Substance P -- and blogging

It is 3 a.m. in Belfast, and for the third night in a row I'm wide awake in the middle of the night. In recent weeks I've been tossing and turning at about this time because of discomfort due to a pinched nerve that has been causing me quite a bit of pain during the day. But typically I have been too tired or medicated to allow that discomfort to keep me awake. However, a few days ago I began applying a capsaicin-based cream to the area from which the pain emanated, and that seems to be the source of this new problem. Looks like I've cut Faustian deal -- the pain level is definitely down, but here I am in the middle of the night, wide awake and wondering whether the trade-off is a good one. It is one of the more interesting benefits of access to the Web that I can make this self-diagnosis almost immediately (more on that point in a later blog). I googled "capsaicin" and discovered a great deal more about this "medication" than discussed by my prescribing physician (this is not over-the-counter stuff we're dealing with) or on the little information sheet neatly wrapped around the tube. As is widely known by anyone who watches the Food Channel (at least in the US), capsaicin is that natural ingredient that makes chiles hot. How much heat can it generate? Here is one paragraph from an informative web site (http://www.fiery-foods.com/dave/capsaicin.asp, quoting from The Chile Pepper Encyclopedia): Pure capsaicin is so powerful that chemists who handle [it in] the crystalline powder [form] must work in a filtered "tox room" in full body protection. The suit has a closed hood to prevent inhaling the powder. Said pharmaceutical chemist Lloyd Matheson of the University of Iowa, who once inhaled some capsaicin accidentally: "It’s not toxic, but you wish you were dead if you inhale it." "One milligram of pure capsaicin placed on your hand would feel like a red-hot poker and would surely blister the skin," said capsaicin expert Marlin Bensinger. And it seems that the medicinal qualities of capsaicin have been known for quite a while, especially its capacity to ease pain when applied to the affected area of the body. Clinical studies show that it's effective in dealing with pain associated with diabetic neuropathy, osteoarthritis, postherpetic neuralgia, psoriasis and a few other ailments. While my particular problem is not that specific, I agreed with my GP that it was worth a try in lieu of all the pain pills I've been taking for weeks. And after a few days I can say it's working: the cream, applied four times a day, has elevated my pain threshold to the point that I can function most of the day without major discomfort. But there are drawbacks. First, it's obvious that the treatment is only working on the symptom (pain) and not the other dimensions of the problem. This particular pinched nerve episodically generates involuntary muscle "flutters" on my left side, particularly in my left arm. (This is as bizarre to witness for others who are standing nearby as it is for me to experience.) In addition, during those episodes I seem to lose strength in my left arm, a fact that is particularly annoying for a "lefty" like me. (This particular symptom gave us a bit of a scare when it first took place. My doctors were using words like "minor stroke" and such -- enough to get me into an MRI....) So while the capsaicin seems to have taken care of the pain, the episodes of muscle flutters and weakness continue. A second drawback was a temporary one: the area where I apply the cream felt like it was on fire after the first few applications. The burning sensation doesn't occur immediately, but rather an hour or so after the application. So in the midst of some conversation with a colleague I would suddenly feel the urge to leap out of my chair and jump, back first, into a tub of ice water. Luckily for all concerned, our new offices at the Institute don't have those kind of facilities.... That effect (as predicted in the literature) only lasted a couple of days. The third drawback is the impact the capsaicin treatment is having on my sleep. The capsaicin works by reducing the presence of something called "substance P" which is found around nerve endings and is associated with transmitting the feelings of pain to the brain. It's only speculation on my part, but it seems that the process of elevating my pain threshold by reducing substance P is wreaking havoc on my capacity to sleep through the night. Making things worse is that I'm not even feeling tired -- the effect is systemic; I am just "wide awake" rather than being kept awake by some specific discomfort. I guess I might have to learn to live with this for awhile and make good use of the time. And so here I am, sitting in the dark at 4 a.m. in front of my computer screen typing a blog....