Trigeminal Neuralgia also known as tic douloureux involves a malfunction of the 5th cranial nerve or the trigeminal nerve. This nerve carries sensations from the face to the brain. Malfunctions of this nerve causes bouts of severe, piercing and burning pain. This pain can last seconds or minutes. Adults of any age can be affected, but it's usually the elderly. This is basically how the Merck Manuel decribes the disorder.
I've read that a true Trigeminal Neuralgia is not common. There are several ways to get Trigeminal Nerve damage or for the nerves to become irritated. I say nerves because this nerve actually branches off into 3. (Tri)
I've also heard the pain described as lightening flashes, burning flares, etc. It's usually brief but can be excruciating.
I was told years ago, after several surgeries for TMJD, that I had surgically induced Trigeminal Neuralgia. During the surgeries the nerves were damaged, nicked or injured in some way. It caused severe burning flares, several times a day.
Some Dcotors now know (in regard to TMJD) that compression of the nerves can cause the same type pain. Many people with TMJD, who do not have surgical damage can suffer this pain due to muscle spasms compressing the nerves. This is nerve pain and regular medications do not help. Medications like Neurotin, Tegretol, Baclofen and I think some newer ones are used now. Sometimes they help, but do have some side effects that a lot of people can't tolerate.
There has been some discussion on this subject. If you're not familiar with the search feature on the board, it's at top right under the reply tab. You just put in the word or phrase and click search. Any threads on this topic will be pulled up for you.
I hope this helps,