Risk factors, mechanisms, and clinical outcomes of stroke in young adults presenting to a North Central London stroke service: UCL Young Stroke Systematic Evaluation Study (ULYSSES)

Introduction: Stroke incidence in younger adults is increasing worldwide yet few comprehensive studies exist from a UK population. We investigated the risk factors, mechanisms, functional outcome and stroke recurrence rate in a cohort of young adults with stroke. Patients and methods: We included consecutive patients (<55 years) with ischaemic stroke or intracerebral haemorrhage (ICH) admitted to the University College London Hospitals Hyperacute Stroke Unit between 2017 and 2020. Ischaemic stroke was classified using Trial of Org 10172 in Acute Stroke Treatment (TOAST) criteria and ICH using modified CLAS-ICH criteria. Multivariable logistic regression was performed to identify predictors of unfavourable functional outcome (modified Rankin Scale [mRS] > 1) at 6 months. Results: Five hundred fifty-two patients were included (median age 47, IQR 41-51; 33% female; 76% ischaemic stroke). Common risk factors included dyslipidaemia (57%), hypertension (40%), and cigarette smoking (34%). Ischaemic stroke was mostly due to cardioembolism (22%). Probable cerebral small vessel disease was the most frequent ICH aetiology (53%). Unfavourable functional outcome was prevalent in 50% at 6 months and was associated with ICH (OR 2.02, 95%CI 1.14-3.58, p = 0.017), female sex (OR 1.62, 95%CI 1.03-2.55, p = 0.037), admission stroke severity (per point increase, OR 1.11, 95%CI 1.07-1.16, p < 0.001) and pre-morbid mRS 2-5 (OR 3.16; 95%CI 1.11-9.03, p = 0.032). 4.4% had a recurrent stroke within 6 months. Discussion and conclusion: Traditional cardiovascular risk factors are common in young adults with stroke. Unfavourable functional outcome is associated with female sex, ICH, severe stroke and pre-morbid disability. These findings can inform national stroke prevention and rehabilitation strategies.