Advances in MRI Imaging for Trigeminal Neuralgia

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The following article is cross-posted from the bi-monthlynewsletter of the TN Association of the US. Their website may be accessed at http://www.tna-support.org. This article may be worth discussing with your neurologist or neurosurgeon, as an indicator for improved diagnosis and treatment in facial pain.

High-Resolution Diffusion MRI Can Help Map the Microstructure of the Trigeminal Nerve, Improve Treatment Options for Trigeminal Neuralgia Sufferers

Newswise — NEW ORLEANS (May 1, 2013) — Today during the 81st

American Association of Neurological Surgeons (AANS) Annual Scientific

Meeting, researchers described their study regarding the use of highresolution

diffusion MRI to evaluate the microstructure of the cranial nerves.

The researchers noted that the pathophysiology of trigeminal neuralgia

(TN) remains unknown and present treatments are conducted based on

empirical evidence. Up to now, MRI has only been used to exclude other

pathological conditions such as skull base tumors — which can mimic TN

— but not to localize the affected area, improve treatment methods or

evaluate the effects of such procedures.

For the study, researchers sought out to demonstrate the feasibility and

advantages of ultra-high field diffusion MRI at the skull base, which could

lead to improved TN characterization. Healthy volunteers were scanned

on a 7T Siemens scanner with the following protocol: T1-, T2- and PD weighted

structural MRI with resolution 0.3x0.3x0.6mm3; diffusion MRI

with 0.6x0.6mm2 in-plane resolution, 18 slices of 1.2mm, 100 gradient

directions at b-value=1000s/mm2, 11 non-diffusion-weighted images, and

TR/TE=5000/64ms.

The results of this study, High-Resolution diffusion MRI of the Trigeminal

Nerve using 7T MRI, will be presented by Andrew

Grande, MD, from 12:06-12:17 p.m. on Wednesday, May 1. Co-authors

are Christophe Lenglet, PhD; Julien Sein, PhD; Julian Tokarev; Bharathi

Jagadeesan, MD; and Pierre-François Van de Moortele, MD, PhD.

The researchers’ imaging protocol generated high-resolution FA and ADC

maps, as well as fiber orientation estimates successfully used to

characterize the microstructure of the trigeminal nerve and its divisions at

the skull base using deterministic and probabilistic tractography

algorithms. The researchers concluded that their findings open up new

possibilities for further understanding of the pathophysiology of TN, with

the prospect of improving treatments based on this new knowledge.

“Trigeminal neuralgia is a rare disease with only 150,000 new cases per

year, and has been described as perhaps the worse pain imaginable

Most patients experience shock or lightning-like shocks in their face

triggered by various stimuli such as eating, wind, brushing teeth or just

simply talking. Patients fear this stimuli and consequently avoid eating, or

going outside or talking,” said Andrew Grande, MD. “In this study, we have

investigated the feasibility and advantages of ultra-high field magnetic

resonance imaging (MRI), at 7 Tesla, of the skull base. 7T MRI, by

comparison with clinical imaging typically performed at 1.5T or 3T,

provides greater image resolution and contrast, thereby improving our

ability to identify and assess the integrity of structures like the trigeminal

nerve. More specifically, we have focused on high-resolution diffusion

MRI, which characterizes the three-dimensional configuration and

microstructural properties of axonal pathways. This work opens new and

exciting possibilities to further our understanding of the pathophysiology of

trigeminal neuralgia and, ultimately, improve available treatments. In the

future, in addition to aiding our understanding of the pathophysiology of

trigeminal neuralgia, such imaging may allow us to better diagnose and

could potentially be used to guide some forms of treatment directly to the

afflicted portion of the nerve.”

==========================

Regards,

Red Lawhern, Ph.D.

Resident Research Analyst,

Living With TN

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WOW! this seems hopeful! I have has so many MRI's I wrote and recorded a Suite of jazz and electronic music using their sounds. what is noise to some can be music to others...a little John Cage influence there..make that a lot of.

