title: Characteristics of wake-up stroke.
abstract: BACKGROUND
  Wake-up stroke (WUS) accounts for up to 29.6% of ischemic strokes, but its mechanisms are poorly understood. The purpose of this study is to identify risk factors and characteristics of WUS.
  
  
  METHODS
  Seven-two ischemic strokes were classified as WUS or non-WUS. Collected were demographic information, medical history, cholesterol profile, and stroke characteristics including severity (National Institutes of Health Stroke Scale [NIHSS]) and mechanism (Trial of Org 10172 in Acute Stroke Treatment criteria). Subjects completed questionnaires screening for sleep apnea (Berlin questionnaire) and assessing sleep characteristics.
  
  
  RESULTS
  There were 72 ischemic strokes, of which 28 WUS (38.9%). WUS and non-WUS patients were similar in regard to stroke risk factors. WUS patients tended to be African American and were significantly younger. WUS was significantly more likely to result from small-vessel disease mechanism (42.9% versus 14.0%; P=.006) and tended to be less severe WUS (NIHSS score 3 [1, 4] versus 4 [2, 11]; P=.13) than non-WUS. Groups did not differ in regard to scoring positively on the Berlin questionnaire, but WUS sufferers were more likely to snore frequently (90.5% versus 70.0%, P=.08). The lipid profile was significantly worse in WUS compared with non-WUS (low-density lipoprotein 124.6±38.4 versus 103.7±36.8; P=.03; cholesterol to high-density lipoprotein ratio 5.2±1.6 versus 4.3±1.6; P=.02).
  
  
  CONCLUSIONS
  WUS is more likely to result from small-vessel disease mechanism. Poorer cholesterol profile and frequent snoring may contribute to WUS.
authors.affiliation: Case Western Reserve University School of Medicine, Cleveland, Ohio.
authors.forename: Aki
authors.initials: A
authors.lastname: Tanimoto
authors.affiliation: Department of Neurology, Case Western Reserve University School of Medicine, Cleveland, Ohio.
authors.forename: Prachi
authors.initials: P
authors.lastname: Mehndiratta
authors.affiliation: Department of Neurology, Case Western Reserve University School of Medicine, Cleveland, Ohio. Electronic address: koobri@gmail.com.
authors.forename: Brian B
authors.initials: BB
authors.lastname: Koo
mesh_terms: D000328:Adult; D001741:Black or African American; D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D002545:Brain Ischemia / Q000175:diagnosis* / Q000503:physiopathology; D002940:Circadian Rhythm / Q000502:physiology*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D012307:Risk Factors; D020521:Stroke / Q000175:diagnosis* / Q000503:physiopathology; D014481:United States; D014851:Wakefulness / Q000502:physiology*
keywords: Wake-up stroke; cholesterol; sleep apnea; small vessel