Stroke Like Event

I am a 54 year old women. I have Hashimoto's of the Thyroid which was diagnosed in Jan. 2007.
In May I had a stroke-like event. Slurred speech and lack of coordination. When the event first occured I was teaching at school and was in the nurses office within 5 minutes. My blood pressure was 90/60. Persons who observed me said my eyes were wide open and I went in and out of consciousness, but could be awakend. Upon arriving at the E.R. I had improved to being more alert but the slurred speech and coordination problems continued. They did their typical stroke tests, a doppler of my carotids and sent me home. Severe memory problems persisted for 3 months. The neurologists say I did not have a stroke, maybe a seizure. My worry is that my symtoms (symptoms) match almost to the word of that of a patient in which the Hashimoto's is affecting my brain. Because of it's rarity I don't believe it is being considered to the fullest extent possible. I know I can't have another event like the last stroke-like event without loosing more memory and perhaps worse. I am a puzzle to my neurologist. I'm afraid that while we're waiting to see what happens next the event will happen again. My only positive tests were mild encelfalopaty on an EEG one month after the test and one small new white spot on my brain.