Inclusion Criteria- Minimum 6 months post injury/insult with unilateral upper limb spasticity of the elbow, wrist and/or finger flexors.
- Preinjection Modified Ashworth scores > 2 in at least one of the following areas: elbow, wrist, or finger flexors.
- Subjects must meet criteria for CMA Hand Impairment Scale Stage 2 and be able to complete Task 3 (thumb to index finger) of the CMA Hand Impairment Scale Stage 3, or demonstrate 50% gross grasp to be included.
- Botulinum toxin A (Botox®) stable patients (have received at least two prior doses of the agent with first dose occurring at least 6 months prior to study enrollment).
- Able to answer reliably to yes/no questions.
- Able to follow reliably 1-step instructions.
- Written informed consent.
- Females enrolled in this study who are of childbearing age will be required to use adequate measures of birth control for the entire study period. Those who do not agree will be excluded.
Exclusion Criteria- Uncontrolled, clinically significant medical condition other than the condition under evaluation.
- Severe, fixed joint contracture in the affected arm. Patients with mild contracture that does not significantly impact function will be included based upon the assessment of the PI.
- Known allergy or sensitivity to any of the components in the study medication.
- Females who are pregnant, breast-feeding, or planning a pregnancy during the study or who think that they may be pregnant at the start of the study, or females of childbearing potential who are unable or unwilling to use a reliable form of contraception during the study.
- Concurrent participation in another investigational drug or device study or participation in the 30 days immediately prior to study enrollment.
- Treatment with botulinum toxin of any serotype for any reason in less than 3 months prior to initial date of injection for the study.
- Any medical condition that may put the subject at increased risk with exposure to botulinum toxin type A including diagnosed myasthenia gravis, Eaton-Lambert syndrome, amyotrophic lateral sclerosis, or any other disorder that might interfere with neuromuscular function.
- Evidence of recent alcohol or drug abuse.
- Infection or skin disorder at an anticipated injection and/or electrical stimulation sites.
- Any condition or situation that, in the investigator's opinion, may put the subject at significant risk, confound the study results, or interfere significantly with the subject's participation in the study.
- Use of aminoglycoside antibiotics, curare like agents, or other agents that might interfere with neuromuscular function.
- Individuals with a cardiac pacemaker, a defibrillator, or baclofen pump.
- Individuals with an unhealed or healing fracture or dislocation in the arm to be evaluated.