Abstract TP439: Temporal Evolution of Blood-brain Barrier Permeability After Acute Spontaneous Intracerebral Hemorrhage: A CT Perfusion Study

Abstract

Introduction: Spontaneous intracerebral hemorrhage (ICH) is associated with increased blood-brain barrier (BBB) permeability, potentially contributing to hematoma expansion, edema development and exacerbation of brain injury. Though we know BBB permeability with time after the onset of ICH, little is about the temporal evolution of BBB permeability in humans after ICH. A more detailed understanding the timeline of BBB permeability change after ICH would be important for guiding future ICH treatments. Hypothesis: We want to test the hypothesis there is two increase in BBB permeability in ICH patients. Methods: Patients with ICH were divided into five groups based on the period between ICH onset and computed tomography perfusion (CTP) assessed, which are hyperacute (<24 hours), acute (1~3 days), early subacute (3~7 days), late subacute (7~14 days) and chronic (>14 days) groups. Maps of BBB permeability-surface area product (PS), a measure of extravascular contrast leakage rate, were calculated from CTP source images. Mean PS was measured in regions of interest defining the hematoma, a 1cm radial peri-hematoma region,in both ICH and contralateral non-ICH hemispheres. Results: PS maps were generated in 61 patients (17 female, mean age 53 years old). The median (interquartile range) PS in ICH hemisphere of 31 patients underwent CTP in hyperacute phase is 1.4 (5.3), 8 patients in acute phase is 1.6 (3.2), 11 patients in early subacute phase is 1.2 (0.8), 8 patients in late subacute phase is 0.7 (1.2), and 3 patients in chronic phase is 0.9. The BBB permeability has an early increase in hyperacute phase, is followed by a decrease period in acute and subacute phases, and a delayed second increase in chronic phase. The permeability pattern is similar in non-ICH hemisphere; however, the second increase in permeability was from late subacute phase. Discussions: In conclusion, acute ICH patients have a generalized increase in BBB permeability, which affects the entire brain diffusely. The BBB permeability is not continually elevated but follows a triphasic course in ICH patients.