Cerebral Autoregulation Monitoring to Evaluate for Clinical Outcome After Decompressive Hemicraniectomy for Acute Ischemic Stroke: Case Series

Background and Clinical Significance: Decompressive hemicraniectomy (DHC) is a life-saving intervention for malignant middle cerebral artery (MCA) infarction, but postoperative secondary injury mechanisms and functional outcome remain difficult to evaluate using intracranial pressure (ICP) alone. The pressure reactivity index (PRx), calculated as the moving correlation coefficient between ICP and mean arterial pressure (MAP), provides a measure of cerebral autoregulation. The utility of PRx monitoring in ischemic stroke, especially following DHC, remains uncertain. Case Presentation: We describe two patients presenting with acute ischemic stroke in the MCA territory who underwent DHC followed by postoperative ICP and PRx monitoring. Case 1 is a 40-year-old female with a left proximal MCA occlusion initially treated with endovascular thrombectomy (EVT) who required emergent DHC due to re-occlusion. Postoperatively, ICPs remained controlled, and PRx values were favorable (<0.2), indicating preserved cerebral autoregulation. She later showed moderate neurological improvement. Case 2 was a 68-year-old female with a left proximal MCA occlusion treated with EVT who developed worsening cerebral edema and midline shift, necessitating emergent DHC. Despite adequate ICP control, PRx values remained markedly elevated (0.45 to 0.73), consistent with impaired cerebral autoregulation, and her neurologic state remained poor at discharge. Conclusions: These contrasting cases suggest that PRx may provide physiologic information not reflected by ICP metrics alone post-DHC. PRx monitoring may provide complementary physiologic insight into postoperative autoregulatory status following DHC. Further investigation is warranted to define its role in individualized post-DHC management and prognostication in malignant ischemic stroke.