This trial is a multicenter, open-label study to evaluate the safety and efficacy of GSK1358820 for treatment in post-stroke subjects with focal wrist, finger and in some cases, thumb spasticity. Qualified patients who complete GSK double-blind study 112958 will be enrolled. Subjects will receive a single treatment session of intramuscular GSK1358820 "200U or 240U (if thumb spasticity is present)". The subjects will be observed until 12 weeks post injection. Outcome measures include changes from baseline at every post injection visit as measured on the Modified Ashworth Scale (MAS), Disability Assessment Scale (DAS) and Global Assessment Scale. Safety parameters will be measured including adverse events, vital signs (pulse and blood pressure) and clinical laboratory tests (haematology, serum chemistry and urinanalysis).