The subject of this talk on referred pain, is the clinical diagnosis of pain referred to the front of the trunk, from the back – as distinct from that arising from viscera.
The common mechanism by which such pain arises, I assume is referral from pain-sensitive structures in the spinal column and related muscles. Two illustrations from Hockaday and Whitty show the areas to which pain was referred from interspinous ligaments C7-T1 and T 6-7.
To put this into clinical perspective, I recorded a small consecutive series of cases of trunk pain, seen in general (family) practice. As you can see from the totals, the question of a source of pain in the back arose in nearly half. Also there was some doubt in 16 of 48 (1/3.)
To underline the importance of this, I would like to tell two stories against myself, from when I was just becoming aware of this problem.
The first case was a 25 year old woman with acute, severe lower abdominal pain. On examination she had a very tender ovarian cyst. A pre-operative diagnosis of a complication of the ovarian cyst proved incorrect at laparotomy. The cyst was removed but she had recurrent pains post-operatively until some time later when I put her in a lumbar brace for back pain. She then took herself to a chiropractor, who relieved both pains by manipulating her back.
The second case was a 14 year old girl whom I diagnosed as having acute appendicitis, only to be proved wrong at operation (“lily white” appendix, not inflamed.) Some months later, the pains having persisted, I found the cause in her back and cured the pain with a manipulation.
You have probably all seen the patient with chronic right iliac fossa pain, bearing the scar of an appendicectomy which failed to cure the pain. Some of these people have the pain referred from their spine.
Professor Terry Bolin of Sydney, has been recognizing the spinal origin of pain in patients referred to him, suspected of having complicated gastro-intestinal disorders (as he is a consultant gastro-enterologist.)
These people would already have undergone extensive investigations, involving them in expense, inconvenience and delay in correct diagnosis and effective treatment.
A girl aged 10 presented complaining of sore breasts, more on the right. On examination she did not have what I expected to find – a tender disc of breast tissue the size of a penny, placed symmetrically behind the nipple. She had normal breast development.
Here I expected to find the syndrome of “juvenile hormonal mastopathy,” but part of the syndrome was missing. On examination she had one mid-cervical joint on the right stiff and sore and also a left temporo-mandibular syndrome.
You have to watch for inconsistencies, to not miss referred pain.
A man aged 53 presented with lower retrosternal pain. His mother had died at 56 of a heart attack and one of his brothers developed heart trouble at the same age of 56.
He was using a maddock to dig out a bush in his garden. After three or four swings of the maddock he would get a pain like a stitch and down tools to walk around for a few minutes to get rid of the pain.
He was very worried about his heart, so my starting point had to be to consider the diagnosis of angina of effort. The story so far could be consistent with this, but on further questioning he could walk into the wind and even run the quarter of a mile to his bowling club.
On examination he had signs at Thoracic 4-5 level in his spine.
Now, there are positive features of the history in favour of this diagnosis of referred pain from the back. Some are illustrated in the following cases.
Mrs. E, aged 71, had pain as shown and was tender over her mid-thoracic spine. The retrosternal pain was aggravated by deep inspiration or coughing. The interscapular pain hurt when she straightened up.
Mr. G was 40 years old. He had a past history of duodenal ulceration but his story was as shown and he was tender over T3 and 4 spinous processes.
Other features one hears are pain “catching one to breath;” aggravated or sometimes relieved by twisting; on prolongued standing, bending down, sewing, playing the piano etc.
The symptoms often have a relationship to holding certain postures, particularly bent over, or to movements – either voluntary or coughing/sneezing.
The time relationship to activity can be useful, pain coming after activity.
The duration of pain can also be of help. Most pain from viscera lasts minutes to hours. If it lasts longer the cause is pretty obvious. In referred pain from the spine, there may be very brief stabs – the sort of thing described as the “soldiers heart syndrome” of brief stabs under the left breast, in which the cause is usually found in the back. The pain may last continuously for long periods without much change. One commonly reassures people that “if the pain has been present for years, and you are otherwise well, then it cannot be due to anything serious.” I would add to that , that it will often be due to spinal derangement.
