Case Study Report
Population: Adult
Brooke N. Klatt, PT, DPT, NCS, Physical Therapist, University of Pittsburgh bnk12@pitt.edu
Brooke Klatt, PT, DPT, NCS, Physical Therapist, University of Pittsburgh bnk12@pitt.edu
Tian Bao, BS, Graduate Student in Department of Mechanical Engineering, University of Michigan baotian@umich.edu
Kathleen Sienko, PhD, Engineer, University of Michigan sienko@umich.edu
Susan Whitney, PT, DPT, PhD, NCS, FAPTA, Physical Therapist, University of Pittsburgh whitney@pitt.edu
Keywords: Plasticity, Vibrotactile Feedback, Vestibular Rehabilitation
Background & Purpose: Rehabilitation for individuals with vestibular hypofunction utilizes the strategies of adaptation, habituation, or substitution. One type of substitution technique is the use of vibrotactile feedback (VTF), which works by replacing the disrupted or absent vestibular function with supplemental information to the intact sensory inputs. The literature indicates that the use of real-time vibrotactile feedback applied to the trunk of individuals with vestibular deficits results in decreased postural sway in both quiet and perturbed stance. The impact on functional outcomes using this type of sensory substitution device during balance training sessions has not been explored. The purpose of this report is to highlight the functional outcome scores for two subjects prior to and one month after completion of vestibular rehabilitation with VTF.
Case Description: Two females with vestibular hypofunction received VTF during 18 vestibular rehabilitation sessions. Within each training session, participants completed six repetitions of six different exercise categories (center of gravity perturbations in standing; firm surface static standing; foam surface static standing; gait; gaze stabilization; and weight shifting). An inertial measurement unit and vibrating tactors on the trunk were used to provide immediate feedback of body tilt to the participants during training. The tactors vibrated when the participant exceeded a pre-determined threshold and the participants were trained to make corrective trunk tilt responses based on the feedback they received.
Outcomes: Subject 1 (Pre-training to 1 month post training): Sensory Organization Testing (SOT) Composite score (35 to 46); gait speed (0.91 to 1.02 m/sec); Dynamic Gait Index (DGI) (19 to 20/24); Functional Gait Assessment (FGA) (18 to 20/30); Five Times Sit To Stand test (FTSTS) (14.32 to 11.84 sec); Activities-specific Balance Confidence (ABC) scale (67 to 63%); and Dizziness Handicap Inventory (DHI) (52 to 38/100).
Subject 2 (Pre-training to 1 month post training): SOT Composite score (30 to 46); gait speed (0.81 to 0.92 m/sec); DGI (17 to 20/24); FGA (15 to 17/30); FTSTS (unable to complete); ABC (55 to 43%); and DHI (26 to 58/100).
Discussion: In both cases, plasticity was demonstrated by improved functional outcomes following participation in vestibular rehabilitation with VTF. This included, improved SOT Composite scores greater than the minimal detectable change and movement out of the fall risk range per the DGI scores. Gait speed improvements were noted to be > 0.1 m/sec for both individuals. Subject 1 had a minimally clinically important difference in the FTSTS. The lack of improvement in the ABC and DHI might be explained by the chronicity of their vestibular disorder. Further analysis is ongoing to investigate the long-term effects of training with VTF, and to examine the differences between individuals who receive VTF during vestibular rehabilitation and those who receive traditional vestibular rehabilitation alone.
Citation:
Klatt, Brooke N., PT, DPT, NCS; Klatt, Brooke N., PT, DPT, NCS; Bao, Tian , BS; Sienko, Kathleen H., PhD; Whitney, Susan L., PT, DPT, PhD, NCS, FAPTA. Short-term Outcomes for Two Individuals with Vestibular Hypofunction Following the Application of Vibrotactile Feedback during Vestibular Rehabilitation.. Poster Presentation. IV STEP Conference, American Physical Therapy Association, Columbus, OH, July 17, 2016. Online. https://u.osu.edu/ivstep/poster/abstracts/046_klatt-et-al/