It's a mystery!!!

Would love some advice from you guys.  My son is 5 with a diagnosis of severe autism and very severe learning disability.  He has been unable to focus or engage to even learn the simplest of tasks and stands out from his peers with similar diagnosis at his special school.  Around 18 months ago I began to suspect that my son may be experiencing seizures as he was waking up in night shrugging shoulders, appearing absent, some mouthing and blinking.  However all of these could also be down his neurological disability.  In October last year he had an eeg and the results were abnormal which showed query around poss nocturnal seizures. It showed spikes and waves over right temporal, parietal and occipital regions increasing in frequency during drowsiness. I wasn't surprised by this result and thought he would get a diagnosis of epilepsy.  An MRI was also done which was normal.  Our Consultant (who has some expertise in epilepsy but not a neurologist) said that she would need concrete video evidence to make a diagnosis. Any video evidence we had was brief and not sustained.  So she made the decision to refer us to a Paediatric Neurologist and we had the appointment in July.  He looked at our video evidence and concluded that he was in the 8% of the population that would have abnormal EEGs but not have epilepsy.  Our Consultant had hoped that he would oganise a 24 hr EEG.  I wasn't entirely happy with his decision but I figured he was the expert and was happy that my son did not have epilepsy as medicating him is very problematic. 

However in since August (just a few weeks after we were seen by Paediatric Neurologist) my son started experincing bouts of extreme fatigue.  He's been to his GP several times and doesnt have a fever.  I've been sending him to school but he's falling asleep.  The fatigue lasts around 4-5 days and he basically just lies down the whole day and sleep 11-12 hours in the night which is unheard of.    I should mention that in between these bouts at tmes he is hyper and it is from one extreme to the other.  After chatting on the phone to his Consultant my son was admitted to hospital on Wednesday for observation and she suspects he may be having seizures that aren't obvious which is very scary.  To date all blood work has came back normal to test for thyroid etc.  He's due an EEG on Tuesday and it's been suggested that if this one comes back abnormal they may medicate despite the lack of video evidence.  I'm just wondering has anyone any advice for me.  Thanking you in advance.