title: Initial body temperature in ischemic stroke: nonpotentiation of tissue-type plasminogen activator benefit and inverse association with severity.
abstract: OBJECTIVE
  Body temperature (BT) is an important physiological factor in acute ischemic stroke. However, the relationship of initial BT to stroke severity and degree of benefit from thrombolytic therapy has been delineated incompletely.
  
  
  METHODS
  We analyzed the public data set of the 2 National Institute of Neurological Disorders and Stroke Tissue-Type Plasminogen Activator (tPA) stroke trials, comparing patients with lower (<37.0°C) and higher (≥37.0°C) presenting BT.
  
  
  RESULTS
  Among 595 patients (297 placebo and 298 tPA treated) with documented initial BT, 77.1% had initial BT <37.0°C and 22.9% ≥37.0°C. Patients with higher initial BT had lower baseline stroke severity in both tPA-treated patients (the National Institute of Health Stroke Scale median, 11 versus 15; P=0.05) and placebo-treated patients (median, 13 versus 16; P<0.01). Patients with higher initial BT also had lower infarction volume on computed tomography at 3 months in both tPA-treated patients (median, 9.6 versus 16.7 cm(3); P=0.08) and placebo-treated patients (median, 13.1 versus 28.1 cm(3); P=0.02), but no clinical outcome differences. Analysis of lytic treatment effect found no heterogeneity in the degree of tPA benefit in both higher and lower BT groups (≥37.0°C: odds ratio for the modified Rankin Scale 0-1 outcome, 2.55; 95% confidence interval, 1.05-6.21 and <37.0°C: odds ratio, 2.30; 95% confidence interval, 1.38-3.84; heterogeneity P=0.83).
  
  
  CONCLUSIONS
  In patients with hyperacute stroke, higher presenting temperatures are associated with less severe neurological deficits and reduced final infarct volumes. Presenting temperature does not modify the benefit of tPA on 3-month favorable outcome.
authors.affiliation: From the Department of Neurology, Yonsei University Wonju College of Medicine, Wonju, Korea (S.H.K.); and Department of Neurology, Comprehensive Stroke Center, David Geffen School of Medicine at the University of California, Los Angeles (J.L.S.).
authors.forename: Seo Hyun
authors.initials: SH
authors.lastname: Kim
authors.affiliation: From the Department of Neurology, Yonsei University Wonju College of Medicine, Wonju, Korea (S.H.K.); and Department of Neurology, Comprehensive Stroke Center, David Geffen School of Medicine at the University of California, Los Angeles (J.L.S.). jsaver@mednet.ucla.edu.
authors.forename: Jeffrey L
authors.initials: JL
authors.lastname: Saver
mesh_terms: D000368:Aged; D001831:Body Temperature; D001921:Brain / Q000000981:diagnostic imaging*; D002545:Brain Ischemia / Q000150:complications / Q000000981:diagnostic imaging / Q000188:drug therapy*; D005260:Female; D005343:Fibrinolytic Agents / Q000627:therapeutic use*; D006801:Humans; D008297:Male; D008875:Middle Aged; D012720:Severity of Illness Index; D020521:Stroke / Q000000981:diagnostic imaging / Q000188:drug therapy* / Q000209:etiology; D015912:Thrombolytic Therapy; 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: body temperature; outcome measures; stroke; tissue-type plasminogen activator