Abstract P380: Eloquence Mapping in Acute Ischaemic Stroke
Introduction: Patient selection for acute stroke revascularisation therapies is commonly based on clinical-imaging mismatch paradigms. Anatomical scores or total volumes of brain affected are assumed to correlate with clinical deficit without reference to the functional eloquence of the regions involved. In this study we used the relationship between presenting hypoperfusion abnormality and the corresponding NIHSS to generate functionally weighted atlases from patients with acute ischaemic stroke. Methods: Patients with acute large vessel occlusion (LVO) of the anterior circulation and with CTP at the time of presentation were included in this study. CTP was analysed with e-CTP (Brainomix Ltd., Oxford, UK) and hypoperfusion maps defined (Tmax >6s). Voxelwise lesion to symptom mapping was used to generate probability maps associating regions of hypoperfusion with clinical deficit at presentation. Results: 58 patients with itemised NIHSS and CTP were included. Discrete patterns of deficit were associated with each NIHSS domain. Total NIHSS correlated most strongly with left MCA involvement, consistent with the weighting towards language in this clinical scale. Regions associated with upper and lower limb deficits identified the respective motor cortex regions and descending motor tracts. Example mapping is presented in the Figure (A: total NIHSS, B: left arm paresis, C: left leg paresis). Data from a larger cohort will be presented at the meeting. Conclusions: Functional mapping using associations between presenting NIHSS and hypoperfusion lesion can be used to create eloquence-weighted atlases. Such atlases from stroke patients may be helpful to develop tools to predict clinical deficit associated with a presenting ischemic core lesion defined on non-contrast CT or CTP. This approach could refine clinical-imaging mismatch concepts, expanding endovascular treatment to a wider group of patients who would not currently be treated.