Abstract Details Title Novel Dual-pressure Framework Explains Paradoxical Ischemia in Hypertensive Encephalopathy Through Transverse Pressure Collapse Topic Cerebrovascular Disease and Interventional Neurology Presentation(s) P5 - Poster Session 5 (11:45 AM-12:45 PM) Poster/Presentation Number 4-022 Objective To develop a mathematical framework explaining paradoxical regional ischemia observedin hypertensive encephalopathy despite elevated mean arterial pressure (MAP). Background Traditional hemodynamic models fail to explain why hypertensive encephalopathy causesselective ischemic injury to deep and superficial perforators while sparing cortical vessels. Current pressure flow models focus on longitudinal pressure dynamics but cannot account for branch vessel perfusion failure at elevated MAP. Design/Methods We developed a dual-pressure mathematical model distinguishing longitudinal pressure (P(l)=(½)ρv(l)^2) from transverse pressure (ΔP(t)=ρε(Δv(t)^2), where ε represents vessel wall elasticity and Δv(t) is transverse velocity gradient. The model predicts critical MAP thresholds (MAP(crit)) where transverse pressure collapses due to flow laminarization. Theoretical predictions were evaluated against known MRI patterns in hypertensive encephalopathy Results The model demonstrates that as MAP increases, wall-proximal turbulence diminishes, causingtransverse pressure gradient collapse even with maximal elasticity (ε=1). At MAP(crit), Δv(t) → 0 leads to ΔP(t) → 0, impairing branch perfusion despite rising global cerebral blood volume. Vessels with reduced elasticity (ε < 1) show earlier collapse. This mechanism explains selective perforator vulnerability while cortical vessels remain perfused through preserved longitudinal pressure. Conclusions Regional ischemia in hypertensive encephalopathy results from transverse pressure collapse,not inadequate MAP. This dual-pressure framework reconceptualizes autoregulatory failure as structural coherence loss rather than simple pressure deficit. The model provides theoretical basis for refined pressure management protocols emphasizing vessel geometry and directional flow dynamics beyond global MAP targets. Authors/Disclosures Mustafa Khan, MD (Sevaro Health Inc.) PRESENTER Dr. Khan has nothing to disclose.