The signs of anterior tongue movements and reduced tongue elevation observed during a swallow trial after a brainstem stroke most strongly indicate a disorder of which phase?

• A. Oral Phase
• B. Pharyngeal Phase
• C. Esophageal Phase
• D. None

Answer: (A)

The key idea is that this pattern points to an oral-phase problem. The oral phase is the voluntary stage where the tongue shapes and propels the bolus toward the back of the mouth for swallowing. Efficient anterior-to-posterior tongue movement and adequate tongue elevation are essential for forming, containing, and pushing the bolus posteriorly. If a brainstem stroke affects the tongue muscles—often via involvement of the hypoglossal nerve—the result is tongue weakness or impaired elevation and abnormal anterior tongue movements. These deficits disrupt bolus control and propulsion in the oral phase, which is exactly what would show up during a swallow trial. In contrast, the pharyngeal phase involves airway protection and pharyngeal constriction after the swallow is triggered, and the esophageal phase is about peristalsis in the esophagus, not tongue motion, so they wouldn’t be the primary explanations for these signs.