PRecisiOn Medicine In StrokE: Evolution of Plasma Brain-Derived Tau in Acute Stroke

The investigators recently identified Brain-derived tau (BD-tau) as a sensitive blood-based biomarker for brain injury in acute ischemic stroke: in patients with acute ischemic stroke, plasma BD-tau was associated with imaging-based metrics of brain injury upon admission, increased within the first 24 hours in correlation with infarct progression, and at 24 hours was superior to final infarct volume in predicting 90-day functional outcome. While informing on the relation of BD-tau with imaging-based metrics of brain injury, this cross-sectional study was restricted to BD-tau assessments upon admission and at day 2 and could not inform on key characteristics of the evolution of plasma BD-tau, including when exactly it starts to rise, how long it continues to rise, and how it is determined by infarct characteristics as well as comorbidities. Here, the investigators aim to assess plasma BD-tau every hour from admission to 48 hours after onset to evaluate the hypothesis that BD-tau rises immediately after onset and plateaus between three and 48 hours after onset.

Inclusion Criteria: * clinical diagnosis of acute ischemic stroke * presentation within 9 hours of symptom onset * large- or medium-vessel occlusion (i.e. an occlusion of the ICA, MCA \[segments M1-M4\], ACA \[segments A1-A3\], basilar artery, or PCA \[segments P1 to P3\]) confirmed by CT or MRI angiography * at least 18 years of age * written informed consent Exclusion Criteria: * CT or MRI showing intracranial hemorrhage upon admission * A history of ischemic stroke, subarachnoid hemorrhage, intracerebral hemorrhage, subdural hematoma, epidural hematoma, CNS tumor, meningitis, or encephalitis within the last three months * dementia * pre-stroke disability defined as a premorbid modified Rankin Scale score \> 2