Saturday, March 26, 2011
I have a condition that punches holes in my memory and cognition. This means that, even though this biomedical stuff is meat and drink to me, I have to look up things that -- with my old brain -- I used to know like the back of my hand. (That is, the hand where the CRPS started, naturally.)
Really basic things, like the names of our handful of neurotransmitters, each with its many jobs; or the role of the pituitary gland and its intense relationship with ... well, with every other regulatory part of the body.
So I'll post a couple of tutorials on these subjects here, for both you and me to refer to at need. If I'm really clever, I'll post them as pages which you can access easily; for now, I'll be happy to get them up at all.
Soooo .... [drumroll, please]
- A quick rundown on neurotransmitters, with interesting dietary notes.
- Tutorial on the Limbic-Hypothalamic-Pituitary-Adrenal axis.
Saturday, March 12, 2011
My arms hadn't hurt so little in years. My spine, back, neck and head had never hurt so much in my entire freaking _life_. At the mere rememberance, I still feel the shoulder, scapular and upper-back muscles twist themselves into that ghastly position that caused the least pressure against my cord. My neck is going to be cramping the rest of the day. Wish I hadn't mentioned it.
So yeah, that was bad. I wrote Medtronics a bunch of notes from the nurse/patient/biogeek/engineer perspective. I have seen no indication that they did anything but circular-file them, so I feel free to discuss it now. They've had their grace period.
There's no reason for such flat-out stupid, ham-handed, ignorant engineering. I've tried to see an upside to the current SCS tech, and I just can't.
Shoving titanium into someone who's allergic to surgical steel? Check your MSDS sheets, gentlemen. Cramming cubic centimeters into a space that's painfully sensitive to pressure changes of cubic millimeters? Hang on, who thought _that_ would be a good idea?
Welcome to the future of implantable devices -- especially those going into immunoreactive, sensitized systems:
Meet the carbon nanotube: body-friendly, weavable, conductive, cheap, easy to work with. Does its job on, easily, one thousandth the scale of silicone and wire.
Why is this on my mind? (Gentlemen, look away and hum.) First day of my cycle after a month of progress in rebuilding basic endocrine responses. EVERYTHING is supersensitive and hyperreactive. I want a carbon nanotube *body!*
Best I can do is coconut water. It really smooths out the bumps, if I drink enough of it. Here's to 21st century tech, and hoping it makes it into something as profitable as biomedicine!
Monday, March 7, 2011
Spinal cord histopathological alterations in a patient with longstanding complex regional pain syndrome
The authors did an autopsy on one person with longstanding CRPS and did comparative autopsies on 4 people who did not have CRPS. They checked samples from the neck, thorax, and low-back for microglia and astrocytes. These are the kinds of cells that not only are part of the nervous system's immune response, but also increase the transmission of pain signals. That means, inflammation plus more pain! They found plenty in the CRPS patient's spine.
They also found that the normal cells in the dorsal horn of the spine -- the ones that carry sensations of light touch, vibration, and proprioception (the sense of the body in space) -- are significantly fewer in the CRPS patient. This makes sense of the fact that allodynia (light touch) gets worse, vibration is so agonizing (making both riding public transit and holding a steering wheel pretty horrible), and we get clumsy over time because we can't quite feel where our bodies are in space.
These strange cellular changes were found "most prominently at the level of the original injury, but extending throughout the entire length of the spinal cord." That means that the allodynia, diminished balance, etc. physically spread from the original dorsal root, all the way up and down the spine, affecting the whole physical self.
So, with more cells for pain and immune attack, and fewer cells to transport normal messages of light touch, vibration, and proprioception, we have some stunningly clear evidence that the spreading allodynia, clumsiness, and intolerance to vibration is NOT IMAGINARY.
Given how many people get told that it's all in their heads, they're hurting because they're thinking wrong or because they were abused as children, etc., this is an important thing to keep in mind. Let's keep the cart behind the horse.