Dr Thomas E Smith MBBS(Hons)MD FRCA FFPMRCA
What are occipital nerve blocks?
Local anaesthetic and corticocosteroid are injected around nerves at the back of the head, just above the neck
Why is it done?
Greater occipital nerve blocks reduce the headache load (combination of number of headaches and their severity) in around two thirds of people who have chronic or disabling headaches. The benefits may last months, or longer. They are also a treatment for occipital neuralgia – pain from occipital nerve irritation or entrapment.
Are there side-effects?
With any injection local tenderness, bruising and infection are risks. The headaches may not improve. A headache flare is possible but unlikely. Nerve injury is possible but very unlikely. Infection is exceedingly rare.
Injection of steroids around nerves is not a licensed use for these drugs, but steroids have been used in this way for decades and their use in occipital nerve blocks is a well established treatment. The steroid in the injection may raise the blood sugar in people with diabetes for a couple of days. The steroid may give some people a feeling of facial flushing for a few days.
Tell us if you have had recent steroid injections for other reasons as other side effects are possible regular steroid use.
Tell us if you are using antiviral drugs as some of these can interact with steroids.
The local anaesthetic may make the back of the head feel numb or otherwise strange for a few hours. Dizziness or feeling faint is possible, so plan to stay for 20 minutes after the injection and drink water, tea or coffee before leaving.
What happens during the procedure?
You will be asked to sit comfortably on a chair looking forward. If you have long hair, please use a hair band to lift it from neck and lower back of head for the procedure. The doctor will feel gently for the right location and then inject using a very fine needle. You will experience a pressure feeling with the injection. You may hear the injection – don’t worry about that. The local anaesthetic in the injection may briefly sting but this settles very quickly.
What happens after the injection?
Some people feel dizzy after the injection so we ask you to wait for around 20 minutes before leaving. Please don’t drive a car afterwards on the same day (if there were an accident, the fact that you had an injection may be highlighted by other parties).
What is the follow up?
The therapeutic effect of the blocks develops over days and weeks. Do not expect an immediate benefit. Please keep three month daily headache diary to help determine the effect of the block. Clinic review is usually at three months.