Klinische Neurophysiologie 2006; 37 - A219
DOI: 10.1055/s-2006-939302

Non invasive detection of hypoperfusion and deoxygenation by near-infrared spectroscopy (NIRS) in acute ischemic stroke

C Terborg 1, K Gröschel 1, OW Witte 1, A Kastrup 1
  • 1Klinik für Neurologie, FSU Jena

Background:

Non-invasive monitoring cerebral hemodynamics and oxygenation might be of major importance in acute ischemic stroke. The aim of our study was to measure cerebral blood flow and tissue oxygenation in middle cerebral artery infarction by NIRS and indocyanine green (ICG) and compare it with perfusion-weighted MRI (PW-MRI).

Patients and Methods:

In 21 patients with acute infarction of the middle cerebral artery we measured cerebral perfusion by monitoring kinetics of an intravenous bolus of ICG, and tissue oxygenation 2.0±2.3 days after stroke onset. NIRS optodes were placed bitemporally with an interoptode distance of 4 or 5cm, and absolute concentration changes were measured. For ICG kinetics, time-to-peak, maximum ICG concentration, time interval between 0% and 100% ICG maximum (interval), rise time (time between 10% and 90% ICG maximum), slope (maximum ICG/interval), and blood flow index (BFI=maximum ICG/rise time) were calculated. In 7 patients PW-MRI and NIRS-measurements were performed within 24 hours.

Results: Patients with ischemic stroke had increased time-to-peak (p<0.01), time interval (p<0.01), and rise-time (p<0.02), while ICG maximum (p<0.02), slope (p<0.01), and BFI (p<0.01) were diminished at the site of infarction as compared to the unaffected hemisphere. In patients measured within the first 3 days after stroke onset tissue oxygenation was diminished at the affected hemisphere (p=0.02). In patients with simultaneous PW-MRI and NIRS interhemispheric differences of the parameter interval were closely correlated (r=0.7).

Conclusions:

Non-invasive measurement of cerebral ICG kinetics and NIRS provide useful informations about decreased cerebral blood flow in patients with acute stroke, and parameters correlate with those assessed by PWI-MR. If measurements were performed early after stroke, diminished tissue oxygenation can be detected at the site of infarction. NIRS monitoring might, therefore, guide therapy in order to optimize cerebral perfusion and oxygenation in patients with ischemic stroke.