title: Unclear-onset stroke: Daytime-unwitnessed stroke vs. wake-up stroke.
abstract: OBJECTIVE
  The onset of wake-up stroke and daytime-unwitnessed stroke is unclear. Though the clinical importance is similar by both being excluded from reperfusion therapy, the characteristics of daytime-unwitnessed stroke are less known than that of wake-up stroke. Here, we compared the characteristics between daytime-unwitnessed stroke and wake-up stroke.
  
  
  METHODS
  Unclear-onset (i.e., last-known normal time ≠ first-found abnormal time) stroke patients admitted within 24 h of recognition of stroke between February 2011 and October 2013 were reviewed. Demographics and clinical and imaging variables were compared between patients with daytime-unwitnessed stroke and those with wake-up stroke.
  
  
  RESULTS
  Among the 762 ischemic stroke patients, 276 (36.2%) had unclear-onset stroke (104 daytime-unwitnessed stroke and 172 wake-up stroke). Compared to wake-up stroke, daytime-unwitnessed stroke patients had a higher prevalence of cardioembolic stroke and more frequently presented altered mental status (p < 0.001) and/or aphasia (p < 0.001) with more severe neurological deficit (p < 0.001). However, the time from symptom recognition to hospital arrival was shorter (p < 0.001), and diffusion-weighted image-fluid-attenuated inversion recovery image mismatch (p = 0.02) and perfusion-diffusion mismatch (p = 0.001) were also more frequently observed in daytime-unwitnessed stroke. Finally, the proportion of patients eligible for thrombolysis (p < 0.001) was higher in daytime-unwitnessed stroke patients.
  
  
  CONCLUSIONS
  Clinical and imaging characteristics of daytime-unwitnessed stroke significantly differ from those of wake-up stroke. Daytime-unwitnessed stroke patients are more likely to receive reperfusion therapy, as they arrive at the hospital earlier after symptom recognition, compared to wake-up stroke patients.
authors.affiliation: Department of Neurology, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea.
authors.forename: Yeon-Jung
authors.initials: YJ
authors.lastname: Kim
authors.affiliation: Department of Neurology, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea.
authors.forename: Bum Joon
authors.initials: BJ
authors.lastname: Kim
authors.affiliation: Department of Neurology, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea.
authors.forename: Sun U
authors.initials: SU
authors.lastname: Kwon
authors.affiliation: Department of Neurology, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea.
authors.forename: Jong S
authors.initials: JS
authors.lastname: Kim
authors.affiliation: Department of Neurology, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea dwkang@amc.seoul.kr.
authors.forename: Dong-Wha
authors.initials: DW
authors.lastname: Kang
mesh_terms: D000368:Aged; D038524:Diffusion Magnetic Resonance Imaging; D005260:Female; D006801:Humans; D008297:Male; D059906:Neuroimaging; D015424:Reperfusion / Q000706:statistics & numerical data; D012189:Retrospective Studies; D020521:Stroke / Q000175:diagnosis*; D063189:Symptom Assessment; D015912:Thrombolytic Therapy / Q000706:statistics & numerical data; D013997:Time Factors
keywords: Infarction; magnetic resonance imaging; thrombolysis; unclear-onset stroke