Background: Subjective visual vertical (SVV) deviations have been correlated to abnormal cerebellar function in individuals diagnosed with multiple sclerosis (MS). It has been shown that individuals with MS have increased incidence of SVV abnormalities, yet this is not routinely tested in this population during physical therapy evaluation.
Objective: This study aims to determine if there is a relationship between SVV and balance performance in people with MS who have cerebellar involvement. We hypothesize that individuals with greater SVV deviations will have worse balance performance.
Methods: Fifteen females and five males (mean age 54.5 years [±7.03 SD]) with the diagnosis of MS and cerebellar involvement participated. Computerized SVV testing included rod and rod-and-frame conditions. None of the balance outcomes were correlated with the rod-only condition. Because there was a difference in magnitude of results within the rod-and-frame condition, based on whether the frame was rotated clockwise (CW) or counterclockwise (CCW), they were analysed independently.
Results: For all six of the balance outcomes, there was a statistically significant moderate correlation with SVV deviations when the frame was tilted CCW: Barthel Index (r = -0.47, p = 0.018), Berg Balance Score (r = -0.59, p = 0.003), gait velocity (r = -0.52, p = 0.010), International Cooperative Ataxia Rating Scale (r = 0.56, p = 0.006), Scale for the Assessment and Rating of Ataxia (r = 0.62, p = 0.002), and Timed Up and Go (r = 0.58, p = 0.003). Interestingly, the Barthel Index was the only outcome that had statistical significance with a moderate correlation (r = -0.66, p = 0.001) when the frame was rotated CW. In this cohort, greater deviations during the rod-and-frame condition of SVV testing correlated with worse functional outcomes, especially when the frame was tilted CCW.
Conclusion: Individuals with MS who demonstrate decreased balance performance may rely more heavily on visual backgrounds. Implementation of SVV assessment for individuals with MS may provide clinicians with valuable information to identify clinical interventions.
Keywords: balance; multiple sclerosis; subjective visual vertical; vestibular rehabilitation.
© 2018 John Wiley & Sons, Ltd.