Glossopharyngeal and Vagus Nerve Damage

Damage to the glossopharyngeal and vagus nerves often occurs simultaneously, mainly presenting as hoarseness, difficulty swallowing, regurgitation of liquids, and absence of the gag reflex, clinically referred to as bulbar palsy (true bulbar palsy). When one side is damaged, symptoms are mild, and the paralyzed side of the soft palate arch is lower when the mouth is opened, with the uvula deviating to the healthy side. When the patient says "ah," the soft palate on the affected side is limited in elevation, accompanied by sensory loss in the pharynx and absence of the gag reflex. This is seen in conditions such as Guillain-Barré syndrome and Wallenberg syndrome. The motor nuclei of the glossopharyngeal and vagus nerves are bilaterally innervated by the corticobulbar tracts. When one side is damaged, bulbar palsy symptoms do not appear; only when both corticobulbar tracts are damaged do dysarthria and dysphagia occur, with the gag reflex present, referred to as supranuclear bulbar palsy or pseudobulbar palsy. This is commonly seen in bilateral hemispheric vascular lesions. The differentiation between true and pseudobulbar palsy is shown in the table.