title: Flow diversion in transcranial Doppler ultrasound is associated with better improvement in patients with acute middle cerebral artery occlusion.
abstract: BACKGROUND
  Flow diversion (FD) can occur with an acute middle cerebral artery (MCA) occlusion. FD is thought to represent the collateral blood flow to the occluded MCA territory, but it is unclear whether or not FD lessens the stroke severity or leads to improved outcome.
  
  
  METHODS
  Patients with a proximal MCA occlusion were selected from the CLOTBUST trial data bank. FD to the anterior or posterior cerebral artery was determined using transcranial Doppler ultrasound. Stroke severity and clinical improvement were measured using the National Institutes of Health Stroke Scale (NIHSS) scores.
  
  
  RESULTS
  We evaluated 47 patients with an isolated M1 MCA occlusion who received intravenous tissue-type plasminogen activator (t-PA) within 3 h of symptom onset. FD was present in 83% of the patients. Median baseline NIHSS scores were 15.5 in the FD- group and 18 in the FD+ group (n.s.). Complete recanalization rates were 25 and 25.6% (n.s.). In 35 patients with a persistent occlusion, the average NIHSS score reduction was 22% (FD+) and 0.52% (FD-) during 90 min after t-PA bolus (p=0.017), and 29 versus -25% during the first 24 h after the t-PA bolus, respectively (p=0.01).
  
  
  CONCLUSIONS
  In patients with persistent MCA occlusions after thrombolytic treatment, arterial blood flow diversion is associated with earlier and better neurological improvement. FD has protective effects on the ischemic brain tissue with persistent MCA occlusion.
authors.affiliation: Department of Neurology, Wonkwang University School of Medicine and Wonkwang Medical Science Research Center, Jeonbuk, Korea. yosik28@yahoo.com
authors.forename: Yo Sik
authors.initials: YS
authors.lastname: Kim
authors.forename: John Stirling
authors.initials: JS
authors.lastname: Meyer
authors.forename: Zsolt
authors.initials: Z
authors.lastname: Garami
authors.forename: Carlos A
authors.initials: CA
authors.lastname: Molina
authors.forename: Aleksandra M
authors.initials: AM
authors.lastname: Pavlovic
authors.forename: Andrei V
authors.initials: AV
authors.lastname: Alexandrov
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D002560:Cerebrovascular Circulation / Q000502:physiology*; D003097:Collateral Circulation / Q000502:physiology*; D005260:Female; D005343:Fibrinolytic Agents / Q000627:therapeutic use; D006801:Humans; D020244:Infarction, Middle Cerebral Artery / Q000000981:diagnostic imaging* / Q000188:drug therapy / Q000503:physiopathology*; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies; D012720:Severity of Illness Index; D010959:Tissue Plasminogen Activator / Q000627:therapeutic use; D016896:Treatment Outcome; D017585:Ultrasonography, Doppler, Transcranial
chemical_list: D005343:Fibrinolytic Agents; D010959:Tissue Plasminogen Activator