Early Change in Stroke Size Performs Best in Predicting Response to Therapy

Abstract

Background: Reliable imaging biomarkers of response to therapy in acute stroke are needed. The final infarct volume and percent of early reperfusion have been used for this purpose. Early fluctuation in stroke size is a recognized phenomenon, but its utility as a biomarker for response to therapy has not been established. This study examined the clinical relevance of early change in stroke volume and compared it with the final infarct volume and percent of early reperfusion in identifying early neurologic improvement (ENI). Methods: Acute stroke patients, enrolled between 2013 and 2014 with serial magnetic resonance imaging (MRI) scans (pretreatment baseline, 2 h post, and 24 h post), who received thrombolysis were included in the analysis. Early change in stroke volume, infarct volume at 24 h on diffusion, and percent of early reperfusion were calculated from the baseline and 2 h MRI scans were compared. ENI was defined as ≥4 point decrease in National Institutes of Health Stroke Scales within 24 h. Logistic regression models and receiver operator characteristics analysis were used to compare the efficacy of 3 imaging biomarkers. Results: Serial MRIs of 58 acute stroke patients were analyzed. Early change in stroke volume was significantly associated with ENI by logistic regression analysis (OR 0.93, p = 0.048) and remained significant after controlling for stroke size and severity (OR 0.90, p = 0.032). Thus, for every 1 mL increase in stroke volume, there was a 10% decrease in the odds of ENI, while for every 1 mL decrease in stroke volume, there was a 10% increase in the odds of ENI. Neither infarct volume at 24 h nor percent of early reperfusion were significantly associated with ENI by logistic regression. Receiver-operator characteristic analysis identified early change in stroke volume as the only biomarker of the 3 that performed significantly different than chance (p = 0.03). Conclusions: Early fluctuations in stroke size may represent a more reliable biomarker for response to therapy than the more traditional measures of final infarct volume and percent of early reperfusion.

Long-Term Survival After Intravenous Thrombolysis for Ischemic Stroke

“…The precise mechanism or mechanisms by which thrombolysis improves survival are unknown, although there is an evidence thrombolysis decreases infarct size 30 and reduces the risk of readmissions because of pneumonia, 31 although the impact on other factors is still unclear. Nevertheless, previous studies have shown that good functional outcomes in the short term (ie, within 6 months) are associated with improved long-term survival, in part because of fewer complications and more independence.…”

The Efficacy of IV Tissue Plasminogen Activator for Restoring Cerebral Blood Flow in the Hours Immediately after Administration in Patients with Acute Stroke

“…The pretreatment PWI scan was processed to identify a region of interest (ROI) defined as having a time‐to‐peak (TTP) gadolinium concentration of greater than 4 seconds beyond normal tissue from the unaffected hemisphere. This ROI, which represents the pretreatment perfusion lesion, was then moved into the 2‐hour PWI using transformation matrices extracted from the image coregistration process . The percentage of the ROI that no longer had a TTP greater than 4 seconds was used to define the percent reperfusion (Fig ).…”

“…This ROI, which represents the pretreatment perfusion lesion, was then moved into the 2-hour PWI using transformation matrices extracted from the image coregistration process. 11 The percentage of the ROI that no longer had a TTP greater than 4 seconds was used to define the percent reperfusion (Fig 1). This can be described with the equation:…”

Proceedings from the Neurotherapeutics Symposium on Neurological Emergencies: Shaping the Future of Neurocritical Care

“…A relatively large ischemic burden reflected by Alberta Stroke Program Early CT Score (ASPECTS) scores of 5 or 6 is often used as a reason to not proceed with EVT within 6 h of last known well, though in some cases this score could reflect injury to areas of the brain that are less eloquent, and therefore, less likely to portend a poor outcome. Other limitations of using imaging as a strict criterion for therapy eligibility include early diffusion weighted image (DWI) reversibility [42][43][44] and CT perfusion "ghost" core [45]. Similarly, the presence of preexisting disability (e.g., inability to ambulate independently) is often used as an exclusion, yet providers should interpret preexisting disability from the perspective of the individual patient, not as an immutable construct.…”