'What puts the 'Hic' into Hiccups?'

Abstract

Recurrent and persistent bouts of hiccups impact the quality of life by interfering with eating, social interaction and work. Popular home remedies, such as breath holding and drinking ice water, target activity in the vagal and phrenic nerves that are thought to trigger these repetitive, myoclonic contractions. However, the pathophysiology of hiccups and the mechanism by which any of these methods work are unclear. Indeed, so little is known that there is no agreement whether the 'Hic' sound is due to the abrupt closure of the epiglottis or the glottis, including the vocal cords.Investigations were performed in a 50-year-old, otherwise healthy male with recurrent hiccups, in whom contractions persisted for up to 4 hours. Hiccups were initiated by drinking carbonated soda. The aerodigestive tract was visualised by video fluoroscopy. Hiccups were terminated by drinking a non-viscous contrast agent through a forced inspiratory suction and swallow tool. This device requires significant suction pressure (-100 mm Hg) to draw fluid into the mouth and is effective in approximately 90% of cases. The images were analysed together with concurrent audio recordings to gain insight into 'what causes the 'hic' in hiccups' and how this commonplace but annoying problem can be treated.

Keywords: functional bowel disorder; gastroesophageal reflux disease; neurogastroenterology.

Figure 1

Forced inspiratory suction and swallow tool (‘HiccAway’, Aim Dynamics, Longmont, Colorado, USA). The tool has a mouthpiece on the top, a rigid body and a cap with a pressure valve on the bottom. The valve and the body’s dimensions were designed to generate high-negative suction pressure. The cap is removable and can be rotated to set the valve to the adult or child settings. The tip is submerged in a half-filled cup of water. The lips are pursed around the mouthpiece and forceful suction draws water into the mouth and is immediately swallowed. Hiccups usually stop after one to three attempts.