by Nicole Berardoni M.D., Tory McJunkin M.D., and Paul Lynch M.D.
The greater occipital nerve arises from the second cervical nerve root and travels deep to the cervical paraspinous musculature and becomes superficial just below the superior nuchal line and lateral to the occipital protuberance of the skull, just lateral to the occipital artery. The lesser occipital nerve is a terminal branch of the superficial cervical plexus and arises from the second and third cervical nerve roots. It then travels through the cervical paraspinous musculature and becomes superficial over the inferior nuchal line of the skull. The lateral section of the posterior scalp is supplied by the lesser occipital and great auricular nerves. These nerves are commonly involved in patients suffering from cervicogenic headaches and occipital neuralgia.
The procedure involves inserting a small fine needle through the skin beneath the scalp in order to get the anesthetic and corticosteroids around the area of the nerve. In order to minimize this discomfort, your pain specialist may numb the skin in the injection area with an even smaller needle with a local anesthetic before inserting the block needle. The injection blocks both the greater and lesser occipital nerves. There are two major benefits to using this block. Not only is it useful in treating occipital neuralgia, relieving or reducing pain in the back of the head in the scalp, but if symptoms improve after the injection then the block is also useful in diagnosing occipital neuralgia.Typically if you respond well to the injection and have pain relief then it is recommended that you return and receive repeat injections. Usually, a series of block injections is needed to treat the problem adequately, however the response to the block varies from patient to patient. Also, if you respond well to the occipital nerve block then you will most likely benefit even more with the addition of occipital nerve stimulation. A 2006 study reported that if a patient receives repeated nerve stimulator guided occipital nerve blockade for the treatment of cervicogenic headache, the patients experienced significant reduction of symptoms with no recurrence for at least six months in addition to alleviation of associated symptoms. Eighty-seven (87%) of the patients who experienced relief required more than one injection to achieve a six-month period of pain relief (Naja 2006).
Occipital nerve block injections are considered safe; however, with every procedure there are associated risks, side effects, and possible complications. With nerve blocks in general, the most common is the superficial pain from the scalp where the needle was inserted. This pain comes after the local anesthetic wears off, but this pain is temporary and typically mild. Another frequently seen occurrence is bleeding, since the scalp is highly vascular (there is an abundance of tiny blood vessels near the surface of the skin). Bleeding is common but is easily stopped and temporary. This risk is significantly reduced if ice is placed at the injection site immediately after the procedure. The other less common risks involve excessive bleeding, infection, and nerve damage. Patients with an allergy to any of the anesthetics used, or those who are on blood thinning medications, have an active infection, or are pregnant should consult with their pain physician before receiving the procedure.