Neuropathic Pain – Pathophysiology of Pain

00:00 Neuropathic pain is caused by an injury to a peripheral nerve. This can be caused by trauma, or it can be caused by disease. And we most commonly see it in people with chronic, often Type 2 Diabetes, but it can happen in Type 1 Diabetes as well, and it usually occurs in the legs, although it can occur in the upper limbs as well. And in this situation, if we look at the nerves microscopically, we can see there's actually deterioration of the nerve.

00:31 And in those areas where there's been nerve injury caused by trauma, we can actually see regeneration of the nerve and kind of a shower of nervelets coming off the injured end of the nerve.

00:43 And this can form a little nodule or nidus that's exquisitely sensitive. The pain that these folks have is flitting, it's shock-like, it happens completely unexpectedly, so they can't prepare for it.

00:55 So we've already noted that neuropathic pain can occur in the presence of diseases such as diabetes, and can occur after nerve damage and when the nerves are examined microscopically they do appear to be damaged. But it can occur with absolutely no underlying disease. And it can occur without any diagnosis whatsoever other than neuropathic pain. My wife, who is a completely healthy woman, has neuropathic pain in her legs and in her feet. For the last 3 years, she's been largely incapacitated by this pain. There have been periods where she's had to crawl up the stairs in our house, because the pain was so severe she couldn't stand. The good news is, she's starting to respond to therapy. The bad news is, I suspect she's going to have neuropathic pain for the rest of her life, and all we can hope for is the treatment will make her more comfortable. Very, very difficult to treat. And it requires more than any single discipline to treat it. It needs physicians, and nurses, and all that whole pain team I mentioned to you earlier. Neuromodulation is one of the treatments. It's a late treatment. It's extremely costly. It costs between $30,000 and $50,000 to place neuromodulation systems in the spinal cord.

02:19 This is a spinal cord stimulator. Very expensive and it doesn't always work. When it works, it's a dream. But it doesn't always work, and frequently doesn't work. So, when it comes to chronic pain, a lot of the management of the pain is not to treat it or cure it, but to teach the patient how to live with it. But, as I mentioned, neuropathic pain can occur with diabetics, but it can occur with no apparent cause at all. And the focus has to be on, “This is what you have to live with. We're not going to get rid of it. You have to learn to live with it.” It's a discouraging statement to give to a person. So, in summary, in this lecture we've discussed the complexity of pain, the various definitions of pain and the different types of pain. Acute, Chronic and my Transitional. We've talked about some of the treatment modalities for pain and how we approach patients with pain, and how important it is to have a multidisciplinary approach to pain management. And how we try to assist patients in learning to live with pain.

03:25 We're going to have a second lecture on Pain Management that will go into more detail on the various drugs that are used in management of pain. And then we'll have some case summaries to discuss.

03:37 And we'll follow that up with a discussion of Treatment And Management Of Obstetrical Pain.