4-Aminopyridine (4-AP) and Visual Evoked Potentials (VEP)

Rationale: 4-Aminopyridine (Fampyra®) has been approved for the symptomatic treatment of impaired gait in multiple sclerosis. It has been suggested that it acts by blocking voltage-gated potassium channels in demyelinated axons, thereby preserving the action potential and improving nerve conduction. Method: We investigated the effects of 4-AP on VEP in 9 patients with MS (2 men, 7 women, mean age 52 ± 10 years, duration of disease 8.9 ± 4.5 years, EDSS 5.4 ± 0.6). Each patient received 4-AP 10 mg bid for 2 weeks. Clinical evaluation and VEP recording was performed both at baseline and after two weeks of treatmen…