It makes a difference if you matched neuro in the earlier match, b/c then you are supposedly bound to a contract to accept that match result. I guess who's gonna stop you from breaking it and not taking that spot if you match at an anesthesia program and would rather do that, but realize you've kinda screwed the neuro program then b/c they could have matched someone else in your spot and now if you leave they'll have that spot unfilled.
Lots of people apply to both matches if they are going for competetive specialties - say ENT or Urology with Gen Surg regular match as a backup, but that would be backup if they don't match in the SF match at all. If they get a spot in the SF match, they're usually planning to take it. In your case it sounds like you haven't decided what you want, and that's okay...but just realize that since Neuro is relatively easy to match in, you will likely match somewhere and then be put in quite an uncomfortable position if you plan to do another specialty at the same program. That being said, people often switch even after being in a year or two of a certain residency specialty (and sometimes while staying at the same hospital/program), so you would not be the first one to make a specialty switch and I guess it would be better for all involved if you leave the Neuro program after the match rather than after a year or two of residency if you really are trying to pursue Anesthesia in the end. Tough situation. Good luck.
