What Causes Trouble In Walking And Holding Up Head In A 2 Year Old?

I just found out that a freind of mine has a two year old son that was healthy, above normal, etc. until about 6 weeks ago. He has regressed so much now that he no longer walks, has trouble holding up his head, can t eat so he is being fed with a G-tube. They ve done tons of tests, but no answers. They are considering putting him into a coma while they wait for test results at the Children s Hospital in Denver. He is failing fast. Can you point them in any directionbefore it is too late??