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.
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 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:
- Wikipedia on NCV.
- Answers.com on EMGs
- Engadget not having a clue what the machine is.
- The testing apparatus.
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.