title: Wake-up Stroke and Stroke within the Therapeutic Window for Thrombolysis Have Similar Clinical Severity, Imaging Characteristics, and Outcome.
abstract: BACKGROUND
  Wake-up stroke (WUS) represents 25% of all ischemic strokes. There is conflicting evidence concerning clinical severity, imaging characteristics, and outcome when WUS is compared with stroke of known time of onset. Our aim was to compare WUS patients with patients with ischemic stroke within the therapeutic window (STW) for thrombolysis.
  
  
  METHODS
  This is a retrospective hospital-based study of all consecutive patients hospitalized for acute ischemic stroke during 2013. Patients with STW, WUS, and WUS with computed tomography (CT)  at 3 hours or less after awakening (WUS≤3h) were selected for the study. The methods used include a review of clinical records, an independent quantification of early signs of ischemia on admission CT scan, and determination of functional outcome on follow-up.
  
  
  RESULTS
  Of 554 patients evaluated, 190 had STW, 113 had WUS (20.4%), and 25 had WUS≤3h. Among all WUS patients, 33.6% did not have any other formal contraindication for thrombolysis besides undetermined time of onset. WUS patients had demographic characteristics, vascular risk factors, and clinical severity similar to STW patients. Mild or absent early signs of ischemia on admission CT in WUS≤3h patients were similar to those in STW patients when adjusted for clinical severity (odds ratio [OR] = .50, 95% confidence interval [CI]=.17-1.47). Favorable prognosis in WUS≤3h was similar to STW when adjusted for age, clinical severity, and thrombolysis (OR = .53, 95% CI=.09-3.14).
  
  
  CONCLUSIONS
  This study strengthens the evidence that clinical and early imaging characteristics of WUS patients are similar to those of patients with stroke who are eligible for thrombolysis based on the time window criteria, and patients with WUS do not have a worse short outcome.
authors.affiliation: School of Health Sciences, University of Minho, Portugal.
authors.forename: Ricardo
authors.initials: R
authors.lastname: Costa
authors.affiliation: Neurology Department, Hospital de Braga, Portugal. Electronic address: jdpinho@gmail.com.
authors.forename: João
authors.initials: J
authors.lastname: Pinho
authors.affiliation: Neurology Department, Hospital de Braga, Portugal.
authors.forename: José Nuno
authors.initials: JN
authors.lastname: Alves
authors.affiliation: Neuroradiology Department, Hospital de Braga, Portugal.
authors.forename: José Manuel
authors.initials: JM
authors.lastname: Amorim
authors.affiliation: Neuroradiology Department, Hospital de Braga, Portugal.
authors.forename: Manuel
authors.initials: M
authors.lastname: Ribeiro
authors.affiliation: Neurology Department, Hospital de Braga, Portugal.
authors.forename: Carla
authors.initials: C
authors.lastname: Ferreira
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D002545:Brain Ischemia / Q000150:complications; D005260:Female; D005343:Fibrinolytic Agents / Q000627:therapeutic use*; D018575:Home Care Services, Hospital-Based / Q000706:statistics & numerical data; D006801:Humans; D008297:Male; D015999:Multivariate Analysis; D012189:Retrospective Studies; D012720:Severity of Illness Index; D020521:Stroke / Q000000981:diagnostic imaging* / Q000188:drug therapy* / Q000209:etiology; D010959:Tissue Plasminogen Activator / Q000627:therapeutic use*; D014057:Tomography, X-Ray Computed; D016896:Treatment Outcome
chemical_list: D005343:Fibrinolytic Agents; D010959:Tissue Plasminogen Activator
keywords: Wake-up stroke; computed tomography; ischemic stroke; stroke outcome