This website has some more info.
01 Seizure Disorders - VeterinaryPartner.com - a VIN company!
My border collie had seizures from time to time and it progressively got worse. Then her pupils completely dilated and she went blind. Spent almost a year and a couple thousand dollars getting down to the bottom of it. Turned out she had a very rare disorder where her system wasn't processing cholesterol properly and it was crystalizing in different areas of her body. The cholesterol crystals destroyed her retinas and the crystals in her brain were what was causing the seizures. Thing is, we wouldn't have figured it out had she not gone blind. A specialist took a sample from her eye and sent it to Ames Lab. The specialists were sure it was some sort of fungal infection. Results said it was cholesterol. She was started on a lowfat diet and she only eats dog food with less than 10% crude fat in it. Once she was on lowfat food the seizures subsided almost immediately and she hasn't had one in over two years. Don't think it is the same thing but a change in food is an inexpensive guess. We went through the same thing when Ginger was having her seizures and they thought it was a fungal infection. Lots of guesses. Food dye? Allergy? Bacteria? You name it. We spent close to two thousand dollars to find out it was the fat in her food.
She was about two and a half years old when the seizures started. They were small at first and and happened once a month. Then they slowly happened more frequently. The specialist figured her youth's metabolism masked it until she was older. Best wishes to you. It was a very difficult year to handle and we really questioned our efforts when the bills passed the thousand dollar mark.