I believe that the story about this little boy may be true. I imagine that it is possible that it is a scam or hype. But, there are enough things about this that ring true--as bizarre as it may sound.
With Chiari Malformation, young Rhett's brain stem and just above it may be being forced down through the opening from his brain to his spinal column due to Chiari Malformation. The hypothalamus, which is responsible for several primitive functions is also responsible for our circadian rhythms. If there is pressure from compression from the area near to or within his hypothalamus it may result in the inability to sleep along with a host of other symptoms.
I saw one of the saddest documentaries I've ever seen about a man who could not sleep. He had the rare Fatal Familial Insomnia that has been mentioned here. I googled and found info about Michael Corke, the man in which the documentary I watched was about. Michael and his family suffered through this, and Michael inevitably didn't survive.
The video was real, and the man truly couldn't sleep even after being given high doses of IV anesthesia and not having slept for months. I would have had my doubts had I not watched that documentary. Much of it was filmed while he was in the hospital, but there was a scene where after having not slept for months he wanted to be there for the high school band one more time at a high school event. His students and his family loved him so much, and he seemed to have been a very, very nice man. It made me cry my eyes out that he didn't survive.
Here is a link that mentions Michael Corke and Fatal Familial Insomnia.
http://sleep-disorders.suite101.com/article.cfm/the_man_who_never_slept
Rhett Lamb and Michael Corke have/had completely different causes for complete, long term insomnia. I find it both fascinating yet very troubling and sad that anyone could go without sleep until they die. But, it does happen, albeit rarely.