Changes in heart-brain integration precede psychogenic pseudosyncope

<h3></h3> Psychogenic pseudosyncope (PPS) is a condition characterized by transient subjective loss of consciousness that mimics syncope but without true loss of consciousness. Recent work has explored changes in heart-brain integration in the context of functional seizures using the heartbeat-evoked potential. The present study aimed to explore this in the context of PPS. PPS is routinely diagnosed based on history and examination but can be confirmed with simultaneous ECG and electroencephalography (EEG) recordings during a tilt-table test. We used EEG and ECG data recorded from patients with PPS during a tilt-table investigation. Previous work from our group has shown that changes in the heartbeat-evoked potential (HEP, which can be considered a measure of heart-brain integration) precede functional seizures. The present study examined this in the PPS group. The HEP demonstrated a decrement prior to the onset of the syncopal episode. This may represent changes in interoception, that is the moment-by-moment mapping of bodily signals at conscious and preconscious levels, during these events. Considering these changes alongside the semiological similarities and differences with functional seizures may help us understand more about the pathophysiology of paroxysmal functional neurological disorders.