@article{ref1,
title="Serial monitoring of CO(2) reactivity following sport concussion using hypocapnia and hypercapnia",
journal="Brain injury",
year="2013",
author="Len, Trevor K. and Neary, J. Patrick and Asmundson, Gordon J. G. and Candow, Darren G. and Goodman, David G. and Bjornson, Bruce and Bhambhani, Yagesh N.",
volume="27",
number="3",
pages="346-353",
abstract="Primary objective: This study examined the effects of mild traumatic brain injury (mTBI) on cerebrovascular reactivity (CVR). Research design: A repeated measures design was used to examine serial changes in CVR. Methods and procedures: Twenty subjects who recently suffered a mTBI were subjected to a respiratory challenge consisting of repeated 20 s breath-holds (BH) and hyperventilations (HV). Testing occurred on days 2 (D2), 4 (D4) and 8 (D8) post-injury as well as a baseline (BASE) assessment (after return-to-play). Transcranial Doppler was used to assess mean cerebral blood velocity (vMCA) and expired gas analysis provided end-tidal carbon dioxide (PETCO(2)) levels. Results: There was no significant difference in resting vMCA across all testing days for mTBI. No significant differences in PETCO(2) were found throughout the testing protocol. A significant effect (p < 0.001) of testing day on vMCA was found during BH and HV challenges for mTBI. Post-hoc analysis revealed significant differences (p < 0.05) in vMCA between D2 and the other testing days. Conclusions: These data suggest that, following mTBI: (1) CVR is not impaired at rest; (2) CVR is impaired in response to respiratory stress; and (3) the impairment may be resolved as early as 4 days post-injury.<p /> <p>Language: en</p>",
language="en",
issn="0269-9052",
doi="10.3109/02699052.2012.743185",
url="http://dx.doi.org/10.3109/02699052.2012.743185"
}