Low Back & Leg Pain - Part III

Strange leg numbness that spread to whole body  Top

Question

Seven years ago while my left leg was cramping it went numb. It has remained numb from the sciatic nerve, down the back of my leg, wrapping around the outside of my shin, including my foot bottom, except for my big toe. Most of the top of my foot is involved too. The numbness is like Novocain numbness. I also cannot feel cold in these areas of my leg and foot.

The strange part comes with 'flashes' of numbness on my face and body. The other body parts included are my arms, chest, belly, and back. In May of this year my back, down my spine, became permanently numb too. This numbness in my back is the only change in 7 years. The 'flashes' come and go.

I have been to two neurologists. They have said that I do not have MS. Beyond that, they (and the MD's) have been clueless.

2 weeks ago I went to have an EEG because I fainted and seized. I have never seized before. My blood tests and EEG returned normal. While getting tested, the tech. suggested I get an EMG for my numbness. It is quite surprising that this has not been offered to me by anyone else. I will speak to my MD about it soon.

My chiropractor says that it hits so many nerve areas that it totally baffles him too. He has been in practice since 1962. He did a test that seems similar to the EMG at his office. I had NO response to the electrical current. I felt nothing. He was surprised because he said that I should have been jumping off the table with the varied currents he was sending through me!

I get flashes of numbness too. They can be so strong that I'll be awakened out of a sound sleep. I will be curious as to what the doctor suggests causes them. Best of luck. Thank you for your informative website, as well as this forum. Do you have any suggestions from my description of numbness?

Answer 1

I read your post carefully. My first thought was also MS, and I take it, the Neurologists are fairly confidant that it is not. Fainting and seizures however are definitely not part of MS. Needless to say, the object of this exchange is not to make a diagnosis over the Internet, but just reading through your post, I wonder if you are having any toxic exposure in your environment. That may cause peripheral (the numbness) and central (the fainting and seizures) problem. An EMG would be helpful to show whether or not you have a neuropathy. If you do and if there is no obvious reason for the neuropathy, I would definitely look into toxic exposure (at home or at work). Good luck.

Answer 2

Urgent, Please reply. How long have you seen this chiropractor? I am sure that this is the source of all your numbness and pain, if you are receiving alignments. The body is only designed to withstand so much jerking and pulling. Also there are nerves and nerve roots that can be affected by frequent adjustment. I suggest you stop seeing him and see a rheumatologist, neurologist, orthopedist, and a physical therapist to evaluate your condition. If the treatment the chiropractor is giving hasn't relieved the pain or caused additional pain, give up and try something else. In the long run you will find it's cheaper and safer to do without the chiropractor.

Radiculopathy with negative EMG for nerve damage Top

Question

I have constant numbness/tingling in my R LE (bi lateral at times), increased with activity. Can you explain how I can have the diagnosis of radiculopathy with a negative EMG? What exactly does it mean, and will epidural steroid injections help? Does it mean it's permanent? Also, how could a sensory root lesion be detected, by NCS?

Answer

To explain further why the EMG is negative in some cases with radiculopathy. The medical reasons were pointed out in previous posting. But I would like to say, if you have a car with maximum speed limit of, say 120, then it cannot go faster than that. Similarly, in EMG it has its own limitations we cannot exceed. We cannot do more than what it could give; otherwise, we do not need any other tests. The EMG is complementary or extension to medical examination and it does not replace or substitute a good medical examination by all standards. To go back to your question of epidural steroid injection, it may help, and it is up to your treating doctor to decide. A negative EMG in your case does not mean that your symptoms are permanent. On the contrary, a negative EMG can be reassuring. Finally, I am sorry, I do not know how to help you with the last point.

Question about normal values for peroneal and tibial nerves latency. Also what about safety? Top

Question

What would be normal values for peroneal and tibial nerves (latency in ankle, motor amplitude...)

Answer

Peroneal nerve values: Terminal Latency: 2.6-6.2 ms Amplitude: 2.6-20.0 mV Motor velocity: 42.9-55.0 m/sec

Tibial nerve values: Terminal Latency: 3.0-6.1 ms Amplitude: 5.8-32.0 mV Motor velocity: 40.0 -62.1 m/sec

All the best.

Comment

I wanted to ask about THE EMG safety also... what is the amount of electric stimulations (the maximal) you give in EMG? (in Ampere) I read somewhere it is 10-75 MA WHICH AMAZED ME AS I KNOW A CURRENT OF 30 MA is enough to kill a person!!! So how come it is safe?? (May be it is micro Ampere rather than Milli Ampere???)

Also, Does the electricity you give really travels through our body or it just the sensory stimulation (natural) that travels?

Are there any web site with information on EMG SAFETY

Answer

Thank you for this point. It is important issue. Your numbers are correct, in mA (maximum 100 mA), not MicroA. The point is that this amount of stimulation is given for very brief period range from 0.05-1.0 milliseconds only. There are always safety regulations and no EMG machine is approved unless it fulfills all safety rules by law. The patient safety is always on the top.

Regarding the electricity, it travels only through the nerve under study. For the web sites, I am sure there are web sites for EMG Safety but I do not recall or have any at present.

