TY - JOUR
T1 - Reduced heart rate variability and lower cerebral blood flow associated with poor cognition during recovery following concussion
AU - Purkayastha, Sushmita
AU - Williams, Benjamin
AU - Murphy, Megan
AU - Lyng, Sydney
AU - Sabo, Tonia
AU - Bell, Kathleen R.
N1 - Funding Information:
This study was supported in part by funds provided by the University Research Council Grant at the Southern Methodist University (SMU), Dallas, Texas and the Texas Institute for Brain Injury & Repair (TIBIR) at University of Texas Southwestern Medical Center , Dallas, Texas. The authors also wish to thank the athletes for volunteering in the study and the Athletic Department at SMU for their support.
Funding Information:
This study was supported in part by funds provided by the University Research Council Grant at the Southern Methodist University (SMU), Dallas, Texas and the Texas Institute for Brain Injury & Repair (TIBIR) at University of Texas Southwestern Medical Center, Dallas, Texas. The authors also wish to thank the athletes for volunteering in the study and the Athletic Department at SMU for their support. Conception and design of research: SP, and KRB. Data collection and analyses: SP, BW, MM, & SL. Manuscript was drafted by SP, BW, MM, SL, TS and KRB. All authors contributed to data interpretation, editing, and revision of the manuscript. All authors approved the final version of the manuscript.
Publisher Copyright:
© 2019 Elsevier B.V.
PY - 2019/9
Y1 - 2019/9
N2 - Although physiological deficits such as altered cerebral blood flow (CBF), and autonomic nervous system (ANS) dysregulation have been reported following a concussion, the relationship between CBF and ANS with functional outcome post-injury remains unclear. Our present study was designed to examine heart-rate variability (HRV) using percentage of successive NN intervals (pNN50) and CBF on day-3 (T1), day-21 (T2), and day-90 (T3) following a concussion in collegiate athletes (N = 31) in comparison to non-injured controls (N = 31). Continuous RR-interval (3-lead electrocardiogram), middle cerebral artery blood velocity (MCAV; transcranial Doppler ultrasonography), mean arterial pressure (MAP; finger photoplethysmography) were obtained at rest. Cerebrovascular conductance index (CVCi) was estimated as a ratio of MCAV to MAP. Cognition was evaluated with standard assessment of concussion (SAC), and Trails A & B. Compared to the controls, lower HRV (43 ± 15 vs. 27 ± 20%; p < 0.0001) was observed at T1 with normalization at T2 and T3. No difference in MCAV between the control and the concussed groups across the three time points were observed. However, post-hoc analyses indicated a positive relationship between MCAV at T1 phase with HRV and CVCi during T2, and T3 phases. Higher MCAV at T1 was also associated with better cognition scores during the asymptomatic T2 phase in the concussed athletes. Therefore, our results indicate ANS dysregulation during the acute recovery phase after a concussion. Differences in CBF may be one of the underlying causes behind heterogeneity in clinical symptoms and functional outcomes after a concussion and future studies are warranted to validate this finding.
AB - Although physiological deficits such as altered cerebral blood flow (CBF), and autonomic nervous system (ANS) dysregulation have been reported following a concussion, the relationship between CBF and ANS with functional outcome post-injury remains unclear. Our present study was designed to examine heart-rate variability (HRV) using percentage of successive NN intervals (pNN50) and CBF on day-3 (T1), day-21 (T2), and day-90 (T3) following a concussion in collegiate athletes (N = 31) in comparison to non-injured controls (N = 31). Continuous RR-interval (3-lead electrocardiogram), middle cerebral artery blood velocity (MCAV; transcranial Doppler ultrasonography), mean arterial pressure (MAP; finger photoplethysmography) were obtained at rest. Cerebrovascular conductance index (CVCi) was estimated as a ratio of MCAV to MAP. Cognition was evaluated with standard assessment of concussion (SAC), and Trails A & B. Compared to the controls, lower HRV (43 ± 15 vs. 27 ± 20%; p < 0.0001) was observed at T1 with normalization at T2 and T3. No difference in MCAV between the control and the concussed groups across the three time points were observed. However, post-hoc analyses indicated a positive relationship between MCAV at T1 phase with HRV and CVCi during T2, and T3 phases. Higher MCAV at T1 was also associated with better cognition scores during the asymptomatic T2 phase in the concussed athletes. Therefore, our results indicate ANS dysregulation during the acute recovery phase after a concussion. Differences in CBF may be one of the underlying causes behind heterogeneity in clinical symptoms and functional outcomes after a concussion and future studies are warranted to validate this finding.
KW - Autonomic nervous system
KW - Cerebral blood flow
KW - Concussion
KW - Heart rate variability
KW - Traumatic brain injury
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U2 - 10.1016/j.autneu.2019.04.004
DO - 10.1016/j.autneu.2019.04.004
M3 - Article
C2 - 31331690
AN - SCOPUS:85066012890
SN - 1566-0702
VL - 220
JO - Autonomic Neuroscience: Basic and Clinical
JF - Autonomic Neuroscience: Basic and Clinical
M1 - 102548
ER -