Difference in clinical characteristics between functional syncope and vasovagal syncope in children

BACKGROUND: Functional syncope and vasovagal syncope (VVS) in children both present with transient loss of consciousness (TLOC) and are clinically challenging to differentiate. This study aims to delineate the distinguishing features among factors associated with TLOC induction in these two conditions. METHODS: A total of 31 children presenting with syncope and diagnosed as functional syncope were enrolled in the functional syncope group; concurrently, 40 children presenting with syncope and diagnosed with VVS were enrolled in the VVS group. Clinical manifestations— including demographic characteristics, precipitating factors, prodromal symptoms, syncope episode characteristics, family history, and psychosocial stressors—were systematically compared between the two groups. RESULTS: Body weight was significantly higher in the functional syncope group than in the VVS group (P < 0.05). No statistically significant differences were observed between the groups in terms of sex distribution, age, body height, or baseline resting heart rate (P > 0.05). Compared with the VVS group, the functional syncope group exhibited significantly fewer identifiable triggers, fewer presyncope symptoms, and a lower prevalence of familial syncope history (all P < 0.05). Conversely, the functional syncope group demonstrated significantly longer syncope duration, higher syncope frequency, and greater exposure to emotional stress events (all P < 0.05). Disease duration did not differ significantly between the two groups (P > 0.05). CONCLUSIONS: Children with functional syncope exhibit distinct clinical profiles relative to those with VVS, characterized by fewer precipitating factors and prodromal symptoms, longer duration and higher frequency of syncope episodes, reduced familial syncope history, and increased association with emotional stress events.