(The following is the transcript for the video above)
The third type of pain that I want to talk about is Neuropathic pain.
Neuropathic pain occurs when you have pain because there is some sort of a damage or stress to our nerves (1). Now this can sound awfully like nociceptive pain that we discussed two videos earlier, where certain nerves called nociceptors get simulated and send signals to our brain that can be interpreted as pain.
The difference is, in nociceptive pain, the nociceptors are responding to stresses to SURROUNDING structures, like ligaments, muscles, or bones. Neuropathic pain occurs when the nerves THEMSELVES are compromised, and begin to behave rather irritably.
For example, in shingles, a virus attacks the nerves in our spinal cord, and consequently you'll have pain, and even blisters, wherever that nerve goes. Some with diabetes develop peripheral neuropathy where the nerves in the hands and feet become compromised.
And one of the most common neuropathic condition is "sciatica" where the nerves that come out of the spine to supply one of the legs become compressed by something - usually a bulging disc.
It is also probably worthwhile to mention that when this does happen there are effectively TWO conditions that we're dealing with - a bulging, unstable disc, AND an angry, irritated nerve.
That means even if you have a surgery to slice off the part of the disc that's pushing on the nerve, the irritated nerve does not always resolve automatically and THAT may require some separate attention. Something like carpal tunnel syndrome is similar in that regard.
So these are the most critical aspect of neuropathic pain:
1) neuropathic pain is a separate entity to the condition itself. The condition, like shingles, may have passed, but the pain might remain. It's not like where you break a bone and the bone's fixed and you'll be ok. The PAIN needs to be looked at separately (2).
2) the behaviour of neuropathic pain is not as predictable as the previous two types of pain. In nociceptive and inflammatory pain, the resolution of the pain is pretty consistent with a number of factors. Neuropathic pain, often is not so.
3) and lastly, and this is more for the health professionals, neuropathic pain needs to be intervened quickly.
So if you see someone with a suspected bulging disc and raging sciatic pain, don't just settle for finding a solution only for the disc, you must treat the neuropathic pain separately, and AS EARLY AS POSSIBLY, before alterations in neuroplasticity and in gene expressions occur both of which will prolong the pain very much unnecessarily (3). And this multimodal and mechanism-specific approach applies to most neuropathic pain conditions.
1. Costigan M, Scholz J, Woolf CJ. Neuropathic pain: a maladaptive response of the nervous system to damage. Annu Rev Neurosci. 2009;32:1-32.
2. Woolf CJ. Pain: Moving from Symptom Control toward Mechanism-Specific Pharmacologic Management. Annals of Internal Medicine. 2004;140:441-51.
3. Jensen TS, Finnerup NB. Allodynia and hyperalgesia in neuropathic pain: clinical manifestations and mechanisms. The Lancet Neurology. 2014;13(9):924-35.