Cerebral Blood Flow Ultrasonography as a Diagnostic Tool for Monitoring Recovery from Concussion in Children and Adolescents

Abstract

Approximately 70% of concussions are sports‐related, accounting for up to 1.9 million children and adolescents in the USA every year. Despite the high rates of injury, there are currently no consistent agreements regarding objective measures of diagnosis or severity of injury. Our pilot study determined whether cerebral blood flow (CBF) in the internal carotid artery can be utilized as an objective marker of concussion and recovery trajectory in concussed children and adolescents. We recruited individuals being seen at a concussion clinic with post concussive symptoms (mean= 40 ± 31 days post injury; range= 8–101 days) vs a group of controls who were being seen at the clinic for musculoskeletal injury. Concussed (n=10, 7 male; 12 ± 3 years) and healthy controls (n=8, 5 male; 13 ± 2 years) underwent ultrasound assessments of internal carotid artery blood flow during resting conditions when seated and supine. Continuous blood pressure, ECG, and end‐tidal CO2 were also obtained in participants. Preliminary results showed a trend for an increase in CBF in concussed children when seated (concussed= 644 ± 167 ml/min vs control= 535 ± 118 ml/min; p=0.122) but not when supine (concussed= 628 ± 142 ml/min vs control= 602 ± 140 ml/min; p=696). When comparing the percent of supine CBF when seated, concussed children showed a trend for greater CBF (concussed= 104 ± 19% vs control= 90 ± 11% p=0.101). Interestingly, in our 10 concussed participants, the ratio of seated to supine CBF negatively correlated with the number of days since injury (r= −0.738; p=0.015), suggesting elevated seated CBF may be returning towards normal values. There were no differences in end‐tidal CO2 between concussed and controls when seated (concussed= 40.4 ± 3.0 mmHg vs control= 40.8 ± 3.3 mmHg) or supine (concussed= 40.4 ± 3.8 mmHg vs control= 41.1 ± 3.8 mmHg). However there was significantly increased mean arterial pressure in controls when supine (concussed= 83.4 ± 4.8 mmHg vs control= 92.4 ± 11.9 mmHg; p=0.036) and a trend when seated (concussed= 86.2 ± 5.2 mmHg vs control= 96.0 ± 12.2 mmHg; p=0.074). If additional subjects follow the same pattern, our preliminary data would suggest that concussed children appear to be hyperperfused when seated. While it is unclear why CBF may be elevated when seated, one possibility is that flow is matching the increased metabolic demand associated with neural remodeling after injury. Our preliminary data supports that ultrasonography may be a useful diagnostic tool to monitor recovery from concussion in children and adolescents when taking into account body posture.Support or Funding InformationThe study was supported by the MARCS Institute for Brain, Behaviour and Development, Western Sydney University, Sydney, AUS.This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.