Wake-up stroke: clinical and neuroimaging characteristics

Cerebrovasc Dis. 2010;29(4):336-42. doi: 10.1159/000278929. Epub 2010 Jan 30.


Background: Approximately 25% of ischemic stroke patients awaken with neurological deficits. In these patients, in whom the time from symptom onset is uncertain, brain imaging is a potential strategy to characterize the ischemia duration and the presence of salvageable brain tissue.

Methods: We prospectively evaluated consecutive patients with acute ischemic stroke. CT angiography and CT perfusion (CTP) were performed in patients within 24 h of symptom onset. The patients were classified into 'known onset', 'indefinite onset but not on awakening' and 'wake-up stroke' groups.

Results: Of 676 patients evaluated, 420 had known-onset strokes, 131 wake-up strokes and 125 strokes with an indefinite time of symptom onset. Ischemic lesion volumes were higher in patients with indefinite-onset strokes (p = 0.04). The frequencies of CTP mismatch and of large-vessel intracranial occlusions were similar among the groups (p = 0.9 and p = 0.2, respectively).

Conclusion: The considerable prevalence of CTP mismatch and of intracranial artery occlusions in our patients with wake-up strokes suggests that arterial and perfusion imaging might be particularly important in this population. Revised indications for thrombolysis by using imaging-based protocols might offer these patients the prospect of receiving acute stroke treatment even without a clear time of symptom onset.

Publication types

  • Comparative Study
  • Multicenter Study
  • Research Support, N.I.H., Extramural

MeSH terms

  • Aged
  • Aged, 80 and over
  • Brain Damage, Chronic / epidemiology
  • Brain Damage, Chronic / etiology
  • Brain Ischemia / diagnostic imaging*
  • Brain Ischemia / pathology
  • Cerebral Angiography
  • Cohort Studies
  • Contraindications
  • Female
  • Fibrinolytic Agents / administration & dosage
  • Hospitals, University / statistics & numerical data
  • Humans
  • Image Processing, Computer-Assisted*
  • Male
  • Middle Aged
  • Perfusion Imaging
  • Prognosis
  • Prospective Studies
  • Reperfusion
  • Severity of Illness Index
  • Single-Blind Method
  • Thrombolytic Therapy*
  • Time Factors
  • Tomography, X-Ray Computed / methods*
  • Wakefulness*


  • Fibrinolytic Agents