Comment

About the safety...

Do you know of any researches about the long term effects of an EMG test (the "electric part") such as possible nerve problems, cardiac problems (that show up after long time) etc... For example with people who had several EMGs over the years?

Do you know of any short-term hazards? (Such as people who feel bad or faint right after the EMG?

* I read somewhere that increased exposure to electric shocks has been linked to a variety of fatal disorders such ALS and renal cancer... (That is why pilots get more ALS and RENAL CANCER according to this research...)

Answer

I am not aware myself and I did not read about any long term effects of our "diagnostic" nerve stimulation electrical tests, even if several tests are performed per year for a normal person or patient in child or adult, female or male, animals or human. For short term, talking usually about minutes, pain (variable between persons), usually tolerable. I have not seen a person fainted from nerve stimulation tests. The final point, I am not sure what sort of electrical shocks and for how long the exposure to be linked to fatal disorders. It would be interesting if I can read this article.

Comment

here is the article....

Electric shocks linked to Gehrig's disease

August 18, 1998

NEW YORK, Aug 18 (Reuters) -- A study of utility company employees in Denmark suggests a link between amyotrophic lateral sclerosis (ALS) and exposure to electromagnetic fields or electric shocks, according to a study published in the August issue of the American Journal of Epidemiology.

ALS -- also known as Lou Gehrig's disease -- is a rare, fatal disease characterized by weakness and atrophy of muscles and a degeneration of the nerves that transmit messages to muscles in the brain and spinal cord.

In the study, Drs. Christoffer Johansen and Jorgen H. Olsen with the Danish Cancer Society in Copenhagen examined National Death Certificate files for the cause of death in 21,236 men employed in 99 utility companies in Denmark between 1900 and 1993. Medical records were obtained to determine cases of ALS.

Overall, 3,540 deaths were noted in these workers, slightly fewer than the 3,709 expected based on national mortality rates. Analysis of the records revealed a twofold increase in deaths from ALS in these men and a tenfold increase in deaths from electrical accidents on the basis of 14 and 10 deaths, respectively. Death from ALS was also found to increase with time since first employment in a utility company.

"The excess mortality from amyotrophic lateral sclerosis seems to be associated with above-average levels of exposure to electromagnetic fields and may be due to repeated episodes with electric shocks," the authors write.

However, the study did not find that increased rates of other neurological conditions such as senile dementia and Alzheimer's disease in these men, nor an increased risk of suicide. Previous studies have linked these conditions and suicide to above-average exposures to electromagnetic fields.

"The pattern of mortality from ALS, however, suggests an association within jobs entailing medium to high exposure to 50-Hz EMFs (electromagnetic fields), possibly due to an increased number of episodes with electric shocks," the authors conclude.
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So what is your opinion on that Doctor? Is there a great difference between the electric shocks they mention there and the electric shocks in EMG?

Answer

I am sorry for being late in reply. I will not discuss whether the relation is proven or not, but I want to say this kind of electrical exposure (EMF) is different from that used in field of nerve conduction studies. The exposure, however, in nerve stimulation is low and very brief indeed.

Can we promote healing of damaged nerve by more than Vit. B supplementation  Top

Question

I have been on Neurontin for 6 months for damaged nerves in my right thigh area (on the top part). I have been waiting/hoping to get over the numbness, jabbing pain, etc. It all started last December after three surgeries to repair part of the pelvis bone that broke off after neck surgery where donor bone was taken from my pelvis. At this point, I have some very slight improvement, but not much. I seem to be the same with no improvement for the last three months. I have gained 15 lbs. since being on the Neurontin and hesitate to take it in large doses. I take 300 mg daily, which only helps slightly. If I take 600 mg daily, I don't notice any difference.

Am I going to have to live with this for the rest of my life? Will it ever get better? Can the neurologist do any more than what is being done now?

I have written to you before and would appreciate any advice/suggestions you might have. Thanks.

Answer

Certainly the level of Neurontin prescribed for cases like yours can be much higher than this. I usually advise patients to get on the maximum dose of Neurontin they can tolerate (you must discuss this with your Doctor) to see if there are any improvements. If there aren't any, then switching medication could help.

Significance of low peroneal F wave persistence  Top

Question

Several weeks ago, when I had my EMG, THERE was a problem with the peroneal F wave bilaterally. THEY had to give many shocks until they could elicit the peroneal f wave. (Not so with the tibial F wave, which was elicited right after the first shock) - when they did elicit it, IT was completely normal on both sides - THE latency was 43 MS in the right and 42 MS in the left, WHICH is normal (IS it?) but again, many shocks were needed to elicit it. THE doctor who did the EMG told me that the peroneal F wave is always more difficult to get.

* Except that, totally normal EMG

I did some self research on that, yet I could not find the answer to several questions:

1. WHAT IS THE pathological significance of totally normal f wave, which is very difficult to elicit (low persistence)- this is the most important question - I could not find answers anywhere?

