I'm shocked!

Myke's 'blob.

I'm shocked! Thu, Oct 26. 2006

No really - I've had eletrical shocks administered for a prescribed, medical purpose!

...

Diagnostic, not theraputic. Nice try - I'm not ready for electro-shock therapy. Yet.

I went for an EMG/NCV test today because I've been experiencing numbness/loss of sensation in my right hand. (It's been going on since the summer, but blame my slow moving GP and his ever-changing support staff.) I suspect the reason for the problem is something to with the shoulder/neck pain I've been experiencing, but apparently my GP doesn't agree. Shoulder X-rays came back normal.

Basically the test is to determine if the nerves are functioning properly. And since I couldn't find very much in the 'Net about EMG or 'electromyleogram', I'll briefly describe how the test is performed.

A common electrode is attached to the back of the hand.
A pair of sensing/timing eletrodes are attached to a finger, about an inch apart. (It's an actual measured distance.)
The tech then takes a handheld, dual-eletrode stimulator to the wrist (again, a measured distance) and triggers a dischage between the handheld's electrodes. The computer then measures the latency of the nerve response on the sensor eletrodes attached to the finger. This is repeated with increasing current (or voltage, I forget now) and with the stimulator behind the wrist and on the elbow. The test is repeated for the other fingers.

The test is not painful, but with most encounters with electricity, it's the surprise that gets you. Of course it's over before you even have a chance to react.

My right ulnar nerve response: The nerve in question.
Click for full-size

Note that this isn't measuring how long it takes the eletricity to travel down the nerve (that would be daft.) What's happening is that a nerve-firing is being triggered by the stimulator, and that electrochemical reaction takes a bit of time, which is what's being measured.

The Wrist & Hand

The most common diagnosis reached from this test is carpal-tunnel syndrome, where the nerves are constrained by swelling in the wrist - which quite stunningly (for me), I do not have. Unfortunately, the entire result-set was normal. Ain't nothin' wrong with my wrists.

Which means there's a problem somewhere else. Cervical spine? Yikes. I hope not. I assume not for now anyway.

I just wonder if I'm going to hear back from my GP at all at this point, what with the No-news-is-good-news policy most physicians have...

And since I couldn't find much info on this test, here's some links. Hopefully Google will index this page for others' future use.

Links:
Total tangent here. The first time I saw a Honda Element, it was near my home and an elderly man was driving it. There was a pair of handicap parking passes on the flip-down visors.
Combine this incident with the 6 Elements I saw at the parking lot, and now I'm really wondering...
As James May said on TopGear - "Would the Element be a car for people who like hip-hop, or for people waiting for a hip-op?"
Am I completely uncool now? Or have I already been doomed?! Scratch that, I've never been cool. I'm so uncool I'm probably becoming cool in some sick and twisted retro way.
No matter - I still love it. :-)

And if anyone has any corrections to what I've said above - please let me know via email or the comments section below. I'll correct things as I become aware of them. That goes for the physiology stuff too, not just about how cool I'mn't.
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#1 - Sarahbellum said:
2006-10-26 21:53 - (Reply)

Hi Myke! Yay glad it doesn't seem to be anything immediately serious.... hrm I hope they figure it out soon.

You might have had trouble finding links because it's spelt electromyogram (no extra E in there - maybe you were thinking of the myelin sheath?). There is also something called a Nerve Conduction Study (NCS) which sounds like what you had: I'm not absolutely clear on the difference but it sounds like EMGs invovlve needles in muscles (ow) and and NCS involves electrodes (much nicer).

Some clicky linkies:
Electromyogram and Nerve Conduction Study / North American Spine Society
http://www.spine.org/fsp/troubleshooting-electro.cfm

Electromyography and Nerve Conduction Velocities / Muscular Dystrophy Association
http://www.mdausa.org/publications/Quest/q75ss.html

Nerve Conduction Study / Wikipedia.com
http://en.wikipedia.org/wiki/Nerve_conduction_study

Your friendly neighbourhood health information specialist :-P
Sarah

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#1.1 - MyX0R said:
2006-10-26 22:43 - (Reply)

Thanks for the links, but honestly - a good result today, to me, is a bad thing. :-(

Comments (2)

#2 - Mel 2007-01-03 20:18 - (Reply)

Hi,

Sooo, how did your NCV turn out? I have to have one due to similar sounding symptoms, but my GP thinks I have a degenerated disc in my neck causing pain / numbness, etc... Like you, I can't find a thing about it!

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#2.1 - MyX0R said:
2007-01-04 00:56 - (Reply)

As expected, I've never heard back from my GP. Unfortunatly, the problem hasn't gotten any better, and my present workload is still skyrocketing... I really need to get a new job! :-(

The NCV was really a piece of cake. You've got nothing to worry about on that front.

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#3 - ron 2007-02-25 23:24 - (Reply)

Nerve Conduction Studies (NCS) measure how good and how fast your nerves are reacting. On the screen you will see a graph formed by horizontal and vertical lines. The horizontal lines represent time measured in meters per second (the closer the wave is to the left, represents how fast the nerve is reacting). The vertical lines allow us to measure the Amplitudes or elevation of wave from baseline (O onset) to peak (P)(amplitudes indicate essentially how healthy the nerves are, the higher the wave, the healthier the nerve is).
ElectroMyoGraphy (EMG) is a test in which the Medical Doctor will insert a Needle Electrode into specific muscles which are fed electricity by specific nerves coming from specific spinal Levels, ie: C5-6, C6-7, L4-5, L5-S1, etc. In the case of Carpal Tunnel Syndrome the doctor, after doing a complete physical and neurological assessment, will order and or perform ElectroDiagnostic Studies to comfirm the preliminary diagnosis. NCS will first be performed to see if there is a median peripheral neuropathy (sensory and/or motor)to see if there is any compression over the carpal tunnel canal formed by Carpal bones of the wrist. Whether NCS is positive or Not physician then will confirm Carpal tunnel through insertion of the needle over the APB muscle (between thumb and wrist) if this is positive CTS is confirmed. The Doctor will then explore the Cervical ParaSpinal muscles to see if the CTS is the result of a ROOT compression of the nerve or Radiculopathy. A lot of times the doctor finds out that nerve is being compressed at the wrist (CTS) and also at the corresponding cervical spinal level.

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