Trigeminal Neuralgia - Possible Misdiagnosis?

Hello,
I have been diagnosed with atypical trigeminal neuralgia, which my neurologist believes to be caused by inflammation of two front teeth in my lower jaw and the surrounding bone following a root canal treatment and multiple root end surgeries on those teeth. It took 8 months for the diagnosis (I went to see several doctors during that time because of lasting pain until finally I went to see the neurologist). I have been taking Neurontin 500mg/day and large doses of B vitamins for the past 3 weeks, occassionally Tramadol and Paracetamol. I also go for acupuncture treatment weekly. So far, I haven't noticed much of an improvement in my condition, the first week of treatment went ok and then it was downhill from there. Is it possible that I have been misdiganosed? I have not had either a CT or MRI scan. I have had TMJ Disorder for the past 4 months, my  "worse" TMJ side is the same one on which I feel the neuralgic pain in my teeth. The neuralgic pain doesn't move around my jaw, it stays in those two teeth which received surgeries. It only hurts during the day, and mostly it's a constant, dull pain. On a "bad" day the pain is like that of abcessed teeth. On an x-ray, it seems that the bone that had been removed due to infammation is healing up fine. I have severe scars on my gums after the surgeries and they seem to be sensitive to touch. Half of my chin is really sensitive and looks swollen all the time - it's been 4 months since the last surgery.  If this is TN in its atypical form, are there any other treatment options next to the ones I am already using? If it's not TN, what else could be causing the pain and what type of examination should I ask my neurologist to refer me to (x-ray is probably not good enough for this). Thank you for your reply.
Kind regards,
Oldriska

[Jeffrey Kim, M.D.]

Thanks for using the forum. I am happy to address your questions, and my answer will be based on the information you provided here. Please make sure you recognize that this forum is for educational purposes only, and it does not substitute for a formal office visit with a doctor.

Without the ability to examine and obtain a history, I can not tell you what the exact cause of the symptoms is. However I will try to provide you with some useful information.

Trigeminal neuralgia would be a consideration for your tooth pain, but as your neurologist has rightly acknowledged, there are atypical characteristics to your symptoms.  The pain in trigeminal neuralgia is usually characterized by brief episodes of severe pain with pain free intervals in between.  The pain may also be triggered by trivial stimuli such as talking, brushing teeth, eating.  The diagnosis is largely clinical (meaning based on history and physical exam).  An MRI may be obtained to rule out other causes, such as tumor or vascular abnormalities that may be a source of nerve root compression.  Gabapentin may be one of the medications to treat this type of pain.  There are many other drug options, including carbamazepine, oxcarbazepine, baclofen, topiramate, etc.  If medical therapy has been exhausted, there are surgical options as well including trigeminal nerve decompression or radiofrequency ablation.

I would make sure that all other possible causes for your pain are ruled out.  Other considerations may include persisting oral/dental disease, and disorders of the temporomandibular joint (which you have a history of).  If you find that you have pain with chewing, another condition that should be ruled out is temporal arteritis.  This is a condition that is due to an inflammation in the temporal artery and other arteries in the body.  This can be associated with headaches, and vision loss.  Diagnosis may involve sending an ESR, or performing a blood vessel biopsy.

I would recommend continuing to work with your neurologist on treatment of your pain as there are many medical options that have not been tried.  Pain conditions are often difficult to treat and may take time.  An MRI would not be unreasonable if trigeminal nerve involvement is suspected.  

Thank you for this opportunity to answer your questions, I hope you find the information I have provided useful, good luck.