Inclusion Criteria:

• Age > 18 years old.
• Clinical diagnosis of spasticity as a result of upper motor neuron dysfunction.
• Spasticity of upper or lower extremities, resulting in either cervical, thoracic or lumbar catheter location.
• Previous targeted drug delivery device with baclofen monotherapy > 90 days.
• The use of oral opioid and non-baclofen antispasmodic medications are permissible.
• Documented MAS assessment.

Exclusion Criteria:

• Use of oral baclofen within the previous 3 days.
• Targeted drug delivery device utilizing medications other than baclofen monotherapy.
• Targeted drug delivery device that was implanted < 90 days prior to recruitment.
• Unstable patient requiring hospitalization for management of life threatening medical issue.
• End-stage liver (Child-Pugh classification A or greater) or kidney disease (creatinine clearance < 30 ml/min).
• Presence of a psychiatric disorder that would limit obtaining informed consent or functioning in an ambulatory environment (e.g., dementia, schizophrenia, severe depression, substance abuse disorder).