Cranial nerves - Quix?

[steph74]

Thanks for the anatomy lesson on the Bell's Palsy thread.  I have a question about what you said.  The cranial nerves are all part of the CNS?  So a lesion on one of the CN would be considered damage to the CNS, just like a lesion on the spine or brain?

Much of the MS information I've seen describes the optic nerve as part of the CNS, but not the other CNs.  I've often wondered why this is.  What is the technical difference between the peripheral and central nerves, if it's not just hte brain & spine vs. everything else.  (This may be a technical question, but I love medicine, and if I hadn't just spent most of my adult life so far in graduate school getting a PhD, I'd probably go to medical school--I think the body is really fascinating!)

Part of the reason I'm asking this is also because I clearly have a problem with my cranial nerves (and am un-dx).  I have bilateral TN and some mild problems with CN-VII (twitches and small spasms in my cheek and eyelid).  The damage to the trgeminal nerve is also affecting my muscles in my jaw--I've never seen this problem mentioned *anywhere* on any TN websites.  But CN-V also controls the muscles of the lower jaw, and I have some pronounced spasticity in my jaw.  (I see the neuro tomorrow about this.)

The neuro had mentioned the problem was in the pons, but it sounds like it could be anywhere on the nerve and still be a CNS problem.  Is that correct?

Sorry for all the questions.  I just like to understand what's going on.   :-)

Stephanie

[wadeheather]

I tried Gabapetin, but that was before the facial stuff became so regular (besides the Bell's 9 years ago). The neuro told me to stop it and "be tough." I didn't really care for it anyway and my symptoms would be better for a little while, then worse again and they'd up the dosage.

Just part of the adventure, I suppose.

[Nancy T]

Hi Stephanie. I don't take any medication for the facial stuff; it's not nearly bad enough. It has also become generally less prominent and bothersome as the years have passed. (Lucky me.) Thanks for passing on what your neuro said.

Your poor little girl! Warts are disgusting enough without being in the nail bed!! Good luck getting that resolved.

Nancy

[steph74]

My understanding of the trigeminal nerve is that it's just facial sensation, except for the "muscles of mastication" (chewing), so a twitch in your eye would be from the 7th CN (I think).  You could have problems with both at the same time, though.  I am, though the 7th is MUCH less affected for me than the 5th.

[steph74]

Thanks for your explanations.  I think the stapedius (sp?) is the place where I was briefly having trouble with the "sound being turned up" in my right ear.  There was suddenly no dampening of the sound and things got VERY loud.  Luckily it was a short lived sx.  The beating you describe sounds pretty unpleasant.

I asked my neuro if the fact that all three sensation distributions of the nerves were affected, and the motor function, meant that it was more likely to be a nerve root problem.  She said no.  But she didn't clarify whether if it wasn't on the nerve root meant that it could still be MS-related.  (e.g. the cranial nerves are part of the CNS, like Quix said.)  

Thanks for your sympathy about the appointment.  I don't feel great about it, but I don't feel as badly as I did the first day.  [On to other things to deal with--my 7 year old has a gigantic wart on her little toe, in the NAIL bed....!!!  Poor thing.  Now we need to see a podiatrist.]  :(  

Do you get any relief from your sx with medication?  When I finally got up to 1800 mg/day of gabapentin was when I finally felt some actual relief, though it's not perfect.

Stephanie

[wadeheather]

PS - I also have twitches in my eyelids (specifically my right) and tingling in the rest of the right side of my face. Over the last two days it has been different though. A lot in my jaw line as well.

[wadeheather]

That was a little confusing to me..... So, can TN be felt all the way down the neck and into the middle of the spine, is that what I am understanding? So, the "stampeding" could be just an arethmia (sp?)?  Could that connect somehow with the phonophobia some of us had with headaches?

Here's the deal, my headaches are back along with unusual tingling in my jaw/ neck.  Almost felt like I was being strangled for a while today.  Even though I have had long term issues with headaches and neck/shoulder pain, the "choking" feeling and the "heart beating out of my chest" Feeling are new.  It kind of sounded like what you are talking about???

[Nancy T]

Hi Steph. Yes, I thought the same thing that you said--that the facial symptoms would presumably have to come from the nerve root, not an extension of the nerve. But I'm not an expert and was looking for straws to grasp at from that appointment (as my goal is to just set it all aside now; my neuro exam is normal, so that's doable for me).

I did find some stuff on the Web about TN not always being a "supraspinal" phenomenon, but I think your doctor's view is much more common. I did ask a neurologist in 2002 if my face symptoms could be from the spine, and SHE said no.

And as I mentioned elsewhere, the neuro I saw last week has some off-the-wall ideas!

In my case, too, I think all 3 distributions of the trigeminal nerve must be affected, because my shocks run from above the eye to the upper lip, and I've also had stabs in my jaw, tingling in my chin, and shocks in my upper and lower teeth. Also a bad itchy spot on one side of my forehead.

