Hi Paintguy. I also was wondering the same question: What kind of diagnostic tests have you had to rule out the obvious. Facial pain can be from so many different things it's hard to figure out a source sometimes. Ask your dentist for a thorough exam to rule out anything dental or TMJ issues needing further investigation. You will need some kind of xray and/or scan/mri to see what you do or do not have (sinus issues, ms, tumors, bloodvessels). Sometimes ( a lot) you won't see a thing, but still have the pain. Trial and error. Have you seen a neurologist? You say the usual drugs - are they over the counter or prescription? Many of the ones prescribed for TN and other issues give you major brain fog. Keep track of pain/side effects. I find myself still foggy brained, I think it's the constant pain in my head/face, it scrambles my thoughts, like interference for lack of a better answer. How scientific is that, lol.
I hope this helps you. Also check out www.endthepain.org which will give you good information. I don't think the health care provider section will apply to you, but being in Toronto you should be able to find a great neuro. You'll just have to wait forever. (I know, I used to live there...)
Hope you feel better and get some answers. Let me know if I can help anymore.
The marijuana won't help your long term concentration either. Did the neurologist order an MRI of your brain to look for tumors or cysts, etc. and blood vessels of your head (with the pulsing tinnitus) to look for aneurysm? Did your neurologist measure your B 12 levels in regards to your extreme forgetfullness?
Did he talk about the possibility of TMJ involvement? I believe I have trigeminal pain related to TMJ problems. I had pain in the left face under my eye in addition to my usual migraines that was so bad that I came close to getting nerve block injections (insurance approved) but took a major committment to keep doing them and I believe a 50 dollar co-pay was attached to each injection, plus risk involved in doing them, so I didn't get started. I found out this year (some time later) that I have a torn disc in my left jaw joint besides the arthritis I already knew I had. Have you ever tried acupuncture for the pain? Biofeedback? Botox injections?