title: Dynamics and embolic activity of symptomatic intra-cranial cerebral artery stenoses.
abstract: OBJECTIVE
  To investigate the occurrence of microembolic signals (MES) and hemodynamic features in patients with acute symptomatic intracranial cerebral artery stenoses by transcranial Doppler (TCD).
  
  
  METHODS
  Twelve patients with acute hemispheric ischemic events and corresponding intracranial cerebral artery stenoses as identified by TCD, and exclusion of extracranial or cardiac emboli sources were repeatedly studied by TCD monitoring of the affected and the contralateral vessel. The occurrence of MES and MES clusters (> or =3 MES per second) and of flow velocity changes was examined.
  
  
  RESULTS
  Nine patients presented with MES in the affected artery during the first measurement. In seven patients sudden flow velocity changes could be detected in the affected vessel. In five patients these changes were accompanied by MES clusters. MES and velocity changes disappeared in all patients during follow-up, and the degree of stenosis decreased in nine patients.
  
  
  CONCLUSIONS
  The high prevalence of MES and sudden velocity changes in acute intracranial cerebral artery stenoses indicates that acute intracranial stenoses may be formed at least in part by mobile thrombotic material.
authors.affiliation: Department of Neurology, Krupp Hospital, Essen, Germany. rolf.diehl@krupp-krankenhaus.de
authors.forename: R R
authors.initials: RR
authors.lastname: Diehl
authors.forename: C
authors.initials: C
authors.lastname: Samii
authors.forename: A
authors.initials: A
authors.lastname: Diehl
mesh_terms: D000328:Adult; D000368:Aged; D005260:Female; D006801:Humans; D020765:Intracranial Arterial Diseases / Q000000981:diagnostic imaging / Q000209:etiology / Q000503:physiopathology*; D002542:Intracranial Embolism and Thrombosis / Q000150:complications / Q000000981:diagnostic imaging / Q000503:physiopathology*; D002546:Ischemic Attack, Transient / Q000503:physiopathology; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D020521:Stroke / Q000503:physiopathology; D017585:Ultrasonography, Doppler, Transcranial