Hello all. I relate to a lot of the things discussed in this thread. Though there are some differences / aspects that I've not noticed anyone mention yet, and that is mainly a very strong connection to pressure and bodily position. Sitting at my desk for long periods worsens symptoms, and sitting up in bed for any length of time is more-or less impossible without triggering the numbness and discomfort.

My first sign of a problem was a tingling / pins and needles in my left toes, exacerbated by sitting for long periods. This quickly expanded (though remained intermittent) and eventually came to affect all four of my limbs, peaking with numbness, tingling, nerve pain (both sharp and burning) and fasciculations / twitches in all extremities. The fasciculations are much worse at night when the muscles are relaxed. They take a back seat (but are sometimes still present) while I'm active during the day. I have had several notable flare ups/spikes. One seemed triggered by my giving blood a couple of months ago. I don't know why that might be. Something to do with blood pressure? Who knows.

Another interesting thing to note is that at some point before everything really kicked off, I had a few occurrences where the 'funny bone' nerves in my elbows were evidently physically enflamed, to the extent that resting my elbows on a table would be painful. The nerves hit the surface before the bone of my elbow did. This seems to me to point to some kind of systemic infection, but after that little flare up it ceased to be an issue. Those particular nerves are no longer enlarged or painful.

These symptoms all began more than a year after both my covid infection and the vaccine (+booster), so I don't know that there's much to connect symptoms to those, in my case.

Treatment-wise, I was referred to a neurologist, who sent me for various MRIs. These all came back normal. I've had multiple blood tests - these are also normal. The most recent specialist I saw is referring me for a nerve conduction test, and has also ordered more blood tests, this time looking at possible genetic indicators as well as the more usual bloodwork.

That most recent Neurologist suspects BFS in tandem with a possibly over-active Trigeminovascular complex (basically area of the brain responsible for filtering sensory input before relaying it to the conscious mind, if my understanding is correct). He also said that he's seen a few cases like this since Covid, and has noticed that Covid makes these symptoms last longer than they may have done pre-Covid. My next appointment with him is in six months, after the other tests are done.