A Multidomain Characterization of Persistent Postural-Perceptual Dizziness Reveals Visual Dependence as Its Main Behavioral Feature

BackgroundPersistent postural-perceptual dizziness (PPPD) is a chronic functional dizziness disorder characterized by unsteadiness, hypersensitivity to motion and visually complex environments. Although increasingly investigated, the role of the different factors involved remains unclear. This study aims to comprehensively characterize PPPD across clinical, biological, and behavioral domains. MethodsData from 18 PPPD patients and 20 age- and sex-matched healthy control volunteers (HC) were analyzed, including clinical and psychological questionnaires, a neuropsychological battery, salivary markers, posturography under different conditions, and gait analysis under single- and dual-task demands. ResultsPatients reported greater depressive symptoms, higher perceived stress, and reduced quality of life than HC, but showed no neuropsychological deficits and comparable past psychological trauma and personality traits. Salivary stress marker levels were similar to HC. Gait analysis revealed a slower, cautious gait in patients, which worsened without vision, with no differences in automaticity (stride time variability). Postural assessments showed greater sway and enhanced low-frequency oscillations, exacerbated by absence of visual input in PPPD. Visual reliance for postural control correlated negatively with subjective symptom severity, but not other symptom-related measures. ConclusionPPPD patients have lower mood and increased perceived stress, with no increase in biological stress markers compared to HC. Cognition, personality, and exposure to past trauma might be less relevant than previously hypothesized. Patients show visual dependence for gait and postural control, likely a maladaptive compensatory mechanism. These findings support interventions targeted at reducing visual dependence and at improving mood, rather than interventions focusing on psychological trauma. SummaryO_LIWhat is already known on this topic - PPPD (Persistent Perceptual Postural Dizziness) is a functional dizziness disorder characterized by different biopsychosocial factors, often investigated in isolation. C_LIO_LIWhat this study adds - PPPD patients have higher depression and perceived stress scores, lower quality of life, but show no differences in past trauma, personality traits, and biological stress markers, compared to healthy controls. They also show a reliance on vision both for gait and for postural control, with increased low-frequency oscillations in the anteroposterior direction. Visual dependence is likely maintained by its perceived role in symptom reduction. C_LIO_LIHow this study might affect research, practice or policy - These findings support rehabilitation strategies aimed at reducing reliance on vision and increasing reliance on vestibular inputs, but not interventions focusing on past traumatic experiences. C_LI