Relation between motion sickness susceptibility and vasovagal syncope susceptibility.

Motion sickness is common in the population, especially in children, but its physiopathology is only partially understood and the true nature of the particular susceptibility of certain subjects remains completely unknown. Some symptoms of motion sickness, like pallor and cold sweating, are of an autonomic nature and the role of the autonomic nervous system in vasovagal syncope is well known. Our aim was therefore to study the relationship between motion sickness susceptibility and vasovagal syncope susceptibility. Questionnaires about susceptibility to motion sickness and to vasovagal syncope or presyncope in adulthood and childhood, filled in by 899 students (20.4 +/- 2.1 years, 405 men), were analysed. Motion sickness susceptibility in childhood was 31.1% and in adulthood 7.9% (p < 0.001). Vasovagal syncope susceptibility in childhood was 36.4% and in adulthood 33.9% (NS). A relationship between motion sickness susceptibility in adulthood and vasovagal syncope susceptibility in childhood and adulthood (p = 0.004 and 0.005, respectively) was found. Despite the limitations of a retrospective study this relationship between motion sickness susceptibility and vasovagal syncope susceptibility may indicate that a common mechanism exists, explaining the particular susceptibility of some subjects to both disorders. This paradigm may prove useful in better understanding the true nature of motion sickness and vasovagal syncope.