Evaluating Postural Instability in Patients With Persistent Postural-Perceptual Dizziness (PPPD) Exposed to Moving Visual Stimuli

Introduction This study investigated postural instability in patients with persistent postural-perceptual dizziness (PPPD) in response to moving visual stimuli, using posturography to assess visual-ratio-derived sway responses. While visual factors exacerbate symptoms, the neural mechanisms remain unclear. Methods We studied six individuals with PPPD, six healthy controls (HCs), and 35 patients with various vestibular dysfunctions lasting more than three months. Using posturography, we measured sway area with eyes open and closed for 60 seconds. Participants fixated on visual stimuli for 60 secs: a checkerboard, vertical stripes, or optic flow. Measurements were taken during stimulation, calculating visual ratios (VRs) with open eyes. Results No significant pre- or post-stimuli differences in sway area were found. However, VR was significantly higher in PPPD patients compared to other disease groups, indicating increased instability during visual stimuli, consistent with visually induced dizziness. Conclusion Postural instability during moving visual stimuli suggests a potential objective diagnostic tool for PPPD. These findings offer insights into the neural mechanisms of PPPD symptom exacerbation by visual stimuli and support the utility of visual-stimulus-based posturography as an adjunctive diagnostic tool for PPPD.