Swallow Syncope After Whiplash Neck Injury

Abstract

Swallow syncope is a rare dysautonomic syndrome characterized by temporary loss of consciousness upon swallowing solid foods or liquids, displaying primarily in individuals with an underlying structural or functional esophageal or cardiac pathology. However, the evidence also suggests that isolated vagal dysfunction or abnormal reactions of esophageal mechanoreceptors after mechanical irritation, demyelination, or trauma can potentially evoke  a cardioinhibitory response or vasodepression upon swallowing. We present a case of a 49-year-old otherwise healthy female patient who developed swallow syncope two weeks after whiplash neck injury acquired in a rear-end collision. After no evident anatomical and/or functional cardiac or esophageal pathology was diagnosed using several diagnostic procedures, the final diagnosis was confirmed by a provocative tilt-table test while ingesting solid food. Subsequently, a dual-chamber pacemaker was implanted, relieving the patient from troublesome symptoms. Abnormal reactions of esophageal mechanoreceptors to stimuli associated with food ingestion and/or dysfunction of afferent and efferent vagal fibers due to stretch injury and related neck trauma (acquired during the car accident) may be the leading pathophysiological mechanisms of swallow syncope in our patient.