EMG TEST

[Guest guest]

In a message dated 10/3/2002 3:00:42 PM Pacific Daylight Time,

toby_stevenson@... writes:

> Could someone please explain what the test actually

> entails? I have a bit of an adversion to needles,

> getting shots or bloodwork done, and I am a little

> nervous about the EMG because I have a sneaking

> suspicion that needles are involved.

>

> Toby son

>

Toby, The EMG hurt me bad. I hate to scare you but I would rather have a

baby.

Well maybe it wasen't that bad! But it did hurt. The needles did not hurt. I

couldn't really feel them. It was the electric volts that got to me.

jenny

[Guest guest]

When I had my EMG, it did involve tiny needles, like acupuncture needles, but

it didn't bother me a bit. I watched the lines on the screen jump, but I

didn't feel anything. Afterwards, I did ask the operator if my legs would

leak from all the holes she put in them. >^.^<

This is probably more than you want to know, but maybe some of it will help.

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

http://www.mdausa.org/publications/Quest/q75ss.html

QUEST Volume 7, Number 5, October 2000

------------------------------------------------------------------------

Simply Stated . . .

Electromyography and Nerve Conduction Velocities

Diagnosis of neuromuscular disease hinges on a doctor's ability to identify a

specific defect of neuromuscular function. Sometimes, a doctor can infer this

functional defect - and the disease associated with it - by giving a physical

exam, doing a blood test or looking at the anatomy of nerves and muscles.

But other times, the doctor may have to directly evaluate the functions of

nerves and muscles and the connections between them by using two

complementary techniques - nerve conduction velocity testing (NCVs) and

electromyography (EMGs).

Action Potentials

Both NCV and EMG rely on the fact that the activity of nerves and muscles

produces electrical signals called action potentials. A nerve is actually a

bundle of axons, cables that conduct action potentials from one end of a

nerve cell (or neuron) to the other.

In motor neurons (neurons that connect to muscle), these action potentials

travel toward the muscle, where they cause release of a chemical called

acetylcholine. Acetylcholine opens tiny pores in the muscle, and the flow of

sodium and potassium ions through these pores creates action potentials in

the muscle, leading to contraction.

In NCV and EMG, these tiny electrical events are amplified electronically,

then visualized on a TV-like monitor called an oscilloscope and even heard

using audio equipment.

NCV and Axons

NCV measures action potentials conducted by axons, so doctors use it for

diagnosing diseases that primarily affect nerve function, such as different

forms of Charcot-Marie-Tooth disease (CMT).

It's done by placing surface electrodes (similar to those used for

electrocardiograms) on the skin at various points over a nerve. One electrode

delivers a mild electrical shock to the nerve, stimulating it to generate an

action potential. The other electrodes record the action potential as it's

conducted through the nerve.

Doctors often use NCV to determine the speed of nerve conduction (hence, its

name). Conduction speed is influenced by a coating around axons, called

myelin. Myelin insulates each axon and normally forces action potentials to

" jump " quickly from one end of the axon to the other. If the myelin breaks

down (as in CMT1), the action potential travels more slowly.

NCV also can measure the strength of the action potential in the nerve, which

is proportional to the number of axons that contribute to it. If axons

degenerate (as in amyotrophic lateral sclerosis) or become clogged with

debris (as in CMT2), the action potential becomes smaller.

EMG and Muscle

An electromyogram measures the action potentials produced by muscles, and is

therefore useful for diagnosing diseases that primarily affect muscle

function, including the muscular dystrophies. Also, some EMG data can reveal

defects in nerve function.

In EMG, the doctor inserts a needlelike electrode into a muscle. The

electrode records action potentials that occur when the muscle is at rest and

during voluntary contractions directed by the doctor.

While a healthy muscle appears quiet at rest, spontaneous action potentials

are seen in damaged muscles or muscles that have lost input from nerve cells

(as in ALS or myasthenia gravis). During voluntary contraction, dystrophic

(wasted) muscles show very small action potentials, and myotonic (stiff)

muscles show prolonged trains of action potentials. Altered patterns of

muscle action potentials can indicate defects in nerve function.

A Little Discomfort

Though NCVs and EMGs are valuable tools for doctors, they can be distressing

for patients. Some people find the electric shocks of the NCV or the needle

penetration of the EMG uncomfortable or even painful. Young children might

struggle during the tests, making it difficult for doctors to carefully

monitor nerve and muscle activity. To ease discomfort, topical anesthetic can

be applied to the skin - but it won't prevent muscle pain during the EMG.

