ABSTRACT NUMBER: ESOC2026A478 RISK FACTORS, CHARACTERIZATION AND OUTCOME OF INTRACEREBRAL HEMORRHAGE IN YOUNG ADULTS

Abstract Background and aims Non-traumatic intracerebral hemorrhage (ICH) is an important and often devastating manifestation of stroke in young adults, but there is a lack of larger studies on specific risk factors, clinico-radiological characterization and outcomes. Methods We included individual patient data from twelve cohorts from seven European countries on young adults with ICH aged < 55 years. Demographic, clinical, radiological and follow-up data were collected. Results Altogether 1633 patients (median age 46 years, 60% male) were included. Risk factors included hypertension (48.4%), smoking (30.0%), alcohol abuse (19.9%), diabetes (7.4%), drug abuse (7.2%) and previous stroke (4.7%). ICH locations were deep (47.9%), lobar (34.8%), brainstem (8.0%) and cerebellar (5.8%), the median ICH volume was 14 mL (IQR 5-32 mL). Of 1004 (61.5%) of patients with available brain MRI, 53.2% had white matter hyperintensities (Fazekas 2-3 in 18.3%), 29.9% microbleeds and 15.9% chronic lacunes. The most frequent cause of ICH was cerebral small vessel disease (43.0%), followed by macrovascular (16.9%) and other secondary causes (10.5%). At a median of six months post-stroke, 46.6% had modified Rankin Scale scores of 0-2, 33.0% had scores of 3-5, and 20.4% had died. Over a median total follow-up period of 2.8 years, recurrent ICH occurred in 93 patients (6.6%), ischaemic strokes in 51 (4.0%) and other vascular events in 48 patients (2.9%). Conclusions ICH in young adults is diverse in terms of risk factors, causes, severity and outcome, with different spectrums compared to general populations and frequent poor outcome. This collaboration will allow for an in-depth analysis of these factors. Conflict of interest All authors report: Nothing to disclose.