CHRONIC PAIN SYNDROME MECHANISMS

Chronic pain syndrome has taken over from "chronic regional pain syndrome."

It does not only include currently measurable disturbance of sympathetic nerves, so the old name "reflex sympathetic dystrophy" has been dropped.

The term pain-spasm-pain cycle is also out of fashion, but describes real phenomena.

"Wind up" is the nickname for central sensitization, really sensitization at all levels of the pain sensing mechanism.

Referred pain in chronic pain syndrome

Firstly, a lot of pain is “referred.”

Your pain may not be coming from where you feel it.

Our brain is very good at telling us where a pain is coming from, on the skin of the face and hands.

Elsewhere on the skin, we are not so accurate.

For pain originating from muscles and joints, bones and internal organs– anything under the surface – we are much less able to tell where the pain is coming from.

The brain may only know that the pain has come via a particular nerve. We may then feel the pain wherever in our body that nerve brings messages from.



"Rhonda" provided an example of referred pain. She returned to see me 3 weeks after complaining of pain at the base of her left thumb.

This spot had been tender and is certainly a common site for osteoarthritis. Further examination however, had shown that she was tender over muscles just below the elbow and on the left shoulder blade.

She had massaged these and now her thumb was better.


The pain spasm pain cycle in chronic pain syndrome

Where “referred” pain, or any pain coming from structures under the skin is felt, muscles tighten up.

This happens automatically. It happens whether or not you are tense emotionally or physically.

These tight muscles then become painful themselves. You know how your muscles feel sore when you work at something you’re not used to doing. Overworked muscles get sore.

This makes the pain worse, and it spreads more and persists producing a chronic pain syndrome.

Where the pain spreads to, other muscles tighten up and the whole thing is repeated.

In this way, pain can start in the back or neck and spread down arms or legs, or up into the head or around to the front of the chest or abdomen.

You may have experienced back pain, which started at the base of the spine and spread over some days or weeks, right up to the neck and head.

Due to muscle guarding and restricted movement, the tightness and soreness can then persist, sometimes even if the original problem causing the referred pain, gets better.

Whatever else you do, and whatever is the apparent cause of your chronic pain (anywhere in your body,) do appropriate muscle stretching.

Wind up and central sensitization

This is a condition where long standing pain causes the brain to change, so as to make the pain worse.

Any part of the body given a regular job, is likely to get better at doing it.

This applies to the nervous system when you have a persistently painful condition. The part of the brain involved, is where feelings of pain come from, called the “nociceptive” part.

Our brain extends down into our spine, almost to the small of the back. This part is called the “spinal cord.”

Some nerve cells in this part, which are normally involved in feeling touch, become over-sensitive and start to relay pain sensation messages.

The nerve endings in our skin become over sensitive too.

You can easily test for this complication. Brush your hand lightly, rapidly back and forwards over the skin in the area of the pain.

Compare how this feels with the same area on the opposite side of the body. Is the skin of the painful area tender to brush over?

We call the above finding, “brush allodynia.”

When wind up is found, I use neural therapy. This involves injection of homeopathic or local anesthetic into the skin surface, at tender spots.

These tender spots tend to be largely closer to the spine than the area of pain, as well as near it. They are found by systematically poking a finger into the skin all over these areas.

Tender ("active") scars and chronic pain syndrome

Neural therapy also includes treatment of tender parts of scars, mostly surgical scars and often from years before.

These tender scars can cause pain in the most unlikely of places, so I run over every scar to check. I use a smoothly rounded glass rod, pressing reasonably firmly. The spots are quite discrete and quite tender

Prof. Karel Lewit⁶ writes

"The treatment of active scars can be of importance in a great number of cases; untreated, active scars are an important cause of therapeutic failure [in chronic pain syndrome.] Treatment also widens the scope of manipulative therapy."

He uses soft tissue manipulation, and there is a kinesiology technique. I use injection of local anaesthetic into the tender parts of the scar.

The response is so quick that it has been dubbed the "flash, or lightning phenomenum" by the originator Dr. Huneke

Trophic changes in complex regional pain syndrome (RSD)

Where pain from deep structures spreads, a number of other phenomena occur. The most common are tenderness over bony points in the area of pain, and tightening of muscles there.

