Hi,
I am 18 years old and female. I am a runner (6X per week 3 miles each time) and last fall I the initial symptom of flashes in my vision after runs. Then i noticed in winter i was tripping and on small imperfections in sidewalks or nothing at all. I would also skid on flat surfaces. Then is spring i would have tingling like water dripping/pricking going up my legs (usually when it was warm out). I also occasionally have sensitivity to touch of my clothing and dizziness upon standing. I have been to a neurologist and his first diagnosis was peripheral neuropathy (which my grandmother has - idiopathic). I had an MRI which ruled out MS. Blood work which ruled out vitamin deficiencies. Most recently i had an EMG which came back ... normal....does this mean that i dont have peripheral neuropathy? what else could cause all of this?

thanks so much!

Welcome to NeuroTalk:

You will want to double check with your doctor, for the exact level of B12 you tested at. Lab ranges in US are low, and if you are below the new standard cut off of 400, you could have NOT normal results. Some doctors don't know this yet.

That feeling of water going down the legs, is also present when there is compression in the spine somewhere or elsewhere. I had that symptom for my MP (meralgia paresthetica), before it became very painful. MP is a compression of the lateral femoral sensory nerve. Mine was from a C-section surgery. MP can come from wearing too tight jeans, or from surgery or trauma.

Please read our subforum above, and see if anything is familiar to you. Many PNs are environmental, meaning something you are eating or not eating, or exposed to (toxins, drugs, vaccines) can be triggering it. There are hereditary PNs...
http://neurotalk.psychcentral.com/thread121564.html

Flashes in vision, suggest a circulation problem, or low blood sugar. Sometimes they are auras of a migraine. Flashes in vision without the headache are called silent migraines.
Did you have a homocysteine test? When elevated this can affect the blood vessels and damage them. If the flashes are more towards the end of your run, it is the stress somehow from the run I'd look at.
Also you may be low in potassium and magnesium, which create weakness and circulation problems. About 70% of Americans do not eat foods with magnesium in them. So they walk around in a partially deficient state, and then add to that vigorous exercise and you have an electrolyte problem.

Sometimes you have to be your own detective to find your trigger. Since you are heavily into running, I'd suggest you stop for a month or two and see what develops or changes.

--normal EMG's or nerve conduction studies do not rule out all kinds of neuropathy, as those tests are too gross to measure problems with the smaller, unmyelinated fibers; to gauge those one would need very special testing, such as qualitative sensory testing, sudomotor axon reflex testing, or a skin biopsy (the current gold standard).

I tend to think,, though, from what you're saying, this sounds somewhat systemic, though, and investigating along the lines Mrs. D mentions is likely a good idea. I'd also be tested for gluten sensitivity/celiac if you haven't already been titred up for that.

So is it possible that all of these symptoms could be the result of a pinched nerve? I am unsure of what env. factors could be causing this - I eat very healthy (especially for my age) and live in an area that is not near any kind of toxins/factories. Also i looked up MP and it doesnt sound quite like it fits because i have had tingling as high as my stomach area. Also isnt CMT ruled out by the EMG test? I feel like my symptoms most closely match MS or CIDP but it seems through the tests i have had that both are ruled out...what kind of causes are left that would not affect the EMG (glenntaj - what diseases affect unmyelinated fibers)? I forgot to mention that I have very high arches in my feet (not sure if it matters). mrsD what is a homocysteine test? (it sounds like a normal blood test to me). Thank you guys so much! I am working very hard to figure this out before mid august because then I go back to school in a different state which will make further testing almost impossible.

Also arent the only kind of neuropathies which affect things like walking usually the ones which show up with an EMG (i guess this is why i am so confused).

Homocysteine is a blood test, but not in the standard chem panels which are groupings normally used.

In a young person, it is not typically done either. But if it is elevated, it would point to a low B12 utilization factor, or a genetic problem where the body cannot convert/methylate B12 and folic acid. This is pretty common, and not rare. But not all doctors look for it either.

When you engage in extreme exercise you place yourself on an edge of sorts. Without the activity, you might present later in life with the same symptoms. WITH the activity, it may accelerate whatever your weaknesses are. They could be metabolic, (light flashes in eyes point to this), or mechanical, as in disc stress in the spine.

