This month I would like to highlight an always-interesting diagnostic challenge: namely, chronic pain in the upper shoulder. (By upper shoulder I mean that area between the glenohumeral joint and the neck).
What I find interesting about pain in this particular part of the anatomy is the wide variety of possible causes. Even when the pain seems to be "musculoskeletal" in origin, many other parts of the anatomy may be causing or at least contributing to it. These multifactorial situations are the most difficult to sort out. In fact, I am embarrassed to admit that a recent case that I saw in my office led me astray for awhile. The diagnosis was eventually made, but it was delayed and so was the treatment for longer than it should have. Here is the story:
A 58 year old man presented with slowly worsening left upper shoulder pain of 4 years duration. No preceding history of trauma or strain could be elicited. The pain could be exacerbated by elevating the arm and by carrying objects in front of the body.
His health was generally good and the only medication he used was a nasal spray to relieve congestion at night. Certain foods provoked heartburn especially if consumed late in the evening. Past trauma included a broken nose in his teens, and past surgery a left carpal tunnel release three years before.
Physical exam showed significant body asymmetry with the left shoulder lower than the right. Active and passive elevation of the arm allowed only 90° of movement. Flexion of the arm across the chest exacerbated the pain and the acromio-clavicular joint was tender. Right side-bending of the neck was restricted; the atlanto-axial joint was in left rotation and craniosacral movement of the vault, ethmoid and temporal bones was severely restricted. Unwinding of the nasal bones and the occiput resulted in a profound release.
However 3 weeks later he reported no relief. Over the subsequent months, increments of relief were obtained by treating the restricted side bending of the neck with manipulation, by treating an interference field in the left stellate ganglion with neural therapy and by administering prolotherapy to the acromioclavicular joint (9 session!). But after 8 months, the pain level was still 50% of that before beginning treatment.
Clearly, something was still missing! Oddly, even after all this treatment, the stellate ganglion was continuing to signal (autonomic response testing) as an interference field. The area that the stellate ganglion serves was reexamined and the carpal tunnel scar was noted. (This had not been considered significant previously, as the surgery had been performed after the onset of the shoulder pain). Nevertheless, infiltration of the scar (followed by an intravenous bolus of procaine) resulted this time in complete relief from the upper shoulder pain.
Upper shoulder pain has numerous potential causes. A good first place to look is somatic dysfunction of the neck, but somatic dysfunction almost anywhere in the body is also possible, especially shears of the sacroiliac joints and cranial lesions. Acromio-clavicular joint arthritis (or strains) refer pain proximally to the C4 dermatome (mostly upper shoulder). Interference fields from scars (almost anywhere) can be causative and teeth, especially upper eye teeth, are possible culprits. Pain can also be referred from the diaphragm and abdominal viscera - liver and gall bladder to the right and stomach and pancreas to the left. Large and small intestines can refer pain to either side.
As so often happens in chronic pain, more than one "pain generator" may be present. In this case, the carpal tunnel scar was almost missed because the surgery was performed after the onset of the pain. However it turned out that it was an important player and treatment was necessary to give the patient complete relief from his pain. In the upper shoulder especially, attention to many possibilities is sometimes required to solve these diagnostic puzzles.