Overview Study to Evaluate the Long-Term Safety, Tolerability and Efficacy of Dalfampridine. Status: Terminated Trial end date: 2017-01-01 Target enrollment: Participant gender: Summary This is an extension study to evaluate the long-term safety, tolerability, and efficacy of two dose strengths of dalfampridine-ER. Phase: Phase 3 Details Lead Sponsor: Acorda TherapeuticsTreatments: 4-Aminopyridine