Background and purposeThe main aim of the study was to document the occurrence and evolution of post-stroke spasticity (PSS). The secondary goal was to identify predictors for increases and decreases in PSS rates during 12months of subsequent follow-up. MethodsIn a longitudinal, multicenter, prospective cohort study, assessments were done at 7days (V1), 6months (V2), and 12months (V3) after stroke onset. A total of 307 consecutive patients from four comprehensive stroke centers with the first-ever stroke of carotid origin and the presence of motor deficit at day 7 were included. The demographic data, baseline characteristics, Barthel index, degree and pattern of paresis and muscle tone were evaluated and recorded. Spasticity was assessed using the modified Ashworth scale. ResultsSpasticity was present in 45.0% of patients at V1, in 49.5% at V2, and in 43.2% at V3. A significant number of patients experienced changes in spasticity between visits: increased/new occurrence of spasticity in 32.5% (V1 and V2) and in 13.6% (V2 and V3) of patients; decreased occurrence/disappearance of spasticity in 18.5% (V1 and V2) and in 18.3% (V2 and V3) of patients. The number of patients with severe spasticity increased throughout the year, from 2.6% to 13.0% (V2) and 12.5% (V3). ConclusionsSpasticity developed in almost half of the included patients. The degree of spasticity often changed over time, in both directions. The rate of severe spasticity increased during the first year, with the maximum at 6months following stroke onset.