Background: Young stroke incidence has increased worldwide with lifestyle changes. Etiology and risk factors for both ischemic and hemorrhagic stroke in young Asians remain underexplored. Methods: We retrospectively reviewed consecutive acute stroke patients aged 16–45 years admitted to the Taipei Veterans General Hospital between 2009 and 2019 to analyze etiologic subtypes, risk factors, and serial modified Rankin Scale scores for 1 year and compare the age groups of 16–30 and 31–45 years. Results: Among 670 young Taiwanese patients (mean age at onset 37.5 ± 7.0 years; male 65.1%), there were 366 nontraumatic spontaneous hemorrhagic stroke (including 259 intracerebral hemorrhage [ICH] and 107 subarachnoid hemorrhage, SAH), 292 ischemic stroke and 12 cerebral venous thromboses. Notably, ICH was more prevalent in patients aged 16–30 than in those aged 31–45 (54.8% vs 36.8%). Specifically, structural vasculopathy (e.g., arteriovenous malformation, cavernoma) was the most common etiologic subtype in patients aged 16–30 (p < 0.001), whereas hypertensive ICH was the most common subtype in patients aged 31–45 (p < 0.001). On the other hand, the top ischemic subtype for both age groups was other determined diseases (e.g., arterial dissection, autoimmune diseases, moyamoya disease, etc.) rather than large artery atherosclerosis. Hyperlipidemia, diabetes, and cigarette smoking were more common risk factors for infarction than ICH. Familial stroke patients whose first- or second-degree relatives had a stroke by age 80 (n = 104, 15.5%) had more infarctions than those without a familial stroke history. In multivariate analyses, initial stroke severity, and infarction type were important predictors of favorable outcomes after 3 months. At the 1-year follow-up, patients with ICH and SAH had worse functional outcomes and survival rates than those with infarction. Conclusion: An aggressive approach to elucidate the etiology of stroke is indicated because structural vasculopathy-induced ICH and other determined infarction are distinctively prevalent in young adults, particularly those aged 16–30.

Background Early-onset adult stroke has not been fully characterized in Asians. Objectives We investigated the etiologic subtypes, risk factors and 1-year outcomes of early-onset stroke (16 – 55 years of age) in a Taiwanese cohort. Methods We retrospectively reviewed consecutive patients with acute stroke admitted to the Taipei Veterans General Hospital in Taiwan between 2009 and 2017. Patients were classified by age of onset (≤ or > 55) and etiologic subtypes and regularly followed for 1 year. Results Among all stroke patients (n=8155), 17.6% (n=1310) were early-onset, who had slightly more spontaneous hemorrhagic stroke (50.8%) than ischemic stroke (49.2%). The most common etiologic subtypes of hemorrhagic stroke were hypertensive intracerebral hemorrhage (ICH), subarachnoid hemorrhage and undetermined ICH. The most common subtypes of infarction were large artery atherosclerosis, other determined diseases (52.5% arterial dissection) and embolic stroke of undetermined source. Smoking, alcohol overdrink, obesity, ischemic heart disease and family history of stroke were more in the early-onset than the elderly patients. The early-onset patients with familial stroke (n=87, 6.6%) were more males and more commonly had infarction than those without familial stroke. Monogenic diseases accounted for 5.7% of young familial stroke. At 1-year follow-up, the early-onset patients with infarction displayed greater functional improvements but more stroke recurrence than those with ICH. Conclusions Hypertensive hemorrhagic stroke and large artery atherosclerosis or dissection occlusion are characteristically common etiologies of young stroke in Taiwan. Early-onset infarction had higher recurrence yet better 1-year outcomes than early-onset ICH. Patients with familial versus non-familial aggregation had more ischemic infarction and monogenic diseases.