My daughter has Angelman's and started having seizures at 13 months - we had a very bad day right before she was medicated and she was having clusters of 5 separated by 30 seconds with the clusters separated by about 5 minutes - that went on for about an hour. She was put on Depakote (sodium valproate) and has had great results. She had lost a lot of ground when she was having seizures, but slowly recovered it as soon as the seizures were under control. We haven't had an identifiable seizure since about a week after she started medication. Hope this helps!
Hi
Got to this link!
http://www.angelman.org/angel/index.php?id=89
I see that in the second paragraph of this page it stipulates that "About as often as not, Angelman children initially will not get better, and may get worse, with anticonvulsant **************."
Hope you find out what's wrong.
Frankie