Cricopharyngeal muscle dysfunction occurs when the upper esophageal sphincter fails to relax properly during swallowing, making it difficult for food, liquids, or pills to pass from the throat into the esophagus.
What Causes CPM Dysfunction?
CPM and UES dysfunction occur for varying reasons. It may result as a side effect of the normal aging process or due to changes in the CPM or nerve signaling pathways. Specifically, muscle enlargement (called hypertrophy), scarring of the muscle (called fibrosis) from radiation therapy or trauma, stroke, and reflux (heartburn) can all damage the swallowing mechanism at the UES.
To test for CPM and/or UES dysfunction, your ENT (ear, nose, and throat) specialist, or otolaryngologist, may examine your throat and larynx (voice box) by passing a small flexible camera through your nose. In addition, your ENT specialist may order an X-ray swallowing test called a modified barium swallow, esophagram, and/or manometry (pressure testing) of the valve area.
During the modified barium swallow, also known as a Videofluoroscopic Swallow Study (VFSS), you swallow various barium-coated foods, liquids, and pills while a speech language pathologist takes X-ray video. For an esophagram, a radiologist looks at the esophagus with X-rays as barium is swallowed in order to evaluate esophageal function.
In CPM dysfunction, a narrowing of the valve may be seen, although narrowing of the PES may not be abnormal or require intervention. Manometry is a test that measures throat and esophageal pressures during swallowing by placing a thin tube through the nose into the esophagus and having patients swallow water. In CPM dysfunction, the valve may have high pressures at rest and/or during swallows.




