Thanks. Our Daughter-in-law's Aunt Recently Experience Disorientation, Headache And General

Thanks. Our daughter-in-law's aunt recently experience disorientation, headache and general confusion and was taken to the nearest hospital. Upon arrival, her blood sugar level was determined to be zero. I did not know it was possible to live with a level that low. She was sent home, i.e., not admitted, and subsequently slipped into a coma during that night. She was taken by ambulance to the same hospital and was determined to be in a comatose state, but with brain activity. This was on a Tuesday. The following Saturday, four days later, it was determined she had no brain function in her frontal lobe and that she had suffered a small stroke in the interim. After obtaining a second opinion from a neurologist, concurring with the no brain activity findings, she was removed from life support and lived a few more hours. What, in your opinion, caused all of this?