The greater occipital nerve arises from between the first and second cervical vertebrae, along with the lesser occipital nerve. It supplies sensation to the skin along the back of the scalp to the top of the head.
Sometimes, when the occipital nerve is irritated, the pain of this irritation is felt near the eye of the same side of the head. This is known as referred pain.
These nerves may also contribute to headaches. Sometimes blocking (numbing) the occipital nerve will reduce headache in the front of the head. This is known as Occipital Nerve Block
During an occipital nerve block, a local anesthetic and steroids are injected into the scalp where the trunk of the nerve is. The injection is done at the back of the head, just above the neck. The skin is numbed before the injection is done. A very fine needle is used for the nerve block.
If the injection has been well located, the scalp on that side of the head will go numb quickly. Pain relief can be felt sometimes within minutes. The doctor may ask what the patient is feeling in terms of his or her symptoms.
If there is a lot of swelling in the nerve, the steroids will relieve the pain of that. The full effect of the steroids may not be felt for two or three days. Their effect is more long lasting — sometimes weeks or months.
After an occipital nerve block, a patient can usually drive home and return to normal daily activities the following day. The effects of the local anesthetic may wear off in a few hours, but the effects of the steroid begin to increase over the next several days.
The best responses to an occipital nerve block usually come from patients whose pain is relatively recent rather than long-standing.
If the first occipital nerve block doesn’t relieve the patient’s symptoms in a week or two, it may be necessary to have a second injection. Additional nerve blocks may be done to keep the symptoms under control.
On the other hand, a lack of results may be a sign that the occipital nerves are not the source of the pain and further work should be done to diagnose the cause of the pain.
It is rare to do more than three occipital nerve blocks in a six-month period. The more injections of steroids that are given, the greater the chance of side effects. If more frequent injections are needed, another type of treatment will probably be considered.