The distribution of the pain is useful, referred pain often being felt only on one side of the midline.
Associated complaints such as difficulty turning the head to back the car, can be useful.
I’ll leave the history now, and move on to examination of the thorax and abdomen. Local tenderness where symptoms are felt, is quite characteristic. This may be the hyperalgesia accompanying referred pain, as illustrated from Hockaday and Whitty. In this type, it is usually more marked over the bony prominences. In the thorax, a few adjacent ribs will be found to be tender.
The tenderness here may follow a different pattern, however, with individual intercostals muscles being both tender (more than adjacent ribs) and stiff. The technique for assessing spasm of intercostals muscles is this. My right foot is on a small stool and the patient leans over with his armpit on my thigh. His left hand is behind his neck. As he bends over and inspires, I assist by pulling on his left elbow, while assessing the movement apart of adjacent ribs.
In the abdomen there are two signs I have found particularly helpful.
The first is pressure on one spot producing pain elsewhere in the abdomen. An example is Rovsing’s sign in acute appendicitis. This can occur anywhere in the abdomen, and strongly suggests an intra-abdominal cause for the pain.
The second sign is determining the effect on tenderness, of tensing the abdominal muscles compared with them relaxed. I usually keep my hand moving in a small circle, rubbing the tender spot. When the patient lifts their legs my pressure is kept constant, the fingers being lifted up by the abdominal muscles. If the tenderness is less with the muscles contracted, this suggests an intra-abdominal cause. If it is unchanged or more tender, the cause may be in the back.
An example of the use of this sign, is the case of Mr. A, AGED 58. He presented with a one day of episodes of intermittent epigastric pain. He has similar episodes 5 and 10 years earlier. This attack was severe. It came on suddenly and ended suddenly. He also had a 20 year history of continual pain in his right groin and right iliac fossa, which would be worse if he was tired.
He was in considerable distress, tender in the epigastrium and right iliac fossa. On tensing his abdominal muscles the epigastric tenderness was less and the iliac fossa tenderness was worse. A large dose of liquid antacid followed by sublingual Anginine eased his pain and the epigastric tenderness.
If the history and examination so far, suggest a cause in the back, this is now examined. On examination of his spine, the abnormality was found at the lumbo-sacral level, corresponding with the RIF tenderness.
I place considerable emphasis on detecting unilateral straight segments on sidebending, which I have tried to illustrate here. These are often indicative of stiff, tender “hitched” apophyseal joints. I do this examination with the patient standing.
Positional faults are very easily diagnosed, with the patient laying prone. I am indebted to Howard Rivett, for pointing out this type of lesion, which occurs in the thoracic spine. I quickly run my fingers along the sides of the spines, to see if they are all in line. In this lesion they are all in line, except for one level with a sideways step. After a successful manipulation, one can then demonstrate in the same way, that they are all lined up correctly.
Tenderness can be elicited in various ways. Individual joints can be stressed or sprung or steady pressure can be applied to vertebral spines. This can be straight postero-anterior or to opposite sides of adjacent spines as described by Maigne.
The skin may show vasomotor or sudomotor changes, with reddening or increased perspiration, alongside involved joints. There may be hyperaesthesia also, or numbness.
The muscles may be tight and tender.
The mobility of individual joints must be tested, looking for marked differences between adjacent joints.
This examination may thus support a diagnosis if referred pain, if abnormalities are present at an appropriate level in the spine to account for the pain complained of.
Sometimes steady pressure on vertebral spines will induce the pain complained of in the front of the trunk. This makes the diagnosis much more certain. An example of this was Mrs. W.S., 26, who complained of inframammary pain and palpitations, on and off for months. On examination, pressure on T4 spine produced both her pain and palpitations.
One is often, however, still uncertain as to the source of a pain. This is usually as some features suggest visceral disease and there are also abnormalities in the back.
