I'm about to harp on about the neck as a possible cause, a heads up if you want to sign off now, and in writing the below I'm not claiming I'm correct, it is just an opinion.
TN1 and TN2 are both rare, and we have the distinction due to IHS classification for one. A rare disorder, possibly two rare disorders, or the same given that many would appear to have an overlap of the two. Yet great controversy as to the treatment/ surgical intervention; MVD for TN1 but not TN2 as a generalisation, yet the two coexist in many patients. A diagnosis of either is an expression of symptom patterns, it does little if anything to indicate the cause of the symptoms, but gives a box for the medics to embark on a course of symptomatic relief at best (pain relief important when needed).
If an individual is suffering symptoms of TN, is suppression of symptoms through medication an adequate course, in my opinion no, we haven't addressed the cause, so at best we get pain relief, worse we don't address the underlying cause and may introduce medication side effects, some of which can add to a recurring problem.
If in certain folk, vascular compression on the peripheral nerve causes the problem, why the changing symptom pattern- first this then that then this etc., a continuous pressure on a peripheral nerve will give the same symptom pattern though continuous pressure might make the same symptom pattern worse. Why remission? would tend to suggest environmental factors such as posture, stress and/ or diet. Does the vascular compression disappear?
The neck has a central causation for TN, at the trigeminalcervical nucleus and as such offers an explanation for a changing symptom pattern.
A patient turns up at our physical therapist clinic and (disregarding the compliant) more often than not expects us to 'cure' them with no input from themselves. They are to used to the magic bullet that hides symptoms. We can help with said complaint, more often than not, but if the other factors are not addressed then you might feel OK right now but you may as well book in for say two months if your not about to take action.
Today, I've had a patient with TN. 16 years worth, 2 MVD procedures just last year, contemplating what I can gather is a SP block. A very pleasant lady and in a world of emotional trauma, to the point she mentions my children are old enough.
Now I'm kinda normal, but as a PT, or human, it isn't easy to control your own emotions but job done, and hopefully through what ever avenue I offered her some support.
Despite suffering for 16 years, having osteoporosis, fibromyalgia, and neck pain including episodes of acute torticollis prior to TN did anyone in NHS UK suggest the neck could be a cause? NO!!, and since MVD she has, although improving, dizziness, and a numb nose which is constant.
Patient " I always thought it had something to do with my neck, but you listen don't you?"
Can we help, time will tell, though I'm optimistic, symptoms since MVD, unsure, but less likely if due to destruction, although the body given the right tools is a great healer.
Jane, not intending to hijack your thread, but add to it, the idea of changing symptoms due to peripheral nerve irritation escapes me.