{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2025,10,8]],"date-time":"2025-10-08T21:58:09Z","timestamp":1759960689305},"reference-count":18,"publisher":"Ovid Technologies (Wolters Kluwer Health)","issue":"7","content-domain":{"domain":["www.ahajournals.org"],"crossmark-restriction":true},"short-container-title":["Stroke"],"published-print":{"date-parts":[[1997,7]]},"abstract":"<jats:p>\n            <jats:italic>Background and Purpose<\/jats:italic>\n            It remains uncertain whether the annual stroke risk of 7% to 8% in middle cerebral artery (MCA) stenosis is of embolic or hemodynamic origin. Preliminary reports provide evidence of emboli exiting from acute MCA stenoses, detected by transcranial Doppler (TCD) sonography. With multirange monitoring before and after the stenosis, TCD monitoring may help for the first time to differentiate microemboli exiting from the MCA stenosis from those with a source proximal to the MCA stenosis. We searched for microembolic signals (MES) using multigated monitoring in patients with chronic MCA stenoses.\n          <\/jats:p>\n          <jats:p>\n            <jats:italic>Methods<\/jats:italic>\n            Fifty-eight patients with 78 chronic stenoses of the MCA were enrolled in the study. Additional sources of embolism were ruled out by extensive clinical workup. Twenty-four patients were treated with coumarin, whereas 28 patients received aspirin. The remaining 6 patients discontinued their medication after a few weeks. The sample volume of the multirange probe was placed on either side of the stenotic area of the MCA.\n          <\/jats:p>\n          <jats:p>\n            <jats:italic>Results<\/jats:italic>\n            Twenty-three (29.5%) of the stenoses were low grade, 18 (23%) were moderate, and 37 (47.5%) were severe. Thirty-seven (47%) of the stenoses were symptomatic and 41 (53%) were asymptomatic before study entry. During follow-up, 2 strokes and 7 transient ischemic attacks occurred. Computer tomography revealed two watershed-type infarcts. Sufficient insonation of the prestenotic and poststenotic segments of the MCA was possible in 70 stenoses (90%). No MES could be detected during a total of 1740 minutes\u2019 monitoring time distal to the MCA stenoses, regardless of the patients\u2019 medication. MES were also absent in the contralateral MCA.\n          <\/jats:p>\n          <jats:p>\n            <jats:italic>Conclusions<\/jats:italic>\n            MES are not detectable in patients with chronic MCA stenoses of different degrees. No MES were found in either symptomatic or asymptomatic stenoses, regardless of the patients\u2019 medication. These results indicate that chronic MCA stenoses do not represent a significant embolic source. The absence of MES in the prestenotic Doppler sample volume, the watershed-type infarcts during follow-up, and the absence of small-vessel disease on computed tomography suggests that hemodynamic mechanisms are responsible for recurrent cerebral ischemia.\n          <\/jats:p>","DOI":"10.1161\/01.str.28.7.1324","type":"journal-article","created":{"date-parts":[[2011,6,17]],"date-time":"2011-06-17T20:08:03Z","timestamp":1308341283000},"page":"1324-1327","update-policy":"http:\/\/dx.doi.org\/10.1161\/crossmarkpolicy","source":"Crossref","is-referenced-by-count":30,"title":["Do Chronic Middle Cerebral Artery Stenoses Represent an Embolic Focus?"],"prefix":"10.1161","volume":"28","author":[{"given":"Ulrich","family":"Sliwka","sequence":"first","affiliation":[{"name":"From Friedrich-Schiller University, Department of Neurology (U.S.), Jena, Germany; Krupp Hospital, Department of Neurology (C.K., O.P., P.B.), Essen, Germany; and University Hospital (RWTH), Department of Neurology (U.S., K.B., P.S., J.N.), Aachen, Germany."}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Christof","family":"Klo\u0308tzsch","sequence":"additional","affiliation":[{"name":"From Friedrich-Schiller University, Department of Neurology (U.S.), Jena, Germany; Krupp Hospital, Department of Neurology (C.K., O.P., P.B.), Essen, Germany; and University Hospital (RWTH), Department of Neurology (U.S., K.B., P.S., J.N.), Aachen, Germany."}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Octavian","family":"Popescu","sequence":"additional","affiliation":[{"name":"From Friedrich-Schiller University, Department of Neurology (U.S.), Jena, Germany; Krupp Hospital, Department of Neurology (C.K., O.P., P.B.), Essen, Germany; and University Hospital (RWTH), Department of Neurology (U.S., K.B., P.S., J.N.), Aachen, Germany."