My stuttering is neurogenic, so if people ask I tell them that. I don't bring it up unless people ask though because people get curious and start asking questions and I'd rather not go through my entire medical history with them! In terms of work, I have found people don't treat me any differently really. Its always good to let a supervisor or manager know in case you ever have any really difficult days, but everything you do is down to what suits you best to be honest.