Balance worsening associated with nabiximols in multiple sclerosis.

We performed a dual-task experiment to explore the effect of nabiximols on postural control in 22 patients with multiple sclerosis. They were assessed with static posturography and Stroop test in single- and dual-task conditions at treatment start and after 1, 3 and 12 months. At follow-up, we found more impaired postural control in single-task ( F = 3.07, p = 0.044) and dual-task ( F = 4.90, p = 0.005) conditions in patients who continued treatment (continuers, n = 11) compared with those who discontinued (quitters, n = 11). Continuers were more impaired at Stroop test only in dual-task condition ( F = 3.17, p = 0.038). Our findings suggest that nabiximols had a detrimental effect on postural control, especially in multi-tasking conditions.