2. What is your own experience with the peroneal f wave - DO you also find it difficult to elicit? HOW many stimulations are needed for it in your experience (more than for other nerves)

3. Does the fact it was difficult to elicit it in both sides gives you any clue about the possible cause?

4. Position- HOW do you check for the peroneal f wave – only when I was sitting, could the doctor elicit the f wave, SO maybe it has something to do with position..

I posted on this issue in the past, yet since then I did some reading and these questions came up..

Answer

1. WHAT IS THE pathological significance of totally normal f wave, which is very difficult to elicit (low persistence)- this is the most important question - I could not find answers anywhere?

Answer: it could happen with any disease causing nerve damage, such as neuropathy, radiculopathy. It may happen without clinical significance in practical terms, especially with peroneal nerve. This is related practically and usually to habit of sitting (squatting).

2.what is your own experience with the peroneal f wave - DO you also find it difficult to elicit? HOW many stimulations are needed for it in your experience (more than for other nerves)

Answer: It might be difficult to elicit due to previous explanation. The number of stimulation is variable, but to mention numbers, then 4-6 extra stimulations are usually enough.

3.Does the fact it was difficult to elicit it in both sides gives you any clue about the possible cause?

Answer: It may help, but we need to see other parameters and clinical history and examination.

4. position- HOW do you check for the peroneal f wave –

only when I was sitting, could the doctor elicit the f wave, SO maybe it has something to do with position..
Answer: I do not think so, position does not actually affect the F wave parameters.

EMG/neurological tests in multiple level disc and upper and lower limb complains Top

Question

I suffer from extreme low back pain and neck pain and weakness in my arms pains in my shoulders...and more. I had surgery on my back 10 years ago. I had an MRI and it shows multiple levels of bulging. I have numbness in hands and feet, sciatica,,,etc...My question is why do I have to go to a neurosurgeon or get EMG test?? I am going tomorrow for the neurology tests. However I already met with a neck surgeon who said he would be happy to operate on my neck...He didn’t need Nero tests???? It seems to me I should see a orthopedic surgeon not a neurosurgeon...I heard that neck surgery may stabilize a back...Is that true??? The multiple levels of bulging are in my neck...

Answer

Various doctors rely on different tests to establish a diagnosis and it may well be that in cases like yours, there are too many doctors involved in the care who might not know what the others are thinking. It is always best to narrow down the number of doctors you're dealing with to avoid such situations.

EMG of Soles of Feet  Top

Question

Is nerve conduction of soles of the feet subject to the same limitations as the needle exam? Is the 47 m/s normal conduction velocity limit for index to palm applicable to the LL?

Answer

In answer to your questions:

Nerve Conduction of the soles of the feet (for plantar nerve branches) is not subject to the same limitations as the needle exam of muscles. There are well-described techniques and normal values for that.

As for your questions about a 47 m/s index to palm conduction, it depends on what the normal values are for the lab that did the study (depends on machine, electrode position, stimulation paramaters etc.) and that's the real gold standard. In our lab, this value is within normal limits.

Comment

Thanks very much for your response. This is a very helpful site. Here are the stimulation parms... I tried to scan the image but scanner is not working....

The lab indicated a temp of 33.6 C, though I do NOT remember them ever putting a thermometer on my hand. My hands felt very cold. I'm 6' 3" tall.

SNC Record     Switch: N-R     Stim: 1     Rate: Non-Recurrent     Level: 21.7 mA    Dur: 0.1 ms   SINGLE

Stimulus Site:

Lat1 ms Lat2 ms Amp uV Area uVms

Palm 2.1 3.9 25 54

Segment: Dist mm Diff ms CV m/s Temp C CVco m/s

Index finger-Palm 100 2.1 47

The lab that did the recording concluded that sensory Nerve conduction was 'minimally' slow with motor conductions/f-waves normal. They diagnosed a peripheral neuropathy. The folks in Boston (Brigham and Womens) reviewed it and said that it all appeared quite normal. B and W also seemed a bit concerned about the accuracy of the temp.

If this information is enough for you indicate normal/slow, then great. If not I understand perfectly. I'm just trying to get a sense for whom to believe.

Thanks again for your time and effort and particularly patience,

Answer

Again these values are different from Lab to Lab however in my Lab these figures will be within the normal limits.

Comment

Thanks much. What I have learned from going through this is that it is of critical importance that Drs and Techs have an extremely high level of training on EMG/NCS technology. This is NOT straightforward material. I am very grateful of the time and effort you have put into answering my questions. Great Web site !!!

Answer

I would definitely describe it in the exact same words.

EMG report for suspected herniation of lumbar disk Top

Question

I have suffered from low back/left leg pain for over 9 years now, and was finally, after much misdiagnosis, diagnosed with a herniated L4-5, and bulging at L3-4 disk. They wanted an EMG done prior to approving the surgery and it was done. I got a copy of the report, but don’t understand it. It says the "EMG revealed no evidence of radiculopathy, neuropathy or distal nerve entrapment of the lumbosacral spine and both lower extremities."
What would normal EMG numbers be?

Answer

As I read the narrative of this report, the doctor is saying that no abnormalities were found in the test, which is usually another way of saying that the test is Normal.