@article {Claassenjnnp-2012-304736, author = {Jens Claassen and Rainer Spiegel and Roger Kalla and Mary Faldon and Christopher Kennard and Chotipat Danchaivijitr and Stanislaw Bardins and Nicole Rettinger and Erich Schneider and Thomas Brandt and Klaus Jahn and Julian Teufel and Michael Strupp and Adolfo Bronstein}, title = {A randomised double-blind, cross-over trial of 4-aminopyridine for downbeat nystagmus{\textemdash}effects on slowphase eye velocity, postural stability, locomotion and symptoms}, elocation-id = {jnnp-2012-304736}, year = {2013}, doi = {10.1136/jnnp-2012-304736}, publisher = {BMJ Publishing Group Ltd}, abstract = {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\<0.05; post hoc: 5 mg 4-AP: p=0.04). The rate of responders was 57\%. Increasing age correlated with a 4-AP-related decrease in SPV (p\<0.05). Patients improved in the {\textquoteleft}get-up-and-go test{\textquoteright} with 4-AP (p\<0.001; post hoc: 5 mg: p=0.025; 10 mg: p\<0.001). Tandem-walk time (both p\<0.01) and tandem-walk error (4-AP: p=0.054; placebo: p=0.059) improved under 4-AP and placebo. Posturography showed that some patients improved with the 5 mg 4-AP dose, particularly older patients. Near VA increased from 0.59 at baseline to 0.66 with 5 mg 4-AP (p\<0.05). Patients with idiopathic DBN had the greatest benefit from 4-AP. There were no differences between 4-AP and placebo regarding patient satisfaction and side effects. Conclusions 4-AP reduced SPV of DBN, improved near VA and some locomotor parameters. 4-AP is a useful medication for DBN syndrome, older patients in particular benefit from the effects of 5 mg 4-AP on nystagmus and postural stability.}, issn = {0022-3050}, URL = {https://jnnp.bmj.com/content/early/2013/06/28/jnnp-2012-304736}, eprint = {https://jnnp.bmj.com/content/early/2013/06/28/jnnp-2012-304736.full.pdf}, journal = {Journal of Neurology, Neurosurgery \& Psychiatry} }