New Year, New Thoughts?

So the start of a New Year with lots of great ideas and lots of chances to improve on everything from last year. Too bad it's starting with so much drama. If anyone has any ideas of what do to about an elder cat who seems to be showing signs of kitty Alzheimers and has his days and nights mixed up, please let me know. It's light being tortured - slowly - painfully - five minutes at a time - me and my family - not the cat. He gets up and wanders around at night - not unlike most cats - but proceeds to meow, then Meow, then MeoW, then MEOW and it gets higher in volume and goes on for hours, literally. Last night - two hours sleep tops - if you put all the ten minute intervals together. I finally gave up at 4:45 and got up - and stayed up - guess where he is right now - yep, curled up sound asleep on my nice heated waterbed! I'm so tempted to have him put down - he's 18 - isn't going to get any better - but other than that, he's healthy. So tell me, what would you do?