I've experienced some pretty significant memory impairment after beginning to take Lamictal, and it's probably more likely that your experiences are caused by the new drug regimen, rather than by an underlying neurological problem. It's a really frustrating side effect! Perhaps you should bring it up with your prescribing doctor if you're concerned, and he/she may be able to help you with it. Good luck!
I also work in health care and have memory problems. I forget to do tasks, I forget to schedule people, I forget things almost instantly sometimes. I was diagnosed last June. Did lamictle for about a month, was allergic, started lithium in December. But, I was having these problems while unmediated. I'm not sure what causes it.
Both of the drugs will impact your memory; I take Lamictal and it causes me some cognitive problems. I seriously doubt you have Alzheimer's disease, although the meds can make you feel that way.