term (5-15 min) recordings, by using resting state or short-term physical exertion testing to elucidate changes following concussion. The novelty in utilizing a 24 h recording methodology is that it has the potential to capture natural variation in autonomic function, directly related to the activities a youth athlete performs on a regular basis. Within a prospective, longitudinal research setting, this novel approach to quantifying autonomic function can provide important information regarding the recovery trajectory, alongside traditional self-report symptom measures. Our objectives regarding a 24 h recording methodology were to (1) evaluate the physiological effects of a concussion in youth athletes, and (2) describe the trajectory of physiological change, while considering the resolution of self-reported post-concussion symptoms. To achieve these objectives, non-invasive sensor technology was implemented. The raw beat-to-beat time intervals captured can be transformed to derive time domain and frequency domain measures, which reflect an individual's ability to adapt and be flexible to their ever-changing environment. By using non-invasive heart rate technology, autonomic function can be quantified outside of a traditional controlled research setting.

Heart rate variability following youth concussion: how do autonomic regulation and concussion symptoms differ over time postinjury?

OBJECTIVES: Following youth concussion, objective physiological indicators are needed to corroborate changes in subjective clinical measures. The objectives of the current study were to: (1) explore the effect of concussion on heart rate variability (HRV) across days postinjury in youth athletes aged 13-18 years old, compared with healthy age-matched and sex-matched controls and (2) examine the relationship between postconcussion symptom domains (physical, cognitive, fatigue and emotional) and HRV. METHODS: Prospective, longitudinal, case-control study (N=44). This study comprised 29 concussed athletes between the ages of 13 and 18 years old (21 females, 8 males) and 15 age-matched and sex-matched controls). All participants completed baseline testing, which included demographic information (age, sex, concussion history), self-reported concussion symptoms (Post-Concussion Symptom Inventory [PCSI]) and a 24-hour heart rate recording via the Polar RS800CX system. The PCSI and HRV were collected weekly while the participant was symptomatic and then 1, 3 and 6 months following symptom resolution. HRV variables included time and frequency domain measures. Data visualisations and mixed effects modelling were used to derive parsimonious models. RESULTS: HRV increased across days postinjury. Concussion symptom domains (physical, cognitive, fatigue and emotional) all had a significant main effect on HRV; concussed participants who reported more symptoms had higher HRV compared with those who reported fewer symptoms. Visualisations of HRV depict the recovery trajectory as non-linear across time. No significant differences on HRV measures were found between concussed and control participants. CONCLUSION: These preliminary findings provide the foundation to understand the varied trajectory and relationship between objective physiological measures and subjective symptom reporting.

Postural Stability in Healthy Child and Youth Athletes: The Effect of Age, Sex, and Concussion-Related Factors on Performance.

BACKGROUND: Postural stability plays a key role in sport performance, especially after concussion. Specific to healthy child and youth athletes, little is known about the influence development and sex may have on postural stability while considering other subjective clinical measures used in baseline/preinjury concussion assessment. This study aims to describe age- and sex-based trends in postural stability in uninjured child and youth athletes at baseline while accounting for concussion-related factors. HYPOTHESES: (1) Postural stability performance will improve with age, (2) females will display better postural stability compared to males, and (3) concussion-like symptoms will affect postural stability performance in healthy children and youth. STUDY DESIGN: Cross-sectional study. LEVEL OF EVIDENCE: Level 3. METHODS: This study comprised 889 healthy/uninjured child and youth athletes (54% female, 46% male) between the ages of 9 and 18 years old. Participants completed preseason baseline testing, which included demographic information (age, sex, concussion history), self-report of concussion-like symptoms (Post-Concussion Symptom Inventory [PCSI]-Child and PCSI-Youth), and measures of postural stability (BioSway; Biodex Medical Systems). Two versions of the PCSI were used (PCSI-C, 9- to 12-year-olds; PCSI-Y, 13- to 18-year-olds). Postural stability was assessed via sway index under 4 sway conditions of increasing difficulty by removing visual and proprioceptive cues. RESULTS: In children aged 9 to 12 years old, there were significant age- ( P < 0.05) and sex-based effects ( P < 0.05) on postural stability. Performance improved with age, and girls performed better than boys. For youth ages 13 to 18 years old, postural stability also improved with age ( P < 0.05). In both child and youth subgroups, postural stability worsened with increasing concussion-like symptoms ( P < 0.05). CONCLUSION: There are developmental and baseline symptom trends regarding postural stability performance. CLINICAL RELEVANCE: These findings provide a preliminary foundation for postconcussion comparisons and highlight the need for a multimodal approach in assessing and understanding physical measures such as postural stability.

Dove and hawk profiles in youth concussion: Rethinking occupational performance.

BACKGROUND: Youth concussion and its subsequent recovery have been described as heterogeneous; no one injury is the same, and each youth is different in how he or she recovers. PURPOSE: This paper proposes a theoretical perspective on the management of youth with persistent concussion symptoms. KEY ISSUES: When managing concussion within youth, further consideration of person, occupation, and environment factors may provide insight on (a) the differential spectrum of profiles that exist among youth who have experienced a concussion and (b) how these profiles can support client-centred rehabilitation. Passive-dove and active-hawk stress profiles from evolutionary literature will be used to contextualize return to occupational performance. An innovative, novel model-the Dove-Hawk Model of Allostatic Load for Youth With Persistent Concussion Symptoms-is proposed to illustrate these concepts, and approaches to rehabilitation across the spectrum of profiles are offered. IMPLICATIONS: Viewing persistent youth concussion recovery in this way may elucidate different approaches to client-centred rehabilitation.

