Beyond vestibular recovery: Functional gait improvement through sensorimotor adaptation after COVID-19

Introduction: Vestibular neuritis leads to deficits in postural control and gait stability. Recovery is often assumed to depend on restoration of vestibular function; however, emerging evidence suggests that functional mobility may improve through adaptive sensorimotor mechanisms even in the presence of persistent vestibular deficits. This study examined the relationship between vestibular recovery and functional improvements in postural control and gait following rehabilitation that included adaptation exercises and habituation, with and without biofeedback, in a patient recovering from a COVID-19 infection. Methods: A 54-year-old patient with vestibular neuritis, diagnosed 3 weeks after contracting COVID-19, underwent a personalized rehabilitation program emphasizing gaze stabilization, dynamic balance, and gait adaptability. Assessments were conducted at baseline (T0), 6 weeks (T1), and 6 months (T2). Outcome measures included the Dizziness Handicap Inventory (DHI), Activities-specific Balance Confidence (ABC) scale, Zur Balance Scale, and Dynamic Gait Index (DGI). Vestibular function was assessed using the video head impulse test to assess vestibular-ocular reflex VOR) gain and the functional head impulse test (fHIT). Results: Substantial improvements were observed in functional domains despite incomplete vestibular recovery. DHI improved from 40 % to 0 %, and ABC increased from 35 % to 97.5 %. Postural control improved from 66 % of normal for the age-matched group to 100 %. Gait performance normalized, with the DGI increasing from 17 (fall risk) to 24. In contrast, VOR gain on the affected side improved only partially (0.3–0.73), and fHIT improved from 30 % initially to 80 % at 6 months. This difference indicates that recovery of gait and postural control exceeded the degree of peripheral vestibular restoration. Conclusions: Functional recovery following vestibular neuritis after COVID-19 infection may be driven more by sensorimotor adaptation than by normalization of vestibular input. These findings challenge a vestibular-centric model of recovery and highlight the importance of targeting dynamic stability and gait adaptability in rehabilitation.