title: Ischemic stroke as first manifestation of essential thrombocythemia. Report of six cases.
abstract: BACKGROUND
  Ischemic stroke as a presenting sign of essential thrombocythemia has been infrequently reported. We describe six patients in whom cerebrovascular disease was the first manifestation of this myeloproliferative disease. A positive endogenous megakaryocyte and/or erythroid colony growth from blood was a diagnostic criterion of essential thrombocythemia in patients with platelets counts lower than 600 x 10(9)/L.
  
  
  METHODS
  These six patients represented 0.54% of all patients with first stroke, 42.8% of all hematologic disorders associated with stroke, and 12.5% of all patients with essential thrombocythemia diagnosed from 1986 to 1992 at our institution. Eleven acute cerebrovascular accidents (6 transient ischemic attacks, 5 definitive cerebral infarcts) were registered. Mean time from ischemic stroke to diagnosis of essential thrombocythemia was 4.5 months (range, 1 to 12 months). The mean platelet count was 597 x 10(9)/L (range, 414 to 760 x 10(9)/L). Four patients had platelets counts lower than 600 x 10(9)/L. All patients had circulating erythroid progenitors, megakaryocytic progenitors, or both.
  
  
  CONCLUSIONS
  Ischemic stroke as a presenting manifestation of essential thrombocythemia is probably underrecognized. The diagnosis of thrombocythemia should not be excluded on the basis of platelet counts lower than 600 x 10(9)/L. The availability of in vitro culture of hematopoietic progenitors from peripheral blood makes it possible to diagnose early and atypical cases.
authors.affiliation: Acute Stroke Unit, Hospitals de-Barcelona de L'Aliança, Spain.
authors.forename: A
authors.initials: A
authors.lastname: Arboix
authors.forename: C
authors.initials: C
authors.lastname: Besses
authors.forename: P
authors.initials: P
authors.lastname: Acín
authors.forename: J B
authors.initials: JB
authors.lastname: Massons
authors.forename: L
authors.initials: L
authors.lastname: Florensa
authors.forename: M
authors.initials: M
authors.lastname: Oliveres
authors.forename: J
authors.initials: J
authors.lastname: Sans-Sabrafen
mesh_terms: D000328:Adult; D000368:Aged; D002561:Cerebrovascular Disorders / Q000209:etiology* / Q000503:physiopathology; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010976:Platelet Count; D013922:Thrombocytosis / Q000150:complications* / Q000175:diagnosis / Q000503:physiopathology