title: Diffusion-weighted imaging identifies a subset of lacunar infarction associated with embolic source.
abstract: OBJECTIVE
  Small infarcts in the territory of penetrator arteries were described as causing a number of distinct clinical syndromes. The vascular pathophysiology underlying such infarcts is difficult to ascertain without careful pathological study. However, the occurrence of multiple, small infarcts, linked closely in time but dispersed widely in the brain, raises the possibility of an embolic mechanism. The current study determines the frequency and clinical characteristics of patients with well-defined lacunar syndromes and the diffusion-weighted imaging (DWI) evidence of multiple acute lesions.
  
  
  METHODS
  Sixty-two consecutive patients who presented to the emergency room with a clinically well-defined lacunar syndrome were studied by DWI within the first 3 days of admission.
  
  
  RESULTS
  DWI showed multiple regions of increased signal intensity in 10 patients (16%). A hemispheric or brain stem lesion in a penetrator territory that accounted for the clinical syndrome ("index lesion") was found in all. DWI-hyperintense lesions other than the index lesion ("subsidiary infarctions") were punctate and lay within leptomeningeal artery territories in the majority. As opposed to patients with a single lacunar infarction, patients with a subsidiary infarction more frequently (P<0.05) harbored an identifiable cause of stroke.
  
  
  CONCLUSIONS
  Almost 1 of every 6 patients presenting with a classic lacunar syndrome has multiple infarctions demonstrated on DWI. This DWI finding usually indicates an identifiable cause of stroke and therefore may influence clinical decisions regarding the extent of etiologic investigations and treatment for secondary prevention.
authors.affiliation: Stroke Service of the Neurology Department, Massachusetts General Hospital, and Harvard Medical School, Boston 02114, USA.
authors.forename: H
authors.initials: H
authors.lastname: Ay
authors.forename: J
authors.initials: J
authors.lastname: Oliveira-Filho
authors.forename: F S
authors.initials: FS
authors.lastname: Buonanno
authors.forename: M
authors.initials: M
authors.lastname: Ezzeddine
authors.forename: P W
authors.initials: PW
authors.lastname: Schaefer
authors.forename: G
authors.initials: G
authors.lastname: Rordorf
authors.forename: L H
authors.initials: LH
authors.lastname: Schwamm
authors.forename: R G
authors.initials: RG
authors.lastname: Gonzalez
authors.forename: W J
authors.initials: WJ
authors.lastname: Koroshetz
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D020526:Brain Stem Infarctions / Q000175:diagnosis / Q000209:etiology / Q000473:pathology; D002539:Cerebral Arterial Diseases / Q000000981:diagnostic imaging; D002544:Cerebral Infarction / Q000175:diagnosis* / Q000209:etiology / Q000473:pathology; D018450:Disease Progression; D004452:Echocardiography; D005260:Female; D006331:Heart Diseases / Q000150:complications / Q000000981:diagnostic imaging; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged