Hyperthermia and Early Growth of Cerebral Infarct: The Potential Role of Blood-Brain Barrier Permeability

Hyperthermia within the first 24 h following ischemic stroke (IS) has been associated with poor outcomes. We sought to determine whether blood-brain barrier (BBB) permeability contributes to the relationship between hyperthermia and early infarct growth (EIG). A retrospective analysis was conducted on a prospective stroke biobank. EIG was defined as the percentage difference between the initial volume (mL) determined by the diffusion-weighted imaging at admission and the volume (mL) from the control CT image on the 4 th-7 th day. Hyperthermia was defined as an axillary body temperature ≥ 37.5 °C within the first 24 h. Soluble tumor necrosis factor-like weak inducer of apoptosis (sTWEAK) serum levels were measured by ELISA. One-hundred and two (19.7%) patients showed EIG from a cohort of 519 patients (45.6% females). Linear correlation was observed for axillar body temperature and EIG (Pearson's r = 0.46; p < 0.001). sTWEAK serum levels showed a c-statistic of 0.74 (95% CI: 0.69-0.79), with an optimal cut-off point > 3000 pg/mL for EIG prediction. Moreover, microalbuminuria levels strongly correlated with sTWEAK levels (Pearson's r = 0.75; p < 0.001). In the multivariate analysis for EIG was observed an independent association with hyperthermia (adjusted OR 24.21; 95% CI: 12.03-39.12), sTWEAK levels > 3000 pg/mL (adjusted OR 16.43; 95% CI: 3.71-72.70), leukoaraiosis (adjusted OR 10.42; 95% CI: 2.68-39.08), and microalbuminuria (adjusted OR 1.02; 95% CI: 1.00-1.12). In our cohort, hyperthermia was independently associated with EIG after IS. The fact that microalbuminuria, leukoaraiosis, and sTWEAK were also associated with EIG suggests a relationship with increased BBB permeability.