To get enough magnesium, you have to have 400mg a day and an example of foods to consume are 3oz of Almonds a day (270mg right there) and beans, oatmeal as examples.

Having a V8 vegetable juice after a run will provide 800mg of potassium. This is one of the highest sources. Energy drinks in comparison are very low, with Gatorade at 30mg.
An average person now is suggested, to consume 4.5 grams (4500mg) of potassium rich foods a day.

If your Vit D is low, there can be derangements in calcium and when this happens, you get paresthesias, or odd tingling/numbness. So getting Vit D tested can be helpful. Many young women have been found low in calcium and their bones are being robbed for it, today.
http://www.nof.org/aboutosteoporosis...oungadultwomen
I saw an ABC medical segment over 10 yrs ago on this subject and it is still a serious issue. If your running is impacting your periods, it is a greater issue even.
Your goal for Vit D today is 50, that is the newer suggestions.
If you don't have good Vit D status, then you are not absorbing calcium from foods. Don't assume that if you are eating well, all those nutrients are going where they are supposed to be going.

There are many factors that could be going on. A neurologist will be looking for organic factors, tissue/nerve damage only. Typically they don't address metabolic nutritional factors.

Looking at your lifestyle, the flashes in your eyes happen after a run, and to me they are the most important sign, unless you haven't told us everything. They can come from the retina itself, or the brain. If from the retina, that can be low blood pressure, spasms of the little vessels, high blood pressure clamping down on them, low blood sugar, or some autoimmune problem in the cells themselves. You might want to see a good opthamologist MD for this if it continues. If from the brain, I'd be concerned if you take birth control pills, as these can cause strokes in otherwise healthy young women.
Homocysteine elevations often show up in the vessels of the eye. And while you are young, you could still have this, if you are not methylating B12 and folic acid properly (this is genetic).

Reliance on fancy conduction tests, will only reveal damage to nerves and not all sensory damage even shows up on them.
So do consider these other issues, as well.

hi again
i have never had normal periods even before i began running...usually only have like 5 each year but the doctors always said this is because i am athletic....wouldnt all of these low vitamins have been tested for with eth blood? they tested like 10-15 different things and all came back normal

also i forgot to mention i have been to an eye doctor and they said that my eyes are fine...

Regular doctors do not interpret vitamin testing accurately. That is just the way it is.

Labs in US still report levels of B12 at 250 as "normal", when new guidelines for doctors are in place which start at 400.

What I post here is also at this medical website:
http://www.aafp.org/afp/2003/0301/p979.html

You are only 18 yrs old. Doctors don't look for dunning things at your age.

PN is not common in your age group. Unless you have CMT that you inherited.

All PNers benefit from looking at lifestyle factors, and making adjustments based on them. For your age, the largest potential, is vaccine injury, and/or gluten intolerance. Next comes mechanical compressions to your spine from the running activity.
Next is low Vit D, which impacts calcium metabolism, then comes low blood sugar (since your symptoms are worse after running).

The fact you have few periods, suggests low hormone status, which then suggests calcium problems. It is your choice to follow up on these potentials. Unless you go to a holistic doctor and have another type of thorough check up you will not find answers completely with a neurologist IMO.

When a person gets symptoms from an activity, that is a cardinal sign IMO to follow. But not all doctors will do this. So it is up to you to do this if you wish to feel better. But be advised, running is no guarantee at all of good health. It has high impact, and stresses your body, as you are now noticing. Substitute swimming or a lower impact type activity for a while and see if or how your symptoms change.

Learning about PN and how your body works is a task you need to consider. Do a little homework each day. Our subforum has many links for you to look over.
Your issues may not even be PN, they may be symptoms of something else. Only time, and learning will point the way for that.

4700mg is the current RDA for adolescents and adults, but what's 4% among friends?
http://lpi.oregonstate.edu/infocente...index.html#rda

Here's a 2010 chart for potassium-rich foods
See Appendix 12 (bananas don't even make the top 20):

...which is different in many cases to the previous 2005 chart, but I would spoze there are a lot of variables in this kind of testing/evaluation.
PN is one of those things that has multiple meanings; it's a condition, yes, but it can also be a symptom of something else (supporting what MrsD & Glenn have said).

Doc