The greater occipital nerve is responsible for most of the sensation in the back and top of the head. Irritation or inflammation of the greater occipital nerve can cause debilitating headaches. Patients with occipital nerve irritation often report pain starting from the base of the skull on one side of the head. The pain may extend to the temple, forehead, and behind the eyes.
An occipital nerve block is one of the most common procedures used to provide pain relief from migraines and chronic headaches. During a nerve block, pain-relieving medicine is injected into the area where the greater occipital nerve crosses the skull. Typically, the patient is lying on his or her stomach. The needle is then placed near the nerve and an anesthetic, or a combination of an anesthetic and steroid, is injected. Patients may report immediate pain relief due to the activity of the anesthetic. Once the steroid takes effect, within a matter of two or three days, long-lasting pain relief may be experienced for up to several months.