Injections are often made around nerves in the investigation and treatment of pain. We often inject nerves in the groin, the scalp and the arms and legs.
The injection will confirm that the pain is coming from the nerve, and will help to treat it. Without other treatment, the pain will sometimes return. We often arrange for other treatment after the injection to help the nerve work in a more normal way.
Local anaesthetic in the injection will reduce the pain within a few minutes, and will work for several hours. There may be some weakness, a feeling of heaviness and sometimes a feeling of numbness that usually lasts for a few hours at most.
A steroid is often included in the injection to prolong the effects: the steroid is chosen to remain around the nerve, and has little effect on the rest of the body. It takes more than a day to have an effect, and the pain may return as the local anaesthetic wears off before the steroid begins to work.
Because of the effects of the injection, you should not travel home alone, and someone should stay with you on the day of the injection. The strength and sensation around the nerve should be normal by the next day.
A few people feel faint for a short time after their injection. If this happens you wili be asked to lie down, and may be given medication through a needle inserted into a vein.
You cannot have an injection if you are allergic to local anaesthetics. We put a dressing over the injection, and you should tell us if you are allergic to plasters, tapes or dressings.
