- Data Analysis: Imaging is evaluated during the acute phase. Further, the diagnostic imaging will be systematically and retrospectively evaluated by two senior neuroradiological consultants that are blinded to clinical information except the side of symptoms. X2-test, t-test/Mann-Whitney-test will be used depending on the distribution of the material, as well as uni and multivariate logistic regression analysis. It will be tested if the age, gender and severity affect the results. Data relating to risk factors and co-morbidity will be used to characterize the patient population. Function after 3 months expressed as mRS will be assessed, but the study was not designed to be able to detect an eventual difference in level of functioning after 3 months.