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Neurol."],"abstract":"<jats:p>Concussions have been shown to result in autonomic dysfunction and altered cerebral vascular function. We tested the hypothesis that concussed athletes (CA) would have altered cerebral vascular function during acute decreases and increases in blood pressure compared to healthy controls (HC). Ten CA (age: 20 \u00b1 2 y, 7 females) and 10 HC (age: 21 \u00b1 2 y, 6 females) completed 5 min of lower body negative pressure (LBNP; \u221240 mmHg) and 5 min of lower body positive pressure (LBPP; 20 mmHg). Protocols were randomized and separated by 10 min. Mean arterial pressure (MAP) and middle cerebral artery blood velocity (MCAv) were continuously recorded. Cerebral vascular resistance (CVR) was calculated as MAP\/MCAv. Values are reported as change from baseline to the last minute achieved (LBNP) or 5 min (LBPP). There were no differences in baseline values between groups. During LBNP, there were no differences in the change for MAP (CA: \u221223 \u00b1 18 vs. HC: \u221221 \u00b1 17 cm\/s;<jats:italic>P<\/jats:italic>= 0.80) or MCAv (CA: \u221213 \u00b1 8 vs. HC: \u221218 \u00b1 9 cm\/s;<jats:italic>P<\/jats:italic>= 0.19). The change in CVR was different between groups (CA: \u22120.08 \u00b1 0.26 vs. HC: 0.18 \u00b1 0.24 mmHg\/cm\/s;<jats:italic>P<\/jats:italic>= 0.04). Total LBNP time was lower for CA (204 \u00b1 92 s) vs. HC (297 \u00b1 64 s;<jats:italic>P<\/jats:italic>= 0.04). During LBPP, the change in MAP was not different between groups (CA: 13 \u00b1 6 vs. HC: 10 \u00b1 7 mmHg;<jats:italic>P<\/jats:italic>= 0.32). The change in MCAv (CA: 7 \u00b1 6 vs. HC: \u22124 \u00b1 13 cm\/s;<jats:italic>P<\/jats:italic>= 0.04) and CVR (CA: \u22120.06 \u00b1 0.27 vs. HC: 0.38 \u00b1 0.41 mmHg\/cm\/s;<jats:italic>P<\/jats:italic>= 0.03) were different between groups. CA exhibited impaired tolerance to LBNP and had a different cerebral vascular response to LBPP compared to HC.<\/jats:p>","DOI":"10.3389\/fneur.2021.620757","type":"journal-article","created":{"date-parts":[[2021,4,9]],"date-time":"2021-04-09T04:57:54Z","timestamp":1617944274000},"update-policy":"https:\/\/doi.org\/10.3389\/crossmark-policy","source":"Crossref","is-referenced-by-count":15,"title":["Preliminary Evidence of Orthostatic Intolerance and Altered Cerebral Vascular Control Following Sport-Related Concussion"],"prefix":"10.3389","volume":"12","author":[{"given":"Morgan L.","family":"Worley","sequence":"first","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Morgan C.","family":"O'Leary","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"James R.","family":"Sackett","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Zachary 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