that ampyra is unique. like all the other ms drugs. those are called disease modifying drugs. they're very important drugs, but you can potentially take ampyra together with one of those drugs. >> how many people are doing that? what's the percentage of people taking ampyra versus who could take it? >> over 80,000 people with m.s. have already tried the drug since we launched it. we think there are another 120,000 or so who have walking impairment who haven't tried it and who ought to give it a try. >> is that because doctors don't know about it, or they're afraid >> the doctors almost 100% know about it. we have a very good understanding among the doctors. it's really among the patients and their care givers. there are so many new drugs coming for ms that it takes time to sort through what is this one for, what is that one for? we're seeing gains in awareness. >> let's talk about the neuropathic pain assets acquisition and what that means for you. it seems much smaller. not a lot of money involved but it's