The next phase of diagnosis may then be a therapeutic trial.
In epigastric pain I have found considerable value in giving a large (100ml) dose of liquid antacid then getting the patient to lay down for a few minutes. Their pain or epigastric tenderness may then be reduced, indicating an upper GI cause.
If the pain or tenderness are unchanged, IV metoclopamide or sublingual or topical glyceryl trinitrate may reduce them, suggesting colic from viscera.
If good indications are found for it, I will use a spinal manipulation as a therapeutic trial and the start of management. Sometimes the pain is relieved immediately, confirming the diagnosis. Otherwise they are given medication or home exercises and reviewed later.
The first and obvious problem is that the patients frequently do not have pain in their back. They may have other symptoms in their back, such as numbness or itch.
Visceral disease may produce both pain and tenderness in the back.
One of our local endoscopists had a case of a person with pain wholly in the back, with a patch of obvious tenderness there. X-ray of the back was normal and the patient was not improving. Endoscopy showed an ulcer in the second part of the duodenum. Cimetidine cured the pain and also the tenderness in the back.
I don’t think that any abnormality found on examination of the back can be taken to prove that a pain is originating there.
Visceral disease may produce pain that is related to posture. This is well known for pancreatitis and pericarditis, for example.
Visceral and spinal disease often co-exist. It is often not so much a question of where the pain is coming from, but rather what are the relative contributions of the visceral disease and spinal derangement. An observation made by Hockaday and Whitty is pertinent here. They studied the effect of pre-existing pain, on the reference of pain from injection of interspinous ligaments. They observed in one experiment, referred pain and hyperalgesia from T6, developing not where it had done in previous experiments on this subject, but rather in the area of pre-existing pain at T10. Thus a person may perceive only one pain, when there are two wholly separate causes for the pain.
A further difficulty highlighted by this experiment is that of deciding whether spinal abnormalities are at an appropriate level to be possibly causing a pain in the trunk. The reference of pain from the lumbo-sacral joint to the iliac fossa is well known. Involvement of the sympathetic nerves and branches of the Nerve of Luschka, also explain some extrasegmental pain reference.
The next difficulty is multiplicity of associated complaints, such as in patients with the post-taumatic headache syndrome of Barre-Lieou or in patients with considerable functional overlay.
Again, another problem is the inaccuracy of clinical assessment due to our observing what we want to rather than what is actually there. This is particularly important when one is assessing the back as the abnormalities are often subtle. Some of the tests require careful standardization of pressure. It is easy to unconsciously press harder when or where the patient “should” be more tender (according to one’s preconceived ideas.)
With all these problems and difficulties, one may be left with both evidence of visceral and spinal disease. The implications of this for treatment, are that one should treat both possible causes at once, with the expectation that one’s patient will be given the best possible help to recover.
I would like to end on a different note. We have seen an attempt to investigate spinal treatment in migraine. It is quite possible that fruitful findings may occur in other functional diseases, such as coronary artery spasm, pylorospasm etc.
This lecture was given at an AGM of the Australian Association of Manipulative (now Musculoskeletal) Medicine I helped organize in the 1970s.
You don't have to be experiencing neck and back pain nor have a sore back, for chest or abdominal pain to be coming from your back.
Liniment rubbed where you feel the pain may relieve it, but it is better to alleviate the pain by treating the source. This also establishes the pain diagnosis.
Referred pain from viscera can be felt in the back and can be accompanied there by local tenderness over spinous processes. This happens with duodenal ulcer and gallbladder disease. It therefore cuts both ways, referred pain can go in both directions.
I independently developed this test and later found that it had been described long ago by a surgeon named Carnett. There is nothing new under the sun. I use the notation "internal" if the tenderness is less with muscles tight, "external" if it is the muscles themselves which are tender.
I no longer use this straight segment examination, but use the prone sidebending test for all thoracic and lumbar segments. It is more useful and accurate.