A sad and difficult death out of no where...

Question
QUESTION: Trixie was my fourteen year old Boston Terrier. My Mom payed to have her Mother mated so she could sell a litter, but Trixie was all that was born.  She was royalty. A runt with ears that never conformed to spike like other Bostons.  
Two years ago she got blind, catarax in one eye and a wound from a bigger dog that got too rough with her in the other.  Soon after she became completly deaf.  
When my Mom passed away this summer I decided to adopt Trixie from my step dad.  She just wasn't getting the TLC that he gave the other dogs.  
For a month Trixie lived with me in my apartment.  We would go on three or four short walks a day.  (She hated to walk and to express her displeasure, she would insist on turning in a circle at least every twenty feet, other wise she would dig her heels in).  
She only went to sleep when she was sleeping besides me. She got the attention she always needed.  Problem was, when I went to work she would have bad seperation anxiety that she never used to have before.  She would poop and pee all over the house and knock stuff over and pant like mad until I got home. I threw out many towls and blankets.
Yet, we were both happy.  The day I got her ear mite drops for her ears, (using 15 mg in each ear) I took her to a visit to her old home place in Winthrop.  Yet, back home, later that evening she started acting real strange, always moving and acting nervous.  She then threw up globs of slime stuff and food she had that day.  Then she went into a seziure, foaming at her mouth, panting.  Her legs would stiffin out or flog like wind mills.  Her whole body tensed and spasamed.  This lasted two minutes each time before she collapsed in exaustion.  She ate little but threw it all up.  She couldn't hardly drink either.  
The next night I stayed up all night with her, her symtoms got worse.  More vomiting, panting, standing in corners, sezures and spasims.  By the next morning, these seizures and foamings happened every few minutes. I called my vet and told them I would be there in forty minutes. Yet, just when my friend knocked on my door to take us to Winthrop, Trixie, in her last seizure died.  Legs were stretched out.
She looked like she went through a lot of pain and anxiety these last two days before she finally died.  I DO NOT KNOW WHAT HAPPENED or would could have been done.  She had no history of seizures or of any of the other symtoms I listed above that had just started less than two days before she died.  
Please let me know. I can't seemed find out, though I have been researching most of today.

ANSWER: I'm sorry for your lose, but, without having seen the dog, I can't even venture a guess as to what happened to her.  Some dogs develop seizures as they age.  They could have been caused by any number of things...something she ate, a brain tumor or any many other reasons.  Again, sorry for your lose.

---------- FOLLOW-UP ----------

QUESTION: Thank you. I appericate your reply.  

Maybe if I can try to give a better description of the events that led her up to her death, it might be easier to give a more specific answer.  

Trixie had been blind for two years before she died. One eye had catarax and the other, which was developing catarax too, was clipped by a tooth or nail from a larger pet that had just recently come into size and perhaps didn't know her own strength.  
About a year later she became completly deaf. Before we were to take her to vet to find out why, my Mother passed. It wasn't until months later that I was given Trixie.  
The same evening I treated her ears with 15mg of Excel Ear Mite Remedy was also the evening that her sezurs began. She had also taken a trip with me to revisit her old home.  She hates to travel and go to new places. She can panic if confused. But nothing seemed that out of place until her first seizure.  Then it was all down hill.

Answer
Without having seen the dog, the best I can do is speculate.  It could have been a reaction to the ear mite remedy, the stress of the trip or as I said, 15 is old for a dog, it could just be seizure onset due to old age.  If you haven't disposed of her body yet, you could have a necropsy done and they can determine for sure what caused the seizures and why she died.  Again, sorry for your loss.