# Arterial ischaemic stroke in adolescents and very young adults—results of a European cohort

## TL;DR

This study compares stroke risk factors in adolescents and young adults, finding similar causes but highlighting the need for age-specific classification systems.

## Contribution

The study introduces a comparative analysis of stroke risk profiles in adolescents and young adults using both pediatric and adult classification systems.

## Key findings

- Cryptogenic stroke was most common in both adolescents (43%) and young adults (32%).
- Sex distribution differed by age: male predominance in adolescents and female in young adults.
- Current classification systems may be inadequate for identifying stroke causes in this age group.

## Abstract

Arterial ischaemic stroke (AIS) in adolescents and young adults differs from older populations due to its variety of risk factors and aetiologies. This study compares the risk factor profiles and age- and sex-related differences between adolescents and very young adults.

Pooled data from three multicentre cohort studies in Europe (Germany, France, The Netherlands) were analysed. First-ever symptomatic AIS cases in adolescents (10–18 years) and very young adults (18–30 years) were classified using both a paediatric AIS classification (multiple risk factor category system) and the modified Trial of ORG 10172 in Acute Stroke Treatment criteria for adults.

The cohort includes 142 adolescents (median age 15) and 131 very young adults (median age 25). Using the adult AIS classification, cryptogenic stroke was most common (43% in adolescents, 32% in young adults). Thirty-two percent had other determined aetiologies. The paediatric classification showed similar results regarding identified causes; 29% resulted in cryptogenic stroke, respectively. Sex distribution differed by age: male predominance in adolescents (61%) and female predominance in young adults (57%).

Adolescence and young adulthood may represent a shared age group with similar causes and risk profiles for AIS. The high rate of cryptogenic stroke suggests potential limitations in current classification systems for AIS aetiology at these ages.

This cohort highlights the need for an age-adapted risk factor system that accounts for the transitional nature and the complexity of stroke in this age group.

Graphical Abstract