Can exostoses of the external occipital protuberance and superior nuchal lines cause headache? A report of two cases

Compression of the occipital nerves can cause occipital headache. Several potential compression points have been identified along their course. One of these points is the hitherto undescribed instance of exostoses of anatomic structures of the occipital bone. A 34-year-old man with a prominent external occipital tuberance and superior nuchal lines complained of headache in the area of distribution of the greater occipital nerve with tenderness near the bony protrusion on palpation. A 44-year old woman experienced stabbing pain in the lateral orbital region with pressure on the ossified insertion of the ipsilateral trapezius muscle near the external occipital protuberance. Local nerve block achieved temporary relief of pain. Exostosis of the external occipital protuberance and superior nuchal lines may impinge on the greater and third occipital nerves. The characteristics of the pain in our cases differ in some aspects from those of occipital neuralgia.