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

Abstract

ObjectivesFollowing 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.MethodsProspective, 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.ResultsHRV 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.ConclusionThese preliminary findings provide the foundation to understand the varied trajectory and relationship between objective physiological measures and subjective symptom reporting.

Predictive Value of Subacute Heart Rate Variability for Determining Outcome Following Adolescent Concussion

“…Furthermore, a greater HRV during physical exertion was associated with slower cognitive performance as indexed by the reaction time and reaction time variability on the ONB task at the subacute evaluation (RMSSD). These findings corroborate prior research that observed associations between higher HRV and poorer emotional and cognitive symptoms in concussed adolescents [ 35 ]. Recent literature demonstrates that concussed patients may exhibit an inappropriate increase in vagal tone in response to physiological and cognitive stress compared to healthy controls [ 32 , 33 ].…”

“…Recent evidence has shown that HRV metrics are associated with symptom severity and postinjury deficits in cognitive function following a concussion [ 34 , 35 ]. Although promising, the current literature is incomplete and has not yet examined HRV as a predictive marker of the adolescent concussion outcome.…”

An Evaluation of Heart Rate Variability in Female Youth Soccer Players Following Soccer Heading: A Pilot Study

“…Heart rate variability may be adequately sensitive to identify effects in short term testing conditions. Changes in HRV analyses are demonstrated following concussion injury in youth [26]. Accordingly, future work should explore the importance of HRV measures and the potential influence of cumulative header impacts on brain health.…”

Neuroprotection Following Concussion: The Potential Role for Cannabidiol

“…Administration of ABN-CBD has been shown to attenuate these effects in rats and even promote vagal responses (such as decreased heart rate and mean arterial pressure), supported by a high frequency increase in the electrocardiogram (ECG) R-R index spectral analysis. 187 It is important to note that heart rate variability impairments have been noted following concussion, 74,188,189 although the specific physiological mechanism(s) is still unknown.…”