I have been going through this particular symptom for about 7 months now. I could be doing nothing at all, sometimes I am turning around, walking about, looking down at my smartphone, typing on the computer, etc. and I get a 1-second jolt of dizziness. It makes me panic afterward. It literally feels like a shot of adrenaline. It's enough to send me into a panic attack and it's very unsettling because the symptom is very unpredictable. What can this be?