Comparative Efficacy of Vestibular Rehabilitation, Noisy Galvanic Vestibular Stimulation, and Their Combination on Postural Control, Dizziness, Anxiety, and Depression in Patients with Persistent Postural-Perceptual Dizziness

Background and Aim: Persistent Postural-Perceptual Dizziness (PPPD) is a chronic vestibular disorder characterized by persistent dizziness, non-spinning vertigo, or unsteadiness exacerbated by moving visual stimuli and upright postures. Vestibular Rehabilitation Therapy (VRT) has shown favorable outcomes. While noisy Galvanic Vestibular Stimulation (nGVS) has been associated with improvements in various psychiatric and neurological conditions, its efficacy in PPPD remains unclear. This study aimed to assess the effectiveness of VRT, nGVS, and their combination on patients with PPPD in terms of postural control, dizziness, anxiety, and depression. Methods: Twenty-seven patients diagnosed with PPPD were randomly assigned to three groups receiving treatment for six weeks: 1) VRT, 2) GVS, and 3) VRT+GVS. Outcome measures included static postural control parameters, Dizziness Handicap Inventory (DHI), and Hospital Anxiety and Depression Scale (HADS) scores. Results: All groups demonstrated significant improvements in subjective measures (DHI and HADS) following treatment. Postural control improvements were observed only in specific conditions within each group, with no overall significant differences between the groups except for Mediolateral (ML) path length with eyes closed on a soft surface. Significant correlations were observed between improvements in postural control outcomes and questionnaire scores within each group. Conclusion: VRT and GVS, both individually and in combination, were effective in subjective measurements but had minimal impact on static postural control. Adding nGVS to VRT did not provide additional benefits for PPPD patients. The correlations between postural control and psychological outcomes suggest that improvements in perceived dizziness, anxiety, and depression may be linked to postural stabilization. Trial Registration Number: The study was registered in the Iranian Registry of Clinical Trials on 18 September 2023 (IRCT20160131026279N6).