Prevalence and triggers of syncope and orthostatic dizziness in young people with Down syndrome – brief report

Abstract
Background: The objective of this study is to determine the prevalence and triggers of syncope episodes in people with Down syndrome.
Method: A random sample of 1000 relatives of people with Down syndrome received a questionnaire consisting of 29 questions on general personal and clinical characteristics and specific questions concerning episodes of transient loss of consciousness (TLOC), dizziness upon standing, cardiac history and epilepsy.
All data were entered into a database and analysed using SPSS.
Results: Seventy three (12.9%) of 564 people had experienced a TLOC-episode during their life sofar, 25 (4.4%) of them during the last year. The median age when having their first TLOC was 12 years (range 0-27). Sixty-three persons suffered from a reflex syncope. The top six of most frequently mentioned triggers of syncope included illness, emotion, warm environment, insufficient food intake, menstruation and standing up. These syncope triggers were related to conditions that affect orthostatic blood pressure regulation and vasomotor responses.
Conclusion: For people with Down syndrome reflex syncope is the most common cause of TLOC, though other causes are more frequent than in a normal young population.
Key words: Down syndrome; transient loss of consciousness;
reflex syncope; vasovagal syncope;
orthostatic hypotension