}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Katrin","family":"Brandt","sequence":"additional","affiliation":[{"name":"From Friedrich-Schiller University, Department of Neurology (U.S.), Jena, Germany; Krupp Hospital, Department of Neurology (C.K., O.P., P.B.), Essen, Germany; and University Hospital (RWTH), Department of Neurology (U.S., K.B., P.S., J.N.), Aachen, Germany."}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Peter","family":"Schmidt","sequence":"additional","affiliation":[{"name":"From Friedrich-Schiller University, Department of Neurology (U.S.), Jena, Germany; Krupp Hospital, Department of Neurology (C.K., O.P., P.B.), Essen, Germany; and University Hospital (RWTH), Department of Neurology (U.S., K.B., P.S., J.N.), Aachen, Germany."}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Peter","family":"Berlit","sequence":"additional","affiliation":[{"name":"From Friedrich-Schiller University, Department of Neurology (U.S.), Jena, Germany; Krupp Hospital, Department of Neurology (C.K., O.P., P.B.), Essen, Germany; and University Hospital (RWTH), Department of Neurology (U.S., K.B., P.S., J.N.), Aachen, Germany."}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Johannes","family":"Noth","sequence":"additional","affiliation":[{"name":"From Friedrich-Schiller University, Department of Neurology (U.S.), Jena, Germany; Krupp Hospital, Department of Neurology (C.K., O.P., P.B.), Essen, Germany; and University Hospital (RWTH), Department of Neurology (U.S., K.B., P.S., J.N.), Aachen, Germany."}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"276","reference":[{"key":"e_1_3_2_1_2","doi-asserted-by":"publisher","DOI":"10.1161\/str.26.1.14"},{"key":"e_1_3_2_2_2","doi-asserted-by":"publisher","DOI":"10.1056\/NEJM198511073131904"},{"key":"e_1_3_2_3_2","doi-asserted-by":"publisher","DOI":"10.1161\/str.17.6.3544347"},{"key":"e_1_3_2_4_2","doi-asserted-by":"publisher","DOI":"10.1161\/str.27.4.683"},{"key":"e_1_3_2_5_2","doi-asserted-by":"publisher","DOI":"10.1161\/str.27.8.1347"},{"key":"e_1_3_2_6_2","doi-asserted-by":"publisher","DOI":"10.1161\/str.26.6.1123"},{"key":"e_1_3_2_7_2","doi-asserted-by":"publisher","DOI":"10.1016\/0090-3019(87)90149-2"},{"key":"e_1_3_2_8_2","doi-asserted-by":"publisher","DOI":"10.1001\/archneur.1988.00520270067022"},{"key":"e_1_3_2_9_2","doi-asserted-by":"publisher","DOI":"10.1161\/str.25.10.7916499"},{"key":"e_1_3_2_10_2","doi-asserted-by":"publisher","DOI":"10.1159\/000108494"},{"key":"e_1_3_2_11_2","doi-asserted-by":"publisher","DOI":"10.1212\/WNL.45.8.1488"},{"key":"e_1_3_2_12_2","first-page":"281","volume":"46","year":"1996","unstructured":"K\u00fchnen J, Steinke W, Kern R, Artemis N, Hennerici M. Long-term course of symptomatic and asymptomatic middle cerebral artery stenosis. Neurology. 1996;46:281. Abstract.","journal-title":"Neurology"},{"key":"e_1_3_2_13_2","unstructured":"Sliwka U Kl\u00f6tzsch C Popescu O Brandt K Berlit P Noth J. Anticoagulation versus antiaggregation in patients with middle cerebral artery stenosis. Cerebrovasc Dis. 1996;6(suppl 3):8. Abstract."},{"key":"e_1_3_2_14_2","doi-asserted-by":"publisher","DOI":"10.1161\/str.24.4.8465370"},{"key":"e_1_3_2_15_2","doi-asserted-by":"publisher","DOI":"10.1007\/BF00314376"},{"key":"e_1_3_2_16_2","doi-asserted-by":"publisher","DOI":"10.1212\/WNL.42.2.289"},{"key":"e_1_3_2_17_2","doi-asserted-by":"publisher","DOI":"10.1161\/str.22.9.1926254"},{"key":"e_1_3_2_18_2","doi-asserted-by":"publisher","DOI":"10.1007\/BF00338199"}],"container-title":["Stroke"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.ahajournals.org\/doi\/full\/10.1161\/01.STR.28.7.1324","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2024,5,12]],"date-time":"2024-05-12T22:20:34Z","timestamp":1715552434000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.ahajournals.org\/doi\/10.1161\/01.STR.28.7.1324"}},"subtitle":["A Multirange Transcranial Doppler Study"],"short-title":[],"issued":{"date-parts":[[1997,7]]},"references-count":18,"journal-issue":{"issue":"7","published-print":{"date-parts":[[1997,7]]}},"alternative-id":["10.1161\/01.STR.28.7.1324"],"URL":"https:\/\/doi.org\/10.1161\/01.str.28.7.1324","relation":{},"ISSN":["0039-2499","1524-4628"],"issn-type":[{"type":"print","value":"0039-2499"},{"type":"electronic","value":"1524-4628"}],"subject":[],"published":{"date-parts":[[1997,7]]},"assertion":[{"value":"1997-04-04","order":0,"name":"received","label":"Received","group":{"name":"publication_history","label":"Publication History"}},{"value":"1997-05-06","order":1,"name":"accepted","label":"Accepted","group":{"name":"publication_history","label":"Publication History"}},{"value":"1997-07-01","order":2,"name":"published","label":"Published","group":{"name":"publication_history","label":"Publication History"}}]}}