Traveling with mother today on plane. She was fine. Then, all of a sudden when I looked at her there was a blank stare, no response, and then she began vomiting with no reaction on her part. The vomit just kept coming and she could not stop it and seemed not to care. Totally not my mother! These episodes have occurred before, but when she was with my father or by herself. Her doctor has ran a CAT scan and stress test with no diagnosis.Any thoughts?