title: Differential pattern of tissue plasminogen activator-induced proximal middle cerebral artery recanalization among stroke subtypes.
abstract: OBJECTIVE
  We aimed to evaluate the timing, speed, and degree of tissue plasminogen activator (tPA)-induced recanalization in patients with proximal middle cerebral artery (MCA) occlusion of different stroke subtypes.
  
  
  METHODS
  We evaluated 72 patients with acute stroke caused by proximal MCA occlusion treated with intravenous tPA in <3 hours. Transcranial Doppler monitoring of recanalization was conducted during tPA infusion and at 6 hours. Strokes were categorized as large-vessel disease strokes, cardioembolic strokes, or strokes of undetermined origin according to Trial of Org 10172 in Acute Stroke Treatment criteria.
  
  
  RESULTS
  During 1-hour tPA infusion, recanalization occurred in 34 patients (47%); 32% showed a sudden, 50% showed a stepwise, and 18% showed a slow pattern of recanalization. One-hour recanalization was more frequent in patients with cardioembolic stroke (59%) compared with large-vessel disease (8%) and undetermined origin (50%) strokes. A cardiac source of emboli was identified in 81% of patients who showed a sudden clot breakup during tPA infusion. Rate of complete recanalization at 6 hours was higher (P=0.006) in patients with cardioembolic stroke (50%) compared with other stroke subtypes (27%). Sudden recanalization was associated (P=0.002) with a higher degree of neurological improvement at 24 hours compared with stepwise, slow, and no recanalization. A graded response in long-term outcome was observed in relation to the speed of clot lysis during tPA administration.
  
  
  CONCLUSIONS
  We demonstrate that the pattern of tPA-induced MCA recanalization differs among stroke subtypes. Early recanalization was more frequent, faster, and more complete in patients with cardioembolic stroke compared with other stroke subtypes.
authors.affiliation: Neurovascular Unit, Department of Neurology, Hospital Vall d'Hebrón, Passeig Vall d'Hebrón 119-129, 08035 Barcelona, Spain. cmolina@vhebrom.net
authors.forename: Carlos A
authors.initials: CA
authors.lastname: Molina
authors.forename: Joan
authors.initials: J
authors.lastname: Montaner
authors.forename: Juan F
authors.initials: JF
authors.lastname: Arenillas
authors.forename: Marc
authors.initials: M
authors.lastname: Ribo
authors.forename: Marta
authors.initials: M
authors.lastname: Rubiera
authors.forename: José
authors.initials: J
authors.lastname: Alvarez-Sabín
mesh_terms: D000208:Acute Disease; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002560:Cerebrovascular Circulation / Q000187:drug effects; D003710:Demography; D005260:Female; D005343:Fibrinolytic Agents / Q000627:therapeutic use*; D006331:Heart Diseases / Q000150:complications; D006801:Humans; D020244:Infarction, Middle Cerebral Artery / Q000000981:diagnostic imaging / Q000188:drug therapy* / Q000503:physiopathology; D008297:Male; D008875:Middle Aged; D020768:Middle Cerebral Artery / Q000000981:diagnostic imaging / Q000187:drug effects* / Q000503:physiopathology; D012307:Risk Factors; D012720:Severity of Illness Index; D020521:Stroke / Q000145:classification / Q000000981:diagnostic imaging / Q000188:drug therapy* / Q000503:physiopathology; D013997:Time Factors; D010959:Tissue Plasminogen Activator / Q000627:therapeutic use*; D016896:Treatment Outcome; D017585:Ultrasonography, Doppler, Transcranial
chemical_list: D005343:Fibrinolytic Agents; D010959:Tissue Plasminogen Activator