Not a Seizure but What is it

Does anyone have a child with DWS that has experienced involuntary movement of legs and arms but it was not a seizure. My daughter who is 3 years started in July extending her legs and arms in repeative fashion , moved her eyes upwards and began to sweat tremendously. At first these episodes would last 20 mins and at that point we thought it was a way of her trying to sit up on her own. Last saturnday she did it for 5 hours and we got concerned brought her to the ER. The doctors admitted her to hospital thinking it was seizures. They sedated and did a series of CT, MRI , EEG. Test reveal it was not seizures but we do not know what it is . We are still in hospital for observation and last night she had another episode of repeative leg and arm extensions for 5 hours. They sedated her again and now they are going trying giving her low dosage of sedatives every 8 hours to see if this could prevent her having these episodes.