This single-center observational cohort study will be conducted at Tangdu Hospital, Fourth Military Medical University. Patients presenting parkinsonism and poor levodopa response will be enrolled, including insidious-onset vascular parkinsonism (VaP) and Parkinson-plus syndromes (PPS). Within each diagnostic subgroup, participants will receive either dalfampridine 10 mg twice daily for 4 weeks combined with conventional therapy, or conventional therapy alone. Change in Timed Up and Go (TUG) time, gait speed, balance, daily function, and quality of life metrics assessed from baseline to Week 4.