Dynamic cerebral autoregulation during and 3 months after endovascular treatment in large-vessel occlusion stroke

Abstract

Acute ischemic stroke caused by large-vessel occlusion is effectively treated by endovascular treatment (EVT). However, treatment could be further refined by improved understanding of the pathophysiology, including dynamic cerebral autoregulation (dCA). Near-infrared spectroscopy (NIRS) requires virtually no setup time and enables dCA investigation during EVT by measuring dynamic concentration in cortical oxygenated hemoglobin (OxyHb). We aimed to investigate dCA during EVT, before and after recanalization, and at follow-up (FU) after 24 hours and 90 days. We applied interhemispheric transfer function analysis (TFA) of low-frequency (LF) oscillations (0.07-0.2 Hz) in OxyHb that yields the dCA measures, gain and phase shift. We found higher LF gain in patients with favorable outcome. While dCA was stable for most patients during EVT, LF phase shift increased immediately after recanalization for patients with milder symptom severity and at 24-hour FU for patients with more severe symptoms. Adjusted for age, infarct size before EVT, and recanalization success, average LF gain predicted independent functional outcome, symptom severity and mortality at 90-day FU. In conclusion, interhemispheric TFA based on NIRS provides insights into dCA during EVT that could potentially be applied in the development of individualized treatment. The method relies on intact contralateral dCA which needs further investigation.