Reduction of diffusion-weighted MRI lesion volume after early moderate hypothermia in ischemic stroke

Background - Large areas of restricted diffusion in the middle cerebral artery (MCA) territory are highly predictive of severe and potentially space-occupying MCA stroke. A reduction of diffusion-weighted MRI (DWI) lesions occurs in 20% to 40% of acute stroke patients with early reperfusion. Methods - We report of a patient with a severe stroke syndrome who was treated with early moderate hypothermia but not thrombolysis. Results - The initially large DWI deficit of the whole MCA territory contrasted to the relatively small final lesion restricted to the basal ganglia on MRI and computed tomography scan. Conclusion - This case describes an unexpected reduction of a DWI lesion after early moderate hypothermia and spontaneous recanalization 3 days after stroke onset. We discuss potential reasons for the unexpected DWI lesion reduction.