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I had to request a 3-D image, the Siemens and the GE scanners have the ability to do this. I talked directly to a technician that does MRI and all he said was call your doc and request it. So I did and they did do a 3-D image. I do not see my doctor until the 31st of May to review this scan. I am being scanned at the level of the IAC ordered by a neurotologist, ENT neurosurgeon for ear pain, pressure/fullness, bitter taste, facial pain and some pure tone hearing loss. Thanks Red, I was told it was FIESTA. Sharon

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Well shucks, I am having an MRI today. I was lucky even to get insurance approval for this one. I wonder if I will be able to suck on tictacs during the MRI. I have horrible dry mouth and can't imagine having to go 45 minutes without anything in my mouth.

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Hi Maureen,

I remember I had to stay pretty still with as little movement as possible (including movement of mouth and tongue), so I wouldn't rely on tictacs:( But it's good to discuss any issues you have with the technician/doctor beforehand so that they can do adjustments for your convenience if that´s possible. Good luck, Oli

Maureen said:

Well shucks, I am having an MRI today. I was lucky even to get insurance approval for this one. I wonder if I will be able to suck on tictacs during the MRI. I have horrible dry mouth and can't imagine having to go 45 minutes without anything in my mouth.

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Maureen, there is a spray you can get over the counter for dry mouth. I have dry mouth from meds. No, tick tacks will cause movement and that is not going to allowed. Sharon

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NestleBassMan, interesting name, I actually slept some during my MRI, the sounds and noise don't seem to bother me...they seem very alien, maybe even spiritual, sometimes I think of the sounds as some kind of native American Indian experience. I also sing a song in my head sometimes. I always keep my eyes closed. Sharon

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Thanks, all. I will try to find spray at drug store,

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Sorry I'm a day late for your MRI Maureen...Biotene (sp?) makes some great products. Toothpaste, spray and a gel. I have been using them faithfully for a couple of years and have not had any problems with dry mouth since.

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Ha, not a problem, because it's on-going. So all suggestions are welcome. Especially since I left it too late to hit the drug store before the MRI.

Okay, the tech says, "This is a really important one now, so don't move your tongue or your eyes." Seriously, I am pretty sure my very-up to this time-quiet eyes just started spinning.

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I had a second MRI, same place and this time I realized the tech put the shoulder brace too tight pushing down on my shoulders the first time, very uncomfortable, this time she placed it so it did not feel like it was digging into my shoulders. I have neck and shoulder pain. Just so ya all know...and drink lots of water to get a vein for the dye, it took 3 hits to get a vein on me. The following day I needed blood work and no vein available. NestleBassMan, correct, it is a Biotene product in the spray...I prefer tic tacs. Sharon

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Red, Thanks for this information which gives all of us with TN some encouragement for improved MRI testing and improved treatment options. You are such a great resource for all of us here at "Living With TN"! Keep up the great work. Thank you and have a great holiday!

Jim

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Glad to help, Jim...

Regards, Red

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Red, yes, thank you too for all you do and contribute to this huge site. You offer great research that is reliable and up to date. When I start googling, I look at some of the entries and some of them are as far back as '07 or earlier and I am unsure they have current reliable info. Some research is always right on, like wikipedia. I think so many docs are back in the dinosaur era of their field, they may not be keeping up with current alternative testing, like the 3-D imaging with a FIESTA MRI. I do wish they would do what they did when MRI was not around or unreliable for this complicated area of the grand interstate highway of all these cranial nerves, if a patient says they are hurting, go in and take a look, so many of us suffering have negative MRI's but they sometimes find the problems in surgery. So many are unwilling to do this, they want a positive MRI. My last result is only suspicious for compression, but I just read my last medical record, the doctor says negative MRI. The radiologist does not advise what to do but seems to be pointing right to the area I do need to be scanned at because it is not clear on a brain MRI with contrast.

