In '92 I was diagnosed with Stage IV Non-Hodgkin's Lymphoblastic Lymphoma (Diagnosed at age nine). The tumors were located on the back of my head and left side of the neck. I had biopsies to remove one tumor on the back of my head and one to remove a tumor just behind and below my left ear. I don't remember immediately having FBS during treatment, though it's possible I did and have just been brushing it off. I know I've had it since the late 90's and have assumed it was part of my tinnitus. I am just now learning (2023, 30 years later) that it's FBS. Its occurrence is random. Maybe several times a week, maybe a few times a month. Almost always triggered by something sour/tart, other times anything. It will last 5-15 seconds then will not occur again for days or weeks.