Retrograde Cricopharyngeal Dysfunction
Retrograde cricopharyngeal dysfunction (RCPD) is a disorder of the swallowing mechanism that has only been defined recently, in 2019. The key symptom reported by people with this condition is that they are unable to belch/burp. This causes a number of other symptoms, including chest discomfort, abdominal discomfort and abdominal bloating.
Retrograde cricopharyngeal dysfunction occurs because the cricopharyngeus muscle, the muscle at the junction between the throat and the oesophagus (the tube that connects the throat to the stomach), does not relax properly to allow release of the air that comes up into the oesophagus (from the stomach) into the throat, and then to the outside world. Interestingly, people with RCPD do not report difficulty with swallowing their food (ie. food does not stick as it passes through the cricopharyngeus from the throat into the oesophagus).
The treatment of RCPD is injection of Botulinum Toxin into the cricopharyngeus muscle to relax it. Although the effect of Botulinum Toxin is only temporary (usually 3-4 months), most people with RCPD only require one treatment with Botulinum toxin. It is thought this is because the period of muscle relaxation allows the body to reset the activity of the muscle, restoring its normal function. If the symptoms of RCPD return, either further Botulinum Toxin, or surgery to cut the cricopharyngeus muscle (a cricopharyngeal myotomy), may be required.