Association of Otolithic Integrity With Subjective and Functional Outcomes in Vestibular Rehabilitation: A Pilot Study

Variable recovery in vestibular rehabilitation underscores the need for objective biomarkers to identify patients at risk of poor clinical outcomes. This study aimed to establish proof of concept for a multidimensional prognostic framework using structural cervical vestibular evoked myogenic potential (cVEMP) and functional modified Clinical Test of Sensory Interaction on Balance (mCTSIB) markers to predict therapeutic success. This prospective cohort study was conducted at a tertiary rehabilitation center between June 2023 and May 2025. Participants were adults with peripheral vestibular disorders, including unilateral vestibular dysfunction, Meniere disease, or superior semicircular canal dehiscence. All participants underwent a customized five-session vestibular rehabilitation protocol. Primary outcomes were subjective clinical success, defined as an 18-point reduction in Dizziness Handicap Inventory (DHI) score, and functional success, defined as a 3-point increase in Dynamic Gait Index score. Among 30 participants (mean age 60.8 years; 77% female), the rehabilitation protocol was associated with significant improvements in mean DHI (53.7 to 37.8; P = .003) and Dynamic Gait Index (19.5 to 22.1; P = .003) scores. While 83% of participants showed raw DHI improvement, only 37% achieved the 18-point minimal clinically important difference. Notably, no participants in the bilateral cVEMP absence group achieved subjective success, compared with 52.6% in the bilateral present group (P trend = .08). Multivariable logistic regression identified baseline DHI severity as an independent predictor of success (odds ratio, 1.05; 95% CI, 1.00-1.10; P = .04). Functional gait success was significantly correlated with baseline vestibular and visual preference ratios. These findings suggest that baseline otolithic structural integrity is a primary determinant of subjective recovery. Bilateral structural loss may represent a "structural floor" where meaningful relief is physiologically limited despite functional gains. These results support a precision-based model using structural and sensory biomarkers to tailor rehabilitation