Neuropathic Pain

Neuropathic pain is both interesting and horrible. It's different than ordinary pain in that it involves nerve damage. It doesn't respond well to usual pain medications like NSAIDs or opiates. Weird stuff like antidepressants are used to treat it. Trigeminal neuralgia, which causes high intensity high frequency shock-like pulses in the face, is considered one of the most painful conditions and labeled the suicide disease (Wikipedia) because people simply cannot stand the pain, and medications are inadequate.

There have been a lot of fascinating therapies developed for pain. We talked about ideas as diverse as acupuncture, hypnosis, placebo, deep brain electrical stimulation. Now what's interesting is that opioids (like morphine) are blocked by the pharmacologic antagonist naloxone (narcan). But, the pain relief effects of placebo and acupuncture are also blocked by naloxone, even though there are no exogenous opiates administered. The hypothesis is that these placebo-type interventions cause release of endogenous opioids, which is what relieves pain. I never really realized that placebo drugs have a physiologic effect; it really demonstrates how mind influences body. Oddly enough, hypnosis is not blocked by naloxone, and the hypothesis of how that works has to do with decreasing the emotional content in pain. If you're thinking about how much something is going to hurt, it's going to hurt. But the same stimulus might hurt less if the patient is hypnotized.