The condition characterized by a brief loss of consciousness upon swallowing
Syncope pertains to the brief loss of consciousness. It is also called fainting. Syncope happens when blood pressure shoots down or when there is too much vagal effect on a bradycardic heart or heart block. When syncope occurs during deglutition, it is then referred to as swallow syncope (or deglutition syncope).
Swallow syncope is not uncommon although cases of it were reported as early as 1958.1 It can affect children and adults. It is known to be neurally-mediated (i.e. by the vagus nerve) in origin and involves the afferent impulses from the upper gastrointestinal tract and the efferent impulses (to the heart). 2
Individuals who experienced swallow syncope reported feelings of light-headedness, confusion, and dizziness during the swallowing of food or liquids. Swallow syncope is also said to be not associated with the consistency, temperature, or size of food. There were also no warning signs that a syncope might occur during deglutination.1