Inclusion Criteria- Subjects eligible for enrollment in the study must meet all of the following criteria:
- Patients with lower limb spasticity who are at least 6 months post-stroke and present with equinus deformity (plantar flexion of the ankle) at the start of double-blind phase (Visit 2).
- Patients with MAS ankle score of ≥3 at the start of double-blind phase (Visit 2).
- Male or female between 20 and 80 years of age at the time of informed consent. For males, only those who can practice contraception during the study period are eligible.
- ≥50kg in weight at the start of double-blind phase (Visit 2).
- Inpatient or outpatient; however, the hospitalization status must remain unchanged during the double-blind phase. NOTE: Subjects may be hospitalized for ≤10 days after injection during the treatment period.
- Written informed consent from the subject him/herself. If the subject's signature is not legible, the attendance of a witness is required.
Exclusion Criteria- A subject will not be eligible for inclusion in this study if any of the following criteria apply:
- Bilateral hemiplegia or quadriplegia.
- Presence of fixed contractures of the ankle (absence of range of motion).
- Profound atrophy of the muscles to be injected.
- Previous surgical intervention, phenol block, ethanol block, or Muscle Afferent Block (MAB) for ankle spasticity.
- Casting of the study lower limb within 3 months prior to the start of double-blind phase (Visit 2).
- Current treatment with intrathecal baclofen.
- Use of peripheral muscle relaxants (dantrolene sodium, suxamethonium chloride, pancuronium bromide, vecuronium bromide, rocuronium bromide).
- Concurrent use of antibiotics that interfere with neuromuscular transmission, such as aminoglycoside antibiotics (e.g., streptomycin sulfate, kanamycin sulfate, gentamicin sulfate, neomycin sulphate, spectinomycin hydrochloride), polypeptide antibiotics (e.g., polymixin B sulfate), lincomycin antibiotics (e.g., lincomycin hydrochloride, clindamycin), and enviomycin sulfate.
- Previous or current botulinum toxin therapy of any serotype.
- Diagnosis of systemic neuromuscular disorders (e.g., myasthenia gravis, Lambert-Eaton syndrome, amyotrophic lateral sclerosis).
- Females who are pregnant, nursing, may be pregnant, or planning a pregnancy during the study period.
- Known allergy or hypersensitivity to any ingredient of study medication (e.g., human serum albumin).
- Presence of psychiatric disorder or impairment of intellectual function that may interfere with the subject's ability to give informed consent or the conduct of the study.
- Bedridden patients.
- Presence of clinically unstable severe cardiovascular disease.
- Presence of clinically significant severe renal or hepatic disease.
- Infection or dermatological condition at the proposed injection sites.
- Previous or planned participation in another clinical study (including the upper limb spasticity study of GSK1358820) within 6 months prior to the start of double-blind phase (Visit 2).
- Others whom the investigator or sub investigator considers not eligible for the study.
- Clinically significant severe reduction of muscle strength.
- Angle closure glaucoma or its preposition (narrow angle).