The BPPV (benign paroxysmal positional vertigo) with the (presumed) stapedial spasm on the other side is not something you would have heard about, because I'VE never heard about it in the many years I've been "studying" dizziness, and furthermore I've asked several dizziness specialists (both neurologists and ENTs) and a couple of forum doctors whether they had ever heard of this and they said no.

What happened was that for four days in 2002 or 2003, I had left-sided BPPV. Whenever I'd tip my head leftward, after a couple of seconds the ceiling would appear to jerk up and down (nystagmus). This is normal for BPPV, which is a common thing among the elderly and among people with inner-ear damage of some kind.

What was NOT normal, and apparently unheard-of worldwide, is that during the nystagmus, I would hear and feel a beating/thumping in my RIGHT ear, thus contralateral to the BPPV side. The head of a balance-testing center who answers questions on a dizziness list that I read said it sounded like a stapedial spasm, and a forum doctor here agreed (and I do too). I think the stapedius (a muscle in your middle ear that contracts to dampen loud sounds--I may have got that wrong, haven't looked it up recently) is controlled by the 7th nerve. Thus, there must have been some "aberrant" connection in the brainstem, presumably between the 8th nerve on the left and the 7th nerve on the right.

Sorry to hear that your recent neuro visit caused the usual frustration and confusion. We can try to prepare ourselves for frustration and lack of answers, but you still feel beaten down when it happens, don't you?

Wishing you luck,

Nancy

[steph74]

No one has mentioned upper spine problems as a source of my TN.  I do also have severe headaches, with shock-like sensations arising from ~C2-C3 area.  These have been mostly under control with the gabapentin I take for the TN.  

Your neuro's explanation doesn't make sense to me.  If the trigeminal nerve does extend into the neck area (I don't know if it does or not), then it wouldn't be at the start, near the root.  It would be more "peripheral" and a problem there shouldn't cause a problem in your face, where it goes first.  But maybe my anatomy is mixed up.

Also, the neurosurgeon that I saw specializes in treating TN.  I have bilateral TN, starting at the age of 34.  Most people who get TN are over 50.  In his opinion, the chances of it being caused by a compression problem, on both sides, at my age, were slim.  That said, doctors don't know everything, so we can see.

The other thing that suggests to me that it's a brainstem issue, at the root of the nerve, is that my jaw muscles are also affected.  It seems that it would be unusual to have all three distributions of the sensory nerves AND the motor nerve impacted, if it wasn't happening at the root of the nerve.  But again, it's possible.

I have also had hearing problems, though thankfully they've been temporary (hyperaccusis in my right ear--where it sounds like the volume has suddenly been turned way up!)  I'm not familiar BPPV with stapedial spasm.  Could you tell me what it is?

I think the nercous system is interesting.  I just wish mine was acting normally!

[Nancy T]

I too am very interested in the cranial nerves. One of my symptoms over the last 10 years has been a LOT of shocks and paresthesias on both sides of my face (in my teeth and nose, too). I have also had strong twitching on one side, plus highly abnormal auditory EPs on both sides, which a past neuro called "cranial neuropathy."

Plus the spasmodic episodes of clicking in my left ear with pain/pressure behind the ear, which I believe is a 7th-nerve thing. Plus the episodes of left-side BPPV with stapedial spasm in the contralateral ear, which I think must also be a short circuit in the brainstem involving the 8th and 7th nerves.

Steph, your neurosurgeon says the chances of bilateral TN being anything but MS are very small, but I saw a new neuro last week (the first one in 6 years! and he was all through with me in one visit, which I recounted on the thread titled "Is this a record or what!"); he referred to my symptoms as trigeminal neuralgia but still said I don't have MS. (He also said my Lhermitte's was not Lhermitte's--because it didn't start in the neck and travel down the spine--and was not MS. I argued that it was too Lhermitte's!)

He told me that the trigeminal nerve also extends into the upper spine, at least into C1 and C2 vertebrae, so that the trigeminal-nerve symptoms could be from a neck problem. I was surprised to hear that, but apparently this may be true.

Quix, I'd love to hear what you think about this--trigeminal neuralgia caused by upper-spine problems? (not to hijack your thread, Steph, but I'm sure you'll be interested in anything Quix has to say).

I don't know what is causing my Lhermitte's--the orthopedic spine specialist, whom I saw for my lumbar scoliosis, MRI'd my neck and said nothing showed up to account for the Lhermitte's. The report did mention bone spurs "flattening the anterior surface" of the spinal cord and possibly some canal narrowing but that the signal within the cord was normal. The new neurologist did not see this report or the MRIs.

So, do I believe the neuro or the ortho? I guess I better believe the neuro, even though he was basing his "explanation" for my symptoms on speculation. But he could be right.

Steph, have any of your docs ever mentioned the upper spine as a cause for bilateral TN?

And how is your jaw doing these days?

Nancy