{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,6,30]],"date-time":"2026-06-30T16:30:33Z","timestamp":1782837033998,"version":"3.54.5"},"reference-count":0,"publisher":"Portland Press Ltd.","issue":"3","content-domain":{"domain":["portlandpress.com"],"crossmark-restriction":true},"short-container-title":[],"published-print":{"date-parts":[[2004,3,1]]},"abstract":"<jats:p>Cerebral blood flow is thought to increase at high altitude and in subjects suffering from acute mountain sickness (AMS); however, data from the literature are contentious. Blood flow velocity in the middle cerebral artery (MCAv) may be used as a proxy measure of cerebral blood flow. Using transcranial Doppler sonography, MCAv was measured during normo- and hyper-ventilation in subjects who participated in a trial that tested the effect of magnesium supplementation on the prevention of AMS. First, MCAv was recorded at 353 m (baseline). Subjects were then randomized to receive oral magnesium citrate and matching placebo. A second measurement was taken after a 24\u00b12 h ascent from 1130 m to 4559 m (altitude I), and a third after a 20\u201324 h stay at 4559 m (altitude II). Using multivariate linear regression, an association was sought between MCAv and magnesium supplementation, subjects\u2032 age and gender, altitude itself, a temporary stay at altitude, and the presence of AMS (Lake Louise Score &amp;gt;6 with ataxia, nausea and\/or headache). Subjects with AMS had additional Doppler recordings immediately before and after rescue medication (oxygen, dexamethasone and acetazolamide). Forty-seven subjects had measurements at baseline, 39 (21 receiving magnesium and 18 placebo) at altitude I and 26 (13 receiving magnesium and 13 placebo) at altitude II. During hyperventilation, MCAv decreased consistently (for each measurement, P&amp;lt;0.001). Magnesium significantly increased MCAv by 8.4 cm\u00b7s-1 (95% confidence interval, 1.8\u201315), but did not prevent AMS. No other factors were associated with MCAv. Eleven subjects had severe AMS [median score (range), 11 (8\u201316)] and, after rescue medication, the median score decreased to 3 (range, 0\u20135; P=0.001), but MCAv remained unchanged (65\u00b118 cm\u00b7s-1 before compared with 67\u00b116 cm\u00b7s-1 after rescue medication; P=0.79). MCAv was increased in subjects who received magnesium, but was not affected by exposure to high altitude or by severe AMS.<\/jats:p>","DOI":"10.1042\/cs20030188","type":"journal-article","created":{"date-parts":[[2004,2,24]],"date-time":"2004-02-24T15:34:49Z","timestamp":1077636889000},"page":"279-285","update-policy":"https:\/\/doi.org\/10.1042\/crossmark_policy","source":"Crossref","is-referenced-by-count":14,"title":["Effect of magnesium, high altitude and acute mountain sickness on blood flow velocity in the middle cerebral artery"],"prefix":"10.1042","volume":"106","author":[{"given":"Christopher","family":"LYSAKOWSKI","sequence":"first","affiliation":[{"name":"Neuroanaesthesia Unit, Division of Anaesthesiology, Department of Anaesthesiology, Pharmacology and Surgical Intensive Care, Geneva University Hospitals, Geneva, Switzerland"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Erik VON","family":"ELM","sequence":"additional","affiliation":[{"name":"Perioperative Evidence-Based Medicine Program, Division of Anaesthesiology, Department of Anaesthesiology, Pharmacology and Surgical Intensive Care, Geneva University Hospitals, Geneva, Switzerland"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Lionel","family":"DUMONT","sequence":"additional","affiliation":[{"name":"Neuroanaesthesia Unit, Division of Anaesthesiology, Department of Anaesthesiology, Pharmacology and Surgical Intensive Care, Geneva University Hospitals, Geneva, Switzerland"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Jean-Daniel","family":"JUNOD","sequence":"additional","affiliation":[{"name":"Neuroanaesthesia Unit, Division of Anaesthesiology, Department of Anaesthesiology, Pharmacology and Surgical Intensive Care, Geneva University Hospitals, Geneva, Switzerland"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Ed\u00f6mer","family":"TASSONYI","sequence":"additional","affiliation":[{"name":"Neuroanaesthesia Unit, Division of Anaesthesiology, Department of Anaesthesiology, Pharmacology and Surgical Intensive Care, Geneva University Hospitals, Geneva, Switzerland"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Bengt","family":"KAYSER","sequence":"additional","affiliation":[{"name":"Faculty of Medicine, University of Geneva, Geneva, Switzerland"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Martin R.","family":"TRAM\u00c8R","sequence":"additional","affiliation":[{"name":"Neuroanaesthesia Unit, Division of Anaesthesiology, Department of Anaesthesiology, Pharmacology and Surgical Intensive Care, Geneva University Hospitals, Geneva, Switzerland"},{"name":"Perioperative Evidence-Based Medicine Program, Division of Anaesthesiology, Department of Anaesthesiology, Pharmacology and Surgical Intensive Care, Geneva University Hospitals, Geneva, Switzerland"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"288","container-title":["Clinical Science"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/portlandpress.com\/clinsci\/article-pdf\/106\/3\/279\/435110\/cs1060279.pdf","content-type":"application\/pdf","content-version":"vor","intended-application":"syndication"},{"URL":"https:\/\/portlandpress.com\/clinsci\/article-pdf\/106\/3\/279\/435110\/cs1060279.pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2021,12,1]],"date-time":"2021-12-01T20:37:37Z","timestamp":1638391057000},"score":1,"resource":{"primary":{"URL":"https:\/\/portlandpress.com\/clinsci\/article\/106\/3\/279\/67869\/Effect-of-magnesium-high-altitude-and-acute"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2004,3,1]]},"references-count":0,"journal-issue":{"issue":"3","published-print":{"date-parts":[[2004,3,1]]}},"URL":"https:\/\/doi.org\/10.1042\/cs20030188","relation":{},"ISSN":["0143-5221","1470-8736"],"issn-type":[{"value":"0143-5221","type":"print"},{"value":"1470-8736","type":"electronic"}],"subject":[],"published":{"date-parts":[[2004,3,1]]}}}