Objectives: To evaluate the sensitivity of the balance sway index (SI) to drug-induced functional changes during acute relapse in patients with MS.
Methods: Dynamic posturography was used to derive the SI in 11 healthy subjects and 13 MS patients before and after intravenous high dose methylprednisolone (HDMP).
Results: In both groups, SI was lower in the least demanding task and increased with test complexity. Compared to the healthy group, patients were distinguished by a higher SI both prior to and following administration of HDMP (p < 0.008). However, the effect of the drug on patients' SI was unremarkable. Total Expanded Disability Status Scale score was lower after treatment compared to pre-treatment values (p < 0.001), with significantly lower mean score recorded in patients with pyramidal and cerebellar abnormalities (p = 0.017 and p = 0.011, respectively).
Discussion: The SI measure of dynamic posturography is not sensitive to short-term HDMP-induced functional changes during acute relapse in patients with MS. Further studies are needed to evaluate modified balance protocols and the possible long-term treatment effects of HDMP on SI.
Keywords: Methylprednisolone; Multiple sclerosis; Postural control; Posturography.