What is the role of steroid injection in carpal tunnel syndrome?

Injection of corticosteroid into the carpal tunnel has been used as a treatment for some years. But what does the published evidence have to say about whether it works or not?

In my own experience, injection of steroid and / or local anaesthetic into the carpal tunnel area is effective in about half of the patients that I see. Some of them gain lasting relief of the carpal tunnel symptoms and others find that the symptoms of tingling in the median nerve skin area return a month or two after the injection.

Recent Studies on Steroid Injection for Carpal Tunnel Syndrome

Two small but quite good quality studies have been published recently. These are what is known as randomised controlled studies and the results of this kind of study are usually (but not always) reliable.

Both studies showed that injection with steroid into the carpal tunnel produced benefit with about a month of the injection. The benefit was sustained in many of the patients.

The studies compared carpal tunnel steroid injection with placebo injection. Placebo injection is when both the doctor and the patient think that an active drug is being injected but when - in truth - only an inert and inactive liquid is in the syringe.

The patients who were given the active drug typically reported an improvement in their symptoms of about 70% - compared with improvement of about 15% in the patients who were given a placebo.

The risks of steroid injection into the carpal tunnel are small but not zero. Some people find the injection to be very painful for two or three days afterwards. There is a small risk that the injected liquid may enter a blood vessel or may be injected into the median nerve itself. This last problem is rare but can potentially be very serious.

Dr Gordon Cameron's website contains more information about carpal tunnel syndrome and its treatment

Dr Gordon Cameron is a joint pain specialist based in Edinburgh, Scotland. He has a special interest in whiplash injury assessment, lower back pain treatment and in carpal tunnel syndrome