One of the causes of migraine headaches that emanate in the forehead region is compression of the supraorbital nerve. This trigger point cause of migraines is due to the squeezing or pinching of this nerve by the enveloping muscles. Relief can be obtained through either Botox injections or surgical removal of the muscles (myectomy) around the nerve. Clinical studies have shown that most patients will achieve improvement with about two-thirds having near complete resolution of their migraines long-term.
The supraorbital nerve is a branch of the ophthalmic nerve, which is the first division of the fifth or trigeminal cranial nerve. It supplies feeling primarily to the forehead and the scalp that lies above and behind it. It comes out through a hole in the brow bone known as the supraorbital foramen. In most people this foramen appears on the very edge of the brow bone and is more of a notch. In a minority of patients, it appears as a hole above the brow bone with a thick layer of bone beneath it.
In the surgical treatment of frontal migraines, it is customary to release the muscle around the supraorbital nerve. But could the bone from the supraorbital foramen also be a contributing factor in this nerve’s compression as well? In the April 2012 issue of Plastic and Reconstructive Surgery, this exact issue was studied. Out of Case Western University in Cleveland, a published paper investigated the role of additional decompression of the supraorbital nerve through a foraminotomy procedure. (removal of bone around the nerve) In 86 migraine patients, 43 were treated by muscle resection around the supraorbital nerve alone and another 43 were treated by muscle resection combined with supraorbital foraminotomy.
Based on after surgery migraine frequency, migraine severity, Migraine Headache Index and persistent forehead pain, the foraminotomy patients showed more improvement and better scores than muscle resection only. This study indicates that the supraorbital foramen is a potential site for nerve compression that can contribute to frontal migraine headaches. When surgically possible the nerve should be released down to its exit from the bone and any adherent bands stripped away.
How much the supraorbital nerve can be released from the bone is highly influenced by the surgical approach. In a superior endoscopic technique, the attachments around the nerve can be partially released but not completely. Visualization on the inferior edge of the nerve is not possible. When done through an upper eyelid approach, a 360 circumferential release can be done including removal of some of the bone around the nerve, creating a true foraminotomy procedure. This has become my preferred approach for frontal migraine surgery due to the more complete release of all nerve attachments including bone.
Dr. Barry Eppley