Concern for my Nephew - any ideas?

My nephew and his friend spent last week with us at the lake. We all came home on Thursday. Friday morning my nephew fainted, his mom took him to the ER. While waiting for a room, he had two seizures, his blood pressure was 80 over 25. They did a MRI, heart test ....etc and everything was normal. My nephew said he was couging Friday night and took a tsp of cough medicine that had codene in it. The doctor couldn't find any just cause for his seizure or blood pressure drop. He also had a low grade fever. After fluids through and IV and anti seizure medicine, he was sent home. Yesterday he went to his regular doctor, where he was diagnosed with a sinus infection and given antibiotics. However, they want him to see a neurologist for the cause of the seizure. They can't see him until next week. My nephew said he still doesn't feel very good, no appetite, tired. He also said when he goes into the sun, he feels dizzy, like it will happen again. What could be going on?
Thanks-

With all medical tests showing everything is normal, you may not have so much to worry about. Sounds to me that it's the heat that may be triggering his episodes. Some people just don't do well in the sun and high temperatures. I would say this is what is robbing his appetite. Make sure he follows through with seeing the neurologists. God forbid, it may be a tumor. I say this because my brother had one under similar circumstances. Please let us know how he is doing!

Definitely see a specialist, if you can see a different neorologist sooner then do so by all means, but I would not gamble on your regular doctor.

sun-stroke

I would consult a neurologist ASAP.

It could have also been low blood sugar. That sounds like a simple cause, but I was put in the hospital in August for low blood sugar and dehydration and was having seizure like symptoms, which the doctor said were seizures, but actually turned out to be syncope.

Could be heat exhaustion? sunstroke? dehydration? what did he do at the lake and for how long?
What did he eat at the lake and how much?
has anything like this happened before?
In the list of unlikely things, maybe examine all skin surfaces for small bite marks. spiders/wasps/or bush ticks can do a lot of damage if sensitive to them.

i have no idea but i hope he gets better...fast

I'm not a doctor - and I don't play one on TV - but, I would say that this could be very serious. I don't know what city/state you are in, but I would get him to neurological specialist in the best hospital or university hospital available. It always amazes me that people with "mystery illnesses" in rural areas typically find the answer once they visit a large, metropolitan area hospital with specialists that see a wide variety of symptoms from thousands of patients. But, until they do, they might never find anyone in their area that has ever seen a rare condition like the one you describe.

Another good source of information is the Internet. Type in all of your nephew's symptoms (without words like "the", "one", "and"...) into Google. That's what my wife did when she had a mystery disease. Turns out she had "secondary Addison's disease" and she diagnosed it before the doctor's did. In fact, her research helped the doctors perform the best diagnostic tests that confirmed her conclusion.

Best of luck with this. I'd be worried sick if this were my kid, as I'm sure you are. Don't put off getting this poor young man to a clinic, hospital, or teaching university hospital where a wider variety of diseases and conditions might help determine what's actually wrong.