Clinical and non-clinical depression and anxiety in young people: A scoping review on heart rate variability.

BACKGROUND: Heart rate variability (HRV), a measure of cardiac autonomic nervous system functioning, has emerged as a physiological indicator for emotional regulation and psychological well-being. HRV is understudied in the context of depression and anxiety in young people (10-24years old). Main objectives: (1) describe the nature and breadth of reviewed studies; and (2) synthesize main findings in the context of clinical and non-clinical populations of young people with depression and/or anxiety. METHODS: The Arksey and O'Malley methodology was utilized for this scoping review. CINHAL, EMBASE, Medline, PsychInfo, Scopus, Web of Science, as well as grey literature, were searched. Two reviewers screened titles, abstracts and full papers for inclusion. A total of 20 citations were included in the final review (19 citations peer-reviewed journal articles, 1 journal abstract). Numerical and thematic analysis was used to summarize study findings. RESULTS: In clinical populations of either depression or anxiety, HRV was lower compared to controls. In non-clinical populations of either depression or anxiety, HRV was found to be lower in those who reported more depression or anxiety symptoms. LIMITATIONS: The quality of the reviewed articles was not assessed which limits the ability to generate conclusions regarding study findings. CONCLUSION: Changes in HRV were found across the spectrum of clinical and non-clinical populations of young people with depression or anxiety. Neurophysiological research on depression and anxiety in young people can act as a first step to understanding how physiological flexibility (i.e. HRV) is related to psychological flexibility (i.e. adaptive or maladaptive responses to life events).

Heart Rate Variability in Healthy Non-Concussed Youth Athletes: Exploring the Effect of Age, Sex, and Concussion-Like Symptoms.

BACKGROUND: Heart rate variability (HRV) is a non-invasive neurophysiological measure of autonomic nervous system regulation emerging in concussion research. To date, most concussion studies have focused on the university-aged athlete with no research examining healthy active youths. Corroborating changes in HRV alongside traditional subjective self-report measures (concussion symptoms) in the non-concussed state provides a foundation for interpreting change following concussion. The objectives were to (1) explore the influence of age and sex on HRV and (2) examine the relationship between HRV and baseline/pre-injury concussion symptom domains (physical, cognitive, emotional, and fatigue) in healthy youth athletes. METHOD: Healthy, youth athletes 13-18 years of age [N = 294, female = 166 (56.5%), male = 128 (43.5%)] participated in this cross-sectional study. Age, sex, and concussion-like symptoms were collected as part of a baseline/pre-injury assessment. The Post-Concussion Symptom Inventory-SR13 (PCSI-SR13) was used to collect domain scores for physical, cognitive, emotional, and fatigue symptoms. HRV was collected for 24 h. HRV measures included time (SDNN, RMSSD, and pNN50) and frequency (HF, HFnu, LF, LFnu, and total power) domain HRV measures. Variables were logarithmically transformed to increase robustness of linear regression models. RESULTS: Older youth participants displayed significantly higher HRV compared to younger participants (p < 0.05). Females displayed significantly lower HRV compared to males (p < 0.05). A significant interaction effect between concussion-like symptoms and HRV indicated differential patterns as a function of sex (p < 0.05). Youth athletes who reported more cognitive symptoms had lower HRV (p < 0.05). CONCLUSION: HRV was found to have a significant relationship with a traditional clinical measure (subjective self-report of concussion-like symptoms) utilized in concussion assessment and management. Baseline/pre-concussion trends in HRV were significantly associated with age and sex, highlighting the value in understanding key demographic factors within the context of concussion-like symptoms.

Concussion-Like Symptoms in Child and Youth Athletes at Baseline: What Is "Typical"?

CONTEXT: After a concussion, guidelines emphasize that an athlete should be asymptomatic before starting a return-to-play protocol. However, many concussion symptoms are nonspecific and may be present in individuals without concussion. Limited evidence exists regarding the presence of "typical" or preinjury (baseline) symptoms in child and youth athletes. OBJECTIVE: To describe the frequency of symptoms reported at baseline by child and youth athletes and identify how age, sex, history of concussion, and learning factors influence the presence of baseline symptoms. DESIGN: Cross-sectional cohort study. SETTING: Baseline testing was conducted at a hospital research laboratory or in a sport or school setting (eg, gym or arena). PATIENTS OR OTHER PARTICIPANTS: A total of 888 child (9-12 years old, n = 333) and youth (13-17 years old, n = 555) athletes participated (46.4% boys and 53.6% girls, average age = 13.09 ± 1.83 years). MAIN OUTCOME MEASURE(S): Demographic and symptom data were collected as part of a baseline protocol. Age-appropriate versions of the Post-Concussion Symptom Inventory (a self-report concussion-symptoms measure with strong psychometric properties for pediatric populations) were administered. Demographic data (age, sex, concussion history, learning factors) were also collected. RESULTS: Common baseline symptoms for children were feeling sleepier than usual (30% boys, 24% girls) and feeling nervous or worried (17% boys, 25% girls). Fatigue was reported by more than half of the youth group (50% boys, 67% girls). Nervousness was reported by 32% of youth girls. Headaches, drowsiness, and difficulty concentrating were each reported by 25% of youth boys and girls. For youths, a higher total symptom score was associated with increasing age and number of previous concussions, although these effects were small (age rs = 0.143, number of concussions rs = .084). No significant relationships were found in the child group. CONCLUSIONS: Children and youths commonly experienced symptoms at baseline, including fatigue and nervousness. Whether clinicians should expect complete symptom resolution after concussion is not clear.

A multi-modal approach to assessing recovery in youth athletes following concussion.

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.