title: Bedside assessment of cerebral perfusion reductions in patients with acute ischaemic stroke by near-infrared spectroscopy and indocyanine green.
abstract: OBJECTIVE
  To detect perfusion reductions in patients with acute cerebral infarcts using near-infrared spectroscopy (NIRS) with indocyanine green (ICG) as tracer.
  
  
  METHODS
  Kinetics of an intravenous bolus of ICG were monitored by NIRS in 13 patients with acute infarction in the territory of the middle cerebral artery (mean (SD) age, 62.2 (13.0) years) and 12 controls (64.2 (9.1) years) at 2.8 (2.8) days after onset. NIRS optodes were placed bitemporally, with an interoptode distance of 4-5 cm. Absolute concentration changes in ICG were calculated. The following were assessed: time to peak, maximum ICG concentration, time interval between 0% and 100% maximum ICG concentration (interval), rise time (time between 10% and 90% ICG maximum), slope (maximum Delta ICG/interval), and blood flow index (BFI = maximum Delta ICG/rise time) of each hemisphere. Intraindividual differences were calculated between the two hemispheres.
  
  
  RESULTS
  Patients with ischaemic stroke had increased time to peak (p<0.01), interval (p<0.01), and rise time (p<0.01), while maximum ICG concentration (p<0.03), slope (p<0.01), and BFI (p<0.01) were diminished at the site of infarction compared with the unaffected hemisphere. In stroke patients, intraindividual differences in time to peak (p<0.001), interval (p<0.001), rise time (p = 0.001), maximum ICG concentration (p<0.02), slope (p<0.001), and BFI (p<0.001) were greater than in the controls, with excellent sensitivity and specificity for Delta time to peak (100% and 100%, respectively) and Delta time interval (100% and 91.7%).
  
  
  CONCLUSIONS
  Measurement of interhemispheric differences in ICG kinetics by NIRS detects perfusion reductions in patients with acute middle cerebral artery infarction. This non-invasive bedside test is rapid, repeatable, without major side effects, and avoids transportation of critically ill patients.
authors.affiliation: Department of Neurology, Friedrich-Schiller University of Jena, Jena, Germany. christoph.terborg@med.uni-jena.de
authors.forename: C
authors.initials: C
authors.lastname: Terborg
authors.forename: S
authors.initials: S
authors.lastname: Bramer
authors.forename: S
authors.initials: S
authors.lastname: Harscher
authors.forename: M
authors.initials: M
authors.lastname: Simon
authors.forename: O W
authors.initials: OW
authors.lastname: Witte
mesh_terms: D000328:Adult; D000368:Aged; D002545:Brain Ischemia / Q000175:diagnosis* / Q000503:physiopathology*; D002540:Cerebral Cortex / Q000098:blood supply* / Q000473:pathology*; D004396:Coloring Agents / Q000493:pharmacokinetics; D005260:Female; D006801:Humans; D007208:Indocyanine Green / Q000493:pharmacokinetics; D007275:Injections, Intravenous; D007700:Kinetics; D008297:Male; D008875:Middle Aged; D020768:Middle Cerebral Artery; D012039:Regional Blood Flow; D019265:Spectroscopy, Near-Infrared; D020521:Stroke / Q000175:diagnosis* / Q000503:physiopathology*
chemical_list: D004396:Coloring Agents; D007208:Indocyanine Green