Perfusion Changes of Unexplained Early Neurological Deterioration After Reperfusion Therapy

Abstract

Early neurological deterioration (END) after thrombolysis occurs in 10% acute ischemic stroke (AIS) patients, and its mechanism remains unclear in majority of cases, named as unexplained END. We tested the hypothesis that penumbra/infarct growth beyond the initial penumbra might be the cause of unexplained END. We reviewed the database of AIS patients who received reperfusion therapy. Unexplained END was defined as ≥ 2-point increase of NIHSS from baseline to 24h, without straightforward causes. For each unexplained END patient, we extracted 2 matched controls based on 4 clinical and radiological characteristics which were strongly associated with unexplained END. We defined extra-penumbra and extra-infarct as penumbra and infarct growth at 24h beyond baseline penumbral tissue and then investigated the relationship between extra-penumbra and extra-infarct and the presence of unexplained END. Finally, 44 unexplained END patients and 88 matched controls were included. The volume of both extra-infarct (OR, 1.032 per 1-mL increase; p = 0.018) and extra-penumbra (OR, 1.070 per 1-mL increase; p < 0.001) were associated with the presence of unexplained END, while the absence of recanalization was associated with the presence of either extra-infarct or extra-penumbra (OR, 3.291; p = 0.001). Moreover, 51.4% cases with extra-penumbra at 24h finally progressed to infarct at 7days, and they underwent higher increase of NIHSS from 24h to 7days than those that did not progress to infarct at 7days (4.0 vs 1.0; p = 0.017). Penumbra/infarct growth beyond the initial penumbra is involved in the unexplained END in AIS patients receiving reperfusion therapy.