Apraisal of the diagnostic value of the gag reflex in patients with neurogenic oropharyngeal dysphagia

Introduction: The gag reflex is a protection mechanism that prevents food and unwanted agents from entering the lower airways. It is usually part of the physical examination of swallowing to detect oropharyngeal dysphagia, but it is a potentially ambiguous sign.

Objective: To evaluate the diagnostic value of the gag reflex in patients with neurogenic oropharyngeal dysphagia and adults without it.

Materials and methods: We conducted an analytical observational study in patients with neurogenic oropharyngeal dysphagia (cases) and patients without dysphagia (controls). We evaluated the absence or presence of the reflex bilaterally, by direct visualization, and adjusted it according to sex, age, and other interaction variables.

Results: We included 86 patients with neurogenic oropharyngeal dysphagia and 80 control subjects. The gag reflex on swallowing physical examination showed a positive relationship with the patients (right side: OR = 3.97; 95 % CI: 2.01-7.84; left side: OR = 4.84; 95 % CI: 2.41-9.72), but a negative association with the control group. In both groups, neither sex, nor age, nor other interaction variables modified the gag reflex.

Conclusions: The gag reflex absence or presence does not confirm or exclude the existence of oropharyngeal dysphagia due to neurological and neuromuscular causes. Therefore, health professionals must not rely on this reflex. Clinicians must go beyond a simple reflex revision, even in neurological patients where it is supposed to be absent.