Changes in blood serotonin in patients with tinnitus and other vestibular disturbances

The role of serotonin as a mediator and stress hormone and its function in vessel tonus regulation is proved. The aim of the work is to study the concentration of serotonin in blood in patients with vestibular disturbances before and after vestibular provocation and in patients with tinnitus. The study was performed on 134 persons distributed among three groups: group I, 35 patients with vestibular disturbances; group II, 75 healthy persons; group III, 24 patients with tinnitus. Serotonin was examined twice in patients with vestibular disturbances (group I) and in healthy persons (group II), before and 15 minutes after vestibular provocation realized by a cold caloric test, and once in patients with tinnitus (group III). Vestibular loading provokes changes in blood serotonin: In vestibularly stable persons, serotonin decreases and comparatively weaker vestibular vegetative reactions develop. The role of serotonin in the compensatory mechanisms of the organism related to vestibular crisis is discussed. We recommend its inclusion with routine neurootological examinations for selecting candidates for work in conditions that overload the vestibular analyzer. Patients with tinnitus have serotonin blood values that significantly exceed the referent ones.