I definitely know what you're talking about, but as to medical terms... Thought blocking is probably the closest you'll get. What's really fun is when you forget a whole conversation... Or can't remember if you really had the conversation or just meant to say/discuss whatever. And of course my DH's favorite, simply forgetting you're having a conversation and just kind of mentally or occasionally physically wandering off.

I don't enjoy crossword puzzles quite as much anymore either. And have since turned in my crown as the queen of trivial pursuit, my family long since came up with the rule for me that my answers had to match the cards verbatim for it to count, and I only get one chance. I used to still beat them resoundingly, but now I'm lucky if I can even spit out the main answer, let alone recite a complete answer as it would show on the back of the card. But we get much more time together when we play now