Psychophysiological responsivity and conscious appraisal of affective stimuli in non-organic syncope

Transient losses of consciousness and muscular tone that characterize syncope are due to a sudden decrease of blood flow to the brain. Nevertheless, in part of patients reporting syncope episodes the classic diagnostic process do not lead to a proper organic etiology – e.g. neutrally mediated or cardiac. Psychological non-organic factors like emotional dysregulation or anxiety mechanisms might act as triggers for those clinical manifestations. Given the link between affective experience and sympathetic-parasympathetic autonomic system, this research aims at investigating the hypothesis of a psychogenic etiopathogenesis and at sketching a clearer picture of affective responses in syncope. Control (healthy volunteers) and clinical (syncope patients with no organic etiology) groups were presented with arousing affective visual stimuli and assessed by psychometric tests. In order to explore both automatic and conscious processing of affective information, we recorded participants’ psychophysiological responses (autonomic and EEG) and subjective appraisal ratings (valence and arousal). The comparison of psychometric, electrophysiological and autonomic data across patients and control subjects showed anomalous response profiles, with partially incongruent autonomic automatic psychophysiological responses and conscious appraisal ratings. While the dysregulation of psychophysiological responsivity might characterize syncope profiles, the complexity of clinical pictures suggest that there may exist different non-organic syncope subtypes.