OBJECTIVES/HYPOTHESIS: It has been hypothesized that middle ear pressure can be controlled by the Eustachian tube through a neuronal reflex arc in animal models. We aimed to define the role of the neuronal control mechanisms in regulating middle ear pressure in humans. STUDY DESIGN: Prospective study. METHODS: The study population consisted of 95 ears of 95 volunteers. The mechanoreceptors on the tympanic membrane and the baroreceptors in the middle ear, which are assumed to form the afferent plexus of the neuronal reflex arc, were blocked by topical administration of lidocaine hydrochloride, in various patient groups. The Eustachian tube functions forming the efferent plexus of the neuronal reflex arc were evaluated by manometric tests both before and after blocking the possible afferent plexus in each study group. RESULTS: The baroreceptors established in the tympanic plexus might possibly have an effective role in this mechanism where the mechanoreceptors on the tympanic membrane seem to have a minor effect. CONCLUSIONS: Neuronal control mechanism could play an important role in regulating Eustachian tube function in humans. Laryngoscope, 2009.
OBJECTIVES/HYPOTHESIS: It has been hypothesized that middle ear pressure can be controlled by the Eustachian tube through a neuronal reflex arc in animal models. We aimed to define the role of the neuronal control mechanisms in regulating middle ear pressure in humans. STUDY DESIGN: Prospective study. METHODS: The study population consisted of 95 ears of 95 volunteers. The mechanoreceptors on the tympanic membrane and the baroreceptors in the middle ear, which are assumed to form the afferent plexus of the neuronal reflex arc, were blocked by topical administration of lidocaine hydrochloride, in various patient groups. The Eustachian tube functions forming the efferent plexus of the neuronal reflex arc were evaluated by manometric tests both before and after blocking the possible afferent plexus in each study group. RESULTS: The baroreceptors established in the tympanic plexus might possibly have an effective role in this mechanism where the mechanoreceptors on the tympanic membrane seem to have a minor effect. CONCLUSIONS: Neuronal control mechanism could play an important role in regulating Eustachian tube function in humans. Laryngoscope, 2009.