Improvement of a delayed swallowing reflex following treatment for advanced head and neck cancer.

Background: The latency of the swallowing reflex is an important factor causing dysphagia in head and neck cancer patients. Although there are many reports comparing voluntary swallowing function before and after treatment, few studies have focused on the latency of the swallowing reflex, which is a risk factor for pneumonia due to silent aspiration. The aim of this retrospective study was to clarify the changes in the latency of the swallowing reflex before and after treatment.

Methods: The latency of the swallowing reflex was quantified using the time from the injection of 1 ml of distilled water into the pharynx through a nasal catheter to the onset of swallowing.

Results: The latency time of the swallowing reflex was significantly decreased 3 months after treatment compared to before treatment. A significant reduction was also observed in patients with pharyngeal cancer who underwent chemoradiation therapy.

Conclusions: This retrospective study showed that a delayed swallowing reflex improved with treatment in advanced head and neck cancer patients.

Trial Registration: The Institutional Review Board of Tohoku University Hospital (Number 2014-1-274).