Normally, nerve fibers carry electrical impulses through the spinal cord, providing communication between the brain and the arms and legs. In people with spinal cord injury, some fibers may be destroyed at the site of injury, while others remain connected but do not work correctly to carry electrical impulses. As a result, subjects with an incomplete spinal cord injury may have spasticity which is muscle spasms or muscle stiffness that makes movement difficult. Fampridine-SR is an experimental drug that increases the ability of the nerve to conduct electrical impulses. This study will examine the effects of Fampridine-SR on moderate to severe lower-limb spasticity, as well as the effects on bodily functions such as bladder control, bowel function and sexual function. The study will also examine the possible risks of taking Fampridine-SR.

Inclusion Criteria:

• Incomplete traumatic Spinal Cord Injury (at least 18 months prior and stable for 6 months)
• Moderate to severe lower-limb spasticity
• Able to give informed consent and willing to comply with protocol

Exclusion Criteria:

• Pregnancy
• History of seizures
• Existing or history of frequent Urinary Tract Infections
• History of drug or alcohol abuse
• Allergy to pyridine-containing substances
• Received a botox injection 4 months prior to study
• Received an investigational drug within 30 days
• Previously treated with 4-aminopyridine (4-AP)
• Not on stable medication dosing in 3 weeks prior to study
• Abnormal ECG or laboratory value at screening