I don’t know the answer to this one. I have had a few locals over the years (generally in the lower body) and have never gotten excited (a good thing, given that I had a triple bypass a few years back). I think the big thing about the LP, is to get whoever is doing it to wait a couple of minutes longer for the local to really take effect. It is not an easy thing for the medic to do, and they are probably as worked up about it as the patient, and want to get it over with - and some of this could convey to the patient as well.
On the original thread, I had all my teeth out about 30 years ago - and I have never regretted it.
Geoff