A randomised double-blind, cross-over trial of 4-aminopyridine for downbeat nystagmus-effects on slowphase eye velocity, postural stability, locomotion and symptoms

Objective: The effects of 4-aminopyridine (4-AP) on downbeat
nystagmus (DBN) were analysed in terms of slow-phase velocity
(SPV), stance, locomotion, visual acuity (VA), patient satisfaction
and side effects using standardised questionnaires. Methods:
Twenty-seven patients with DBN received 5 mg 4-AP four times a day
or placebo for 3 days and 10 mg 4-AP four times a day or placebo
for 4 days. Recordings were done before the first, 60 min after the
first and 60 min after the last drug administration. Results: SPV
decreased from 2.42 deg/s at baseline to 1.38 deg/s with 5 mg 4-AP
and to 2.03 deg/s with 10 mg 4-AP (p