{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,9,17]],"date-time":"2026-09-17T02:39:37Z","timestamp":1789612777196,"version":"build-2803163510"},"reference-count":28,"publisher":"S. Karger AG","issue":"1","license":[{"start":{"date-parts":[[2020,4,14]],"date-time":"2020-04-14T00:00:00Z","timestamp":1586822400000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by-nc-nd\/4.0\/"},{"start":{"date-parts":[[2020,4,14]],"date-time":"2020-04-14T00:00:00Z","timestamp":1586822400000},"content-version":"tdm","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by-nc-nd\/4.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Cerebrovasc Dis Extra"],"abstract":"<b><i>Introduction:<\/i><\/b> Low cerebral blood flow can affect cognition in patients with high-grade asymptomatic internal carotid artery stenosis. Current clinical algorithms use stroke risk to determine which patients should undergo revascularization without considering cognitive decline. Although correlations between low-flow and cognitive impairment have been reported, it is not known whether a threshold exists below which such a correlation expresses itself. Such information would be critical in treatment decisions about whether to intervene in patients with high-grade carotid artery stenosis who are at risk for cognitive decline. <b><i>Objective:<\/i><\/b> To determine how reduced blood flow correlates with lower cognitive scores. <b><i>Methods:<\/i><\/b> Patients with \u226580% unilateral internal carotid artery stenosis with no history of stroke were recruited from inpatient and outpatient practices at a single, large, comprehensive stroke center. Patients underwent bilateral insonation of middle cerebral arteries with standard 2-Hz probes over the temporal windows with transcranial Doppler. Cognitive assessments were performed by an experienced neuropsychologist using a cognitive battery comprising 14 standardized tests with normative samples grouped by age. Z-scores were generated for each test and averaged to obtain a composite Z-score for each patient. Multivariable linear regression examined associations between mean flow velocity (MFV) and composite Z-score, adjusting for age, education, and depression. The Davies test was used to determine if there was a breakpoint for a non-zero difference in slope of a segmented relationship over the range of composite Z-score values. <b><i>Results:<\/i><\/b> Forty-two patients with unilateral high-grade internal carotid artery stenosis without stroke were enrolled (26 males, age = 74 \u00b1 9 years, education = 16 \u00b1 3 years). Average composite Z-score was \u20130.31 SD below the age-specific normative mean (range \u20132.8 to +1.2 SD). In linear regression adjusted for age, education, and depression, MFV correlated with cognitive Z-score (\u03b2 = 0.308, <i>p<\/i> = 0.043). A single breakpoint in the range of composite Z-scores was identified at 45 cm\/s. For MFV &#x3c;45 cm\/s, Z-score decreased 0.05 SD per cm\/s MFV (95% CI: 0.01\u20130.10). For MFV &#x3e;45 cm\/s, Z-score change was nonsignificant (95% CI: \u20130.07 to 0.05). <b><i>Conclusions:<\/i><\/b> In high-grade, asymptomatic carotid artery stenosis, cognitive impairment correlated linearly with lower flow in the hemisphere fed by the occluded internal carotid artery, but only below a threshold of MFV = 45 cm\/s. Identifying a hemodynamic threshold for cognitive decline using a simple, noninvasive method may influence revascularization decision-making in otherwise \u201casymptomatic\u201d carotid disease.