The skin color, temperature and perspiration may increase. Swelling under the skin may occur. This is the condition called RSD or CRPS.
Eventually in this condition, tissues may become thinner and cooler, from chronic lack of blood supply.

RSD left arm picture

These are from 17th June and 25th march ( after and before.)
The left arm was swollen to the elbow, following removal of plaster after a fractured wrist. She responded to treatment of her spine, so she didn't get a chronic pain syndrome.



Blood clot obstructing the main arm vein in your armpit⁷, can develop after vigorous exertion, or from a number of different illnesses.
This causes discomfort rather than pain, but the arm and hand may be swollen in the same way. The arm may be a little bluish and surface veins may be more obvious.



If someone comes in complaining of a cool limb, I expect to find a joint out in the appropriate part of their spine. This is far more common than the warm, swollen, sweaty condition - and more common than finding an upper limb cool from a blocked artery.

These changes are due to the little autonomic controlling nerves being interfered with at the deranged spinal joint responsible for the pain starting.



Dr Ralf Baron did interesting research on complex regional pain syndrome.

He adapted a space suit to allow heating or cooling of the subject's whole body, apart from the arm being tested.

Whole body heating reduces sympathetic nerve mediated blood vessel tightening (vasoconstriction) - more skin blood flow to help heat loss from our body.
Cooling increases vasoconstriction to help retain heat in our body.

He tested patients in the early stages of CRPS, with a warmer limb than the unaffected side, through the entire spectrum of sympathetic activity.
The affected side was compared with the normal side.

Even when whole body warming reduced sympathetic outflow to a minimum, their affected limb was warmer, indicating some mechanism independent of sympathetic nerves.

He also tested patients with more long standing CRPS, whose affected limb was cooler.

In whole body cooling, with maximum sympathetic nerve blood vessel constriction, these affected limbs were cooler than the opposite unaffected limb - again indicating some mechanism independent of sympathetic nerves.


RSD (reflex sympathetic dystrophy) is different from causalgia, a chronic pain syndrome where a major, named nerve is damaged or cut.

TREATMENT OF CHRONIC PAIN SYNDROME

If you've been given this diagnosis, find someone who knows how to treat your spine. My experience fits with Bourdillon's. He writes...
"During the fifteen years ...in a busy accident practice, the author did not see any case of secondary trophic change in the wrist or hand except among patients who had initially been treated elsewhere and in whom the syndrome had been allowed to develop before the neck was treated."
He was talking about chronic (regional) pain syndrome in the hand, following injuries from falling on the outstretched hand.

References for chronic pain syndrome

1. Spinal Manipulation p 143 J F Bourdillon Heinemann '73

2. Baron R, Blumberg H, Jänig W. Clinical characteristics of patients with CRPS Type I and Type II in Germany with special emphasis on vasomotor function. In: Reflex Sympathetic Dystrophy - a Reappraisal. Jänig W, Stanton-Hicks M, eds. Progress in Pain Research and Management, Seattle: IASP Press, 1996; pp. 25-48.

3. Baron R, Jänig, W. Human experimentation. In Harden, R.N., Baron, R. Jänig, W. (eds.) Complex regional pain syndrome. Progress in Pain Research and Management, Vol. 22. IASP Press, Seattle, pp. 239-246 (2001)

4. Baron R, Levine JD, Fields HL. Causalgia and reflex sympathetic dystrophy: does the sympathetic nervous system contribute to the generation of pain? Muscle Nerve 1999; 22:678-695.

5. Baron R, Schattschneider J, Binder A, Siebrecht D, Wasner G. Relation between sympathetic vasoconstrictor activity and pain and hyperalgesia in complex regional pain syndrome: a case-control study. The Lancet published online April 23, 2002.

6. Professor, Department of Rehabilitation, Charles University, Prague, Czech Republic

7. Upper extremity deep vein thrombosis (UEDVT) - Axillary or subclavian vein thrombosis, mostly in people with central venous catheters, pacemakers, or cancer (most commonly lung cancer or lymphomas). Paget-Schroetter syndrome is when it follows vigorous use of the limb.


From chronic pain syndrome to emotional matters.


From chronic pain syndrome to home pain page



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