Should I do an MD/MBA for neurosurgery?

I want to become a neurosurgeon but I also like business and maybe later on open up my own business or something. But the thing is, if I complete the 5 year MD/MBA program, then go for 6 year residency for neurosurgery, and I won't be using my MBA for a while, so I could forget what I learned?? I really want to know about business also, so should I just do the MBA after neurosurgery residency?? Or just do the 5 year combined program and not use my MBA for 6-7 years??