Hello finuch: I'm still pretty new here too. I'm not aware of any such group. I have Meniere's Disease which, I believe, produces some similar symptoms. All things considered, it's been pretty mild.
I did, on one occasion a few years ago, have one experience where the room I was in began to spin around me. I was at the top of the stairs on the second floor of the house we lived in at the time & I had to sit down right away. Otherwise, I'm quite certain I'd have gone head-first down the stairs.
Since that one experience I haven't had any repeats... thankfully. But I do pretty much always feel a twinge of dizziness & sort-of a general feeling of being somehow disconnected from reality. I used to ride a bicycle occasionally. But I fell of it & hit my head on the concrete one time (the one time I wasn't wearing my helmet... wouldn't you know.)

Since then I haven't riden it. Where I live there's a lot of fast-moving traffic. It can be dangerous if one doesn't have one's wits about them.
Hope both you, & your friend, are doing well.