title: Thrombotic occlusion of the middle cerebral artery.
abstract: OBJECTIVE
  Epidemiological study of middle cerebral artery occlusion is important because the indication for extracranial-intracranial arterial bypass remains in dispute. To help clarify this issue, we investigated the prognosis of thrombotic middle cerebral artery occlusion in Japanese patients.
  
  
  METHODS
  We studied 40 patients with thrombotic middle cerebral artery occlusion who were selected on the basis of clinical features, computed tomographic findings, and angiographic findings. Patients with causes of embolism (i.e., cardiomyopathy, valvular heart disease, cardiac arrhythmia, and carotid ulceration) were excluded. The 40 patients were classified into three groups according to the site of middle cerebral artery occlusion: there were 13 patients with occlusion of the proximal portion of the M1 segment, 13 with distal M1 segment occlusion, and 14 with occlusion of the M2 segment.
  
  
  RESULTS
  Good collateral circulation was associated with improved outcomes both clinically and by computed tomography in patients with occlusion of the proximal and distal portions of the M1 segment but not in those with M2 occlusion.
  
  
  CONCLUSIONS
  It is reasonable to assume that not only collateral circulation but also the site of occlusion plays an important role in the outcome of middle cerebral artery occlusion. Our finding that good collateral circulation improves the outcome for thrombotic occlusion of the proximal and distal M1 segments supports the possible benefits of such surgery.
authors.affiliation: Department of Neurosurgery, Yokohama City University, School of Medicine, Japan.
authors.forename: S
authors.initials: S
authors.lastname: Ueda
authors.forename: K
authors.initials: K
authors.lastname: Fujitsu
authors.forename: S
authors.initials: S
authors.lastname: Inomori
authors.forename: T
authors.initials: T
authors.lastname: Kuwabara
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002533:Cerebral Angiography; D002536:Cerebral Arteries; D002560:Cerebrovascular Circulation; D003097:Collateral Circulation; D003287:Contrast Media; D005260:Female; D006429:Hemiplegia / Q000209:etiology / Q000503:physiopathology; D006801:Humans; D002542:Intracranial Embolism and Thrombosis / Q000150:complications / Q000000981:diagnostic imaging / Q000503:physiopathology; D008297:Male; D008875:Middle Aged; D011379:Prognosis; D014057:Tomography, X-Ray Computed
chemical_list: D003287:Contrast Media