Etiologies and Risk Factors by Sex and Age in Young Adult Patients with Ischemic Stroke.

Aim: The aim of this study was to explore etiologies and risk factors by age and sex in young adult patients with ischemic stroke.

Methods: We recruited patients with ischemic stroke aged between 18 and 49 years. We assessed pathological etiologies by the Trial of Org 10,172 in Acute Stroke Treatment (TOAST) classification and risk factors by the International Pediatric Stroke Study (IPSS) classification. We explored the distribution of etiologies and risk factors by age and sex and investigated baseline features associated with functional outcomes at 3 months.

Results: Of 8521 stroke patients consecutively admitted, 1017 patients (11.9%) aged between 18-49 years, of whom large artery atherosclerosis was the most common etiology (n=375, 36.9%), followed by other determined cause (n=194, 19.1%) and undetermined cause (n=184, 18.1%). Compared to male patients, female patients had more cardioembolism (16.34% vs 8.42%) and less small artery occlusion (8.56% vs 17.76%). As age increased, the proportions of large artery atherosclerosis (P <0.001) and small artery occlusion (P <0.001) increased, and the proportion of other determined causes decreased (P <0.001). Of 184 patients with undetermined causes, 173 (94.0%) had at least one IPSS risk factor. A higher serum level of D-dimer at baseline was associated with an increased risk of unfavorable outcome (OR 1.118, 95% CI 1.052- 1.189), adjusting for the effect of age and stroke severity.

Conclusion: Approximately one-fifth of young patients with ischemic stroke had undetermined etiology, for whom the IPSS classification helps to explore risk factors. A higher level of Ddimer was associated with a higher risk of unfavorable outcomes at 3 months.