<\/jats:p>","DOI":"10.1159\/000506924","type":"journal-article","created":{"date-parts":[[2020,4,14]],"date-time":"2020-04-14T21:00:44Z","timestamp":1586898044000},"page":"21-27","source":"Crossref","is-referenced-by-count":22,"title":["Cognitive Impairment Correlates Linearly with Mean Flow Velocity by Transcranial Doppler below a Definable Threshold"],"prefix":"10.1159","volume":"10","author":[{"given":"Randolph\u00a0S.","family":"Marshall","sequence":"first","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Marykay\u00a0A.","family":"Pavol","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Ying\u00a0Kuen\u00a0","family":"Cheung","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Iris","family":"Asllani","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Ronald\u00a0M.","family":"Lazar","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"127","published-online":{"date-parts":[[2020,4,14]]},"reference":[{"key":"ref1","doi-asserted-by":"publisher","DOI":"10.1056\/NEJM199108153250701"},{"key":"ref2","doi-asserted-by":"publisher","DOI":"10.1056\/NEJMoa0912321"},{"key":"ref3","doi-asserted-by":"publisher","DOI":"10.1212\/01.wnl.0000176036.07558.82"},{"key":"ref4","doi-asserted-by":"publisher","DOI":"10.1161\/STROKEAHA.111.669267"},{"key":"ref5","doi-asserted-by":"publisher","DOI":"10.1177\/1747493017706238"},{"key":"ref6","doi-asserted-by":"publisher","DOI":"10.1159\/000050765"},{"key":"ref7","doi-asserted-by":"publisher","DOI":"10.1007\/s11011-011-9275-5"},{"key":"ref8","doi-asserted-by":"publisher","DOI":"10.1016\/j.nbd.2019.104608"},{"key":"ref9","doi-asserted-by":"publisher","DOI":"10.1161\/HYPERTENSIONAHA.118.12062"},{"key":"ref10","doi-asserted-by":"publisher","DOI":"10.1016\/j.atherosclerosis.2011.08.032"},{"key":"ref11","doi-asserted-by":"publisher","DOI":"10.1161\/01.STR.0000069725.09499.14"},{"key":"ref12","doi-asserted-by":"publisher","DOI":"10.1161\/STROKEAHA.110.595645"},{"key":"ref13","doi-asserted-by":"publisher","DOI":"10.1212\/WNL.0b013e318295d71a"},{"key":"ref14","doi-asserted-by":"publisher","DOI":"10.1212\/01.wnl.0000345015.35520.52"},{"key":"ref15","doi-asserted-by":"publisher","DOI":"10.1212\/WNL.0b013e31824365d3"},{"key":"ref16","doi-asserted-by":"publisher","DOI":"10.1016\/j.jvs.2017.04.038"},{"key":"ref17","doi-asserted-by":"publisher","DOI":"10.1111\/j.1552-6569.2012.00711.x"},{"key":"ref18","doi-asserted-by":"publisher","DOI":"10.1016\/j.jstrokecerebrovasdis.2019.05.007"},{"key":"ref19","doi-asserted-by":"publisher","DOI":"10.1016\/j.jacc.2014.02.537"},{"key":"ref20","doi-asserted-by":"publisher","DOI":"10.1016\/S0002-9149(00)00959-0"},{"key":"ref21","doi-asserted-by":"publisher","DOI":"10.3171\/2016.10.JNS161041"},{"key":"ref22","doi-asserted-by":"publisher","DOI":"10.1177\/1747493019874732"},{"key":"ref23","doi-asserted-by":"publisher","DOI":"10.1002\/brb3.171"},{"key":"ref24","doi-asserted-by":"publisher","DOI":"10.1212\/WNL.0000000000003322"},{"key":"ref25","doi-asserted-by":"publisher","DOI":"10.1111\/j.1552-6569.2008.00293.x"},{"key":"ref26","doi-asserted-by":"publisher","DOI":"10.1371\/journal.pone.0189727"},{"key":"ref27","doi-asserted-by":"publisher","DOI":"10.1177\/1747493018790088"},{"key":"ref28","doi-asserted-by":"publisher","DOI":"10.1161\/STROKEAHA.110.581058"}],"container-title":["Cerebrovascular Diseases Extra"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.karger.com\/Article\/Pdf\/506924","content-type":"application\/pdf","content-version":"vor","intended-application":"text-mining"},{"URL":"https:\/\/www.karger.com\/Article\/Pdf\/506924","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,4,23]],"date-time":"2025-04-23T15:55:37Z","timestamp":1745423737000},"score":1,"resource":{"primary":{"URL":"https:\/\/karger.com\/article\/doi\/10.1159\/000506924"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2020,4,14]]},"references-count":28,"journal-issue":{"issue":"1","published-online":{"date-parts":[[2020,5,5]]}},"URL":"https:\/\/doi.org\/10.1159\/000506924","archive":["Portico"],"relation":{},"ISSN":["1664-5456"],"issn-type":[{"value":"1664-5456","type":"electronic"}],"subject":[],"published":{"date-parts":[[2020,4,14]]}}}