Thanks for all your comments and feedback. The badges are assigned at the
category level, but if you go into the forum, the Top Answerers should be members who are actually a member of that community. So even though you have a badge for Neurology, if you go to the Neurology forum, you're probably not listed in the Top Answerer panel unless you're also a member of that community. When you're in MS, the Top Answerers listed should be the ones for MS.