[Analysis of etiology and short-term prognosis of childhood arterial ischemic stroke based on the COIST classification].

Objective: This study aims to analyze the etiology and short-term prognosis of childhood arterial ischemic stroke (AIS) in Chinese children, based on the COIST classification system. Methods: A total of 380 pediatric patients with a first-ever diagnosis of AIS treated at Beijing Children's Hospital between September 2015 and April 2024 were retrospectively included. Etiology was analyzed according to COIST classification. The patients were categorized into infant and toddler group with 117 cases (>28 days to≤3 years), preschool group with 90 cases (>3 years to≤7 years), school-age group with 90 cases (>7 years to≤11 years), and adolescent group with 83 cases (>11 years to≤18 years). The etiological distribution across age groups and the short-term prognosis of patients with different etiologies were further analyzed. Results: Among the 380 patients, 235 were male (61.8%) and 145 were female (38.2%), with a mean age at presentation of(6.6±4.6)years. Approximately 2/3 of the patients were admitted in the Department of Neurology, with a mean hospital stay of (13.2±6.7)days. (1) Etiological analysis: "Vascular structural abnormalities" were the most common cause, accounting for 38.2% (145/380), followed by "Inflammatory" causes at 31.1% (118/380), "Undetermined" at 11.1% (42/380), "Other identifiable causes" at 9.2% (35/380), "Cardiac diseases" at 6.3% (24/380), and "thrombophilia" at 4.2% (16/380). (2) Etiological distribution by age group: in the infant and toddler group, "vascular structural abnormalities" were 47.9% (56/117), with basal ganglia infarction following minor trauma(combined with basal ganglia calcification) being the most common (40/117). In the preschool group, there were 34 cases (34/90) of "inflammatory" and 33 cases (33/90) of "vascular structural abnormalities", with Moyamoya disease being the most frequent cause (15/90). In the school-age group, there were 37(37/90) cases of "vascular structural abnormalities", with arterial dissection (12/90)being the most common, followed by FCA-i (11/90), and Moyamoya disease (11/90). In the adolescent group, there were 34 cases of "inflammatory"(34/83), with the highest proportion of FCA-i (13/83) in the subgroup, followed by thrombophilia (9/83) and systemic lupus erythematosus (8/83). (3) Short-term prognosis: based on the PSOM scale, 188 cases had good prognosis, accounting for 49.5% (188/380), while 192 cases had poor prognosis, accounting for 50.5% (192/380). According to the mRS score, 207 cases had good prognosis (54.5%) and 173 cases had poor prognosis (45.5%). Subtypes such as "Inflammatory-noninfectious, " FCA-i, Moyamoya disease, and arterial dissection were associated with relatively better outcomes. Less than 1/3 of patients in the "other identifiable causes" group had favorable prognosis. The in-hospital mortality rate was 3.7% (14/380). Conclusions: Vascular structural abnormalities and inflammatory (including infectious and non-infectious) factors are the predominant causes of pediatric AIS; Approximately half of children with AIS had a favorable short-term outcome.