Ischemic stroke and atherosclerosis at a young age. The Norwegian Stroke in the Young Study

Stroke risk and incidence increase exponentially with age. In Europe about one in three strokes occurs before the age of 65 years, with severe socioeconomic consequences on individual and society level. Despite improved diagnostic techniques and increasing knowledge, in 30-50% of young stroke patients the cause of stroke remains undetermined. However, due to the lack of one consistent definition for “young stroke”, published data are inhomogeneous regarding patient age, stroke types included and variables studied. It has been claimed that young stroke patients have a favorable prognosis, including usually good recovery from neurological deficits, low recurrence risk, a fair social prognosis, and favorable long-term outcome. Newer follow-up investigations documented, however, high rates of stroke recurrence, vascular co-morbidity and mortality. Further, increased rates of psychological disorders, reduced health-related quality of life and impared social activity are frequent long-term consequences. The underlying cause of stroke is related to differing risk of recurrent cardiovascular events, being highest in patients with largeartery atherosclerosis and cardioembolism. Hence, there is a need for systematic investigation and data collection from well-defined young stroke populations aiming to reveal the true cause of stroke, leading to right treatment of underlying conditions, and to optimal and aggressive secondary prevention. In the studies included in this thesis, we aimed to compare stroke characteristics in young ischemic stroke patients to older patient populations, and to controls free of cardiovascular disease. Data were obtained from 1217 ischemic stroke patients admitted to Haukeland University Hospital between 2006 and 2009 (the Bergen NORSTROKE study), and from 150 patients aged 15-60 years and 84 controls included in the Norwegian Stroke in the Young Study (NOR-SYS) between 2010 and 2012. Patients