Have a wonderful holiday weekend and I always think of your wife and hope she has some pain free time to spend with you. Sharon

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Thank you Red for all you do on the huge site for sufferers of this type of pain. I hope you have a wonderful holiday weekend and I am always thinking of your wife...I hope she has some pain free time with you.

And, I did get a 3-D MRI, but I know it was 3T, wow, now they can do 7T with 3-D. This is my second MRI, where do they do this imaging or is it still in the experimental stage. I doubt my insurance company will pay for this..but I would out of pocket, I will copy your info and give it to my doctor if this second MRI is negative.

I may have to wait for this one...Sharon

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A couple of thoughts, Sharon. For any surgical "look around" there are also risks. Physicians are ethically required to balance risks against potential benefits. A CSF leak or possible loss of hearing or loss of the tearing reflex of the eye are not trivial risks to take. So we can have some empathy for the professionals who hesitate.

Likewise, though I am very active here, the site isn't all about me. We have excellent moderators and greeters backed by compassionate site owners and administrators. And there are many knowledgeable patients who share the pain journey. That's one reason why I encourage people to use the search window at top right on our screens. Nobody knows it all, but collectively we know more than we realize. And many give of their experience, support, and empathy here.

Go in Peace and Power

Red

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Thank you Red, I do see all the benefits from this site from many sources and I do agree with you about surgeons being hesitant...one did say to me, I do want want to make you worse. If my issue is where they are looking, surgery risks are loss of hearing and facial paralysis, so I am very aware. I get very anxious and just want the pain to go away.

Sometimes what you do for this site Red is help all of us sufferers organize our thoughts and you do direct us to the site or areas on this website that we sometimes just can't find where we need to post or look for help, so thank you for being that person...I sometimes read posts from sufferers that are great and direct you too.

I like your go in peace and power, Sharon

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I asked for a 3-D MRI from my stand -in neurosurgeon and he said "no". MRI showed no occlusion (looking for geniculate neuralgia) although the report just headed with Hx of trigeminal "myalgia". Good grief. I don't know if it was all a $5000 waste or what. I have all the symptoms of GN for 7 mo now, along with all the left-over symptoms of TN not fixed by MVD. His reccomendation was pain clinic...and I'm not even on narcotics, of course it took five tries, the last standing over the person typing in my current med list to correct it as they had been using my 2009 post-op orders with Dilaudid on it, even though I had brought in my list twice, emailed it two more times, was assured it was corrected and the finally at my last visit, most of it was with my help and insistance.

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Kg, what is trigeminal myalgia...that is first time I have heard that dx. And sorry your MVD did not work, are you posting your experience on the MVD page? I am seeing a neurotologist to look for geniculate, my pain is atypical, I just got a 3-D MRI at the IAC level, my first brain MRI had a finding but was ruled out for TN. I had to ask for the 3-D, there are GE and Seimens machines that can do it but they are 3T, it was just a call to the doctor, only about 10 minutes longer in the scanner. I can understand you don't have $5000 to do another one to look for geniculate. New advances in MRI are posted on this page, they are doing 7T, of course if my 3T is negative I will never get my insurance to pay for a 7T when it becomes available.

Sorry, you are having problems with meds, you do have to get that dilaudid off your records to be prescribed something. Don't give up, and keep posting, you are being heard. Sharon

kg said:

I asked for a 3-D MRI from my stand -in neurosurgeon and he said "no". MRI showed no occlusion (looking for geniculate neuralgia) although the report just headed with Hx of trigeminal "myalgia". Good grief. I don't know if it was all a $5000 waste or what. I have all the symptoms of GN for 7 mo now, along with all the left-over symptoms of TN not fixed by MVD. His reccomendation was pain clinic...and I'm not even on narcotics, of course it took five tries, the last standing over the person typing in my current med list to correct it as they had been using my 2009 post-op orders with Dilaudid on it, even though I had brought in my list twice, emailed it two more times, was assured it was corrected and the finally at my last visit, most of it was with my help and insistance.