Cerebral edema in acute stroke: Effect of thrombolytic treatment

Cerebral edema (CED) is a common complication of ischemic stroke in Intensive Care Unit. Although frequently observed in patients undergoing intravenous thrombolytic (IVT) treatment, the pathogenic role of recombinant tissue plasminogen activator (rtPA) in CED induction has not yet been definitively clarified. The aim of our study is to verify the relationship between CED and rtPA in patients affected by acute ischemic stroke, without reperfusion signs, evaluating the CED growth rate in the first week after stroke onset. In this single-center, retrospective observational study, we included all consecutive patients with acute stroke undergone multi-parameter monitoring of vital signs in the sub-intensive care Unit. We included both patients undergoing systemic IVT and standard medical treatment (n-IVT) with the following time of CT scan: within 4.5 h onset, 24 ± 12 h, 72 ± 24 h and 120 ± 24 h from the stroke onset. Of 1753 with acute ischemic stroke patients screened, 810 patients were included in the study (218 IVT and 592 n-IVT). No significant difference was observed at baseline in age, gender, NIHSS score or infarcted area, while hemorrhagic transformation rate was significantly higher in IVT than in n-IVT group. We observed a significant increase of CED growth rate in IVT patients compared to n-IVT patients only between 24 and 72 h from the ischemic event (respectively 1.85cm3/h and 0.89cm3/h; p = 0.031) regardless of the presence of HT. No significant difference was observed in growth rate between 3 and 5 days following rtPA administration or in overall growth rate. Although the pathogenetic mechanism of rtPA determining CED remains uncertain, our data suggests rtPA can act as a “trigger” of edema onset and progression. Therefore, drugs interfering with specific molecular pathways, such as kallikrein-kinin cascade, could constitute an effective strategy to reduce the risk of development and progression of rtPA-related cerebral edema in patients with acute stroke. Further studies are needed to define the molecular pathways involved in the genesis of CE in humans and to verify the efficacy of specific drugs.