Patients will often precede a question with the disclaimer “ this may be a dumb question, but I am wondering if….”. This disclaimer almost always guarantees that they are usually pretty astute in their observation and closing in on some matter of importance.
The latest “dumb question” that came up this week was interesting: could my symptoms be caused by a pinched blood vessel ? The patient had some pins and needles sensations in the front of the shoulder, they had noticed that the skin on the front of the arm was a little darker and a little colder than on the other side. Good logic led them to wonder if there was decreased blood flow in the affected area.
The surprising answer to that question is not only: yes !, but the fact that most instances of pinched nerves probably have some degree of pinched vascular structures that go along with the pinched nerve. And there is a very simple reason for that: if you go back to basic anatomy, nerves, arteries and veins very often travel as a trio before splitting off prior to their final destination. Anyone who has done college level anatomy will recall the acronym NAV, standing for nerve, artery and vein, describing the bundles of the three structures lumped together. And anyone who has done anatomy cadaver dissection recalls how difficult it was to separate the three structures from each other and tell them apart.
From a practical and clinical standpoint, there is a lot of overlap in the symptoms of nerve and vascular compression. Both can cause pain, and both can cause abnormal sensation like numbness and tingling, making it difficult to differentiate them based on symptoms alone. Physical examination can be helpful, but also somewhat limited. Mild vascular compression can cause subtle swelling, changes in color and temperature, but those can be difficult to differentiate from inflammation related edema, and most body areas have collateral circulation that can take over when there is mild vascular compression from one source.
In day to day chiropractic practice, we tend not to aim our treatment to relieve mild vascular compression independent from relieving nerve compression, which is probably why we talk about this topic infrequently. Relieving nerve compression is the main goal, and vascular structures will basically benefit from that approach. Nerve tissue and vascular tissues have distinct features that makes nerves more vulnerable in NAV bundles: they lack collateral back up, and they are not as adaptable to move out of the way of compressive forces. But that is not to say that some patients will show up with unusually strong vascular compression symptoms that need to be taken into account when setting up a treatment plan, for example limiting the use cold pack therapy and compression
