Sleep deprived.

Ok, I am a medical professional but I cannot understand why I need to further sleep deprive a child with a sleep disorder for an EEG that I am going to sedate him for 30 minutes before they attach the leads? The reason we are having the EEG is because he doesn't sleep and awakens during the night with bizarre laughing spells and strange leg movements. So my fiance has taken a nap, brewed a large pot of coffee and is being kind enough to take the night watch so I can sleep and attend work in the morning.
As a nurse I am praying that my son just secretly likes to torture me nocturnally and that they 'laughing spells" are not gelastic seizures but just pleasant hallucinations. His pediatrician tells me he could be having benign Rolandic seizures which he could outgrow however she does not understand Fragile X as well as I wish she did. The only children in my experience I have seen have the type of 'laughing spells" my son has have had encephalopathy or a hypothalmic benign brain tumor. Both of which totally freak me out. I have not met any other Frag X parents who have described this type of seizure. This will be the first EEG in over four years. The last one showed nothing despite a definite 30 minute absence seizure weeks before the test. I am keeping my fingers crossed that whatever is going on, sleep disorder, restless legs, seizures, that it will be seen so it can be addressed.