Therapy of downbeat nystagmus: 4-aminopridine versus 3,4-diaminopyridine

Introduction: Aminopyridines, nonselective blockers of the Kv family of voltage-gated potassium channels, are effective in the symptomatic therapy of vestibular, cerebellar, and ocular motor disorders. Animal experiments have shown that aminopyridines increase Purkinje-cell (PC) excitability. This enhancement of PC activity could restore the inhibitory influence of the cerebellar cortex on vertical eye movements towards normal levels by an increase in GABA release. We showed the efficacy of aminopyridines for the treatment of downbeat nystagmus (DBN). Here, we compared the effects of 4-aminopyridine (4-AP) versu…