Humoral serotonin and neuropsychological status of patients with dizziness

Dizziness is often accompanied by affective disorders such as anxiety and depression, in the occurrence of which the role of the serotonergic system is discussed. Objective : to investigate the serotonin content in blood serum and neuropsychological status in patients with vestibular and non-vestibular dizziness. Material and methods . The study included 97 patients. Two observation groups were formed according to the type of dizziness complaints. The first group (n=47) comprised patients with vestibular (systemic) dizziness against a background of peripheral vestibulopathy, the second group (n=35) comprised patients with non-vestibular (non-systemic) dizziness with a diagnosis of probable persistent postural-perceptual dizziness (PPPD). The control group (n=15) consisted of patients without complaints of dizziness. Neurological and otoneurological status, psychoemotional parameters (level of anxiety and depression) and cognitive functions were analyzed, and the quantitative level of serotonin in blood serum was determined by enzyme immunoassay. Results . The study revealed a significant decrease in the serum serotonin levels in vestibular and non-vestibular dizziness; a lower serotonin level was found in non-vestibular dizziness (p<0.05). The presence of affective disorders did not correlate with a decrease in serotonin levels in vestibular dizziness against a background of peripheral vestibulopathy. It is assumed that a decrease in serotonin content plays a role in pathogenesis of vestibular dizziness on the background of peripheral part of vestibular system involvement. Conclusion . We demonstrated possibility of using the level of serotonin in peripheral blood as an objective laboratory marker of vestibular and non-vestibular dizziness in general clinical medical practice.