The neuroinflammatory response after ischemic brain injury has been identified as a pathomechanism in ischemic stroke. Stroke induces an activation of microglia in the brain, which lasts over months. However, the characteristics and mechanisms of this microglia activation are insufficiently defined.~Our study hypotheses are (i) that a subpopulation of patients with acute stroke develop prominent microglial activation, and (ii) that patients with extensive microglial activation are more likely to experience poor outcome.~Against this background, the investigators set up the Inflammatory faCtors AfteR acUte ischemic Stroke (ICARUS) study as an interventional single-centre hospital-based cohort study. N=36 patients with a cortical (N=18) or strictly subcortical (N=18) acute ischemic stroke will be recruited through the local stroke unit (Department of Neurology, LMU Munich). Study participation involves serial TSPO-PET imaging along with serial MR imaging, immune cell profiling in blood, and both clinical and laboratory assessments. Follow-up assessments at 3 weeks, 3 months, 6 months and 12 months will be conducted at the Institute for Stroke and Dementia Research (ISD) and at the Department of Nuclear medicine, both LMU Munich.~In a substudy, the investigators will include 10 independently recruited patients with acute ischemic stroke to assess MRI arterial spin labelling (ASL) sequences as a marker for perfusion measurement of the TSPO tracer. These patients will receive dynamic PET in addition to the ASL sequences.
ICARUS is an interventional single-centre hospital-based cohort study in patients admitted to the stroke unit with an acute ischemic stroke. The aims of the study are to i) define the characteristics and determinants of microglial activation after human stroke, and ii) assess the correlation of microglial activation with circulating inflammatory markers, structural brain changes on neuroimaging, and neurological outcomes.~ICARUS involves serial TSPO-PET imaging along with serial MRI, immune cell profiling in blood, and both clinical and laboratory assessments in 36 patients with acute ischemic stroke caused by a cortical (N=18) or strictly subcortical (N=18) infarct.~In a substudy, the investigators will include 10 independently recruited patients with acute ischemic stroke to assess MRI arterial spin labelling (ASL) sequences as a marker for perfusion measurement of the TSPO tracer.