title: Etiologic investigation of ischemic stroke in young adults.
abstract: OBJECTIVE
  We attempted to classify causes of ischemic stroke in young adults using a progressive diagnostic algorithm and the ASCO (atherosclerosis, small-vessel disease, cardiac source, other cause) classification system.
  
  
  METHODS
  Patients aged 16-54 years consecutively treated for acute ischemic stroke in a tertiary stroke unit were included in this retrospective analysis. Causes of stroke were classified using the ASCO system, which assigns a graded level of likelihood to each potential cause in individual patients. The initial etiologic workup included brain imaging, magnetic resonance or CT angiography of cerebral and cervical vessels, EKG, and routine blood studies. Patients without a definite cause of ischemic stroke after initial evaluation underwent transesophageal echocardiography.
  
  
  RESULTS
  We included 318 patients (195 men and 123 women); 131 patients were aged 16-44 years, and 187 were aged 45-54 years. A definite cause of stroke (ASCO grade 1) could be identified in 145 patients (45.5%). An uncertain cause of stroke (ASCO grade 2) was found in 59 (18.5%) further patients. Most (130 of 145) definite causes were identified by initial evaluation. The 2 major definite or uncertain causes of stroke were patent foramen ovale associated with atrial septal aneurysm (PFO-ASA) (20 of 131 [15.3%]) and dissection of the cervical or cerebral artery (19 of 131 [14.5%]) in patients aged 16-44 years and large-vessel atherosclerosis (37 of 187 [19.8%]) and PFO-ASA (23 of 187 [12.3%]) in patients aged 45-54 years.
  
  
  CONCLUSIONS
  Our findings suggest that PFO-ASA may be a major cause of ischemic stroke in young adults.
authors.affiliation: Service de Neurologie Vasculaire, Hopital Rangueil, CHU de Toulouse 31059, Toulouse, France. larrue.v@chu-toulouse.fr
authors.forename: V
authors.initials: V
authors.lastname: Larrue
authors.forename: N
authors.initials: N
authors.lastname: Berhoune
authors.forename: P
authors.initials: P
authors.lastname: Massabuau
authors.forename: L
authors.initials: L
authors.lastname: Calviere
authors.forename: N
authors.initials: N
authors.lastname: Raposo
authors.forename: A
authors.initials: A
authors.lastname: Viguier
authors.forename: N
authors.initials: N
authors.lastname: Nasr
mesh_terms: D000293:Adolescent; D000328:Adult; D000783:Aneurysm / Q000150:complications / Q000175:diagnosis / Q000473:pathology; D050197:Atherosclerosis / Q000150:complications / Q000175:diagnosis / Q000473:pathology; D054087:Atrial Septum / Q000473:pathology; D002545:Brain Ischemia / Q000145:classification / Q000175:diagnosis* / Q000209:etiology*; D003952:Diagnostic Imaging / Q000379:methods*; D005260:Female; D054092:Foramen Ovale, Patent / Q000150:complications / Q000175:diagnosis; D006801:Humans; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies; D020521:Stroke / Q000145:classification / Q000175:diagnosis* / Q000209:etiology*; D055815:Young Adult