The diagnostic test for Z-E syndrome is
**Core Concept**
Z-E syndrome, also known as Zenker's diverticulum, is a condition characterized by the formation of a diverticulum in the pharynx, specifically at the cricopharyngeal junction. This occurs due to the abnormal function of the upper esophageal sphincter (UES), leading to the herniation of the pharyngeal mucosa through a weakness in the muscular wall.
**Why the Correct Answer is Right**
The diagnostic test for Z-E syndrome involves barium swallow radiography, which is a type of fluoroscopic examination. During the examination, the patient swallows a barium-containing liquid, and the resulting X-ray images are used to visualize the pharynx and esophagus. The barium outlines the diverticulum and any other abnormalities, allowing for a clear diagnosis. The cricopharyngeal muscle dysfunction and the characteristic "outpouching" of the pharyngeal mucosa are key features that can be visualized on the barium swallow.
**Why Each Wrong Option is Incorrect**
**Option A:** Endoscopy is not typically used for the diagnosis of Z-E syndrome, as it may not provide a clear view of the diverticulum due to its location at the cricopharyngeal junction.
**Option B:** CT scan may be used to evaluate the extent of the diverticulum and surrounding structures, but it is not the primary diagnostic test for Z-E syndrome.
**Option C:** Esophageal manometry is used to assess the function of the esophagus and UES, but it is not a diagnostic test for Z-E syndrome.
**Clinical Pearl / High-Yield Fact**
A key clinical feature of Z-E syndrome is dysphagia, particularly for solid foods, due to the impaired function of the UES. Patients may also experience regurgitation of food and liquids, as well as a feeling of food "sticking" in the throat.
**Correct Answer:** C.