In order to study the effects of 4-AminoPyridine (4-AP) on impulse conduction in Multiple Sclerosis (MS), we studied Motor-Evoked Potentials (MEPs) in the Upper (U/E) and Lower Extremities (L/E) of six MS patients with stable Spastic Paraparesis before and after IntraVenous administration of 4-AP.
As a result, we found a significant increase in mean amplitudes in U/E and L/E (P = 0.008) and a significant decrease in the variability of onset latencies in L/E (P = 0.017) without any significant changes in mean and shortest onset latencies.
In four limbs of three patients in whom there were no detectable MEP responses before 4-AP administration, definite responses were elicited after 4-AP administration.
