My son wakes up in middle of the night a few times a month for 2-3 hrs at time and is wide awake. naps fine. sleeps 10-12hrs night. solutions? reasons

Going through phase: If his energy during the day is good and his growth and development is normal then don't worry. Just try to stick with a regular nap/play schedule and it should resolve. As for your insomnia, you do have my sympathies!

There may not be one: Since you list it in his history i'm assuming you would know if this represented episodes of svt. Otherwise keep a journal of what he eats, what medications he's been given, and his daily activities for a month and see if there is a correlation. Every mind and personality is unique and it may just be his own thoughts or dreams. If he's not upset then no worries.