Hello Oto,
I'm still doing my research to decide between surgery and radiation, and one of the questions I asked the neurosurgeons was "were I to have surgery and deveop a csf leak, how would I be able to tell it wasn't just a runny nose?" He answered that mucus is sticky, while csf is not. Good to know. He also said there's a simple test that can differentiate between csf and everyday mucus, but I didn't ask if it was available over the counter.
I have the tongue thing too, but it's hard to say whether it's more of a bitter taste or a sensation, or both. For me, it can be a warning that a severe vertigo attack is going to happen. Or it can linger for a day or more and make me talk a little funny. The doctors I've mentioned this to seem surprised this is happening since my tumor is small. I hate it when they say "that shouldn't be happening", as if I'm making it up.
Sometimes it helps to drink something really cold. My theory is that it shocks the nerve back to normal, but it doesn't always work.
Boppie, I'm going to try the chocolate thing right now!! (Practicing for next time my tongue gets tingly!)
Betsy