Which of the following is NOT a possible cause of serial swallows in a post-stroke patient?

• A. Excessive lingual rocking
• B. Drooling
• C. Inappropriate laughter while swallowing
• D. Delay in initiation of the pharyngeal response

Answer: (D)

Serial swallows reflect repeated efforts to clear pharyngeal residue after a swallow, a common pattern in post-stroke dysphagia when propulsion or clearance is impaired or when sensory input triggers successive swallows. Excessive lingual rocking disrupts smooth bolus propulsion, often leaving material that the person tries to push back and clear with multiple swallows. Drooling shows saliva pooling due to impaired swallow control, leading to several quick swallows in succession to manage the excess. Inappropriate laughter during swallowing points to disrupted swallow–breath coordination and inhibition, which can cause resets in the swallow sequence and result in serial swallows as the person reattempts the swallow. A delay in initiation of the pharyngeal response, however, delays the swallow itself and tends to produce residue and a slower, single swallow rather than a pattern of repeatedly initiated swallows, so it is not a cause of serial swallows.