Monday, September 9, 2013

Pain part 3

So we have talked already about how pain is produced in the brain, how posture really doesn´t affect pain and how pain can be divided into acute and chronic pain. Acute pain being pain that last 3 to 6 moths and chronic pain, pain that last more than 6 months. So how do you treat the different kinds of pain?

With acute pain it is usually quite easy, the pain is associated with the tissue injury that has been produced and, in many cases, pain medications do work reasonably well. For example, NSAIDs (Nosteroidal anti-inflammatory drugs) have been shown to be effective for injuries (like ankle sprain), and after surgery. But for chronic pain, medications are only slightly effective and this is due to the fact that pain can change your nervous system (1,2).

It has always been said that the brain and the nervous system couldn´t change. But since a decade ago we know that the brain is plastic and can indeed change, it´s called NEUROPLASTICITY. Scientists have seen from imaging and animal studies that persistent pain or pain which last for months and years can change the pain pathway, in other words we become more sensitive. This hypersensitivity causes the brain to interpret anything related to those tissues to be highly threatening. So basically the nervous system and the brain have become more efficient in producing and maintaining pain (3-5). You could say that in chronic pain, the pain has moved up to the nervous system and now has very little to do with the initial damage to the tissues that caused the pain.

Let´s try to clear this up and make it easier to understand with an example: John, age 45, has had lower back pain for the last 2 years. Everytime he bends down to pick up something he experiences pain, so he stops doing that. We know that tissues or bones usually heal in between 3 to 6 moths, so there is really nothing wrong with him from a anatomical point of view. And everytime he bends down it doesn´t mean that he got hurt again or that he re-injured himself. It is just that Johns brain and nervous system have become so good at constructing pain that the slightest of triggers - even those that don´t cause damage, cause pain. So how do we deal with this?

The most important thing would be to educate John about pain, to teach him the role of the brain in pain, and to explain to him that pain doesn´t always equal to damage. When education about pain physiology is included into physiotherapy treatment of patients with chronic pain, pain and disability are reduced (6,7). After this, the next thing would be to gradually expose John to the feared activity (bending down) without causing pain and thereby lowering the threat level in the brain. So we would teach him first how to bend down correctly and to only bend till the point before the pain starts. This process would start to decentralize his pain and eventually make his pain disappear.

To finish I want to hopefully think that people now understand a little bit more of how pain acts and how to deal with pain. These last 3 articles have been difficult and maybe hard to understand but I would be satisfied if people took at least these 3 points home:
  1. Damage does not equal pain; not all damage leads to pain, and not all pain is caused by damage. Example: a study in the journal Arthritis & Rheumatism looked at the relationship between knee osteoarthritis and pain (8). They found out that some people had little arthritis and high pain, and some people had severe arthritis but low pain. The researchers concluded that the level of knee pain was due to central sensitization, rather than the level of osteoarthritis. In other words, the level of pain had more to do with changes in their nervous system, not changes in their knee structure.
  2. You can have a bulged disc or degenerated spine, maybe even impinging on one of your nerves, and still not have pain. Or you could have none of these problems, and still have persistent pain (9-12).
  3. The International Association for the Study of Pain defines pain as an emotion. That is, pain is a perception rather than a sensation. Unless and until the brain senses danger or threat, nothing can cause pain.
To finish I will post 2 links.

In one of them Lorimer Moseley describes how to explain pain to patients and in the second one, which is quite long (44 minutes), he talks about the whole process of pain. Enjoy

http://www.youtube.com/watch?v=jIsF8CXouk8
http://www.youtube.com/watch?v=-3NmTE-fJSo


In my next blog we will change the topic drastically and talk about food. Is food a drug?? Can you get addicted to food? We will see and explain in my next blog. See you then.


Bibliography

1. Ekman EF, Ruoff G, Kuehl K, Ralph L, Hombrey P, Fiechtner J, Berger MF. THe COX-2 sècific inhibitor Valdecoxib versus tramadol in acute ankle sprain: a multicenter randomized, controlled trial. Am J Sports Med. 2006 JUn;34(6):945-55. Epub 2006 Feb 13. PubMed PMID: 16476920

2. Buvanendaran A, Kroin JS, Tuman KJ, Lubenow TR, Elmofty D, Moric M, Rosenberg AG. Effects of perioperative administration of a selective cyclooxygenase 2 inhibitor on pain management and recovery of cuntion after knee replacement a randomized controlled trial. JAMA. 2003 Nov 12,290(18):2411-8. PubMEd PMID: 14612477.

3.Flor H, Nikolajse Li, Stachelin Jensen T. Phantom limb pain: a case of maladaptive CNS plasticity.
   Nat Rev Neuroscience 2006 Nov;7(11):873-81.

4. Flor H, Braum C, Elber T, BIlbaumer N. Extensive reorganization of primary somatosensory cortex in chronic back pain patients. Neuroscience 1997: March 7.224(1)5-8.

5. Ren K, Dubner R. Central nervous system plasticity and persistent pain. J Orofac. Pain.1999.Summer.13(3):155-63.

6.Moseley GL, Nicholas MK, Hodges PW. A randomized controlled trial of intensive neurophysiology education in chronic low back pain. Clin J pain 2004. Sept 20(5): 324-30.

7. Moseley GL. Widespread brain activity during an abdominal task markedly reduced after pain physiology education: fMRI evaluation of a single patient with chronic low back pain. Aust J Physiotherapy 2005: 31(1):49-52.

8.Dallinga JM, Benjaminse A, Lemmink KA. Which screening tools can predict injury to the lower extremities in team sports?: a systematic review. Sports Med. 2012 Sep 1;42(9):791-815.

9. Johnson C. Modernized Chiropractic reconsidered: beyond foot-on-hose and bones-out-of-place. J Manipulative Physiol Ther. 2006 May;29(4):253-4. PubMed PMID:

10. Ernst E. Chiropractic: a critical evaluation. J Pain Symptom Manage. 2008 May;35(5):544-62. Epub 2008 Feb 14. Review.

11. Homola S. Chiropractic: history and overview of theories and methods. Clin Orthop Relat Res. 2006 Mar;444:236-42.

12. Good CJ. The great subluxation debate: a centrist’s perspective. J Chiropr Humanit. 2010 Dec;17(1):33-9. Epub 2010 Sep 21.


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