The condition occurs in both adults and children, but is often seen at younger ages. About 1,400 new cases are diagnosed each year in the United States, according to the National Institutes of Health. About 33,000 Americans have some kind of disability resulting from the disorder.
Transverse myelitis can occur as a complication of measles, Lyme disease and some vaccinations.
"It's not so rare," said Dr. Clifford B. Saper, chairman of the department of neurology at Beth Israel Deaconess Medical Center in Boston, who has not treated the teen, and in some cases it can be reversible.
"If someone were still paraplegic seven years after transverse myelitis, it would not be reversible," he told ABCNews.com. "So the only real question is whether she is paraplegic, not whether she had transverse myelitis as a cause. If she is, she should be eligible. If she is not paraplegic, then you might wonder why she should be competing with people who are. The story is moot on the only relevant point."
Victoria said she remembers "bits and pieces" of the years she was in a partial coma and vegetative state. "I kind of knew what was going on, but I couldn't verbalize or move," she said.
"It started off with flu-like symptoms and pain, then I started feeling really funny," she said. "In two weeks, I was paralyzed from the waist down and it spiraled down from there. Every ability I had was slowly slipping away."
Today, she is able to swim with her arms, but she does so with a lot of upper-body impairment.
It's too late for her to participate in Montreal, and her father said he is convinced the ruling was "political."
"Our [U.S. Olympic Committee has no notes what so ever that the IPC was waiting for any other medical records," Arlen said. "In fact, the new one we submitted stated another disease affiliated with TM is ADEM."
His daughter, on the other hand, has accepted her fate and is looking forward to continuing her motivational speechmaking and pursuing a career in film and television.
"I am doing OK," she said. "And there's not much I can do right now. I just have to put it all in perspective. I know there are a lot more problems to worry about in this world. As hard as it is there are people starving and dying in the world. It is such a blessing to be where I am today.
"I am going to keep my head up and move forward," she said. "I am not going to give up, though obviously there are not races for a little while. Swimming is still very much a part of me. They can't stop me from swimming.
"I love to swim and what I have been able to do -- give people hope," she said. "The fact that I am penalized for having hope is discouraging. If I didn't have hope and believe one day I would get better, I wouldn't be here today."