article_snippet: Scroll down for video .
article_snippet: You know self-preservation kicks in, and I guess a primitive part of my brain just went into operation and that was a primitive part of my brain,' A 75-year-old Virginia woman told the Richmond Times Dispatch. '
article_snippet: If I ran, it would be faster than I would and would just tear me to pieces,' Ms Overton, who was a Tai Chi instructor for 40 years, said.
article_snippet: Activity during the day is an abnormal behavior that could indicate the presence of the disease.
highlights_snippet: Former Tai Chi instructor said it 'took a while' to realize Former Tai Chi instructor killed attacker .