Neurophysiology of Laryngopharyngeal Reflux and Brainstem Reflex

ABSTRACT

Laryngopharyngeal reflux disease (LPRD) is different with gastroesophageal reflux disease (GERD). The lower esophageal sphincter (LES) possesses an intrinsic nervous plexus that allows the LES to have a considerable degree of independent neural control. Sympathetic control of the LES and stomach stems from cholinergic preganglionic neurons in the intermediolateral column of the thoracic spinal cord (T6 through T9 divisions), which impinge on postganglionic neurons in the celiac ganglion, of which the catecholaminergic neurons provide the LES and stomach with most of its sympathetic supply. Sympathetic regulation of motility primarily involves inhibitory presynaptic modulation of vagal cholinergic input to postganglionic neurons in the enteric plexus. The magnitude of sympathetic inhibition of motility is directly proportional to the level of background vagal efferent input. Recognizing that the LES is under the dual control of the sympathetic and parasympathetic nervous systems, we refer the reader to other comprehensive reviews on the role of the sympathetic and parasympatetic control of LES and gastric function. The present review focuses on the functionally dominant parasympathetic control of the LES and stomach via the dorsal motor nucleus of the vagus.