When it happens
Begins at the earliest stages of dementia and can continue throughout the course of the disease. Over time, the frequency of these events increases, with a decreasing lapse of time between incidents.
By the transition from mild to moderate dementia, the person may repeat an entire anecdote almost word for word from just a minute earlier, and do this many times in a row without being aware of the repetition.
Why it happens
The brain's working memory system is one of the first casualties of dementia. Working memory is a kind of short-term memory in which the brain holds a thought long enough to use or store the information in longer-term memory. When the memory of having said something isn't stored even momentarily, the person literally can't remember having just said it.
What you can do
Be patient; it doesn't do any good to point out, "You just said that" or "You just asked that," because the person can't prevent it from happening again.
Calmly give the same answer or response you just gave.
If the loop persists, try to change the environment. It may be that particular prompts are causing the same thought to return. Sometimes you can break the cycle by moving to another room, or distracting the person with a new activity or topic of conversation.
Use "bridge phrases" to turn the conversation in a fresh direction: "Yes, I love your story about the birds you saw. That reminds me of the time we saw penguins at the zoo . . . " Other bridge phrases: "What I'd really like to know more about is . . . " "Your childhood was so interesting. Did you also . . . ?"
Try writing down the answer to a repeated question and handing it to the person: "Your medical appointment is at 10 a.m." The next time it's asked, direct attention to the paper. Just having it in hand to refer to may curb repeated questions.
Leave the room, or try silently counting to 10 before you answer, if you feel like you'll explode if you hear the same thing one more time. It's natural to be stressed when trapped in these conversational loops.