Inability to Belch syndrome

What is retrograde cricopharyngeus dysfunction (R-CPD), or the inability to burp syndrome?

R-CPD is a relatively under-recognised condition. It is sometimes also known by alternative terminology such as the ‘inability to burp syndrome,’ ‘inability to belch syndrome’ or retrograde upper oesophageal sphincter dysfunction (R-UES-D). In R-CPD, patients are unable to burp due to a non-relaxing upper oesophageal sphincter. The cricopharyngeus is the major muscle making up the upper oesophageal sphincter complex.

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How does burping normally occur?

The ‘belch reflex’ has been identified to occur by the following steps:

1. Swallowing of air (aerophagia) is normal – we all swallow air when we eat and drink

2. Swallowed air reaches the stomach, and some may pass further down to the lower gastrointestinal tract and eventually passed as a ‘fart’ (flatulence)

3. Much of the swallowed air in the stomach passes back up (refluxes) into the oesophagus

4. Air refluxed into the oesophagus causes the oesophagus to distend

5. The distension of the oesophagus is sensed by special nerve endings, which then transmit nerve signals to the upper oesophageal sphincter, directing it to relax and open

6. The air built up in the oesophagus can then be vented out through the now open upper oesophageal sphincter, throat, and mouth as a burp (belch)

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What causes someone to be unable to burp (R-CPD)?

In patients with inability to belch, everything up to step 4 above seems to occur as in other persons. However, the reflex relaxation and opening up of the upper oesophageal sphincter (step 5) doesn't happen. This leads to pressure buildup in the oesophagus, and the symptoms of the condition.

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We don’t yet know why exactly this condition develops. However, there are several observations which can give a clue. Firstly, the cricopharyngeus / upper oesophageal sphincter has an important role in swallowing, yet in patients with R-CPD, it appears to open and close normally during swallowing. This implies that R-CPD is not primarily a problem with the muscle/sphincter itself. Secondly, most patients get better after a single course of treatment with nerve paralysis agent (see below), and mostly remain free of symptoms even after the agent wears off (usually within 3-6 months). This suggests that there is an element of learning involved, rather than a fundamental intrinsic problem with either nerve or muscles. It may be that R-CPD represents an unconscious but maladaptive learned behaviour – the patient may have ‘forgotten’ or never 'learned' how to burp, and the treatment we give helps them to relearn.

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How common is inability to burp?

The short answer is, we don’t know. As this is not a condition widely recognised by medical specialists, there are almost certainly many people in the community who have this condition but have not been diagnosed. There is a Reddit community with over 20,000 members worldwide.

 

What are the symptoms of the inability to belch syndrome (R-CPD)

The cardinal symptom is difficulty with burping, and most often a complete inability to burp, which is often longstanding (usually lifelong). The patient typically relate their other symptoms to their burping difficulty, and will often express that they feel that if they were able to burp, all their other symptoms would disappear. Other symptoms include:

• Chest pain or pressure

• Gurgling noises arising from the throat or chest

• Abdominal bloating

• Visible abdominal distension

• Excessive flatulence (wind/farting)

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Other symptoms that have been described, but may or may not be present, include excess saliva production, painful hiccups, nausea, heartburn and shortness of breath.

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How is R-CPD (the inability to burp syndrome) diagnosed?

When the classic symptom profile is present, some physicians who have expertise in this condition will diagnose R-CPD without any specific diagnostic test. However, recently, A/Prof Sanagapalli has devised and validates a diagnostic protocol using oesophageal high-resolution manometry (pressure recording) that is  simple and accurate method to diagnose R-CPD. Ideally, oesophageal manometry should be performed while asking the patient to eat or drink something that will trigger their symptoms (typically, carbonated beverage such as Coca-Cola). The characteristic findings are displayed in the image. Typically, when the patient describes their symptoms, manometry will reveal high pressure in the oesophagus due to gas build-up, and failure of the normal relaxation of the upper oesophageal sphincter – no burping. 

 

Other tests such as barium swallow, gastrointestinal endoscopy, nasendoscopy and laryngoscopy are not necessary for the diagnosis, and will not provide any useful diagnostic information in R-CPD.

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