There is AP-4 (Fampridine - in US not yet FDA approved drug but in Clinical trials in final phases and looks to be approved soon) This medication appears to help SOME in walking. It is available by prescription in US by a doctor and then using a GOOD RELIABLE compounding pharmacy (ask your doctor - your LDN has to be compounded - start with them) I am PPMS- 4-AP did nothing for me which was not unexpected given my type of MS and degree of disability - I'm in a chair) Good luck, keep us updated.