Fig. 2. Outcomes of acute ischaemic stroke with and without cytoprotective therapy and reperfusion.

The aim of cytoprotective therapy administered as early as possible after stroke onset, is to ‘freeze’ the penumbra (left) so that the infarct core does not grow further before definitive reperfusion therapy can be completed. This protection minimizes the size of the final infarct (bottom left). Without cytoprotective therapy, the final infarct size could be larger despite successful reperfusion (bottom right). Cytoprotective therapy can only be beneficial if reperfusion is achieved before the protective effects diminish. If reperfusion therapy is not administered within this time, the final infarct could be as large as it would have been without cytoprotection (bottom centre). Reperfusion injury can lead to haemorrhagic transformation regardless of whether cytoprotective therapy is used.