The anatomy of the greater occipital nerve: Part II. Compression point topography

Advances in the understanding of migraine trigger points have pointed to entrapment of peripheral nerves in the head and neck as a cause of this debilitating condition. An anatomical study was undertaken to develop a greater understanding of the potential entrapment sites along the course of this nerve.

The posterior neck and scalp of 25 fresh cadaveric heads were dissected. The greater occipital nerve was identified within the subcutaneous tissue above the trapezius and traced both proximal and distal. Its fascial, muscular, and vascular investments were located and accurately measured relative to established bony landmarks.

Dissection of the greater occipital nerve revealed six major compression points along its course. The deepest (most proximal) point was between the semispinalis and the obliquus capitis inferior, near the spinous process. The second point was at its entrance into the semispinalis. The previously described "intermediate" point was at the nerve's exit from the semispinalis. A fourth point was located at the entrance of the nerve into the trapezius muscle. The fifth point of compression is where the nerve exits the trapezius fascia insertion into the nuchal line. The occipital artery often crosses the nerve, and this frequently occurs in this distal region of the trapezius fascia, which is the final point.

There are six compression points along the greater occipital nerve. These can be located using the data from this study, serving as a guide for surgeons interested in treating patients with migraine headaches originating in these areas. Long-term relief from migraine headaches has been demonstrated clinically by using both noninvasive and surgical decompression of these points.