Sometimes sedating medications are needed to keep a child calm.

Partly because of these factors, NCVs and EMGs are generally used when it's

not possible to gather the right information from other diagnostic tests.

Muscle biopsy (excising and examining muscle tissue; see Quest, vol. 7, no. 4

) can reveal hallmark anatomical features of some neuromuscular diseases,

making EMG and NCV unnecessary. Genetic tests are now available for

diagnosing some diseases, and in those cases, EMG and NCV usually can be

bypassed.

Nonetheless, NCV and EMG remain the gold standards for evaluating the

function of nerve and muscle. So, when a doctor suspects that a patient has a

neuromuscular disease that isn't clearly associated with anatomical or

genetic defects (like some types of CMT, or myasthenia gravis), NCV and EMG

are among the most valuable diagnostic tools.

http://www.yourhealth.com/ahl/1539.html

(The information obtained from the EMG can be printed out on paper, displayed

on a video screen, or " recorded by sounds " resembling a loud corn popper.

Results are then studied to determine the source or cause of the muscle

problem.)

Electromyogram (EMG)

An EMG or electromyogram is a test that measures the activity of the muscles

to gather information about the muscular and nervous systems.

An EMG may be recommended as a way of diagnosing:

some causes of muscle weakness or paralysis,

muscle or motor problems, such as involuntary muscle twitching,

sensory problems, such as numbness, tingling or pain, and

nerve damage or injury.

Electromyography can be performed in a doctor's office, hospital or x-ray

laboratory by an x-ray technician, nurse or doctor. The test is performed in

a room lined with copper to eliminate any outside electrical interference.

EMG has many benefits:

the results are safe and reliable,

side effects are rare,

there is no risk of allergic reaction,

the test is generally fast, and

it is fairly inexpensive.

Before having an EMG, the patient will be advised to:

stop using body lotions for several days before testing,

stop smoking for twenty-four hours before the test, and

refrain from drinking caffeinated beverages for two to three hours before the

test.

You should alert your doctor before the test if you have

a pacemaker,

any bleeding problems,

any allergies, or

if you have recently taken or are currently taking any medications.

If you fail to let the doctor, nurse or technician know about medications you

are taking or a pre-existing bleeding disorder, problems may result following

the test.

If you are extremely anxious or apprehensive, you may be given a sedative

before the EMG test.

The technique for EMG takes thirty to sixty minutes to perform, depending on

the number of muscles to be tested. During the test, impulses are recorded by

attaching small disc electrodes to the skin surface over the muscle or by

inserting small metal needles into the muscle which is causing the symptoms.

The metal needles record impulses or electrical activity generated by the

muscle when it is:

at rest,

contracting gently, and

contracting vigorously.

The needle or electrode position may be changed and the process repeated four

or more times in the same muscle to obtain a complete study.

The information obtained from the EMG can be printed out on paper, displayed

on a video screen, or recorded by sounds resembling a loud corn popper.

Results are then studied to determine the source or cause of the muscle

problem.

Following the test, there may be some mild or dull aching for up to six

hours, followed by soreness and tingling in the muscle that was tested for an

additional one or two days. You may also have a small bruise where the

needles were inserted that may last for a week or more. If pain persists

longer than two days, apply a warm compress on the test site. To make a warm

compress, soak a small towel or washcloth in warm water and apply it to the

painful area. Be careful not to make the compress too hot, so you don't burn

your skin.

Infection after EMG is rare, but if it does occur, symptoms may include:

increasing pain,

redness,

swelling,

tenderness, or

pus.

Tag line follows this topic. EMG (Electromyogram), Hin report, ahm, 1992.

Search the Online Library for more information on Electromyogram (EMG)

Kathleen

Seattle USA

http://www.icewindow.com

[Guest guest]

Hi Toby.........speaking from my own experience...........I have had several

of these tests done and none of mine involved needles. They simply placed

some " ground " pads on various spots on my body and then touched me here and

there with an electrode that delivered a minor, momentary (but

uncomfortable......especially for an electrician) electric shock. The

machine then measured the amount of time it took to travel from point of

electrode to the ground pad. I didn't like it but it didn't involve being

poked with needles. Good luck!

