I’m recently diagnosed with TN & I may be somewhat in denial still, but does anyone have pain that from onset to completion of an “episode” it lasts roughly 20 minutes consistently?
Type I TN is often medically described or characterized as a "burst" of lightning-strike stabs, each of which may be ~60-90 seconds long, and the burst as a whole perhaps 20 minutes to an hour. If your pain has more of a constant achy, burning, throbbing character that lasts in a single episode about 20 minutes, that might be a bit unusual, but it's probably still within the overall description for Type I TN.
Regards, Red