Galvanic vestibular stimulation promotes visuospatial cognitive recovery in acute unilateral vestibulopathy via targeted neural modulation: a randomized controlled trial

Background: The vestibular system plays a crucial role in spatial orientation and hippocampal-dependent memory. While bilateral vestibular loss is known to impair spatial cognition, recent evidence highlights that even unilateral vestibular deficits—commonly seen in vestibular neuritis—can disrupt visuospatial memory. Galvanic vestibular stimulation (GVS), a non-invasive neuromodulatory technique, has shown promise in enhancing neural plasticity and spatial cognition in preclinical models. Objective: To evaluate the therapeutic effects of near-threshold GVS on visuospatial cognition in patients with acute unilateral peripheral vestibulopathy (AUPV) and to investigate its neuromodulatory potential beyond natural recovery. Methods: In a single-blind, randomized, sham-controlled trial, 83 AUPV patients were assigned to receive either 10 daily sessions of GVS (cathode on lesion side) or sham stimulation in the acute phase. Cognitive assessments included the Visual Object and Space Perception (VOSP) battery, Corsi Block-Tapping Test (CBTT), Block Design Test (BDT), and a virtual Morris Water Maze (vMWM). Intervention and time-dependent effects were analyzed using generalized estimating equations. Results: GVS significantly improved visuospatial memory performance, with enhanced CBTT block span and total scores and superior spatial retention in the vMWM trial. Significant interaction effects between intervention and time suggested that GVS accelerated cognitive recovery beyond spontaneous compensation. No adverse effects were reported. Conclusion: These findings support GVS as a neuromodulatory intervention to enhance spatial memory and facilitate cognitive recovery in AUPV. By modulating vestibulo-hippocampal circuits, GVS may offer a promising therapeutic avenue for cognitive rehabilitation in unilateral vestibular dysfunction. Trial registration: This study was registered with the Clinical Research Information Service (CRIS), Republic of Korea, under the identifier KCT0007058, registered on May 25, 2022.