Bob Weidman

[Guest guest]

In a message dated 10/3/2002 7:13:45 PM Pacific Daylight Time,

scubarw4@... writes:

> Hi Toby.........speaking from my own experience...........I have had several

>

> of these tests done and none of mine involved needles. They simply placed

> some " ground " pads on various spots on my body and then touched me here and

>

> there with an electrode that delivered a minor, momentary (but

> uncomfortable......especially for an electrician) electric shock. The

> machine then measured the amount of time it took to travel from point of

> electrode to the ground pad. I didn't like it but it didn't involve being

> poked with needles. Good luck!

>

> Bob Weidman

This sounds like you had a newer test. I was thinking about my last EMG and

it was 16 years ago.

jenny

[Guest guest]

TOBY,

I HAD MY EMG TEST LAST YEAR AND IT WAS JUST THE TECH. USING ELECTRODES TO

SHOCK MY LEGS, FEET, HANDS, ARMS TO SEE THE RESPONSE HE GOT . HANDS SCORED

ALOT WORSE THAN I THOUGHT BUT IT WAS JUST UNCOMFORTABLE WHEN THE SHOCK HIT

YOU. NOTHING REALLY PAINFUL. GOOD-LUCK AND GOD BLESS.

CHRISTINE

[Guest guest]

Toby, I had this done a while back and had no problem with it. Basically

what they did with me was to attach adhesive pads to the lower leg near the

knee and then connect electrical wire to these. They then touch another wire

to the lower end of the leg at strategic points and send a mild electrical

current into you leg to measure the speed that the cuurent travel up to rthe

adhesive pads. This will tell them the condition of your nerves in the leg,

many of which have a lot to do with the CMT and what it does to you legs and

feet. To me, the current felt tinglely and maybe a little ticklish. My

fourteen year old and my ten year old also had it done and didn't seem to be

bothered with it at all.

Hope that helps,

Larry

[Guest guest]

Good Morning Toby,

My experience with EMG testing is similar to Jennie's ... The needles were small

but when they started cranking the electrical jolts up because they couldn't get

any response on the machine--no thank's. I realize some doctor's insist on

having test results, but I'll never have it done again. When I was tested about

six years ago, the doctor's didn't know what they were looking for so I got the

works: my legs, arms, hands, and spine! It was after they had done the EMG

testing with results they didn't like and two spinal taps--they decided to try

blood work. They took nine different tubes and most of them got misplaced so

the blood tests had to be redone. Then they finally diagnosed CMT.

I would make sure technician really knows what CMT is before they start!

Good Luck!!

JaneGet more from the Web. FREE MSN Explorer download :

http://explorer.msn.com

[Guest guest]

I had an EMG while trying to figure what was wrong with me. It took 6 yrs!!

I believe it measures the speed of the signal the nerve is sending to the muscle. My results were read to have fallen in the normal range. After 2 years I took them to another doc and he told me he found the results to be abnormal for someone my age and I should find a new neurologist. Found a new one and was diagnosed in 2 days!

[Guest guest]

What does a EMG test show?

[Guest guest]

,

I so agree with you...the test is close to mid-evil! I would never have put my

children through it. It's so easy for doctors to recommend things. I think

they should take the test first, and than see how often they would have people

take the EMG test. I had my children tested by the blood test, and one child did

have CMT.

Kay

[Guest guest]

It's not the needles that hurt, it's the electric volts. Tommy are you Type 2?

[Guest guest]

In a message dated 8/23/2005 5:06:14 P.M. Pacific Daylight Time,

GfijiG6@... writes:

<just adding my 2 cents here, but my EMG told me I have CMT

2, and let me tell you, all 2 and 1/2 times I felt it all! >

I am actually glad to hear this. I have had several Type 2s tell me it was a

painless test. I was jealous, lol.

[Guest guest]

I have had 2 EMG's and it didn't bother me I didn't even know they stuck the

needles in to test the muscles. I don't know but everyone I tell I had an EMG

they ask how I can take the pain I may have a high

pain tolerance. I have alot of tattoos so I don't know if that helps because I

have no problem with getting tattoos.

Tommy

[Guest guest]

Hi Tommy,

I too didn't feel that much pain, but I figure the worse my case is maybe that's

why. I also have tattoos and can withstand pain. But this is different.

Someone could cut my foot off and I wouldn't feel it, but a small pebble sends

me through the roof. I thought when my nerve endings weren't working when she

shocked me that was a bad sign. Am I making any sense? I guess everyone is

different.

Take care,

[Guest guest]

,

I have Type 1A and the electric volts don't bother me either. The last EMG I had

was in May and I had my upper and lower extremities done a day apart.

Tommy

[Guest guest]

Tommy,

WOW You do have a HIGH pain tolerance!!!!