My 14 yrs old has had fainting spells since she was in first grade. Her fainting spells looked like she was having a seizure. After she had several fainting spells, she was tested for seizures but all the test came back negative. About three years ago we find out she has an enlarged thyroid and hypothyroidism. About six months ago, she had a sleep study done because she waking up ever couple hours every night. The study showed that she was having seizures every couple minutes. My question is there a connection between hypothyroidism, fainting spells, and the seizures?