PREVALENCE AND DETERMINANTS OF DIASCHISIS IN ACUTE UNILATERAL ANTERIOR CIRCULATION ISCHEMIC STROKE: A CT PERFUSION-BASED STUDY

Diaschisis is a common post-stroke phenomenon characterized by functional suppression in brain regions remote from the primary lesion, reflecting network-level effects of focal ischemic injury. Previous PET, SPECT, MRI studies were limited by small samples and a predominant focus on single subtypes, with insufficient evaluation of subtype prevalence, overlap, and determinants. Using CT perfusion (CTP) imaging, we retrospectively analyzed 698 patients with unilateral anterior circulation ischemic stroke admitted to Erasme Hospital (Belgium) between January 2015 and June 2025. Diaschisis was identified on RAPID-generated CTP maps and classified into crossed cerebellar diaschisis (CCD), ipsilateral thalamic diaschisis (ITD), ipsilateral hippocampal diaschisis (IHD), and combined CCD+ITD. Multivariable logistic regression models were constructed for each subtype to identify independent clinical and imaging determinants, including age, sex, stroke side, site of vessel occlusion, TMax > 6 s volume, hypoperfusion intensity ratio (HIR), and CBF < 30% volume. The prevalence of CCD, ITD, IHD, and CCD+ITD was 48.9%, 19.9%, 15.4%, and 15.4%, respectively, with substantial overlap. CCD showed good model discrimination (AUC = 0.711; Nagelkerke R² = 0.170) and was independently associated with age, stroke side, TMax > 6 s volume, HIR. ITD and CCD+ITD demonstrated acceptable discrimination (AUC = 0.684–0.686) and were consistently associated with TMax > 6 s, HIR. In contrast, IHD showed limited discrimination (AUC = 0.368) and was associated only with age and stroke side. These findings indicate that diaschisis is highly prevalent, heterogeneous, and subtype-specific, representing a network-level functional manifestation of perfusion deficit severity rather than a uniform post-stroke phenomenon.