Still restricted usability of imaging criteria in therapeutic decisions for acute ischemic stroke treatment

A 90-year-old woman developed a severe stroke (National Institutes of Health Stroke Scale Score (NIHSS) 24) due to an occlusion of the left carotid T. Computed tomography 60 min after symptom onset showed a large area of tissue at risk with a relatively large area of reduced cerebral blood volume indicating a relative large infarct core. After successful reperfusion, she recovered very well with only residual facial asymmetry (NIHSS 1). Up to now, therapeutic decisions for intravenous thrombolysis and endovascular treatment were mainly based on these time windows, although it was well known that the individual time window may vary widely due to a large variability of the quality of collateral circulation. The recently presented results of the DAWN trial have demonstrated that patients can be successfully treated in a time window up to 24 h when selected by imaging and clinical criteria. The described case impressively demonstrates that this positive selection of patients beyond established treatment time windows does not implicate in reverse that patient selection for therapy within the established time windows can be based on the same imaging criteria. In conclusion, patient selection beyond the established time windows may be based on the available techniques, but imaging-based decisions against therapy in patients within the established time windows should be made only with extreme caution.