“Why do I have these seizures if it’s not epilepsy?”

It started when I was 11 the first one I went to the doctors for and they did a CT scan and MRI scan and they were both clean. It happened in my sleep this time and was the only one I’ve been to the doctor for I had one more in my sleep about 4-5 months later the rest were when I was awake. Those ones I get really dizzy about 5 seconds before it happens and usually don’t have time to sit down but sometimes I just pass out and sometimes I seize I’ve only had about 10-15 that I know about of them but all them I fall to the ground for and I am alert enough to hear my own thoughts and other people talking but I can’t move or see anything other then blurs. The doctors when I went that one time said it wasn’t epilepsy so I just wanna know what it is but they all happened at least a month apart I have not taken any medications for it.